Azuaje R A, Sánchez J A
Laboratorio de Insumos Biológicos, PROULA, Mérida, Venezuela.
Acta Cient Venez. 1999;50(4):201-9.
Among 3 varieties of Xanthomonas campestris, the variety ocumo (X. campestris pv. ocumo), showed the greatest capacity for producing xanthan. This bacteria grows appropriately and produces this polysaccharide in a wide diversity of carbohydrate sources. However, this strain does not produce xanthan when the carbohydrate comes from lignocellulosic materials. The glucose syrup FAVEPRO was the carbon source that showed the best yield (23 g/l) with the greatest viscosity (7000 cps) of xanthan. The optimum production conditions in 1 L erlenmeyer flasks, with a working volume of 0.2 L and in a 14 L (stirred tank type bioreactor) with a working volume of 10 L, were the following: total sugar 5%, urea 0.05%, di-potassium hydrogen phosphate 0.5%, pH 7.5, inoculum 10%, temperature 30 degrees C, agitation 250-1000 rpm and aereation 0.3-1.0 vvm. This strain of X. campestris pv. ocumo was able to produce xanthan (10 g/l) in a culture medium based on a previously treated agricultural waste, called soluble acid extract of cassava bark. The viscosity of this medium increased up to 1500 cps.
在野油菜黄单胞菌的3个变种中，奥库莫变种（野油菜黄单胞菌奥库莫致病变种）产生黄原胶的能力最强。这种细菌能在多种碳水化合物来源中良好生长并产生这种多糖。然而，当碳水化合物来自木质纤维素材料时，该菌株不产生黄原胶。葡萄糖糖浆FAVEPRO是能使黄原胶产量最高（23克/升）且粘度最大（7000厘泊）的碳源。在1升锥形瓶（工作体积0.2升）和14升（搅拌罐式生物反应器，工作体积10升）中的最佳生产条件如下：总糖5%、尿素0.05%、磷酸氢二钾0.5%、pH值7.5、接种量10%、温度30摄氏度、搅拌速度250 - 1000转/分钟、通气量0.3 - 1.0体积/体积·分钟。野油菜黄单胞菌奥库莫致病变种的这个菌株能够在一种基于先前处理过的农业废弃物（称为木薯皮可溶性酸提取物）的培养基中产生黄原胶（10克/升）。这种培养基的粘度增加到了1500厘泊。
