Mutational studies for hyper producers of L-glutamic acid from Bacillus strains UG1 and OG4 from vegetable proteins

Abstract

An investigation was carried out to produce mutant isolates from Bacillus subtilis UG1 and Bacillus licheniformis OG4 isolated from vegetable proteins using a chemical mutagen N-methyl-N-nitrosoguanidine (NTG) at dosage concentration of 250 µg/ml. The mutant isolates obtained from wild strain of B. subtilis UG1 produced mutants (M1 to M9) and was screened for hyper producing effect. Mutant M1UG1 was obtained. The mutant isolates obtained from wild strain B. licheniformis OG4, produced 11 mutants (M1 to M11) and when screened for hyper producing effect mutant M6OG4, was obtained. Hyper-producing mutant strains M1UG1 and M6OG4 produced L-glutamic acid of 23.0 mg/ml respectively. The quantity produced was higher than the glutamate obtained from Corynebacterium glutamicum ATCC 13032 (14 mg/ml). The developed mutant strain was better adapted to a shift in temperature range of 55 to 60°C, pH 9.0 and biotin concentration of 10 µg/ml. As part of the programme to increase glutamate yields and to use materials of agro-industrial wastes, the developed mutants M1UG1and M6OG4 were found to utilize the tested agro-industrial wastes maximally for growth and glutamic acid production. Key words: L-glutamic acid, agro-industrial wastes, mutants, N-methyl-N-nitrosoguanidine (NTG), fermented vegetable proteins.