Original scientific paper
Sequential Optimization Approach for Enhanced Production of Poly(γ-Glutamic Acid) from Newly Isolated Bacillus subtilis
Ishwar B. Bajaj
; Food Engineering and Technology Department, Institute of Chemical Technology, University of Mumbai, Matunga, IN-400019 Mumbai, India
Rekha S. Singhal
; Food Engineering and Technology Department, Institute of Chemical Technology, University of Mumbai, Matunga, IN-400019 Mumbai, India
Abstract
A bacterial strain of marine origin showing production of poly(γ-glutamic acid) (PGA) has been identified by taxonomical and 16S rRNA studies as Bacillus subtilis. A sequential optimization approach was applied for improving the PGA production. The effect of carbon sources, nitrogen sources and pH on the production of PGA was investigated by one factor-at-a-time method. Plackett-Burman design was then adopted to select the most important nutrients influencing the yield of PGA. After identifying the most significant nutrients, response surface methodology (RSM) was used to develop a mathematical model to identify the optimum concentrations of the key nutrients for higher PGA production, and confirm its validity experimentally. PGA production was further improved by supporting the medium with α-ketoglutaric acid. The PGA production increased from 7.64 to 25.38 g/L by using the sequential optimization methods.
Keywords
poly(γ-glutamic acid); Bacillus subtilis; biopolymer; response surface methodology
Hrčak ID:
39849
URI
Publication date:
7.8.2009.
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