Production of glutamic acid by Corynebacterium glutamicum using dates syrup as carbon source

Abstract

The present study was an illustrative investigation on L-glutamic acid production by usingCorynebacterium glutamicum employing a cheaply available dates syrup. Owing to the high sugar content of dates syrup (total sugar 80%) attempt was made to utilize the date syrup for the production of glutamic acid, in shaking culture. The acid treated dates syrup (ATDS) at concentration of 100g/L was the best sugar sources in the glutamic production. Penicillin addition at concentration of 4 U/ml after 12 h of incubation was superior in glutamic acid production. The selected temperature-sensitive mutants M5AJ2, showed 13.4% increase in glutamic production while, M5AJ4 and M7AJ6 showed 22.4 and 4.6% decrease respectively, in their glutamic acid production than their wild type bacterial strain. The specific production rate of glutamic acid in case of temperature shift-up from 31 to 39°C increased apparently 2 and 1.5 fold respectively on average from that under the constant temperature. 24g/L pure glutamic acid were precipitated in crystal at pH 3.2.   Key words: Glutamic acid, Corynebacterium glutamicum, dates syrup, fermentation, penicillin, mutation, UV, efflux.