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Soluble Starch (soluble + starch)
Selected AbstractsIsolation and identification of Alicyclobacillus acidocaldarius by 16S rDNA from mango juice and concentrateINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2005Pieter A. Gouws Summary In this study we investigate the spoilage of ultra high temperature UHT mango juice as well as a carbonated fruit juice blend to identify organisms contributing to the spoilage. The mango concentrate, the final product, as well as the other ingredients used during manufacturing, were tested for the presence of Alicyclobacillus by polymerase chain reaction (PCR) and sequencing analyses. Microbiological examination of the mango pureé and spoiled fruit juices, using YSG agar [yeast extract 2 g, glucose 1 g, soluble starch 2 g, pH 3.7 (adjust with 2N H2SO4), H2O 1000 mL, bacto agar 15 g] incubated at 55 °C, detected sporeforming, acid dependent and thermotolerant bacteria. The hyper variable region of the 16S rDNA was amplified. The nucleotide sequence of the PCR fragments was determined using the ABI Prism 310 automated DNA sequencer and the collected sequencing data were analysed and compared with the non-redundant database using NCBI-BLAST. Alicyclobacillus acidocaldarius were isolated and identified by 16S rDNA gene sequences analyses. The results indicated that the mango purče, as well as the final product of mango juice and the fruit juice blend, were positive for Alicyclobacillus. The preventative measures of low pH, pasteurization of mango juice and the subsequent use of aseptic packaging were not regarded as sufficient to prevent the outgrowth of Alicyclobacillus spoilage organisms. [source] Cariogenicity of soluble starch in oral in vitro biofilm and experimental rat caries studies: a comparisonJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2008T. Thurnheer Abstract Aims:, Common belief suggests that starch is less cariogenic than sugar; however, the related literature is quite controversial. We aimed to compare cariogenic and microbiological effects of soluble starch in both a standard animal model and an oral biofilm system, and to assess the possible substitution of the animal model. Methods and Results:, Six-species biofilms were grown anaerobically on enamel discs in saliva and medium with glucose/sucrose, starch (average molecular weight of 5000, average polymerization grade of 31), or mixtures thereof. After 64·5 h of biofilm formation, the microbiota were quantitated by cultivation and demineralization was measured by quantitative light-induced fluorescence. To assess caries incidence in rats, the same microbiota as in the biofilm experiments were applied. The animals were fed diets containing either glucose, glucose/sucrose, glucose/sucrose/starch or starch alone. Results with both models show that demineralization was significantly smaller with starch than sucrose. Conclusions:, The data demonstrate that soluble starch is substantially less cariogenic than glucose/sucrose. Significance and Impact of the Study:, By leading to the same scientific evidence as its in vivo counterpart, the described in vitro biofilm system provides an interesting and valuable tool in the quest to reduce experimentation with animals. [source] Ethanol production from raw starch by a recombinant yeast having saccharification and fermentation activitiesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2002Yoshitoshi Nakamura Abstract In order to develop a method for converting raw starch into ethanol efficiently, direct fermentation of ozonized raw starch using a recombinant yeast was investigated. Ozonolysis was carried out as a pretreatment to convert raw starch into ethanol rapidly and efficiently, and then the effect of the ozone degradation conditions on the degree of polymerization and the amount of amylose in a raw starch was determined. Since the degree of polymerization was low and the amount of amylose was high, raw starch treated with an ozone concentration of 40,gm,3 and an ozonation time of 30,min was the material chosen for alcohol fermentation. Though the recombinant yeast could not convert the untreated raw starch, it converted the soluble starch and the ozonized raw starch at a comparatively high yield into ethanol. About 56% of the ozonized raw starch decomposed, and the ethanol concentration obtained from the ozonized raw starch was markedly greater than that obtained from untreated raw starch. The dynamic behavior of cell growth, substrate degradation, and ethanol production was examined in a continuous culture under various dilution rates, and the optimal dilution rate, ie 0.15,h,1, was determined for maximizing the ethanol productivity (amount of ethanol produced per unit time). © 2002 Society of Chemical Industry [source] Intermediate accumulation and efficiency of anaerobic digestion treatment of surfactant (alcohol sulfate)-rich wastewater at increasing surfactant/biomass ratiosJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2002Heiko Feitkenhauer Abstract Textile (eg cotton) finishing industry wastewater is characterised by high concentrations of surfactants (up to 2,g,dm,3) and of readily biodegradable biopolymers (COD 5,15,g,dm,3). The anionic surfactant decyl sulfate (DS) was chosen as model surfactant and soluble starch (size) as model compound for the readily biodegradable fraction of the wastewater. Twenty-two batch experiments with increasing DS/biomass ratio (and starch/biomass ratio) were started simultaneously. Biomass concentrations ranged from 50 to 15,000,mg,dm,3. Minor inhibition effects were found for the surfactant degradation itself at all DS/biomass ratios (maximum biodegradation rate 7.7,mgDS gbiomass,1h,1). The starch hydrolysis started without a lag-phase at DS/biomass ratios of up to 0.15,gDS gbiomass,1. The lag-phase was prolonged to about 100,h at a very high DS/biomass ratio (3,gDS gbiomass,1). The relative importance of the accumulated intermediates was dependent on the DS/biomass ratio. Above 0.3,gDS gbiomass,1 10% of the substrate organic carbon accumulated as ethanol, but no ethanol accumulation was observed at low DS/biomass ratios. Moderate DS/biomass ratios caused a considerable delay of the methanogenesis; high DS/biomass ratios prevented the methanogenesis almost completely. © 2002 Society of Chemical Industry [source] Characterization of Honey AmylaseJOURNAL OF FOOD SCIENCE, Issue 1 2007Sibel Babacan ABSTRACT:, The major ,-amylase in honey was characterized. The optimum pH range and temperature were determined for the enzyme as 4.6 to 5.3 and 55 °C, respectively. The enzyme was stable at pH values from 7 to 8. The half-lives of the purified enzyme at different temperatures were determined. The activation energy for heat inactivation of honey amylase was 114.6 kJ/mol. The enzyme exhibited Michaelis,Menten kinetics with soluble starch and gave KM and Vmax values of 0.72 mg/mL and 0.018 units/mL, respectively. The enzyme was inhibited by CuCl (34.3%), MgCl2 (22.4%), and HgCl2 (13.4%), while CaCl2, MnCl2, and ZnSO4 did not have any effect. Starch had a protective effect on thermal stability of honey amylase. Therefore, it might be critical to process or control the amylase in honey before incorporation into starch-containing foods to aid in the preservation of starch functionality. One step could involve heat treating honey with other ingredients, especially those that dilute and acidify the honey environment. [source] A near-infrared spectroscopic investigation of relative density and crushing strength in four-component compactsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2009Steven M. Short Abstract Near-infrared spectroscopy (NIRS) is commonly employed for the analysis of chemical and physical attributes of intact pharmaceutical compacts. Specifically, NIRS has proven useful in the nondestructive measurement of tablet hardness or crushing strength. Near-infrared (NIR) reflectance and transmittance spectra were acquired for 174 13-mm compacts, which were produced according to a four-constituent mixture design (29 points) composed of anhydrous theophylline, lactose monohydrate, microcrystalline cellulose, and soluble starch. Six compacts were produced for each design point by compacting at multiple pressures. Physical testing and regression analyses were used to model the effect of variation in relative density (and crushing strength) on NIR spectra. Chemometric analyses demonstrated that the overall spectral variance was strongly influenced by anhydrous theophylline as a result of the experimental design and the component's spectroscopic signature. The calibration for crushing strength was more linear than the relative density model, although accuracy was poorer in comparison to the density model due to imprecision of the reference measurements. Based on the consideration of reflectance and transmittance measurements, a revised rationalization for NIR sensitivity to compact hardness is presented. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1095,1109, 2009 [source] Regulation of the catalytic behaviour of L-form starch phosphorylase from sweet potato roots by proteolysisPHYSIOLOGIA PLANTARUM, Issue 4 2002Han-Min Chen Starch phosphorylase (SP) is an enzyme used for the reversible phosphorolysis of the ,-glucan in plant cells. When compared to its isoform in an animal cell, glycogen phosphorylase, a peptide containing 78 amino acids (L78) is inserted in the centre of the low-affinity type starch phosphorylase (L-SP). We found that the amino acid sequence of L78 had several interesting features including the presence of a PEST region, which serves as a signal for rapid degradation. Indeed, most L-SP molecules isolated from mature sweet potato roots were nicked in the middle of a molecule, but still retained their tertiary or quaternary structures, as well as full catalytic activity. The nicking sites on the L78 were identified by amino acid sequencing of these peptides, which also enabled us to propose a proteolytic process for L-SP. Enzyme kinetic studies of L-SP in the direction of starch synthesis indicated that the Km decreased during the proteolytic process when starch was used as the limiting substrate, but the Km for the other substrate (Glc-1-P) increased. On the other hand, the maximum velocities (Vmax) increased for both substrates. Mobility of the nicked L-SP was retarded on a native polyacrylamide gel containing soluble starch, indicating the increased affinity for starch. Results in this study suggested that L78 and its proteolytic modifications might play a regulatory role on the catalytic behaviour of L-SP in starch biosynthesis. [source] Bioartificial dextran and poly[ethylene- co -(vinyl alcohol)] hybrid sponges as support for proteinsPOLYMER INTERNATIONAL, Issue 10 2005D Silvestri Abstract A biological,synthetic hybrid material was prepared as a support for proteinic molecules. To control the conformational stability and ,vitality' of the entrapped compound, an enzyme, which catalyses a chemical reaction, was chosen. The physical immobilisation of ,-amylase on a novel biological,synthetic hybrid material was realised using a synthetic (poly[ethylene- co -(vinyl alcohol)]) and a biological (dextran) component. The supports were obtained in the form of porous sponges using the phase inversion process. The kinetic parameters of enzymatic hydrolysis of soluble starch were obtained by determining the maltose (reaction product) concentration in the test solution by a spectrophotometric method. A high amount of enzyme (10 and 15 mg per g of polymer matrix) was successfully entrapped in the polymer support and a rather good enzyme activity of entrapped ,-amylase and a constant activity for repeated use, compared with native ,-amylase, were observed. The results obtained clearly indicated that the bioartificial polymer sponges, showing an immobilisation of ,-amylase with maintenance of the catalytic function of the enzyme, can be used as suitable supports for proteins. Copyright © 2005 Society of Chemical Industry [source] Effects of carbon sources on fungal morphology and lovastatin biosynthesis by submerged cultivation of Aspergillus terreusASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Zhihua Jia Abstract The influences of various carbon sources on fungal morphological changes and lovastatin production were investigated in submerged cultivation of a mutant of Aspergillus terreus. Lactose produced the least biomass (2.3 ± 0.15 gDCW l,1); however, the highest maximal specific lovastatin productivity (,max) was obtained. Glycerol achieved the highest lovastatin titer (937.5 ± 12.5 mg l,1), while soluble starch resulted in the highest biomass (12.05 ± 0.05 gDCW l,1) and the second highest lovastatin titer (501.3 ± 23.4 mg l,1). With the carbon source turning to be more easily metabolized, the values of ,max dropped gradually while the corresponding Dp and mean filament ratio rose tardily. The value of ,max (19.8 mg gDCW,1 d,1) was obtained in the presence of lactose while glucose resulted in the least ,max (3.0 mg gDCW,1 d,1). This led to a 6.6-fold decrease. The corresponding Dp and mean filament ratios appeared to reverse the effects, thus producing 1.9 and 3.3-fold increases, respectively. The slowly utilizable carbon sources regulated the lovastatin production through both the inducement of fungal morphology differentiation and the control of metabolic regulation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Characterization of electrochemically active bacteria utilizing a high-throughput voltage-based screening assayBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Justin Biffinger Abstract Metal reduction assays are traditionally used to select and characterize electrochemically active bacteria (EAB) for use in microbial fuel cells (MFCs). However, correlating the ability of a microbe to generate current from an MFC to the reduction of metal oxides has not been definitively established in the literature. As these metal reduction assays may not be generally reliable, here we describe a four- to nine-well prototype high throughput voltage-based screening assay (VBSA) designed using MFC engineering principles and a universal cathode. Bacterial growth curves for Shewanella oneidensis strains DSP10 and MR-1 were generated directly from changes in open circuit voltage and current with five percent deviation calculated between each well. These growth curves exhibited a strong correlation with literature doubling times for Shewanella indicating that the VBSA can be used to monitor distinct fundamental properties of EAB life cycles. In addition, eight different organic electron donors (acetate, lactate, citrate, fructose, glucose, sucrose, soluble starch, and agar) were tested with S. oneidensis MR-1 in anode chambers exposed to air. Under oxygen exposure, we found that current was generated in direct response to additions of acetate, lactate, and glucose. Biotechnol. Bioeng. 2009;102: 436,444. © 2008 Wiley Periodicals, Inc. [source] | |||||||||||||||||||||||||