Sarkar Omprakash, Rova Ulrika, Christakopoulos Paul, Matsakas Leonidas
Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, 971‑87, Luleå, Sweden.
Sci Rep. 2024 Aug 8;14(1):18442. doi: 10.1038/s41598-024-68904-8.
Anaerobic digestion (AD) technology can potentially address the gap between energy demand and supply playing a crucial role in the production of sustainable energy from utilization of biogenic waste materials as feedstock. The biogas production from anaerobic digestion is primarily influenced by the chemical compositions and biodegradability of the feedstock. Organosolv-steam explosion offers a constructive approach as a promising pretreatment method for the fractionation of lignocellulosic biomasses delivering high cellulose content.This study showed how synergetic co-digestion serves to overcome the challenges of mono-digestion's low efficiency. Particularly, the study evaluated the digestibility of organosolv-steam pretreated wheat straw (WS) in mono as well as co-digesting substrate with cheese whey (CW) and brewery spent grains (BSG). The highest methane yield was attained with co-digestion of WS + CW (338 mL/gVS) representing an enhanced biogas output of 1-1.15 times greater than its mono digestion. An ammonium production was favored under co-digestion strategy accounting for 921 mg/L from WS + BSG. Metagenomic study was conducted to determine the predominant bacteria and archaea, as well as its variations in their populations and their functional contributions during the AD process. The Firmicutes have been identified as playing a significant role in the hydrolysis process and the initial stages of AD. An enrichment of the most prevalent archaea genera enriched were Methanobacterium, Methanothrix, and Methanosarsina. Reactors digesting simpler substrate CW followed the acetoclastic, while digesting more complex substrates like BSG and WS followed the hydrogenotrophic pathway for biomethane production. To regulate the process for an enhanced AD process to maximize CH, a comprehensive understanding of microbial communities is beneficial.
厌氧消化（AD）技术有可能弥补能源供需差距，在利用生物废弃物作为原料生产可持续能源方面发挥关键作用。厌氧消化产生的沼气主要受原料的化学成分和生物降解性影响。有机溶剂蒸汽爆破作为一种有前景的预处理方法，为木质纤维素生物质的分馏提供了一种建设性途径，可得到高纤维素含量。本研究展示了协同共消化如何有助于克服单消化效率低的挑战。特别是，该研究评估了有机溶剂蒸汽预处理小麦秸秆（WS）在单消化以及与奶酪乳清（CW）和啤酒糟（BSG）共消化底物中的消化率。WS + CW共消化获得了最高的甲烷产量（338 mL/gVS），其沼气产量比单消化提高了1 - 1.15倍。在共消化策略下有利于铵的产生，WS + BSG产生的铵为921 mg/L。进行了宏基因组学研究，以确定主要的细菌和古菌，以及它们在厌氧消化过程中种群数量的变化及其功能贡献。厚壁菌门已被确定在水解过程和厌氧消化的初始阶段发挥重要作用。最普遍富集的古菌属为甲烷杆菌属、甲烷丝菌属和甲烷八叠球菌属。消化较简单底物CW的反应器遵循乙酸裂解途径，而消化较复杂底物如BSG和WS的反应器遵循氢营养途径进行生物甲烷生产。为了调节该过程以增强厌氧消化过程以最大化甲烷产量，全面了解微生物群落是有益的。
