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Growth medium

About: Growth medium is a research topic. Over the lifetime, 1889 publications have been published within this topic receiving 59171 citations. The topic is also known as: culture medium & culture media.


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Journal ArticleDOI
TL;DR: The results demonstrated that growth, PHA production and the composition of cell wall of B. flexus are influenced by the organic or inorganic nutrients present in the growth medium.
Abstract: Bacillus flexus was isolated from local soil sample and identified by molecular methods. In inorganic nutrient medium (IM) containing sucrose as carbon source, yield of biomass and polyhydroxyalkanoate (PHA) were 2 g/l and 1 g/l (50% of biomass), respectively. Substitution of inorganic nitrogen by peptone, yeast extract or beef extract resulted in biomass yields of 4.1, 3.9 and 1.6 g/l, respectively. Corresponding yields of PHA in biomass was 30%, 40% and 44%. Cells subjected to change in nutrient condition from organic to inorganic, lacked diaminopimelic acid in the cell wall and the concentration of amino acids also decreased. Under these conditions the extractability of the polymer from the cells by hot chloroform or mild alkali hydrolysis was 86–100% compared to those grown in yeast extract or peptone (32–56%). The results demonstrated that growth, PHA production and the composition of cell wall of B. flexus are influenced by the organic or inorganic nutrients present in the growth medium. Cells grown in inorganic medium lysed easily and this can be further exploited for easier recovery of the intracellular PHA.

18 citations

Journal ArticleDOI
TL;DR: It is suggested that changes in EPS production and in the specific activities of the key enzymes of the RuMP cycle are necessary for the efficient removal of this toxic metabolite of methanol.
Abstract: Summary: Methylophilus methylotrophus produced viscous and non-viscous exopolysaccharides (EPS) when grown in batch culture. Both types contained glucose, galactose, mannose and an unidentified 6-desoxyhexose, and were substituted with pyruvate and acetate residues. When the organism was grown in continuous culture only the non-viscous EPS was synthesized; the rate of production was 18·5 mg h−1 (g biomass)−1 in methanol-limited cultures and increased by approximately 3- and 4-fold when growth was limited by oxygen or nitrogen respectively. The specific activity of methanol dehydrogenase in cell extracts was relatively low when bacteria were grown under conditions of methanol excess and increased 2-fold in carbon-limited cells, reflecting the need to ‘scavenge’ the small amounts of available methanol. In contrast, the specific activities of several key enzymes of the ribulose monophosphate (RuMP) pathway were greater in cells grown under conditions of nitrogen or oxygen limitation than when growth was Limited by the availability of carbon, indicating the potential for increased carbon flux round the cycle when excess methanol was present in the growth medium. When methylotrophs are grown under conditions of methanol excess it is important that there is a mechanism to prevent the overproduction of formaldehyde, and we suggest that these changes in EPS production and in the specific activities of the key enzymes of the RuMP cycle are necessary for the efficient removal of this toxic metabolite of methanol.

18 citations

Journal ArticleDOI
TL;DR: The cellulolytic activity of the wild type and a mutant strain of A. alternata was investigated and induced by gamma radiation resulted in about 10% survival level.
Abstract: The cellulolytic activity of the wild type and a mutant strain of A. alternata was investigated. Mutants were induced by gamma radiation. A suspension of about 10/sup 5/ condidia/mL in 0.05M phosphate buffer pH 5 were irradiated in a gamma-cell-type (Cammacell 220, Atomic Energy of Canada Limited, Ottawa, Canada) /sup 60/Co source with a dose rate of 2.5 krad/min. The amount of radiation given was 70 krad which resulted in about 10% survival level. The stock culture was maintained on a sterile growth medium supplemented with 1% cellulose 123 and 0.3% agar. Following the incubation period, the fungal biomass was harvested by centrifugation (5000g for 10 min) and the clarified supernatant was used as the source of cellulase and ..beta..-glucosidase.

18 citations

Journal ArticleDOI
TL;DR: Suspension cultures of Catharanthus roseus were established from three different cell lines namely, CWS, C WS‐A and CWS‐G on MS medium supplemented with 2,4‐D (0.4 ppm) and the cell extracts did not show any antidiabetic activity.
Abstract: Suspension cultures of Catharanthus roseus were established from three different cell lines namely, CWS, CWS-A and CWS-G on MS medium supplemented with 2,4-D (0.4 ppm). The three cell lines were cultured in growth and production media. Cell line CWS grown in production medium showed a PCV (packed cell volume) of 70% in 21 days. The cells synthesized 0.10% ajmalicine in the production medium and the cell extract caused a 71% decrease in blood sugar in diabetes induced rats. In growth medium the cells showed a PCV of 97% in 21 days and produced trace amounts of alkaloids. The cell extracts did not show any antidiabetic activity. The CWS-A cell line showed a PCV of 98% in 21 days and synthesized 0.036% ajmalicine in production medium. The extracts had no hypoglycaemic effect. In growth medium the cells showed a 98% PCV in 21 days and produced trace amounts of alkaloids. The cell extract caused an 86% decrease in blood sugar. The CWS-G cell line grown in flasks failed to synthesize significant levels of alkaloids both in growth and production media. The cell extracts did not show any antidiabetic activity.

18 citations

Journal ArticleDOI
TL;DR: In vitro root formation was studied in petiole explants from Pelargonium×hortorom Bailey cv.
Abstract: In vitro root formation was studied in petiole explants from Pelargonium×hortorom Bailey cv. Radio exposed to different irradiance (2.5. 11.6 or 23.0 W/m2). Optimal root formation was found when stock plants were subjected to 2.5 W/m2 and explants were grown on a medium with 20 g/I of sucrose and 5.0 mM of nitrogen. The number of roots per explant decreased with increasing nitrogen or sucrose concentrations in the growth medium and with increasing irradiance applied to the stock plants. Variation in temperature (17, 21 or 25°C) did not affect root formation. The number of roots per explant was higher in explants from young petioles than in explants from older petioles. The initial nitrogen content of the explants was highest at the lowest irradiance. The content of reducing sugars and sucrose increased with increasing irradiance. The endogenous levels of lysine, arginine and ornithine were highest at 2.5 W/m2 and the levels of proline. alanine, γ-aminobutyric acid, glutamic acid, glutaminc, aspartic acid and asparagine were highest at 23.0 W/m2. With rising nitrogen concentration in the medium, the final endogenous content of nitrogen in the explants increased, whereas the content of reducing sugars decreased. When the sucrose concentration in the medium increased, the endogenous content of reducing sugars rose, and the nitrogen level was lowered. Variations in the nitrogen concentration in the growth medium influenced the final level of free amino acids in the explants.

18 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20233
20226
202126
202032
201926
201829