Wojcieszak Martyna, Pyzik Adam, Poszytek Krzysztof, Krawczyk Pawel S, Sobczak Adam, Lipinski Leszek, Roubinek Otton, Palige Jacek, Sklodowska Aleksandra, Drewniak Lukasz
Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Warsaw, Poland.
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Front Microbiol. 2017 Sep 28;8:1881. doi: 10.3389/fmicb.2017.01881. eCollection 2017.
A well-balanced microbial consortium is crucial for efficient biogas production. In turn, one of a major factor that influence on the structure of anaerobic digestion (AD) consortium is a source of microorganisms which are used as an inoculum. This study evaluated the influence of inoculum sources (with various origin) on adaptation of a biogas community and the efficiency of the biomethanization of maize silage. As initial inocula for AD of maize silage the samples from: (i) an agricultural biogas plant (ABP) which utilizes maize silage as a main substrate, (ii) cattle slurry (CS), which contain elevated levels of lignocelluloses materials, and (iii) raw sewage sludge (RSS) with low content of plant origin materials were used. The adaptation of methanogenic consortia was monitored during a series of passages, and the functionality of the adapted consortia was verified through start-up operation of AD in two-stage reactors. During the first stages of the adaptation phase, methanogenic consortia occurred very slowly, and only after several passages did the microbial community adapts to allow production of biogas with high methane content. The ABP consortium revealed highest biogas production in the adaptation and in the start-up process. The biodiversity dynamics monitored during adaptation and start-up process showed that community profile changed in a similar direction in three studied consortia. Native communities were very distinct to each other, while at the end of the Phase II of the start-up process microbial diversity profile was similar in all consortia. All adopted bacterial communities were dominated by representatives of , , , and . A shift from low acetate-preferring acetoclastic (ABP and RSS) and/or hydrogenotrophic , e.g., (CS) prevailing in the inoculum samples to larger populations of high acetate-preferring acetoclastic was observed by the end of the experiment. As a result, three independent, functional communities that syntrophically produced methane from acetate (primarily) and H/CO, methanol and methylamines were adapted. This study provides new insights into the specific process by which different inocula sampled from typical methanogenic environments that are commonly used to initiate industrial installations gradually adapted to allow biogas production from maize silage.
一个平衡良好的微生物群落对于高效生产沼气至关重要。反过来，影响厌氧消化（AD）群落结构的一个主要因素是用作接种物的微生物来源。本研究评估了接种物来源（具有不同起源）对沼气群落适应性以及玉米青贮料生物甲烷化效率的影响。作为玉米青贮料AD的初始接种物，使用了来自以下样本：（i）一个以玉米青贮料为主要底物的农业沼气厂（ABP）；（ii）含有高水平木质纤维素材料的牛粪浆（CS）；以及（iii）植物源材料含量低的原污水污泥（RSS）。在一系列传代过程中监测产甲烷群落的适应性，并通过两阶段反应器中AD的启动操作验证适应后群落的功能。在适应阶段的第一阶段，产甲烷群落出现得非常缓慢，只有经过几次传代后，微生物群落才适应以允许产生高甲烷含量的沼气。ABP群落显示在适应和启动过程中沼气产量最高。在适应和启动过程中监测的生物多样性动态表明，在所研究的三个群落中，群落概况朝着相似的方向变化。原生群落彼此非常不同，而在启动过程的第二阶段结束时，所有群落中的微生物多样性概况相似。所有采用的细菌群落均以 、 、 和 的代表为主。在实验结束时，观察到从接种物样本中占主导的低乙酸偏好型乙酸裂解菌 （ABP和RSS）和/或氢营养型 ，例如 （CS）转变为高乙酸偏好型乙酸裂解菌的更大种群。结果，适应了三个独立的、从乙酸盐（主要）以及H/CO、甲醇和甲胺中合成甲烷的功能群落。本研究为从典型的产甲烷环境中采集的不同接种物逐渐适应以允许从玉米青贮料生产沼气的具体过程提供了新的见解。
