By means of biorefinery, biogas production through anaerobic digestion is one of the most common treatments of wastewater in the palm oil industry. After biogas production, the treated palm oil mill effluent (POME) is generally discharged into the environment. However, certain level of hazardous compounds still exists in the treated wastewater, which can lead to the pollution of water bodies. In this study, we have investigated the dynamics of volatile organic acids dwelling in consecutive POME treatment lagoons as well as identified, and categorized, microbial species responsible for the treatment process. Bacteria and methanogens, both hydrogenotrophic and acetoclastic, related to methane production were identified using mcrA and 16S rRNA genes specific primers. Two hydrogenotrophic methanogens, Methanoculleus marisnigri and Methanoculleus chikugoensis, were found abundant in accordance with high formate concentration throughout the process of anaerobic digestion. This study has also isolated eight consortia of microbes that yielded different methane productions by utilizing formate as the substrate in the synthetic medium. The consortia of a group, containing M. marisnigri, M. chikugoensis, uncultured bacteria, Aminobacterium sp., and Ruminobacillus xylanolyticum, produced the highest methane yield of 259 mL/g COD after 25 days of incubation in the laboratory. The findings from this study are contributing to optimize and increase biogas production in POME, which will allow higher efficiency in palm oil mill wastewater treatment.

中文翻译：

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棕榈油厂废水中甲烷富营养型产甲烷菌的鉴定与培养

通过生物精炼，通过厌氧消化生产沼气是棕榈油工业中最常见的废水处理方法之一。产生沼气后，经过处理的棕榈油厂废水（POME）通常排放到环境中。但是，处理后的废水中仍然存在一定含量的有害化合物，这可能导致水体污染。在这项研究中，我们调查了在连续的POME处理泻湖中驻留的挥发性有机酸的动力学，以及确定和分类了负责处理过程的微生物物种。使用mcr A和16S rRNA基因特异性引物鉴定了与甲烷产生有关的细菌和产甲烷菌，既有氢营养型也有破乳质。两种氢营养型产甲烷菌，在整个厌氧消化过程中，根据高甲酸浓度，发现了Marisnigri甲烷菌和chikugoensis甲烷菌。这项研究还通过利用甲酸作为合成培养基中的底物，分离出了八种产生不同甲烷产量的微生物群落。一个小组的财团，包括M. marisnigri，M。chikugoensis，未培养细菌，Aminobacterium sp.。和木糖腐木在实验室中孵育25天后，产生的最高甲烷产量为259 mL / g COD。这项研究的结果有助于优化和增加POME中的沼气产量，这将使棕榈油厂废水处理具有更高的效率。