己酸厌氧发酵过程的代谢特点研究

A STUDY ON THE FERMENTATIVE PROPERTIES OF PRODUCING CAPROIC ACID FROM CELLULOSE BY ANAEROBIC COCULTURE

对两种分解纤维素的瘤胃菌FibrobactersuccinogensS85或RuminococcusflaveficiensFD－1，与非瘤胃菌Clostridiumkluyveri联合培养，由纤维素生产液体燃料的前体──己酸的发酵特点进行了分析研究。这两种分解纤维素的瘤胃菌可以把纤维素转化为琥珀酸和乙酸；在加入乙醇时，C．kluyveri可以把琥珀酸和乙酸转化为己酸、丁酸。在发酵过程中，纤维素首先降解生成琥珀酸、乙酸，随之同加入的乙醇被消耗而生成己酸、丁酸及少量其它有机酸。与单独培养相比，两种纤维素分解菌在分别与C．kluyveri联合培养时，受到pH的明显影响。而其最终产物己酸和丁酸，对其均有不同程度的毒性和影响。

The conversion of cellulose to caproic acid, a potential liquid fuel precursor, was examined using cocultures of the ruminal cellulolytic bacteria Fibrobacter succinogenes S85, or Ruminococcus flaveficiens FD-1, and the nonruminal anaerobe Clostridium kluyveri. The former two converted cellulose to succinic and acetic acids, which in the presence of ethanol were used by the last organism to produce caproic and butyric acids. Time course studies revealed that cellulose consumption with production of succinate and acetate was followed by the consumption of ethanol and succinate with the production of butyrate and caproate. Unlike the monoculture of cellulolytic bacteria, the coculture was markedly affected by pH. The pH control resulted in an increase in cellulose consumption and complete conversion of succinate to caproate and butyrate. Both the end-products were somewhat toxic to the cellulolytic bacteria.