Enhancement of methionine production by methionine analogue ethionine resistant mutants of Brevibacterium heali

Abstract

In order to improve the methionine yield of the isolate B. heali, attempts were made to isolate mutants resistant to the methionine analogue DL-ethionlne after mutagenesis with N-methyl-N'-nitro-Nnitrosoguanidine (NTG). The minimum inhibitory concentration (MIC) of ethionine for B. heali was found to be 2 mM. After mutagenesis and screening, live mutants resistant to 50 mM of ethionine were isolated. The yield of the best ethionine resistant mutant, B. heali Br EthR:', was 13 mg/l of methionine medium under optimum cultivation conditions.

Optimization of Fermentation Conditions of <i>Bacillus thuringiensis</i> EC1 for Enhanced Methionine Production

“…The isolation of Bacillus organisms as methionine producers agrees with the works of other investigators [14]. However, Bacillus species are not yet known to be very active producers as species of Corynebacterium, Brevibacterium and Arthrobacter [8] [15]. There is need for adequate aeration in microbial production of metabolites [16].…”

Metabolic engineering ofCorynebacterium glutamicumstrain ATCC13032 to producel‐methionine

“…5A). This might be improved by careful selection of the nutrient medium [30][31][32]. Overexpression of metX and metY in QW102 did not significantly increase l-methionine production (data not shown), suggesting that the cell might prefer the transsulfuration pathway to the direct sulfhydrylation pathway (Fig.…”

White Biotechnology for Amino Acids

“…E. coli K-12 mutant resistant to methionine analogues (norleucine, ethionine, and methyl methionine) produced 2 mg/ml of methionine. [70][71][72][73] Mondal et al 74 have reported methionine production from methionine-analogue-resistant mutants of Brevibacterium heali. 69 Methionine production from different analogue-resistant yeasts are also reported in the late 1970s and 1980s.…”