Identification of Propionate-Degrading Microbial Populations in Methanogenic Processes for Waste Treatment: Methanosaeta and Methanoculleus
Identification of Propionate-Degrading Microbial Populations in Methanogenic Processes for Waste Treatment: Methanosaeta and Methanoculleus
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DOI：
10.1089/ees.2021.0067
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发表时间：
2021-11
影响因子：
1.8
通讯作者：
Si Chen;Yongfeng Wang;Huicai Cheng;T. Hazen;Chunguang He;Qiang He
中科院分区：
文献类型：
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作者：
Si Chen;Yongfeng Wang;Huicai Cheng;T. Hazen;Chunguang He;Qiang He
生产甲烷作为一种可再生能源，在可持续处理有机废物方面具有巨大潜力。然而，由于在操作条件波动期间经常遇到工艺不稳定，甲烷生产工艺的更广泛应用受到了阻碍。有机酸的积累，特别是丙酸，被认为是工艺不稳定的重要原因。因此，为了了解微生物在工艺不稳定过程中的反应，必须确定参与利用高水平丙酸的微生物种群。在本研究中，微生物群落分析表明，在丙酸厌氧转化过程中，来自合养细菌和梭菌的细菌种群是主要的合养伙伴。产甲烷间歇生物反应器中的丙酸降解群落主要由与甲烷菌和甲烷藻相关的古菌群组成。丙酸升高与处理动物排泄物的连续厌氧消化器中甲烷和甲烷纤维素种群丰度增加之间的密切对应，进一步支持了甲烷和甲烷纤维素在丙酸厌氧转化中的参与。随后使用额外的产甲烷间歇生物反应器进行的测试显示，甲烷菌群和甲烷球菌群的优势与升高的丙酸盐和丁酸盐的厌氧降解有关，而与甲酸盐、乙酸盐或甲醇转化为甲烷无关。在这项研究中，与高浓度丙酸的厌氧转化有关的微生物种群的鉴定为理解产甲烷废物处理中与过程稳定性相关的微生物过程提供了亟需的见解。
Methanogenic processes have great potential in the sustainable treatment of organic wastes with the production of methane as a renewable source of energy. However, the broader application of methanogenic processes has been hindered by process instability frequently encountered during fluctuations in operational conditions. The accumulation of organic acids, particularly propionate, is considered to be an important cause of process instability. Therefore, to gain an understanding of microbial responses during process instability, it is imperative to identify microbial populations involved in the utilization of elevated levels of propionate. In this study, microbial community analysis showed that bacterial populations from the orders ofSyntrophobacteralesandClostridialeswere the primary syntrophic partners in anaerobic conversion of propionate. Archaeal populations associated withMethanosaetaandMethanoculleusdominated the propionate-degrading communities enriched in methanogenic batch bioreactors. The involvement ofMethanosaetaandMethanoculleusin anaerobic conversion of propionate was further supported by the close correspondence between elevated propionate and increased population abundance ofMethanosaetaandMethanoculleusin continuous anaerobic digesters treating animal waste. Subsequent testing using additional methanogenic batch bioreactors revealed that the dominance ofMethanosaetaandMethanoculleuspopulations was linked to the anaerobic degradation of elevated levels of propionate and butyrate, but not the conversion of formate, acetate, or methanol into methane. The identification of microbial populations specifically linked to anaerobic conversion of elevated propionate in this study provided much needed insight for the understanding of microbial processes relevant to process stability in methanogenic waste treatment.