Goswami Ramansu, Chattopadhyay Pritam, Shome Arunima, Banerjee Sambhu Nath, Chakraborty Amit Kumar, Mathew Anil K, Chaudhury Shibani
Department of Environmental Studies, Visva-Bharati, Santiniketan, West Bengal, 731 235, India.
Department of Zoology, University of Delhi, New Delhi, 110121, India.
3 Biotech. 2016 Jun;6(1):72. doi: 10.1007/s13205-016-0395-9. Epub 2016 Feb 16.
Biogas is a combination of methane, CO, nitrogen, HS and traces of few other gases. Almost any organic waste can be biologically transformed into biogas and other energy-rich organic compounds through the process of anaerobic digestion (AD) and thus helping in sustainable waste management. Although microbes are involved in each step of AD, knowledge about those microbial consortia is limited due to the lack of phylogenetic and metabolic data of predominantly unculturable microorganisms. However, culture-independent methods like PCR-based ribotyping has been successfully employed to get information about the microbial consortia involved in AD. Microbes identified have been found to belong mainly to the bacterial phyla of Proteobacteria, Chloroflexi, Firmicutes and Bacteroidetes. Among the archaeal population, the majority have been found to be methanogens (mainly unculturable), the remaining being thermophilic microbes. Thus, the AD process as a whole could be controlled by regulating the microbial consortia involved in it. Optimization in the feedstock, pH, temperature and other physical parameters would be beneficial for the microbial growth and viability and thus helpful for biogas production in AD. Besides, the biogas production is also dependent upon the activity of several key genes, ion-specific transporters and enzymes, like genes coding for methyl-CoM reductase, formylmethanofuran transferase, formate dehydrogenase present in the microbes. Fishing for these high-efficiency genes will ultimately increase the biogas production and sustain the production plant.
沼气是甲烷、一氧化碳、氮气、硫化氢和少量其他气体的混合物。几乎任何有机废物都可以通过厌氧消化（AD）过程被生物转化为沼气和其他富含能量的有机化合物，从而有助于实现可持续的废物管理。尽管微生物参与了厌氧消化的每一个步骤，但由于主要是不可培养微生物的系统发育和代谢数据缺乏，关于这些微生物群落的知识仍然有限。然而，基于PCR的核糖体分型等非培养方法已成功用于获取有关参与厌氧消化的微生物群落的信息。已发现鉴定出的微生物主要属于变形菌门、绿弯菌门、厚壁菌门和拟杆菌门等细菌门类。在古菌种群中，大多数被发现是产甲烷菌（主要是不可培养的），其余的是嗜热微生物。因此，整个厌氧消化过程可以通过调节其中涉及的微生物群落来控制。原料、pH值、温度和其他物理参数的优化将有利于微生物的生长和活力，从而有助于厌氧消化中的沼气生产。此外，沼气生产还取决于几种关键基因、离子特异性转运蛋白和酶的活性，如微生物中编码甲基辅酶M还原酶、甲酰甲烷呋喃转移酶、甲酸脱氢酶的基因。寻找这些高效基因最终将提高沼气产量并维持生产工厂的运转。
