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Maximum Production (maximum + production)
Selected AbstractsISOLATION AND CHARACTERIZATION OF BACTERIOCIN-PRODUCING MICROORGANISMS FROM AGOS-OSJOURNAL OF FOOD SAFETY, Issue 3 2000JULIE D. TAN ABSTRACT Agos-os, a fermented meat and sweetpotato mixture, was produced and analyzed for its microbial characteristics. pH decreased during fermentation. Mold and anaerobic bacterial counts increased while yeasts and aerobic bacterial counts decreased during the third and seventh day of fermentation. Six isolates with the widest zones of inhibition on the indicator lawn were selected for bacteriocin production. These isolates had exactly the same morphological, physiological and biochemical characteristics. The ribosomal RNA sequence was 99.5% identical with Enterococcus faecalis VRE 1492. The identification was confirmed through DNA homology test by the EMBL Genbank, Canada. This bacterium produced the L-isomer lactic acid. The amount of bacteriocin produced by the bacterium was optimized by growing the bacterium at different growth media, initial pH and fermentation time. Maximum production of bacteriocin was achieved in MRS (De Man Rugosa and Sharpe) medium (with glucose) at pH 7.50. The crude bacteriocin inhibited the growth of gram-positive bacteria such as Lactobacillus sake 15521 and Listeria innocua. The gram-negative bacteria such as Escherichia coli DH 5-alpha (with plasmid, PUC), Salmonella typhii and Staphylococcus aureus were weakly inhibited. Other microorganisms such as Lactobacillus curvatus D31685, Lactobacillus confusius M23036, Lactococcus lactis MG1363, Leuconostoc paramesenteroides S67831, Pediococcus pentosaceus M58834, Saccharomyces cerevisiae SS553 (wild type) and Escherichia coli JM109 (no plasmid) were not inhibited. [source] Basic fibrobrast growth factor induces the secretion of vascular endothelial growth factor by human aortic smooth muscle cells but not by endothelial cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003F. Belgore Abstract Background, Endothelial cell dysfunction and smooth muscle cell (SMC) proliferation are major events in atherogenesis. Both cells are a source of growth factors that mediate cellular proliferation and chemotaxis. Inappropriate production of, and/or response to, these growth factors (such as vascular endothelial growth factor, VEGF, and basic fibroblast growth factor (bFGF)) may contribute to atherogenesis and therefore to disease progression. Methods, Production of VEGF and its soluble receptor (sFlt-1) by human SMCs and human umbilical endothelial cells (HUVECs) after stimulation with bFGF were examined by ELISA of cell culture media and by Western blotting. Results, Smooth muscle cells produced significantly more VEGF than HUVECs (P < 0·05) after 24 h of culture with bFGF levels , 0·001 µg mL,1. bFGF induced dose-dependent production of VEGF by SMCs, where maximum production was present in 1 µg mL,1 of bFGF. Conversely, the SMCs produced less sFlt-1 than HUVECs (P < 0·05). However, bFGF induced dose-dependent phosphorylation of Flt1 and another VEGF receptor, KDR, in HUVECs but not SMCs. There was no VEGF or sFLT-1 after 6 h of culture in any dose of bFGF in either type of cell. Conclusions, Differences in the production of VEGF and sFlt-1 by SMCs and HUVECs are consistent with the role of these cells in angiogenesis. Induction of VEGF production and expression by bFGF in these cells indicates that this growth factor may participate in angiogenesis indirectly by the induction of VEGF. The production of sFlt-1 by both cell types is in agreement with the notion that sFlt-1 may be involved in the regulation of VEGF activity. Additionally, the ability of bFGF to induce dose-dependent phosphorylation of KDR in HUVECs highlights the important role of bFGF in VEGF-mediated angiogenic processes. [source] Beta-glucan production by Botryosphaeria rhodina in different bench-top bioreactorsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2004L. Selbmann Abstract Aims:, Evaluation of the technical feasibility of transferring , -glucan production by Botryosphaeria rhodina DABAC-P82 from shaken flasks to bench-top bioreactors. Methods and Results:, Three different bioreactors were used: 3 l stirred tank reactor (STR-1) equipped with two different six-blade turbines; STR as above but equipped with a three-blade marine propeller plus draft-tube (STR-2); 2 l air-lift column reactor (ALR) equipped with an external loop. STR-1, tested at three different stirrer speeds (300, 500 and 700 rev min,1) appeared to be less suitable for , -glucan production by the fungus, being maximum production (19·4 g l,1), productivity (0·42 g l,1 h,1) and yield (0·48 g g,1 of glucose consumed) markedly lower than those obtained in shaken culture (29·7 g l,1, 1·23 g l,1 h,1 and 0·61 g g,1, respectively). Better performances were obtained with both STR-2 and ALR. With the latter, in particular, the increase of production was accompanied by reduced fermentation time (25·7 g l,1 after only 22 h); productivity and yield were highest (1·17 g l,1 h,1 and 0·62 g g,1 of glucose consumed, respectively). Conclusion:, Using an air-lift reactor with external loop, the scaling up from shaken flasks to bench-top bioreactor of the , -glucan production by B. rhodina DABAC-P82 is technically feasible. Significance and Impact of the Study:, Although culture conditions are still to be optimized, the results obtained using the ARL are highly promising. [source] Effects of Whey Permeate-Based Medium on the Proximate Composition of Lentinus edodes in the Submerged CultureJOURNAL OF FOOD SCIENCE, Issue 6 2006Xiaojun Jeffrey Wu ABSTRACT:, Biomass production, crude water-soluble polysaccharide (WSP), ash content, mineral profile, and crude protein content were determined for Lentinus edodes mycelia grown on whey permeate (WP)-based medium with lactose content of 4.5% or defined synthetic medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 °C. Harvesting time and the type of media interact to alter the chemical content of mycelia. Mycelia grown in WP had greater (P < 0.05) WSP and ash than mycelia grown in the synthetic media. A maximum production of WSP was obtained on the 10th day (4.1 × 102± 71 mg WSP/g dried mycelia) from mycelia grown on the WP-based media. Mycelia grown on WP harvested on the 20th day had the highest value in ash content (18 ± 3%). Potassium was found to be the main constituent in the ash of mushroom mycelia, which was followed by phosphorus, sodium, calcium, and magnesium. A steady increase of ash content was only noted in mycelia grown on WP. The calcium content of WP-grown mycelia was at least 10 times higher compared to mycelia grown in the control media regardless the harvesting time. Data in this research suggested that WP was more favorable than the synthetic media in the production of WSP, which is traditionally known for their medicinal value in L. edodes. [source] Role of casein on induction and enhancement of production of a bacterial milk clotting protease from an indigenously isolated Bacillus subtilisLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2008K. Dutt Abstract Aims:, To isolate and enhance the yield of a bacterial milk clotting protease (MCP) through process optimization and scale up. Materials and Results:,Bacillus subtilis was isolated as MCP producer with good milk clotting activity (MCA) per proteolytic activity (PA) index. The enzyme production was inducible with casein and enhanced with fructose and ammonium nitrate resulting in 571·43 U ml,1 of enzyme. Conclusions:, Medium containing 4% fructose, 0·75% casein, 0·3% NH4NO3 and 10 mmol l,1 CaCl2, pH 6·0, inoculated with 4% (v/v) inoculum, incubated at 37°C, 200 rev min,1 for 72 h gave maximum production. A 6·67-fold increase in MCP yield with very high MCA per PA index was observed after final optimization indicating similarity to rennets. Significance and Impact of the Study:, Mostly fungal MCPs have been reported. The MCA and MCA per PA index of this bacterium is comparable to that of many fungal reports and better than quite a few bacterial MCPs. Thus, this enzyme by B. subtilis has good probability of successful use in cheese production. [source] Analysis of the role of GADD153 in the control of apoptosis in NS0 myeloma cellsBIOTECHNOLOGY & BIOENGINEERING, Issue 7 2002Idsada Lengwehasatit Abstract Apoptosis can limit the maximum production of recombinant protein expression from cultured mammalian cells. This article focuses on the links between nutrient deprivation, ER perturbation, the regulation of (growth arrest and DNA damage inducible gene 153) GADD153 expression and apoptosis. During batch culture, decreases in glucose and glutamine correlated with an increase in apoptotic cells. This event was paralleled by a simultaneous increase in GADD153 expression. The expression of GADD153 in batch culture was suppressed by the addition of nutrients and with fed-batch culture the onset of apoptosis was delayed but not completely prevented. In defined stress conditions, glucose deprivation had the greatest effect on cell death when compared to glutamine deprivation or the addition of tunicamycin (an inhibitor of glycosylation), added to generate endoplasmic reticulum stress. However, the contribution of apoptosis to overall cell death (as judged by morphology) was smaller in conditions of glucose deprivation than in glutamine deprivation or tunicamycin treatment. Transient activation of GADD153 expression was found to occur in response to all stresses and occurred prior to detection of the onset of cell death. These results imply that GADD153 expression is either a trigger for apoptosis or offers a valid indicator of the likelihood of cell death arising from stresses of relevance to the bioreactor environment. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 719,730, 2002. [source] Optimization of medium composition for the production of antimicrobial activity by Bacillus subtilis B38BIOTECHNOLOGY PROGRESS, Issue 5 2009Olfa Tabbene Abstract An antimicrobial activity produced by Bacillus subtilis B38 was found to be effective against several bacteria, including pathogenic and spoilage microorganisms such as, Listeria monocytogenes, Salmonella enteridis, and clinical isolates of methicillin-resistant Staphylococcus species. Nutrients such as carbon, nitrogen sources, and inorganic salts enhanced the production level of the antibacterial activity by B. subtilis B38. A first screening step showed that lactose, ammonium succinate, and manganese most influenced both cell growth and antibacterial activity production. These three factors varied at two levels in eight experiments using full factorial design. Results indicated that maximum cell growth (OD = 10.2) and maximum production of antibacterial activity (360 AU/mL) were obtained in a modified medium containing 1.5% (w/v) lactose, 0.15% (w/v) ammonium succinate, and 0.3 mg/L manganese. Depending on the indicator strain used, the antibacterial activity was 2- to 4-fold higher in the modified culture medium than in TSB medium under the same conditions. Thin layer chromatography-bioautography assay showed the presence of three active spots with Rf values of 0.47, 0.7, and 0.82 in TSB medium. However, the inhibition zone of two spots (Rf values of 0.7 and 0.82) was slightly larger in the modified medium. Moreover, a large zone of inhibition with an Rf value of 0.3, was observed in this modified medium, instead of the spot having an Rf value of 0.47. These results suggest that the nutrients act as environmental factors, quantitatively and qualitatively affecting the production of antibacterial compounds by B. subtilis B38. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Combined Effect of Agitation/Aeration and Fed-Batch Strategy on Ubiquin- one-10 Production by Pseudomonas diminutaCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 6 2010Mahesh V. Bule Abstract The effects of aeration rate and agitation speed on ubiquinone-10 (CoQ10) submerged fermentation in a stirred-tank reactor using Pseudomonas diminuta NCIM 2865 were investigated. CoQ10 production, biomass formation, glycerol utilization, and volumetric mass transfer coefficient (kLa) were affected by both aeration and agitation. An agitation speed of 400,rpm and aeration rate of 0.5,vvm supported the maximum production (38.56,mg,L,1) of CoQ10 during batch fermentation. The fermentation run supporting maximum production had an kLa of 27.07,h,1 with the highest specific productivity and CoQ10 yield of 0.064,mg,g,1h,1 and 0.96,mg,g,1 glycerol, respectively. Fermentation kinetics performed under optimum aeration and agitation showed the growth-associated constant (a,=,5.067,mg,g,1) to be higher than the nongrowth-associated constant (,,=,0.0242,mg,g,1h,1). These results were successfully utilized for the development of fed-batch fermentation, which increased the CoQ10 production from 38.56,mg,L,1 to 42.85,mg,L,1. [source] | ||||||||||||||||||||||