Optimization of Corynebacterium glutamicum Glutamic Acid Production by Response Surface Methodology

Abstract

Response surface methodology (RSM) was used to evaluate the effects of fermentation parameters for glutamic acid (GA) production by Corynebacterium glutamicum CECT690 in submerged fermentation using palm date waste as substrate. To attain this purpose at the first stage, inoculum size, substrate concentration, penicillin concentration, phosphate concentration, and inoculum age were optimized for GA production. The next stage, the level of air flow rate in a 5-l fermenter (batch mode) which was run in optimized conditions was determined. The first stage gave the following results for the fermentation conditions optimized using RSM in 500-ml shake flasks: inoculum size 2% (v/v), substrate concentration 25% (w/v), penicillin concentration 1 U/ml, phosphate concentration 4 g/l, and inoculum age 10 h. Moreover, the maximum GA amount predicted by the model was 39.32 mg/ml. This was in agreement with the actual experimental value (36.64 mg/ml). In the second stage of the study, the amounts of GA were 118.75, 142.25, and 95.83 mg/ml in optimized conditions with the three levels of air flow rate of 0.6, 1.2, and 1.6 vvm, respectively. The present results demonstrate the potential of date waste juice as a substrate for producing GA by cultivation of C. glutamicum.

Date and their processing byproducts as substrates for bioactive compounds production

“…Efforts have been made to improve the GA fermentation process, especially from the standpoint of saving the production cost. Tavakkoli et al (2012) used RSM to evaluate the effect of fermentation parameters for the production of GA using date waste as a substrate. The optimized fermentation conditions were inoculum size 2 % (v/v), substrate concentration 25 % (w/v), penicillin concentration 1 U/mL, phosphate concentration 4 g/L, and inoculum age 10 h, the resulting maximum GA (39.32 mg/mL).…”

The use of date waste for lactic acid production by a fed-batch culture using <italic>Lactobacillus casei</italic> subsp. <italic>rhamnosus</italic>

“…To consider this problem, the utilisation of poor-quality dates and date by-products have been previously investigated in the food product manufacturing of items such as bakery products, ice-cream, caramel products, ethanol, vinegar ( Mehaia, 1991 ), oxytetracycline ( Abou-Zeid et al. , 1993 ), single-cell protein ( Nancib et al , 1997 ), lactic acid ( Nancib et al , 2009 ), glutamic acid ( Tavakkoli et al , 2009 ), carotenoids ( Luna-Flores et al , 2010 ) and curdlan gum ( Ben Salah et al. , 2011 ).…”

Rapid Evaluation and Optimization of Medium Components Governing Tryptophan Production by Pediococcus acidilactici TP-6 Isolated from Malaysian Food via Statistical Approaches

“…Furthermore, molasses was reported as the most suitable carbon source for the synthesis of tryptophan by C. glutamicum [10]. The use of glucose for the production of various amino acid by C. glutamicum [30][31][32] and E. coli [33,34] was also well documented. Furthermore, sucrose was identified as the best carbon source for threonine production by Escherichia coli TRFC [35] and it was used as the sole carbon source for threonine production by a recombinant E. coli in a separate study conducted by Wang et al [36].…”