产酸丙酸杆菌生长特性及5L罐发酵动力学研究

The Growth and 5L Fermentor Kinetics Characteristics of Propionibacterium acidipropionici

论文在摇瓶水平对产酸丙酸杆菌基本生长特性(温度、pH、摇床转速、接种量、种龄等)、碳源、氮源利用情况、产物抑制及5 L罐发酵动力学进行了研究。结果表明,该菌在32℃,初始pH 6.5,摇床转速150 r/min,接种24 h的种子液,接种量为5%条件下,产酸丙酸杆菌生长及产酸水平达最高值;该菌可利用碳源十分广泛,但对氮源要求比较高,只可利用有机氮源;在不同初始葡萄糖浓度下,产酸丙酸杆菌生长及产酸水平差异不大,无明显底物抑制现象;在2 g/L的初始丙酸盐浓度下,该菌生长受到明显抑制;在5 L发酵罐中,初始葡萄糖浓度为58.8 g/L,发酵72 h,葡萄糖消耗完全,丙酸终浓度达22.4 g/L,丙酸得率和产率分别达0.381 g/g和0.295 g/(L·h),丙酸占总酸比例达72.10%。

The basic growth character including temperature,initial pH,speed of incubator,inoculum concentration, inoculum volume of Propionibacterium acidipropinici,the utilizable carbon and nitrogen source,the inhibition caused by the end product and the 5 L fermentor kinetics were studied in the wave bottle level.The result showed that it grew best at 32 ℃,and initial pH 6.5,with incubator 150 r/min and the inoculums volume 5% （24 h cultured broth mL /fresh medium mL）.The utilizable carbon sources were extensive but the only organic nitrogen sources was good for its growth;no evident substrate inhibition phenomenon was observed when cultured in different initial glucose concentrations;it could not grow well at the propionate concentration of 2 g/L;after 72 h of fermentation in 5 L fermentor,the glucose （58.8 g/L）was completely exhausted and the final propionic acid concentration reached 22.4 g/L,with propionic acid yield and productivity 0.382 g/g and 0.295 g/（L·h）respectively,propionic acid/total acids 72.10%.