Xanthan production byXanthomonas campestris in continuous fermentation

Summary

Xanthan production by a strain ofX. campestris was maintained longer under glucose—limited than nitrogen—limited conditions in continuous culture. The turnover Q was 12 at lower pH(5.0–6.0) and 6.5 at neutral pH; xanthan productivity was comparable at both pH in nitrogen—limited continuous cultures. In the Fe—rich continuous fermentation cell degeneration did not occur for 65 turnovers whereas in the Fe—deficient fermentation it occurred in 12 turnovers. The culture stability for xanthan formation is higher under conditions which are favorable for cell growth with limited xanthan production.