peptones and sodium-nitrate

The golden chanterelle represents one of the commonly found, edible mushrooms that is highly valued in various cuisines. The present study focused on assessing the requirements of Cantharellus cibarius such as pH, temperature, as well as the carbon and nitrogen sources for mycelial growth. Optimization of the growth parameters was carried out by one-factor-at-a-time method. The optimal pH and temperature were determined to be 6.0 and 22.5 °C, respectively. Among the various carbon sources studied, sucrose at a concentration of 2% gave maximum mycelial growth and proved to be the most suitable one. Amongst the nitrogen sources studied, peptone, ammonium sulphate, and sodium nitrate, gave the maximum mycelial growth at an optimized concentration of 0.5%. In the presence of beef extract and yeast extract, a change in colony pigmentation from yellow to dark grey was observed. Finally, the carbon to nitrogen ratio of 2:0.5 proved to be optimal for mycelial growth. This study is the first report on the optimisation of in vitro growth requirements of C. cibarius.

Topics: Agaricales; Basidiomycota; Carbon; Hydrogen-Ion Concentration; Laboratories; Nitrates; Nitrogen; Peptones; Sucrose; Temperature

Bacteria thriving in underground systems, such as karsts, adapt to use a variety of nutrients. Most of these nutrients derive from superficial processes. This study shows that bacteria are able to differentially induce carbonate precipitation or dissolution depending on the availability of nutrients for growth. Different bacterial strains isolated from caves, representing the most common components of these microbial communities, were cultured with different carbon and nitrogen sources (e.g., acetate, glucose, peptone, humic acids) and induced changes in pH were measured during growth. Carbonate can either precipitate or dissolve during bacterial growth. The induction of carbonate precipitates or their dissolution as a function of consumption of specific carbon sources revealed the existence of an active nutrient cycling process in karsts and links nutrients and environmental conditions to the existence of a highly significant carbon sink in subterraneous environments.

Topics: Acetates; Actinobacteria; Ammonium Chloride; Bacillus; Bacteria; Bioreactors; Carbon; Carbonates; Culture Media; Glucose; Humic Substances; Hydrogen-Ion Concentration; Nitrates; Peptones; Proteobacteria; Spain; Staphylococcus

Statistics based experimental designs were used to optimize the medium for antifungal active substances production from a newly isolated Paenibacillus polymyxa Cp-S316 in shaker flask cultivation. The medium components having significant effect on the production were first identified using a fractional factorial design. Then steepest ascent method was employed to approach the experimental design space, followed by an application of response surface methodology for further optimization. A quadratic model was found to fit the antifungal active substances production. Response surface analysis revealed that the optimum values of the tested variables for the production of active substances were 12.3 (g/l) lactose, 17.5 (g/l) peptone, 0.4 (g/l) sodium nitrate, 4.5 (g/l) magnesium sulfate and 100 (g/l) potato. A production of 4687.71microg/ml, which was in agreement with the prediction, was observed in verification experiment. In comparison to the production of basal medium, 3.05-fold increase had been obtained.

Topics: Analysis of Variance; Antifungal Agents; Bacillus; Biotechnology; Culture Media; Lactose; Microbial Sensitivity Tests; Models, Biological; Nitrates; Peptones; Reproducibility of Results

Sodium nitrite and sodium chloride may inhibit growth and bacteriocinogenesis of protective starter cultures. To reduce sensitivity of a lacticin 3147-producing starter culture to nitrite, prior to production of salami, Lactococcus lactis DPC 4275 was placed in a number of pre-inoculation treatments, containing (a) 1% glucose, (b) 2.5 ppm manganese (Mn), (c) 250 ppm magnesium (Mg), (d) 2.5 ppm manganese + 250 ppm magnesium (Mn + Mg), and held at ambient temperature for 30 min and 4 degrees C for 2 h. The growth, pH reduction, and bacteriocin production was monitored in beaker sausage over a period of 10 days at 28 degrees C, corresponding to typical salami production time, and compared to untreated starter culture. The effect of 1% tryptone and inoculum level on growth and bacteriocin production was also determined. Challenge tests were performed using Listeria innocua DPC 1770 and Staphylococcus aureus MMPR3 as target strains. All treatments gave a significantly higher (P < 0.05) initial starter level than the untreated starter. Beaker sausage inoculated with either low (10(7)) or high (10(9)) levels of starter culture, treated with Mn + Mg reached significantly (P < 0.05) higher levels by day 10 than other treatments. Trends indicate that Mn + Mg also gave best pH reduction in sausage containing the low-level starter culture, sausage and significantly lower (P < 0.05) values for sausage produced with higher inoculum. Bacteriocin production was also higher in starter culture treated with Mn, or glucose. Pre-treatment with Mg gave a 2-fold increase in bacteriocin, the addition of Mn augmenting this increase further. The incorporation of tryptone gave no additional effect. In beaker sausage, both L. innocua and S. aureus populations showed significant reductions (P < 0.05) in the presence of the bacteriocinogenic strain compared to a non-bacteriocinogenic control strain.

Topics: Antibiosis; Bacteriocins; Carcinogens; Colony Count, Microbial; Hydrogen-Ion Concentration; Lactococcus lactis; Listeria; Magnesium; Manganese; Meat Products; Nitrates; Peptones; Sodium Chloride; Staphylococcus aureus; Temperature; Time Factors

The effect of some medium components, viscous substances and metabolic inhibitors, on catalase production by mutant Aspergillus niger has been studied in shake culture. Altering the composition of the basal medium, particularly substituting NaNO3 for KNO3, and peptone for yeast extract brought an increase in extra- and intracellular catalase activity by 1.5- and 3-fold, respectively. The addition of 2.0-6.0 mg sodium alginate or pectin/ml as viscous additive to the medium, containing glucose as carbon source, increased the medium viscosity and catalase production in shake culture by about 2.8- to 3.0-fold. The highest yield of extracellular catalase activity of A. niger was obtained in the presence of sodium orthovanadate and Triton X-100, which improved the activity of this enzyme by about 1.5-2.2-fold. A significant increase in intracellular catalase activity was observed in the presence of hematin, Tween 80 and sodium orthovanadate (1.7-, 1.6- and 1.4-fold respectively). The time course of growth and enzyme production by A. niger in the optimized medium is also reported.

Topics: Alginates; Aspergillus niger; Catalase; Culture Media; Glucose; Hemin; Nitrates; Octoxynol; Pectins; Peptones; Polysorbates; Potassium Compounds; Vanadates