Waste bread hydrolysate was used as a biosource for xanthan production by various isolates and standard bacteria (Xanthomonas campestris DSM 19000). Influence of operational conditions used in the process of xanthan production were evaluated through yield of xanthan, rheological properties of aqueous solution and fermentation kinetics. For the highest yield and viscosity, optimum conditions including carbon source concentration, inoculum volume and agitation rate were determined for 4 different strains by using response surface methodology. The highest gum yield as 14.3 g/L was obtained by Xanthomonas axonopodis vesicatoria and the highest conversion rate of waste bread to xanthan gum was found as %14.1 for Xanthomonas hortorum pv. pelargonii. Whereas, the highest aqueous solution viscosity of gum produced from standard bacteria was 11.2 Pa.sⁿ at glucose ratio of 4%, inoculum volume of 5% and mixing rate of 225 rpm. For fermentation kinetics; the values of growth associated parameters revealed that they are mostly affected by the rate of xanthan gum production and substrate consumption. In general, optimum conditions to obtain the highest xanthan gum yield were different from that to achieve the highest viscosity. This study shows the potential of waste bread hydrolyzates as the promising economic carbon source for xanthan gum production.

废面包水解物被用作各种分离物和标准细菌（Xanthomonas campestris DSM 19000）生产黄原胶的生物源。通过黄原胶的收率，水溶液的流变性质和发酵动力学评估了黄原胶生产过程中使用的操作条件的影响。为了获得最高的收率和粘度，使用响应表面方法确定了4种不同菌株的最佳条件，包括碳源浓度，接种量和搅拌速率。Xanthomonas axonopodis vesicatoria的口香糖产量最高，为14.3 g / L，而对于Xanthomonas hortorum pv ，废面包向黄原胶的转化率最高，为％14.1 。pelargonii。而由标准细菌生产的口香糖的最高水溶液粘度在葡萄糖比率为4％，接种量为5％，混合速率为225 rpm时为11.2 Pa.s ⁿ。用于发酵动力学；生长相关参数的值表明，它们主要受黄原胶生产速率和底物消耗的影响。通常，获得最高黄原胶产量的最佳条件不同于获得最高粘度的最佳条件。这项研究表明废面包水解物作为黄原胶生产的有希望的经济碳源的潜力。