Improvement of xanthan gum production in batch culture using stepwise acetic acid stress

Abstract

In this study, the effect of acetic acid on the improvement of xanthan biosynthesis by Xanthomonas campestris b82 was investigated. Various concentrations of acetic acid from 1.56 to 6.25 mM were added to the medium in the exponential and stationary phase of growth. Analytical studies revealed a considerable increase in viscosity and xanthan yield after two pulses addition of acetic acid at 24 and 26 h of incubation. ATP assay also showed lower content of ATP in these conditions and was denotative of the consumption of ATP used to produce energy for xanthan biosynthesis. These observations showed the stimulatory effect of acetic acid addition on xanthan production by X. campestris b82.

Key words: Xanthan gum, acetic acid, Xanthomonas campestris b82, ATP assay