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Incubation Time (incubation + time)
Kinds of Incubation Time Selected AbstractsEffects of Varying Levels of Vegetable Juice Powder and Incubation Time on Color, Residual Nitrate and Nitrite, Pigment, pH, and Trained Sensory Attributes of Ready-to-Eat Uncured HamJOURNAL OF FOOD SCIENCE, Issue 6 2007J.J. Sindelar ABSTRACT:, Vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus have been identified as necessary ingredients for the manufacture of uncured, no-nitrate/nitrite-added meat products with quality and sensory attributes similar to traditional cured products. The objectives of this study were to determine the effects of varying concentrations of VJP and incubation time (MIN-HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of ham over a 90-d storage period, compare residual nitrate and nitrite content, and determine if differences exist in sensory properties of finished products. Four ham treatments (TRT) (TRT 1: 0.20% VJP, 0 MIN-HOLD; TRT 2: 0.20% VJP, 120 MIN-HOLD; TRT 3: 0.35% VJP, 0 MIN-HOLD; TRT 4: 0.35% VJP, 120 MIN-HOLD) and a sodium nitrite-added control (C) were used for this study. No differences (P > 0.05) were observed between TRTs and C for CIE L*, a*, b*, and cured color measured by reflectance ratio. Lipid oxidation (TBARS) for combined TRTs and C revealed little change over time while the C had less (P < 0.05) lipid oxidation than TRTs 2 and 4 for combined days. No differences (P > 0.05) were reported for cured pigment concentration between TRTs and C. Trained sensory panel intensity ratings for ham and vegetable aroma, and flavor, color, and firmness showed that a high concentration (0.35%) of VJP resulted in the highest scores for undesirable vegetable aroma and flavor. Treatment combinations with a low concentration (0.20%) of VJP were comparable to the C for all sensory attributes. [source] Preliminary investigation of the combined effect of heat treatment and incubation temperature on the viability of the probiotic micro-organisms in freshly made yogurtINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 1 2006A M MORTAZAVIAN The combined effects of heat treatment and incubation temperature were studied on the viability and fermentation time of probiotics in ABY 1 probiotic yogurt (Lactobacillus acidophilus, Bifidobacterium spp. and yogurt bacteria). Three levels of heat treatment (85°C for 30 min, 95°C for 5 min and 95°C for 15 min) and three levels of incubation temperature (37, 40 and 44°C) were selected. At the end of fermentation, the maximum viability of probiotics (for both L. acidophilus and Bifidobacterium spp.) was observed when the milk was heated at 95°C for 15 min and incubated at 37°C. Incubation time was only affected by the incubation temperature and, at 37°C, the longest incubation time of about 6 h was needed to achieve the highest viable counts of L. acidophilus and Bifidobacterium spp. [source] Incubation time required for neonatal blood cultures to become positiveJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 12 2006Luke Jardine Aim: We aimed to determine the laboratory detection time of bacteraemia in neonatal blood cultures, and whether this differed by: organism; samples deemed to represent true bacteraemia versus contaminants; and blood cultures collected from an infant <48 h of age (early) or ,48 h of age (late). Methods: A retrospective audit of all positive blood cultures collected from neonates in the Grantley Stable Neonatal Unit, Royal Women's Hospital, Brisbane, between 1 January 2000 and 31 December 2004 was undertaken. The bacteraemia detection method used was the BacTAlert system with Peds bottles. Results: Two hundred and three positive blood cultures were included in the analysis. One hundred and sixteen (57%) were deemed septicaemia, 87 (43%) were deemed contaminants. The median (interquartile range) time to positivity for positive blood cultures deemed septicaemia and contaminants were 15.9 (11.6, 22.2) and 30.2 (20.4, 43.9) h, respectively. Fifty-six (28%) positive blood cultures were collected when infants were <48 h of age and 147 (72%) were collected in infants ,48 h of age. Post hoc analysis revealed that the time to positivity for early septicaemia was 13.7 (11, 16.7) h; early contaminant was 25.2 (19.2, 33.8) h; late septicaemia was 17.2 (12.2, 23.4) h; and late contaminant was 37.9 (21.7, 51.2) h. The time to positivity for: Group B streptococcus was 9.3 (8.2, 11.0) h; Escherichia coli was 11.3 (10.0, 13.5) h; and coagulase-negative staphylococci was 28.9 (20.5, 41.2) h. Conclusion: The incubation time for positive blood cultures significantly differs by organism type and whether they are considered early or late septicaemia versus contaminants. We recommend that: infants who are <48 h of age at the time of blood culture collection, who remain clinically well and have negative cultures 36 h after the initial collection can safely have their antibiotic treatment ceased; infants who are ,48 h of age at the time of collection should continue antibiotic treatment for at least 48 h before cessation is considered. [source] P71 Metabolism of delta-3-Carene by human cytochrom 450 enzymesCONTACT DERMATITIS, Issue 3 2004Mike Duisken Occupational exposure to monoterpenes occurs in saw mills, particle-board plants, carpentry shops and other types of wood-treating industries. The bicyclic monoterpene delta-3-Carene, one of the components of turpentine, may irritate the skin and muceous membranes and prolonged exposure may result in allergic contact dermatitis or chronic lung function impairment. The effects of low concentrations of delta-3-Carene on alveolar macrophages in vitro were examined and a dose-dependent relationship between the cell viability and the delta-3-Carene concentration was found. Little is known about the metabolism of delta-3-Carene in mammalians. In order to determine the toxic potential of this monoterpene we studied the human metabolism of delta-3-Carene in vitro. Therefore we used pooled human liver S9 and human liver microsomal cytochrome P450 enzymes. By using GC-MS analysis we found one main metabolite produced at high rates. The structure was identified by its mass spectra. The mass fragmentation indicated hydroxylation in allyl position. After synthesis of the assumed product in a four step reaction, it was characterized as delta-3-Carene-10-ol. There was a clear correlation between the concentration of the metabolite production, incubation time and enzyme concentration, respectively. Kinetic analysis showed that Km and Vmax values for the oxidation of delta-3-Carene by human liver microsomes were 0.39 ,M and 0.2 nmol/min/nmol P450. It is the first time that delta-3-Carene-10-ol is described as human metabolite of delta-3-Carene. [source] Development of specific oligonucleotide probes for the identification and in situ detection of hydrocarbon-degrading Alcanivorax strainsENVIRONMENTAL MICROBIOLOGY, Issue 6 2001Kazuaki Syutsubo The genus Alcanivorax comprises diverse hydrocarbon-degrading marine bacteria. Novel 16S rRNA-targeted oligonucleotide DNA probes (ALV735 and ALV735-b) were developed to quantify two subgroups of the Alcanivorax/Fundibacter group by fluorescence in situ hybridization (FISH), and the conditions for the single-mismatch discrimination of the probes were optimized. The specificity of the probes was improved further using a singly mismatched oligonucleotide as a competitor. The growth of Alcanivorax cells in crude oil-contaminated sea water under the biostimulation condition was investigated by FISH with the probe ALV735, which targeted the main cluster of the Alcanivorax/Fundibacter group. The size of the Alcanivorax population increased with increasing incubation time and accounted for 91% of the 4,,6-diamidino-2-phenylindole (DAPI) count after incubation for 2 weeks. The probes developed in this study are useful for detecting Alcanivorax populations in petroleum hydrocarbon-degrading microbial consortia. [source] Morphological and biochemical changes associated with apoptosis induced by okadaic acid in human amniotic FL cellsENVIRONMENTAL TOXICOLOGY, Issue 5 2009Ming-luan Xing Abstract The marine toxin okadaic acid (OA) is an apoptosis inducer and a tumor promoter. During recent years, extensive studies have demonstrated that OA can induce apoptosis in a wide variety of cell types. In contrast to the relatively longer incubation time or higher treatment concentrations of OA in apoptosis shown previously, relatively lower concentrations (,100 nM) and shorter time (4 h) were designed in the current study to observe the toxic effects of OA in human amniotic cells (FL cells). The present study was undertaken to determine the morphological and biochemical changes of FL cells induced by OA. Results indicated that externalization of phosphatidylserine, cytoskeletal disruption, DNA strand breaks and decrease of Bcl-2 protein expression levels as well as increase of PP2A-A subunit protein were all involved in the apoptosis of FL cells induced by OA. This work not only provided further evidence of apoptosis induced by OA but also suggested that PP2A might play a pivotal role in apoptosis induced by protein phosphatases inhibitors. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009. [source] The Prestige oil spill.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2005Abstract In vitro biodegradation of the Prestige heavy fuel oil has been carried out using two microbial consortia obtained by enrichment in different substrates to simulate its environmental fate and potential utility for bioremediation. Different conditions, such as incubation time (i.e., 20 or 40 d), oil weathering, and addition of an oleophilic fertilizer (S200), were evaluated. Weathering slowed down the degradation of the fuel oil, probably because of the loss of lower and more labile components, but the addition of S200 enhanced significantly the extension of the biodegradation. n -Alkanes, alkylcyclohexanes, alkylbenzenes, and the two- to three-ring polycyclic aromatic hydrocarbons (PAHs) were degraded in 20 or 40 d of incubation of the original oil, whereas the biodegradation efficiency decreased for higher PAHs and with the increase of alkylation. Molecular markers were degraded according to the following sequence: Acyclic isoprenoids < diasteranes < C27 -steranes < ,,-steranes < homohopanes < monoaromatic steranes < triaromatic steranes. Isomeric selectivity was observed within the C1 - and C2 -phenanthrenes, dibenzothiophenes, pyrenes, and chrysenes, providing source and weathering indices for the characterization of the heavy oil spill. Acyclic isoprenoids, C27 -steranes, C1 - and C2 -naphthalenes, phenanthrenes, and dibenzothiophenes were degraded completely when S200 was used. The ratios of the C2 - and C3 -alkyl homologues of fluoranthene/pyrene and chrysene/benzo[a]anthracene are proposed as source ratios in moderately degraded oils. The 4-methylpyrene and 3-methylchrysene were refractory enough to serve as conserved internal markers in assessing the degradation of the aromatic fraction in a manner similar to that of hopane, as used for the aliphatic fraction. [source] Structured lipids from rice bran oil and stearic acid using immobilized lipase from Rhizomucor mieheiEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 1 2008Rajni Chopra Abstract The major objective of the present study was to prepare structured lipids rich in stearic acid from rice bran oil (RBO) using immobilized lipase (IM,60) from Rhizomucor miehei. The effects of incubation time and temperature, substrate molar ratio, and enzyme load on incorporation of stearic acid were studied. Acidolysis reactions were performed in hexane. Pancreatic lipase-catalyzed sn -2 positional analysis and tocopherol analyses were performed before and after enzymatic modification. The kinetics of the reaction was studied and maximum incorporation of stearic acid was observed at 6,h, at 37,°C, when the triacylglycerol and stearic acid molar ratio was maintained at 1,:,6 and the enzyme concentration was 10% of total substrates weight. Stearic acid in RBO after acidolysis was increased from 2.28 to 48.5%, with a simultaneous decrease in palmitic, oleic and linoleic acids. HPLC analysis of tocopherols and tocotrienols was carried out and their content in modified RBO was not significantly affected compared to that of native RBO. The oryzanol content of the modified RBO was reduced from 1.02 to 0.68%. Melting and crystallizing characteristics of the modified fat were studied using differential scanning calorimetry. The total solid fat content at 25,°C increased from 26.12 to 34.8% with an increase in stearic acid incorporation into RBO from 38 to 48%, but it was comparatively less than for cocoa butter and vanaspati. However, the modified RBO completely melted at 37,°C and was useful as plastic fat for various culinary purposes, bakery and confectionary applications. The results of the present study indicated that structured lipids prepared from RBO rich in stearic acid retained their beneficial nutraceuticals; in addition, they do not contain any trans fatty acids. [source] Monitoring bacterial and archaeal community shifts in a mesophilic anaerobic batch reactor treating a high-strength organic wastewaterFEMS MICROBIOLOGY ECOLOGY, Issue 3 2008Changsoo Lee Abstract Shifts in bacterial and archaeal communities, associated with changes in chemical profiles, were investigated in an anaerobic batch reactor treating dairy-processing wastewater prepared with whey permeate powder. The dynamics of bacterial and archaeal populations were monitored by quantitative real-time PCR and showed good agreement with the process data. A rapid increase in bacterial populations and a high rate of substrate fermentation were observed during the initial period. Growth and regrowth of archaeal populations occurred with biphasic production of methane, corresponding to the diauxic consumption of acetate and propionate. Bacterial community structure was examined by denaturing gel gradient electrophoresis (DGGE) targeting 16S rRNA genes. An Aeromonas -like organism was suggested to be mainly responsible for the rapid fermentation of carbohydrate during the initial period. Several band sequences closely related to the Clostridium species, capable of carbohydrate fermentation, lactate or ethanol fermentation, and/or homoacetogenesis, were also detected. Statistical analyses of the DGGE profiles showed that the bacterial community structure, as well as the process performance, varied with the incubation time. Our results demonstrated that the bacterial community shifted, reflecting the performance changes and, particularly, that a significant community shift corresponded to a considerable process event. This suggested that the diagnosis of an anaerobic digestion process could be possible by monitoring bacterial community shifts. [source] Competition between two nitrite-oxidizing bacterial populations: a model for studying the impact of wastewater treatment plant discharge on nitrification in sedimentFEMS MICROBIOLOGY ECOLOGY, Issue 1 2002Christine Féray Abstract Nitrobacter, a ubiquitous nitrite oxidizer in natural and anthropized environments, is commonly studied as the model genus performing the second stage of nitrification. In rivers, wastewater treatment plant discharges may affect the nitrite-oxidizing activity and the responsible genera that are largely associated with sediment. We used a laboratory batch culture approach with Nitrobacter wynogradskyi ssp. agilis strain AG and Nitrobacter hamburgensis strain X14 to characterize the possible stress effect of wastewater effluent on these populations and to study the possible competition between an effluent strain (X14) and a sediment strain (AG) over a 42-day incubation time. Immunofluorescence enumerations of each strain showed that they both survived and settled in the sediment, indicating that there was no significant stress effect due to chemical changes caused by the effluent. The development of the strains' density and activity was directly correlated with the available nitrite concentration. Nevertheless, the potential specific activity was not constant along the so-called mixotrophic (non-limiting nitrite concentration) and heterotrophic (nitrite depletion) conditions. This illustrates the inducibility of the nitrite oxidoreductase and indicates the metabolic versatility of the strains. In our experimental conditions, the preferentially autotrophic AG strain appeared more competitive than the preferentially mixo- or heterotrophic X14 strain, including in heterotrophic environment. [source] Effects of some bacteria (Pseudomonas spp. and Erwinia herbicola) on in vitro growth of Piptoporus betulinusFOREST PATHOLOGY, Issue 6 2000K. Przyby Summary Bacteria including Pseudomonas putida, Pseudomonas fluorescens biovar I, Pseudomonas fluorescens biovar V, Pseudomonas aureofaciens and Erwinia herbicola were isolated from discoloured zones in birch trunks. Antagonistic effects of these bacteria to growth of Piptoporus betulinus mycelium were tested in vitro, both in dual culture and using bacterial cell-free culture filtrates. In dual cultures, P. putida was most effective at inhibiting mycelial growth of Piptoporus betulinus. Filtrates of P. putida inhibited growth of P. betulinus mycelium irrespective of filtrate concentration, incubation time of bacteria and timing of recording mycelium growth. The strongest antagonistic effect (inhibition of fungal growth) was observed on a medium containing 80% of sterile filtrate obtained from 15-day-old bacterial cultures. The highest stimulating effect on mycelium growth was noted on medium containing 80% filtrate obtained from 7-day-old E. herbicola cultures. Résumé Des bactéries, Pseudomonas putida, Pseudomonas fluorescens biovar I, Pseudomonas fluorescens biovar V, Pseudomonas aureofaciens et Erwinia herbicola, ont été isolées de zones colorées de troncs de bouleau. Les effets antagonistes de ces bactéries sur la croissance mycélienne de Piptoporus betulinus ont étéévalués in vitro, en cultures doubles et à partir de filtrats bactériens. En cultures doubles, P. putida a été le plus inhibiteur de la croissance du P. betulinus. Les filtrats de P. putida inhibaient la croissance quel que soit la concentration du filtrat, la durée d'incubation de la bactérie, et le délai dans lequel la croissance mycélienne était mesurée. L'effet inhibiteur le plus fort a été observé sur un milieu contenant 80% de filtrat stérile obtenu de cultures bactériennes de 15 jours. L'effet stimulant le plus fort a été noté sur un milieu contenant 80% d'un filtrat obtenu de cultures de 7 jours de E. herbicola. Zusammenfassung Verschiedene Bakterienarten (Pseudomonas putida, Pseudomonas fluorescens Biovar I, Pseudomonas fluorescens Biovar V, Pseudomonas aureofaciens und E. herbicola) wurden aus verfärbtem Holz in Birkenstämmen isoliert. Antagonistische Effekte dieser Bakterien gegenüber Myzel von Piptoporus betulinus wurden in vitroüberprüft (Dualkulturen und bakterienzellfreie Kulturfiltrate). In Dualkulturen zeigte P. putida den stärksten Hemmeffekt auf das Myzelwachstum von P. betulinus. Filtrate von P. putida hemmten das Wachstum von P. betulinus, unabhängig von der Filtratkonzentration, der Inkubationszeit der Bakterien und dem Zeitpunkt der Messung des Myzelwachstums. Der antagonistische Effekt (Hemmung des Myzelwachstums) war am ausgeprägtesten auf einem Medium, das 80% Sterilfiltrat von 15 Tage alten Bakterienkulturen enthielt. Der stärkste Stimulationseffekt auf das Myzelwachstum wurde auf einem Medium beobachtet, welches 80% Filtrat von sieben Tage alten E. herbicola -Kulturen enthielt. [source] Reproductive strategies of Gammarus lacustris (Crustacea: Amphipoda) along an elevation gradientFUNCTIONAL ECOLOGY, Issue 4 2000Wilhelm F. M. Abstract 1.,The number of eggs, their size, mass and development time, and the starvation time of newly hatched young, was examined in four populations of Gammarus lacustris along an elevation gradient from prairie to alpine lakes (730 m to > 2300 m above sea level). Water temperature and ice-free season decreased with increasing altitude. 2.,Females in the alpine lake produced fewer but larger and heavier eggs than females in the prairie lake. Eggs produced by females in montane and subalpine lakes were intermediate in size, mass and number. Within populations, egg size was not related to the number of eggs or female size. 3.,The development time of eggs declined with an increase in incubation temperature. At all incubation temperatures, large eggs had a longer incubation time than small eggs. All eggs incubated at 4 °C failed to produce young. Young from large eggs were larger in size than young from small eggs. 4.,The starvation time of newly hatched young increased with decreasing temperature. However, slopes of regressions relating starvation time to temperature differed among populations. At 4 °C young from large eggs survived longer than young from small eggs. 5.,The high phenotypic plasticity in reproductive traits contributes to the success of G. lacustris in a wide range of aquatic habitats. It is predicted that in response to climate-induced warming, populations in currently cold montane and alpine lakes would shift their reproduction to produce more eggs of smaller size. However, the accurate prediction of the fate of populations between ecoregions will require knowledge of the extent to which these traits are under genetic control. [source] Biogeochemical changes induced in uranium mining waste pile samples by uranyl nitrate treatments under anaerobic conditionsGEOBIOLOGY, Issue 3 2009A. GEISSLER Response of the subsurface soil bacterial community of a uranium mining waste pile to treatments with uranyl nitrate over different periods of time was studied under anaerobic conditions. The fate of the added U(VI) without supplementation with electron donors was investigated as well. By using 16S rRNA gene retrieval, we demonstrated that incubation with uranyl nitrate for 4 weeks resulted in a strong reduction in and even disappearance of some of the most predominant bacterial groups of the original sample. Instead, a strong proliferation of denitrifying and uranium-resistant populations of Rahnella spp. from Gammaproteobacteria and of Firmicutes occurred. After longer incubations for 14 weeks with uranyl nitrate, bacterial diversity increased and populations intrinsic to the untreated samples such as Bacteroidetes and Deltaproteobacteria propagated and replaced the above-mentioned uranium-resistant groups. This indicated that U(VI) was immobilized. Mössbauer spectroscopic analysis revealed an increased Fe(III) reduction by increasing the incubation time from four to 14 weeks. This result signified that Fe(III) was used as an electron acceptor by the bacterial community established at the later stages of the treatment. X-ray absorption spectroscopic analysis demonstrated that no detectable amounts of U(VI) were reduced to U(IV) in the time frames of the performed experiments. The reason for this observation is possibly due to the low level of electron donors in the studied oligotrophic environment. Time-resolved laser-induced fluorescence spectroscopic analysis demonstrated that most of the added U(VI) was bound by organic or inorganic phosphate phases both of biotic origin. [source] Preliminary investigation of the combined effect of heat treatment and incubation temperature on the viability of the probiotic micro-organisms in freshly made yogurtINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 1 2006A M MORTAZAVIAN The combined effects of heat treatment and incubation temperature were studied on the viability and fermentation time of probiotics in ABY 1 probiotic yogurt (Lactobacillus acidophilus, Bifidobacterium spp. and yogurt bacteria). Three levels of heat treatment (85°C for 30 min, 95°C for 5 min and 95°C for 15 min) and three levels of incubation temperature (37, 40 and 44°C) were selected. At the end of fermentation, the maximum viability of probiotics (for both L. acidophilus and Bifidobacterium spp.) was observed when the milk was heated at 95°C for 15 min and incubated at 37°C. Incubation time was only affected by the incubation temperature and, at 37°C, the longest incubation time of about 6 h was needed to achieve the highest viable counts of L. acidophilus and Bifidobacterium spp. [source] Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivarsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2006Wisal H. Idris Summary The seeds of two cultivars of Sudanese sorghum (Sorghum bicolor), namely Wad Ahmed and Tabat, were germinated for 4 days to obtain 1-, 2- and 4-day-old malts. Sorghum malt (5% and 10%) was added to sorghum flour. The mixtures were incubated at 30 °C with shaking for 30, 60, 90 and 120 min. Malting loss was very slight for both cultivars and for all incubation periods. Phytic acid and tannin contents were assayed for all treatments. The results revealed that phytate and tannin contents were significantly (P , 0.05) reduced when sorghum flour was pretreated with malt. When a mixture containing 10%, 4-day-old malt and sorghum flour was incubated for 120 min, it significantly (P , 0.05) reduced phytate and tannin contents by 92% and 98%, respectively, for Wad Ahmed cultivar, while for Tabat they were reduced by 93% and 96%, respectively. The rate of reduction of phytate and tannin content increased with incubation time and malt age and concentration. [source] Life-history traits of the edible stinkbug, Encosternum delegorguei (Hem., Tessaratomidae), a traditional food in southern AfricaJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2009C. M. Dzerefos Abstract Little is known of the life history of the edible stinkbug, Encosternum delegorguei, although it is an important food for people living in north-eastern South Africa and southern Zimbabwe. The present study aimed to establish key elements influencing long-term sustainable harvesting. Outdoor insectaries of two sizes were constructed to observe: daily activity, utilization of plants, copulation, oviposition, eclosion and survival from May 2006 to February 2007. The rest of the annual life cycle was observed in the field in March and April 2007 and identified as univoltine. In autumn (May) E. delegorguei entered reproductive diapause and aggregated within the escarpment mist-belt where it survived the winter on vapour condensation without feeding. Monthly dissections showed that abdominal fat content was highest in June. In spring (September) E. delegorguei fed on sap of the trees Combretum imberbe, Combretum molle, Peltophorum africanum, to a lesser degree on Dodonaea viscosa and the grass Pennisetum clandestinum. Copulation occurred in October and November. An overall total of 1752 E. delegorguei eggs were laid by 103 females and incubation time averaged 18.7 ± 9.0 days (range 7,37) at outdoor temperature ranging from 11°C to 25°C. The mean number of eggs in 64 egg masses was 27.4 ± 13.9 (range of 2,56 eggs). Shade cloth (68.8%) was the most commonly used substrate for depositing eggs followed by P. clandestinum (12.5%), C. imberbe (7.8%), P. africanum (6.3%), D. viscosa (1.6%), C. molle (1.6%) and C. erythrophyllum (1.6%). The parasitoid wasp, Anastatus sp. (Hymenoptera: Eupelmidae) infected 57% of the eggs deposited by captive females. Availability of food plants in combination with parasitoid threat may be a reason for seasonal migration between overwintering sites within the mist-belt and summer oviposition sites. Diminishing harvests could be attributed to fuelwood harvesting of food plants in the summer sites. [source] Nitrogen fixation in the stag beetle, Dorcus (Macrodorcus) rectus (Motschulsky) (Col., Lucanidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2006T. Kuranouchi Abstract:, Stag beetles are xylophagous insects that feed mainly on dead wood. They play an important role in the decomposition of dead wood in forest ecosystems. Most dead wood contains 1% nitrogen at most. It is suspected that stag beetles can utilize atmospheric nitrogen. We show that the larvae of Dorcus (Macrodorcus) rectus exposed to nitrogen reduce acetylene to ethylene in a time-dependent fashion. No reaction was detected with the dead wood or autoclaved larvae, suggesting that living larvae use the reaction for fixing nitrogen. Acetylene reduction to ethylene by larvae increased with incubation time. This effect was not seen using decayed wood only, autoclaved wood only or autoclaved larvae. Acetylene reduction by the larva proceeded at 1.25 ± 0.37 nmol acetylene/h/g (fresh wt), corresponding to the fixation of 0.25 ,g nitrogen per day per larva. [source] Egg incubation time and hatching success in tench Tinca tinca (L.) related to the procedure of egg stickiness eliminationJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2003D. Gela Summary The experiment showed different results after a short (2 min) enzyme alcalase Merck EC 3.4.21.14 (5.0 ml L,1 concentration) treatment of tench eggs in contrast to the traditional methods of eliminating egg stickiness involving milk solution (50 g L,1) treatment for 70 min followed by the addition of a talc suspension (33 g L,1) for 10 min or treatment by fine clay suspension (20 g L,1) for 60 min or talc suspension (33 g L,1) for 80 min. The alcalase enzyme treatment resulted in decreased egg stickiness compared with the conventional milk/clay/talc treatments, indicated by lower duration of egg incubation and higher hatching rates (anova for hatching rate, P < 0.0084). The highest hatching rate (93.2%) was achieved using the enzyme; the lowest (31.3%) was using a talc suspension (control hatching rate was 86.2%). Duration of egg incubation at degree-days (D°) after enzyme treatment (58.6 D°) was about 4,5 h shorter than the classical method using milk solution and talc suspension (63,65 D°). Prolongation in the latter classical method may also be explained by a hardening of the egg envelopes. [source] Modelling the photosensitization-based inactivation of Bacillus cereusJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2009Y. Le Marc Abstract Aims:, To study and to develop a model for the photo-destruction of the foodborne pathogen Bacillus cereus, initially treated with a precursor of endogenous photosensitizers (5-aminolevulinic acid, ALA). Materials and methods:, The cells were incubated in the presence of ALA (3 or 7·5 mmol l,1) for incubation times ranging from 2 to 60 min, inoculated onto the surface of LB Agar plates and submitted to light irradiation. The Weibull model was used to describe the survival curves of B. cereus. Quadratic equations were used to describe the effects of ALA concentration and incubation time on the Weibull model parameters. Results:, ALA-based photosensitization proved to be an effective tool for inactivation of B. cereus. The decrease in viable counts observed after 20 min of irradiation, ranged from 4 to 6 log CFU g,1. Conclusions:, The developed model proved to be a parsimonious and robust solution to describe the observed data. Significance and Impact of the Study:, The study demonstrates the effectiveness of photosensitization on B. cereus on agar plates. The model developed may be useful to optimize inactivation treatments by photosensitization. [source] Predictive models of the combined effects of curvaticin 13, NaCl and pH on the behaviour of Listeria monocytogenes ATCC 15313 in brothJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2000A. Bouttefroy Thirty-three strains of Listeria monocytogenes belonging to different serotypes were tested for their sensitivity to curvaticin 13, an antilisterial bacteriocin produced by Lactobacillus curvatus SB13, using the well diffusion method in Institut Pasteur agar plates at 37 °C. No relationship between serotype and sensitivity was observed. The sensitivity of this species was strain-dependent and a large variation in tolerance to curvaticin 13 was observed. The combined effects of curvaticin 13 (0,160 AU ml,1), NaCl (0,6% w/v), pH values (5·0,8·2) and incubation time (0,24 h) were investigated on L. monocytogenes ATCC 15313 in trypcase soy,yeast extract broth at 22 °C. For this study, two Doehlert matrices were used in order to investigate the main effects of these factors and their different interactions. The results were analysed using the Response Surface Methodology. Curvaticin 13 had a major inhibitory effect and the response was NaCl concentration-, time- and pH-dependent. This inhibitory activity was the same at pH values between 6·6 and 8·2. Curvaticin 13 was bactericidic at acidic pH values, but the surviving cells resumed growth. For a short incubation time (12 h), the effectiveness of curvaticin 13 was maximal in the absence of NaCl. For longer incubation times (12,48 h), with high NaCl (6%) and curvaticin 13 concentrations (160 AU ml,1), the inhibition of L. monocytogenes was greater than that observed with NaCl or curvaticin 13 alone. [source] Time allocation between feeding and incubation in uniparental arctic-breeding shorebirds: energy reserves provide leeway in a tight scheduleJOURNAL OF AVIAN BIOLOGY, Issue 3 2006Ingrid Tulp Birds with uniparental incubation may face a time allocation problem between incubation and feeding. Eggs need regular warming to hatch successfully, but the parent must leave the nest to feed and safeguard its own survival. Time allocation during incubation is likely to depend on factors influencing egg cooling rates, parental energy requirements and feeding intake rate. How this allocation problem is resolved was subject of this study on arctic-breeding shorebirds. We compared incubation rhythms between four uniparental shorebird species differing in size and expected to find both species differences and weather effects on the organisation of incubation. Attentive behaviour and responses to variation in weather showed a remarkable consistency across species. All species alternated feeding bouts (recesses) with brooding bouts throughout the day. Recesses were concentrated in the warmer parts of the day, while recess duration showed little diurnal variation. Despite continuous daylight, a pronounced day-night rhythmicity was apparent. The four species in this study spent a similar proportion (13,19%) of the time off their nest. After correction for weather effects, the number of recesses was largest in the smallest species, while recess duration was longest in the largest species. Total recess time per day increased on cold days through an increase of mean recess length, while the number of recesses decreased. Comparing our observations to predictions derived from criteria that birds might use to organise their attentive behaviour, showed that the limits are set by parental requirements, while the energy stores of adults provide some leeway for short-term adjustments to environmental variability. If breeding birds trade off feeding time against incubation time, energy stores are expected to be influenced by weather. We expected uniparental species to be more likely to show weather effects on condition than biparentals, as in the latter ,off duty' time is much larger and independent of weather. This prediction was tested by comparing energy stores in two uniparental species and a biparental congener. While body mass of uniparental incubators decreased after a period with low temperatures, body mass of the biparental species did not. [source] Sequential parametric optimization of lipase production by a mutant strain Rhizopus sp.JOURNAL OF BASIC MICROBIOLOGY, Issue 4 2005BTNT- Lipase production by the mutant strain Rhizopus sp. BTNT-2 was optimized in submerged fermentation. Different chemical and physical parameters such as carbon sources, nitrogen sources, oils, inoculum level, pH, incubation time, incubation temperature and aeration have been extensively studied to increase lipase productivity. Potato starch (1.25% w/v) as a carbon source, corn steep liquor (1.5% w/v) as a nitrogen source and olive oil (0.5% v/v) as lipid source were found to be optimal for lipase production. The optimal levels of other parameters are 4 ml of inoculum (2.6 × 108 spores/ml), initial pH of 5.5, incubation time of 48 hours, incubation temperature of 28 °C and aeration rate of 120 rpm. With the optimized parameters, the highest production of lipase was 59.2 U/ml while an yield of only 28.7 U/ml was obtained before optimization resulting in 206% increase in the productivity. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Role of Endothelium/Nitric Oxide and Cyclic AMP in Isoproterenol Potentiation of 17ß-Estradiol-Mediated VasorelaxationJOURNAL OF CARDIAC SURGERY, Issue 6 2002HY Chan Estrogen exerts vasorelaxation and cardiac protection via multiple cellular mechanisms. Estrogen modifies vasodilatation induced by certain relaxants such as ß-adrenoceptor agonists. However, little is known whether low concentrations of ß-adrenoceptor agonists would also influence the acute relaxant response to estrogen. The present study was designed to investigate the synergistic interaction between isoproterenol and 17ß-estradiol, and to study the role of endothelium and cyclic AMP-dependent pathway in this interaction. Changes in vessel tone of the isolated rat mesenteric artery rings were measured by force-displacement Grass transducer. In 9,11-dideoxy-11,, 9,-epoxy-methanoprostaglandin F2, - preconstricted endothelium-intact rings, 17ß-estradiol induced concentration-dependent relaxation with pD2 of 5.074 ± 0.043. Pretreatment of endothelium-intact rings with isoproterenol (1-3 × 10 -9 M, 1-h incubation time) significantly enhanced 17,-estradiol-induced relaxation. Longer incubation (2.5 h) did not produce further amplifying effect. This effect was inhibited by Rp-cGMPS triethylamine (3 × 10 -6 M), and disappeared in the presence of 3 × 10 -5 M NG -nitro-L-arginine methyl ester or in the endothelium-denuded rings. The effect of isoproterenol was partially antagonized by propranolol (3 × 10 -6 M), ICI 118,551 (3 × 10 -6 M) but not by atenolol (10 -5 M). None of three ,-adrenoceptor antagonists affected 17ß-estradiol-induced relaxation in the absence of isoproterenol. Rp-cAMPS triethylamine (3 × 10 -6 M) abolished the effect of isoproterenol. Besides, exposure to 3 × 10 -9 M forskolin for 1 h also potentiated the relaxant response to 17,-estradiol. In summary, this isoproterenol enhancement was dependent on the presence of endothelium and abolished by L-NAME via a ,2 -adrenoceptor-mediated cyclic AMP-dependent mechanism. These data also indicate the possible existence of cyclic AMP-dependent nitric oxide-producing pathway in the regulation of the vascular response to vasodilators. (supported by UPGC Direct Grant) [source] Rapid in vitro conversion of fosphenytoin into phenytoin in sera of patients with liver disease: Role of alkaline phosphatase ,JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 5 2001Amitava Dasgupta Abstract Fosphenytoin, a phosphate ester pro drug of phenytoin, also cross-reacts with the fluorescence polarization immunoassay (FPIA) for phenytoin. We measured fosphenytoin concentrations using the FPIA kit and TDx analyzer. We prepared serum pools from normal volunteers and patients with liver disease. None of them received either fosphenytoin or phenytoin. Fosphenytoin standard solution (1 mg/ml) was prepared in water. We supplemented aliquots of normal and liver pools with known amounts of fosphenytoin and measured the concentrations at different time intervals. The conversion of fosphenytoin to phenytoin was slow in sera with normal alkaline phosphatase activities. The conversion was rapid in sera collected from patients with liver disease who also had high alkaline phosphatase activities. The observed concentrations were close to target concentrations within 0,2 min of supplementation with fosphenytoin. Surprisingly, the observed concentration then started to decline slightly but significantly with longer incubation time. In contrast, the observed concentration increased steadily in serum with normal alkaline phosphatase activity. For example, in the normal pool supplemented with 15.0 ,g/ml fosphenytoin (as the phenytoin equivalent), the observed concentrations were 6.9, 7.3, 7.7, 8.3, and 9.8 ,g/ml at 0,2, 10, 20, 30, and 60 min, respectively. However, in a serum pool prepared from patients with liver disease and supplemented with 15.0 ,g/ml of fosphenytoin (alkaline phosphatase: 2547 U/l), the observed phenytoin concentrations were 12.9, 12.1, 11.0, 10.7, and 10.7 ,g/ml at 0,2, 10, 20, 30, and 60 min, respectively. When we added alkaline phosphatase to the normal serum pool, we observed rapid conversion of fosphenytoin into phenytoin within 10 min, but the concentrations then declined with longer incubation time. However, when we repeated the experiment with protein-free ultrafiltrate, we observed rapid conversion of fosphenytoin to phenytoin, but the concentration did not decline with longer incubation time. J. Clin. Lab. Anal. 15:244,250, 2001. © 2001 Wiley-Liss, Inc. [source] The relationship of oocyte diameter and incubation temperature to incubation time in temperate freshwater fish speciesJOURNAL OF FISH BIOLOGY, Issue 3 2009F. Teletchea Based on the analysis of six egg variables and incubation temperature of 65 temperate freshwater fish species, the possible relationships between oocyte diameter, incubation time and incubation temperature were reassessed and compared to the results obtained from marine fishes. Most freshwater species have eggs (mean ±s.d. 2·19 ± 1·52 mm) larger than marine species, that are chiefly demersal and develop stuck to various substrata, such as plants or rocks. A strong negative relationship was found between incubation time (t, days) and incubation temperature (T, ° C): t = 186·23e,0·197T (r2= 0·87). A strong dependence of incubation time on oocyte diameter (Ø, mm) and incubation temperature was also found and was defined as: log10t= 3·002 + 0·599 log10Ø, 1·91 log10 (T + 2), which explained 92% of the variance of the data set. Five major groups of species were defined based on the principal component analysis (PCA) of four quantitative variables. There were two distinct groups of salmonids, displaying demersal and non-adhesive eggs with a long incubation time at low temperature, the eggs of which required a high number of degree-days. There was a large group of species possessing small, mostly demersal and adhesive eggs developing at high temperature during a short period of time, and requiring a low number of degree-days. Between these two extremes, there was a fourth group displaying intermediate values and a fifth group including three species with large, adhesive and demersal eggs incubating at high temperatures during a short period of time. The burbot Lota lota displayed an unusual combination of variables compared to the remaining species in the data set. [source] Detection of spring viraemia of carp virus (SVCV) by loop-mediated isothermal amplification (LAMP) in koi carp, Cyprinus carpio LJOURNAL OF FISH DISEASES, Issue 4 2008R B Shivappa Abstract Spring viraemia of carp virus (SVCV) is a rhabdovirus associated with systemic illness and mortality in cyprinids. Several diagnostic tests are available for detection of SVCV. However, most of these tests are time consuming and are not well adapted for field-based diagnostics. In this study, a diagnostic tool for SVCV detection based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) has been developed. Based on the nucleotide sequence of the glycoprotein (G) gene of SVCV North Carolina (NC) isolate, four sets (each set containing two outer and two inner) of primers were designed. Temperature and time conditions were optimized to 65 °C and 60 min, respectively, for LAMP and RT-LAMP using one primer set. In vitro specificity was evaluated using four different strains of fish rhabdoviruses and RT-LAMP was found to be specific to SVCV. Serial dilutions of SVCV NC isolate was used to evaluate the in vitro sensitivity of RT-LAMP. Sensitivity of the assays was similar to RT-PCR and detected SVCV even at the lowest dilution of 101 TCID50 mL,1. The ability of RT-LAMP to detect SVCV from infected carp was also tested and the assay detected SVCV from all infected fish. The isothermal temperature requirements, high specificity and sensitivity, and short incubation time of the RT-LAMP assay make it an excellent choice as a field diagnostic test for SVCV. [source] RESPONSE SURFACE METHODOLOGY FOR STUDYING THE QUALITY CHARACTERISTICS OF COWPEA (VIGNA UNGUICULATA)-BASED TEMPEHJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2010GEORGE AMPONSAH ANNOR ABSTRACT Response surface methodology was used to optimize the processing conditions in the preparation of cowpea tempeh. The independent factors studied were boiling time (varying from 5 to 30 min), incubation time (varying from 12 to 48 h) and incubation temperatures (varying from 25 to 50C), whereas the dependent factors were protein content, protein solubility, pH, titratable acidity and total color difference (using L, a* and b*). Regression models were generated and adequacy was tested with regression coefficients (R2) and the lack-of-fit tests. Optimum processing conditions were determined by method of superimposition. There was a strong and significant influence (P < 0.01) of the quadratic effect of the incubation time on the protein content of the cowpea tempeh, with similar significance (P < 0.01) noted in protein solubility with increasing boiling time. The optimum processing conditions observed for the preparation of cowpea tempeh were boiling time of about 20 min, incubation time of about 28 h and incubation temperature of about 37C. PRACTICAL APPLICATIONS Response surface methodology (RSM), as a statistical tool, has been effectively used in food process applications. This study embraced the use of RSM in the optimization of the processing conditions involved in the preparation of cowpea tempeh. Superimposition of the contour plots developed from the regression models indicated that cowpea with optimum quality characteristics should be processed at a boiling time of 20 min, incubation time of 28 h and incubation temperature of 37C. These conditions could be adopted for the industrial production of cowpea tempeh. [source] PHYSICAL, PHYSIOLOGICAL AND CHEMICAL CHANGES IN POTATO AS INFLUENCED BY ERWINIA CAROTOVORA INFECTIONJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2002F. NOURIAN Bacterial soft rot, caused by Erwinia carotovora ssp. carotovora (Ecc), is a major disease in stored potatoes. The pathogen causes different physical, physiological and chemical changes in potatoes, which may affect the acceptability of raw and processed products. This study was carried out to evaluate the effect of disease severity on different physico-chemical and physiological properties of raw and cooked potatoes and to select the parameters most responsive to disease severity. Potatoes were inoculated with bacteria and incubated at 20C for different lengths of time to produce different levels of disease. As incubation time increased the volume of disease (VDS) increased, which in turn influenced the respiration rate (RR). In both raw and cooked potatoes, the physical changes (texture and color) associated with the progress of disease were reduced hardness, firmness and L value, and increased a and b values and total color difference (,E). The chemical changes were reduced ascorbic acid and pH, and increased reducing sugars, total sugars and titrable acidity along with the activities of peroxidase and polyphenol oxidase. The changes in physical and chemical parameters of raw and cooked potatoes during storage were described by fractional conversion equation models. All parameters were quite sensitive to disease except reducing sugars, peroxidase and PPO activity. The correlation matrix indicated that several of the quality parameters were related and thus most of them could be successfully used to predict tuber quality from disease. [source] OPTIMIZATION OF GUAVA JUICE AND POWDER PRODUCTIONJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2001CHETAN A. CHOPDA Enzyme treatment of guava puree was optimized for yield and clarity by first determining the most effective concentration, then varying both incubation time and temperature. Application of Pectinex Ultra SP-L® was optimal using 700 ppm enzyme for 1.5 h at 50C. Clarified guava juice was clearer (89.6%) when prepared using ultrafiltration (MW cut-off 40,60 kDa) rather than plate and frame filtration (82.8%); however, the latter was higher in both soluble solids and ascorbic acid. Clarified guava juice powders were made using freeze-drying, spray drying and tunnel drying. The freeze-dried product had superior quality; however, the spray-dried product was stable and may be more economical. Sensory panelists ranked the cloudy juice prepared from aseptic guava puree highest, and there were no significant differences between the juices from pasteurized, clear nectar, freeze-dried puree powder or juice powder. [source] IMPROVED MEDIUM FOR DETECTION OF KLEBSIELLA IN POWDERED MILKJOURNAL OF FOOD SAFETY, Issue 1 2010HONG GAO ABSTRACT The selectivities to pathogenic Klebsiella strains of different isolation media were compared by known standard strains. The modified MacConkey-inositol-carbenicillin (MCIC) medium (Named MCIAC, MacConkey-inositol-adonitol-carbenicillin) supplemented with adonitol gave no false-negative colonies, and exhibited higher selectivity. MCIC and Simmons citrate agar with inositol (SCAI) media gave two false-negative colonies, respectively. These three media all gave two false-positive colonies, respectively. Salmonella Shigella medium gave four false-negative colonies and five false-positive colonies. Violet red bile glucose agar medium gave the most false-positive colonies, although it gave no false-negative colonies. One hundred samples of powdered milk were examined by MCIAC, MCIC and SCAI plates. The typical positive colonies were further identified using Vitek GNI Auto Microbic system and API 20E system. The results showed that the specificity of the MCIAC medium was higher than MCIC and SCAI media. PRACTICAL APPLICATIONS MacConkey-inositol-carbenicillin (MCIC) is the most commonly used selective medium for the detection of Klebsiella. But some inositol-nonfermenting Klebsiella strains would be missed when selected by this medium. We improved the MCIC medium by supplementing with 1% adonitol. The new modified medium (MacConkey-inositol-adonitol-carbenicillin, MCIAC) had advantages over other selective Klebsiella media in having a higher selectivity and an incubation time of only 16,24 h. MCIAC could be routinely used for pathogenic Klebsiella selection of powdered milk and other food samples. [source] | |||||||||||||||||||||||||||||||||||||||||||