Optimization of L-glutaminase synthesis by Aspergillus oryzae NRRL 32657 in submerged culture

Autor: Nagwa M. El Shimi, W. A. Bazaraa, Reda Mahgoub Mohamed, A. M. Alian
Rok vydání: 2015
Předmět:
Zdroj: African Journal of Microbiology Research. 9:588-597
ISSN: 1996-0808
DOI: 10.5897/ajmr2014.7317
Popis: Various fungal strains have been screened for L- glutaminase synthesis. Aspergillus oryzae NRRL 32657 proved to be the highest producer (24.19 U.ml-1) with the largest pink zone diameter (8 mm). Production of L- glutaminase (E.C. 3.5.1.2. L-glutamine amidohydrolase) by A. oryzae in batch submerged system was optimized. Several factors: incubation period, source and concentration of carbon, source and concentration of nitrogen, initial pH level, incubation temperature, amino acids source and concentrations and sodium chloride concentration were tested for their effect on enzyme synthesis. The highest L- glutaminase synthesis (46.53 U. ml-1) was achieved when A. oryzae was allowed to grow aerobically (30oC for 3 days) in a buffered medium (pH 7.0) containing 2.5% lactose, 2% yeast extract, 0.5% L- glutamine and 0.5% sodium chloride. Key words: L-glutaminase, Aspergillus oryzae, submerged fermentation, optimization.
Databáze: OpenAIRE