peptones and potassium-phosphate

A new thermostable and solvent-tolerant lipase was isolated from newly isolated Staphylococcus warneri from oil-contaminated soil. Optimization of the fermentation media for production of thermostable and organic solvent-tolerant lipase was carried out using two statistical methods, i.e., Plackett-Burman design (PBD) and central composite design (CCD) were used for the optimization of the media components. PBD was used to efficiently select important medium components affecting the lipase production. Out of 15 medium components screened, four components, i.e., olive oil, peptone, maltose, and K2HPO4 were found to contribute positively to lipase production. CCD and response surface methodology (RSM) were used to determine the optimum levels of the selected components using Design-Expert 8.0 software. Production medium with olive oil (1.45 %), peptone (0.28 %), maltose (0.054 %), and K2HPO4 (0.091 %) was optimized with a maximum lipase production of 10.43 IU/ml/min. Similarly, production conditions for the lipase production were optimized by using CCD and RSM. Optimized conditions were found to have an incubation temperature of 55 °C, medium pH of 8.0, agitation of 120 rpm, and inoculum volume of 2 %. RSM revealed the maximum lipase production of 17.21 IU/ml using these optimized production conditions. Crude lipase showed enhanced activity in organic solvents such as diethyl ether, hexane, and cyclohexane.

Topics: Bacterial Proteins; Environmental Pollutants; Enzyme Stability; Factor Analysis, Statistical; Fermentation; Hydrogen-Ion Concentration; Industrial Oils; Kinetics; Lipase; Maltose; Olive Oil; Peptones; Phosphates; Plant Oils; Potassium Compounds; Soil Microbiology; Solvents; Staphylococcus; Temperature

The effect of culture medium compositions on gellan gum production produced by fermentation with a halobacterium Sphingomonas paucimobilis QHZJUJW CGMCC2428 was studied. In this work, a fractional factorial design was applied to investigate the main factors that affected gellan gum production by S. paucimobilis QHZJUJW CGMCC2428. Sucrose was the best carbon source for gellan gum and peptone displayed better inducing effect. Central composite design and response surface methodology were adopted to derive a statistical model for optimizing submerged culture medium composition. These experimental results showed that the optimum culture medium for producing gellan gum was composed of 40.00 (w/v) sucrose, 3.00% peptone (w/v), MgSO4 (w/v), 9.20% KH2PO4 (w/v), 7.50% Na2HPO4 (w/v), 4.30% K2SO4 (w/v), pH 6.8-7.0. The maximal gellan gum was 19.89±0.68 g/L, which was agreed closely with the predicated value (20.12 g/L). After incubated for 72 h under the optimized culture medium in 5-L bioreactor, the gellan gum fermentation reached about 19.90±0.68 g/L, which was higher than that in the initial cultivation medium.

Topics: Bioreactors; Culture Media; Fermentation; Magnesium Sulfate; Nitrogen Compounds; Peptones; Phosphates; Polysaccharides, Bacterial; Potassium Compounds; Sphingomonas; Sucrose; Sulfates

Antrodia camphorata is a well-known Chinese medicinal mushroom that protects against diverse health-related conditions. Submerged fermentation of A. camphorata is an alternative choice for the effective production of bioactive metabolites, but the effects of nutrition and environment on mycelial morphology are largely unknown. In this study, we show that A. camphorata American Type Culture Collection 200183 can form arthrospores in the end of liquid fermentation. Different morphologies of A. camphorata in submerged culture were analyzed using scanning electron microscopy. The optimal carbon and nitrogen sources for sporulation were soluble starch and yeast extract. We found that a carbon-to-nitrogen ratio (C/N) of 40:1, MgSO4 (0.5 g/l), KH2PO4 (3.0 g/l), an initial pH 5.0, and an inoculum size of 1.5×10(5) spores/ml led to maximum production of arthroconidia. Our results will be useful in the regulation and optimization of A. camphorata cultures for efficient production of arthroconidia in submerged culture, which can be used as inocula in subsequent fermentation processes.

Topics: Antrodia; Carbon; Culture Media; Fermentation; Hydrogen-Ion Concentration; Hyphae; Magnesium Sulfate; Microscopy, Electron, Scanning; Nitrogen; Peptones; Phosphates; Potassium Compounds; Spores, Fungal; Starch

Statistics-based experimental designs were used to develop a cost-effective medium for enhanced production of viable cells and bacteriocin by probiotic Enterococcus faecium MC13. Carbon, nitrogen, and mineral sources were first screened by one-variable-at-a-time (OVAT) methods. In order to increase yield production, the selected variables were further statistically optimized using response-surface methodology (RSM) with central composite design (CCD). The maximum and minimum levels of the selected variables were determined and a set of 34 experimental runs was performed. The optimum concentrations of the tested variables for production of viable cells (12.24 log CFU mL(-1)) and bacteriocin activity (25,600 AU mL(-1)) were tryptone (10.0 g/L), peptone (6.0 g/L), maltose (3.0 g/L), glucose (9.0 g/L), NaCl (15.0 g/L), sodium citrate (2.5 g/L), sodium acetate (1.0 g/L), and dipotassium PO(4) (0.1 g/L). Threefold increased yield of bacteriocin was achieved in optimized medium compared to the unoptimized counterpart, and this was two times less cost than commercial MRS medium.

Topics: Bacteriocins; Citrates; Culture Media; Enterococcus faecium; Food Microbiology; Glucose; Industrial Microbiology; Maltose; Models, Statistical; Peptones; Phosphates; Potassium Compounds; Probiotics; Sodium Acetate; Sodium Chloride; Sodium Citrate

The present study was aimed at modifying the original formulation of Commercial Eugon agar (CEA) to develop a new H. pylori growth medium. Initial studies were carried out to determine the number of H. pylori colonies recovered on in-house H. pylori agar (IHPA), IHPA without L-cysteine and sodium sulfite (IHPA-NC), IHPA without L-cysteine (IHPA-C), IHPA without sodium sulfite (IHPA-N) and CEA as the control. Significant differences (P < 0.001) in the number of colonies recovered were observed between IHPA-N, IHPA-NC and IHPA-C. Incorporation of sodium sulfite decreased the number of colonies recovered, indicating that sodium sulfite was inhibitory to H. pylori growth. Removal of L-cysteine reduced the number of colonies recovered, suggesting that L-cysteine is necessary for the growth of H. pylori. In the subsequent study, incorporation of K(2)HPO(4) further increased the number of colonies recovered compared with IHPA-N (P < 0.001), and 0.25% (w/v) of K(2)HPO(4) yielded the highest numbers of colonies (P < or = 0.04). Finally, thirty other H. pylori clinical isolates were evaluated for their growth in the IHPAP-N, a new medium consisting of 1.5% (w/v) pepticase, 0.5% (w/v) peptone, 0.4% (w/v) sodium chloride, 0.03% (w/v) L-cysteine, 0.55% (w/v) dextrose, 0.25% (w/v) K(2)HPO(4) and 1.5% (w/v) agar. The number of colonies recovered in IHPAP-N was significantly (P < 0.005) higher than that of CEA. IHPAP-N with 0.25% K(2)HPO(4) and without sodium sulfite were adequate solid media for the growth of H. pylori.

Topics: Agar; Bacteriological Techniques; Colony Count, Microbial; Culture Media; Cysteine; Glucose; Helicobacter pylori; Peptones; Phosphates; Potassium Compounds; Sodium Chloride; Sulfites

The medium composition for bacteriocin production by Lactococcus lactis ATCC 11454 was optimized using response surface methodology. The selected six factors based on CM medium were sucrose, soybean peptone, yeast extract, KH(2)PO(4), NaCl, and MgSO(4).7H(2)O. Fractional factorial designs (FFD) and the path of steepest ascent were effective in searching for the main factors and approaching the optimum region of the response. By a 2(6-2) FFD, sucrose, soybean peptone, yeast extract, KH(2)PO(4) were found to be significant factors and had positive effects on cell growth, however, only soybean peptone and KH(2)PO(4) were shown to be the two significant factors for bacteriocin production and had negative and positive effects, respectively. The effects of the two main factors on bacteriocin production were further investigated by a central composite design and the optimum composition was found to be 1% sucrose, 0.45% soybean peptone, 1% yeast extract, 2.84% KH(2)PO(4), 0.2% NaCl, and 0.02% MgSO(4) x 7H(2)O. The optimal medium allowed bacteriocin yield to be doubled compared to CM medium.

Topics: Bacteriocins; Biotechnology; Cell Division; Culture Media; Lactococcus lactis; Magnesium Compounds; Models, Biological; Nisin; Nitrogen; Peptones; Phosphates; Potassium Compounds; Sodium Chloride; Sucrose

Experimental design procedure was used to search for optimal medium composition for maximization of glutathione yield using a high-glutathione containing yeast S. cerevisiae S-8H. The effects of the chosen factors (glucose, peptone, KN2PO4, biotin and cysteine) on the relationship between yeast biomass formation and the content of intracellular glutathione were examined. Results obtained showed that glucose and peptone had significant first- and second-order effects, as well as different interactive effects on these overall parameters. On the other hand, cysteine showed only second-order effect for glutathione content and interactive effects for both glutathione content and yield. Its presence had a marked positive effect on the content of glutathione, but reduced the biomass formation. The optimal levels of these factors found were in the range of 2.5%, 4%, 0.027%, 10 micrograms/cm3 and 0.08%, respectively. The average yield obtained at this optimium was 160.1 mg glutathione/dm3 and a glutathione content of 17 mg/g dry biomass.

Topics: Biomass; Biotin; Culture Media; Cysteine; Glucose; Glutathione; Peptones; Phosphates; Potassium Compounds; Saccharomyces cerevisiae

Extracellular polysaccharide (EPS) and capsular polysaccharide (CPS) production by Aeromonas salmonicida A450 and the influence of the capsule on cell surface properties were studied. A. salmonicida did not produce CPS or EPS when glucose, phosphate, magnesium chloride, or trace mineral components were absent from the medium. The addition of yeast extract improved capsule production. Neither EPS nor CPS formation depended on the C/N ratio, although it appeared to be influenced by the level of carbon and nitrogen in the culture. Both EPS and CPS production started at the end of the logarithmic growth phase. The amounts of EPS and CPS produced were not influenced by temperature changes between 15 and 20 degrees C and was maximal from pH 7 to 7.5. Cell surface properties were strongly influenced by capsule production; high CPS production was associated with enhanced cell hydrophilicity and autoagglutination. The effect of CPS on cell surface properties was independent of the presence of the surface protein array (A-layer).

Topics: Aeromonas; Animals; Cell Membrane; Culture Media; Fish Diseases; Fishes; Glucose; Kinetics; Magnesium Chloride; Peptones; Phosphates; Polysaccharides, Bacterial; Potassium; Potassium Compounds; Trace Elements; Virulence

On the basis of the available literature, the history of development of the Rappaport--Vassiliadis (RV) medium, its preparation and applicability in food control methods were described. Results of comparative studies on the effectiveness of Salmonella isolation upon use of different specifically-multiplying media: MK, medium containing sodium acid selenite, R25/37 degrees C, RV, were presented. The number of Salmonella isolations in samples multiplied in RV medium was found to exceed that obtained upon use of the remaining media. Moreover, RV medium was easy to prepare; it proved to be economical and was stable for up to 7 months when refrigerated.

Topics: Culture Media; Drug Combinations; Food Microbiology; Humans; Magnesium Chloride; Peptones; Phosphates; Potassium; Potassium Compounds; Rosaniline Dyes; Salmonella Food Poisoning; Salmonella typhimurium; Sodium Chloride; Solutions; Temperature; Time Factors