采用二重叠皿隔绝空气培养法从铀矿中分离获得1株可利用玉米秸秆高效产氢的菌株w-14,经生理生化及16S rRNA基因序列分析鉴定为丁酸梭菌(Clostridium butyricum);通过两段发酵技术,研究了用木霉、曲霉菌制备的纤维素酶麸曲酵解玉米秸秆的温度、时间、p H、麸曲用量对底物的糖化效率和w-14菌株利用玉米秸秆酵解物产氢的影响,结果表明:玉米秸秆酵解的麸曲浓度为20 g/L,温度为40℃、时间84 h,p H为5.0时酵解物还原糖为402 mg/g-cs,w-14菌株利用此酵解物发酵累积产氢量为99.7 m L/g-cs;采用正交试验优化出w-14菌株以玉米秸秆酵解物为碳源基质产氢发酵最适条件,并在5 L间歇搅拌深层发酵罐中完成验证,结果表明:初始p H 7.0,种龄16 h,接种量10%,发酵温度37℃,w-14菌株的产氢量达140.24 m L/g-cs,比优化前提高了41.38%。经5 L间歇搅拌深层发酵反应器验证,w-14菌株利用秸秆的最高累积产氢量达149.09 m L/g-cs,氢气浓度达到55.63%。
A mathematical model that described the strains growth, product formation and medium consumption was presented to predict the performance of batch fermentation of Zoogloea sp.GY3 which was screened from activated sludge and could synthesize PHAs.A simple model was proposed by using the Logistic equation for growth, the Luedeking-Piret equation for PHAs production and the Luedeking-Piret-like equation for sucrose consumption.The model appeared to provide a reasonable description for each parameter during the growth phase.The production of PHAs was growth-associated.The models were in good agreement with the measured data in experiments.
