Jayachandran Varsha, Basak Nitai, De Philippis Roberto, Adessi Alessandra
Department of Biotechnology, Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, 144 027, Punjab, India.
Department of Agriculture, Food, Environment and Forestry, Florence University, Florence, Italy.
Bioprocess Biosyst Eng. 2022 Oct;45(10):1595-1624. doi: 10.1007/s00449-022-02738-4. Epub 2022 Jun 17.
In the scenario of alarming increase in greenhouse and toxic gas emissions from the burning of conventional fuels, it is high time that the population drifts towards alternative fuel usage to obviate pollution. Hydrogen is an environment-friendly biofuel with high energy content. Several production methods exist to produce hydrogen, but the least energy intensive processes are the fermentative biohydrogen techniques. Dark fermentative biohydrogen production (DFBHP) is a value-added, less energy-consuming process to generate biohydrogen. In this process, biohydrogen can be produced from sugars as well as complex substrates that are generally considered as organic waste. Yet, the process is constrained by many factors such as low hydrogen yield, incomplete conversion of substrates, accumulation of volatile fatty acids which lead to the drop of the system pH resulting in hindered growth and hydrogen production by the bacteria. To circumvent these drawbacks, researchers have come up with several strategies that improve the yield of DFBHP process. These strategies can be classified as preliminary methodologies concerned with the process optimization and the latter that deals with pretreatment of substrate and seed sludge, bioaugmentation, co-culture of bacteria, supplementation of additives, bioreactor design considerations, metabolic engineering, nanotechnology, immobilization of bacteria, etc. This review sums up some of the improvement techniques that profoundly enhance the biohydrogen productivity in a DFBHP process.
在传统燃料燃烧导致温室气体和有毒气体排放量惊人增加的情况下，人们早就应该转向使用替代燃料以消除污染。氢气是一种能量含量高的环境友好型生物燃料。存在多种生产氢气的方法，但能量消耗最少的工艺是发酵生物制氢技术。暗发酵生物制氢（DFBHP）是一种增值、低能耗的生物制氢过程。在此过程中，生物氢可以由糖类以及通常被视为有机废物的复杂底物产生。然而，该过程受到许多因素的限制，例如氢气产量低、底物转化不完全、挥发性脂肪酸积累导致系统pH值下降，从而阻碍细菌的生长和氢气产生。为了克服这些缺点，研究人员提出了几种提高DFBHP过程产量的策略。这些策略可分为与过程优化相关的初步方法，以及处理底物和种子污泥预处理、生物强化、细菌共培养、添加剂补充、生物反应器设计考虑、代谢工程、纳米技术、细菌固定化等的后期方法。本综述总结了一些能显著提高DFBHP过程中生物氢生产率的改进技术。
