驯化和胶囊包裹的假丝酵母LF04发酵玉米芯水解液生产木糖醇(英文)

Xylitol Processing from Corn Cobs Hydrolysates by Isolated and Encapsulated Candida tropicalis LF04 from Soil

玉米芯的酸水解液是木糖醇生产的重要原料,但是该水解液中含有糠醛、酚类等对后续微生物发酵有毒害作用的化合物。本研究从土壤中分离了一株似假丝酵母LF01,通过驯化和微胶囊包裹来提高其对水解液的抗性。结果表明通过多次驯化并进行包裹的假丝酵母LF04能在玉米芯水解液中不经任何脱毒处理发酵木糖生产木糖醇。在pH5.5 溶氧为 0.15vvm 的条件下发酵 88h,木糖转化率为 76%,木糖醇浓度达 61.768g/L。远高于其出发菌株。该结果表明采用该方法有望用于木糖醇的工业化生产。

The sulfuric acid hydrolysates of corn cob fiber is an important raw material for xylitol production. But the hydrolysates contain furfural and phenolic compounds and others, which are toxic to microorginasims during subsequent fermentation. In this study, new microorganisms Candida tropicalis LF01 were isolated from soil. Adaptation and encapsulation were carried out to enhance the inhibitors resistance in corn cob hydrolysate. The results indicated that the isolated and encapsulated strains Candida tropicalis LF04 could ferment xylose to xylitol in condensed corn cob hydrolysate without any detoxification. 76% xylose was fermented after 88 h at pHS.5 with the aeration 0.15vvm, and xylitol produced more than 61.768 g/L. The xylitol yield rate is up to 0.83 g/g, much higher than that of both the parent strains and the only isolated strain. The results also demonstrated that yeast treated with this method has the potential to be applied to xylitol industrial production.