摘要
甘露醇是大型褐藻的主要成分之一,在工业生产海藻酸的过程中,甘露醇成为副产物被废弃。筛选到一株高温厌氧芽孢杆菌Rx1,利用甘露醇发酵,乙醇得率高达1.8 mol乙醇/mol甘露醇,为理论产值的90.5%,是发酵葡萄糖乙醇得率的1.7倍,还发现菌株发酵甘露醇的初期会产生微量的乙酸,随后又被立即消耗。通过添加外源乙酸对Rx1代谢特性进行研究,结果外源乙酸不仅能促进底物的利用,还发现Rx1存在转化乙酸生成乙醇的途径,而该途径关键酶的合成需要甘露醇的诱导。
Mannitol which is one of the major components of large brown algae is a by-product in the industrial process of alginate production. In previous studies, a thermophilic anaerobic bacteria Thermoanaerobacterium calidiformis Rx1 was isolated from hot springs. When fermentation was performed by T. calidiformis Rx1 using mannitol as substrate, ethanol yield was 1.8 mol/mol mannitol, with 90.5% of the theoretical yield, which is 1.7 times as much yield as fermentation with glucose. Furthermore, a small amount of acetic acid was produced in the initial mannitol fermentation, yet it was consumed immediately. Therefore, strain Rx1 metabolic characteristics was studied by adding exogenous acetic acid into medium, and the results showed that the exogenous acetic acid can stimulate utilizing substrate, T.calidiformis Rx1 has a pathway to convert acetic acid into ethanol, and the key enzymic synthesis of this way is induced by mannitol.
出处
《中国生物工程杂志》
CAS
CSCD
北大核心
2013年第10期73-80,共8页
China Biotechnology
关键词
高温厌氧芽孢杆菌
甘露醇
乙醇
代谢途径
Thermophilic anaerobic bacteria Mannitol Ethanol Metabolic pathway
