Optimization of microbial production of xanthan gum by the bacterium Xanthamonas campestris using the hydrolyzed starch

In biological production of low value added bioproducts، the substrate cost comprises a significant part of the total price. Therefore، choosing an inexpensive substrate with a high yield of production can greatly reduce the production cost. Starch as an abundant and cheap carbon source can be a suitable substrate for microbial production of xanthan gum. However، in most of the studies on microbial xanthan gum production، glucose has been used as substrate. Materials and method s: In this study، microbial production of xanthan gum using Xanthomonas campestris PTCC 1473 and hydrolyzed starch as carbon source was investigated. The concentration of carbon source and time were optimized using RSM-CCD method. Both factors were regarded to be significant for production of xanthan using hydrolyzed starch.

Based on the obtained results، optimum carbon source concentration and time were 56 g/L and 38. 4 h، respectively. Under optimum conditions، 8. 34 g/L of xanthan gum was produced. Discussion and

The results of this study indicated that starch could be used as a waste and inexpensive carbon source instead of glucose for the production of xanthan gum. It was also shown that the effect of carbon source concentration was more significant than time for xanthan production. In addition، these two factors were independent and did not have any interaction.