厌氧降解丁酸共培养物中产氢产乙酸细菌与产甲烷细菌的分离与再组合

ISOLATION AND REASSOCIATION OF ACETOGEN AND METHANOGEN IN A SYNTROPHOBIC COCULTURE DEGRADING BUTYRATE ANAEROBICALLY

由处理啤酒厂废水的厌氧消化器颗粒污泥中分离和纯化了一个能厌氧降解丁酸产生甲烷的共培养物BF2。共培养物BF2可降解包括异丁酸在内的含4～18个碳原子的脂肪酸,最适生长温度37℃,最适pH7.7。以巴豆酸为底物,成功地将共培养物BF2分离为专性质子还原产乙酸细菌沃尔夫互营单胞菌嗜脂肪亚种菌株CF2和产甲烷细菌甲酸甲烷杆菌菌株MF2两个纯培养,将它们再组合后仍可降解丁酸。菌株CF2与亨氏甲烷螺菌、布氏甲烷短杆菌菌株1125、甲酸甲烷杆菌菌株1535和普通脱硫弧菌G11组合成人工共培养物,可以厌氧降解丁酸。

Ananaerobic coculture BF2 which degraded butyrate into acetate and produced methane was isolated from granular methanogenic sludge. The coculture is associated syntrophically the Syntrophomonas subsp. saponavida strain CF2 with Methanobactertum formicicum strain MF2 and appeared to degraded C4-C18 fatty acids including isobutyrate. The optimal temperature and pH for growth was 37℃ and 7.7 respectively. The strain CF2 was obtained in pure culture with crotonate as substrate and produces acetate and butyrate. The doubling time of strain CF2 in crotonate media was about 20 hours. Strain CF2 is Gram negative, slightly curved 0.2-0.3×2.0-3.0μm with round ends, motile by lateral flagellation at the concave side, non sporeforming. With a hydrogen scavenging organism, such as Methanos-pillum hungatei JF1, Mehtanobacteriu formicicum 1535, Methanobrevibacterium bry-antii 1125 and Desulfovibrio sp. B11, the strain CF2 paired up and the defined coculture degraded butyrate to acetate. When the strain CF2 associated with the original accompanist, Methanobacterium formicius strain MF2, the reassociated coucul-ture degraded butyrate to acetate and produced methane again.