【摘要】 黄原胶生产中发酵过程的氧限制及分离工序的高醇耗是造成高能耗、高成本的主要原因．作者探讨了一种生产黄原胶的新途径———两步发酵法，可以解决上述两个问题，方法的主要特点是首先在一级罐中培养黄单胞菌以产生合成黄原胶的胞外酶，再利用这些胞外酶在二级罐中以无菌的底物发酵生产黄原胶．发酵在膜式两级发酵罐中进行，确定了最优发酵条件，取得了理想的结果：产胶量比普通法提高２４．５％，直接获得无菌体的发酵产物，简化了分离工序，醇耗量降低４０％．更多还原

【Abstract】 To solve the oxygen_limit problem in the final phase of Xanthangum fermentation and to obtain cell_free broth, a new way of producing Xanthangum by cell_free fermentation was studied. The new method, “Two_Staged Fermentation", included two stages. First, cells cultured in the later period of logarithmic phase were removed from the fermentation broth by the microfilering pipe. Then, non_nitrogenous medium with high carbon source was added to the fermentation broth in the second fermentor. Xanthangum was thus synthesized by the exocellular enzymes produced in the first fermentor. The experimental results show that the Xanthangum production was 24.5% higher in the two_staged fermentation than that in the normal one and alcohol consumption reduced 40%. Moreover, the final fermentation broth was cell_free and do not need to remove the cells. So it is possible to simplify the separation process and to cut the production cost.更多还原