摘要
从牛粪中分离到一株能分解纤维素的高温厌氧梭状芽孢杆菌。该菌接触酶阴性,革兰氐染色阴性。细胞杆状或稍弯(5～10×0.6～0.8μm)。芽孢卵圆形,端生,直径为1.0～1.3μm。极生丛鞭毛,运动。老龄时菌体常呈长丝状(15～30×0.4～0.6μm)。以断裂方式繁殖。最适生长温度为60～65℃,最适pH为6.5～7.0。发酵产物有H_2、CO_2,乙酸、甲酸、乳酸和乙醇等。发酵液中无色素。在纤维素琼脂滚管中形成透明、直径为5～l5mm的圆形分解圈。该菌株在以蛋白胨为唯一碳源和氮源时不生长,能迅速利用葡萄糖或纤维二糖生长。在纤维素上生长时产生孢外纤维素酶,在纤维二糖或葡萄糖上生长时不产生纤维素酶。将在纤维二糖或葡萄糖上旺盛生长的菌接入纤维素培养基中时,需经过10天以上的延迟期才能恢复纤维素分解能力,说明该菌株的纤维素酶是诱导酶。酶的最适温度为65℃,pH为7.2。该菌株的形态、生理生化及酶学性质与Clostridium thermocgllum十分相似,鉴定为同一个种。
A strain of cellulolytie, thermophilic, anaerobic and spore-forming bacteria was isolated from cow faeces. It was Gram negative, peroxidase negative, strict anaerobic and can not grow when peptone was provided as the unique carbon and nitrogen source. Cells were rods or slightly curved rods(5～10×0.6～0.8μm), with polar tufted flagella and motile. In old cultures, cells were filiform ( 15～30×0.4～0.6μm ) . Spores were oval, 1.0～1.3 m in diameter and terminal. Sporulation was irregular, there was no obvious relationship between sporulation and the composition of the medium, the culture time and the state of the medium.Optimum growth occurred at 60～65℃, pH 6.5～7.0 The fermentation products include ethanol, formate, acetate, lactate, CO_2 and hydrogen,about 10%cellulose was converted to ethanol. There was no pigment in fermentation fluid. The clear zones formed by these bacteria in cellulose agar were round, translucent with regular margin and 5～15mm in diameter. The morphological and physiological characteristics of the isolated strain was nearly identical to that of Clostridium thermocellum, thus it was considered a strain of Clostridium thermccellum.Cells grow very well on cellobiose or glucose, but there was no cellulase activities can be detected. When actively growing cells were transfered from cellobiose or glucose medium to cellulose medium, there was a long lag up to ten days. The presence of cellobiose or glucose inhibit the production of the cellulase, therefore, the cellulase syntheses of the isolated strain of C. therocellum was considered inductive. The optimum pH and temperature of the cellulase were 7.2 and 65℃, respectively.
出处
《山东大学学报（自然科学版）》
CSCD
1989年第2期86-92,共7页
Journal of Shandong University(Natural Science Edition)
关键词
纤维素
热纤梭菌
Cellulose
Clostridium thermocellum
