Cheng Huijun, Asakura Yuya, Kanda Kosuke, Fukui Ryo, Kawano Yoshihisa, Okugawa Yuki, Tashiro Yukihiro, Sakai Kenji
Laboratory of Soil and Environmental Microbiology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Laboratory of Soil and Environmental Microbiology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan; Laboratory of Microbial Environmental Protection, Tropical Microbiology Unit, Center for International Education and Research of Agriculture, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
J Biosci Bioeng. 2018 Aug;126(2):196-204. doi: 10.1016/j.jbiosc.2018.02.012. Epub 2018 Apr 13.
Autothermal thermophilic aerobic digestion (ATAD) is conducted for stabilization of sludge waste and is driven by the action of various microorganisms under aerobic conditions. However, the mechanism controlling bacterial community changes during ATAD via three (initial, middle and final) phases is currently unclear. To investigate this mechanism, activity analysis and a microcosm assay with shaking were performed on a bacterial community during the initial, middle, and final phases of incubation. Cell lysis activities toward gram-negative bacteria, but not gram-positive bacteria, were detected in the ATAD samples in the middle and final phases. During shaking incubation in initial-phase samples at 30 °C, major operational taxonomic units (OTUs) related to Acinetobacter indicus and Arcobacter cibarius dramatically increased along with decreases in several major OTUs. In middle-phase samples at 45 °C, we observed a major alteration of OTUs related to Caldicellulosiruptor bescii and Aciditerrimonas ferrireducens, together with distinct decreases in several other OTUs. Final-phase samples maintained a stable bacterial community with major OTUs showing limited similarities to Heliorestis baculata, Caldicellulosiruptor bescii, and Ornatilinea apprima. In conclusion, the changes in the bacterial community observed during ATAD could be partially attributed to the cell lysis activity toward gram-negative bacteria in the middle and final phases. The microcosm assay suggested that certain physical factors, such as a high oxygen supply and shearing forces, also might contribute to bacterial community changes in the initial and middle phases, and to the stable bacterial community in the final phase of ATAD.
自热嗜热需氧消化（ATAD）用于污泥废弃物的稳定化处理，在有氧条件下由各种微生物的作用驱动。然而，目前尚不清楚在ATAD过程中通过三个阶段（初始、中间和最终）控制细菌群落变化的机制。为了研究这一机制，在培养的初始、中间和最终阶段对细菌群落进行了活性分析和摇床微观试验。在中间和最终阶段的ATAD样品中检测到对革兰氏阴性菌而非革兰氏阳性菌的细胞裂解活性。在30℃对初始阶段样品进行摇床培养期间，与印度不动杆菌和西巴弧菌相关的主要操作分类单元（OTU）显著增加，同时几个主要OTU减少。在45℃的中间阶段样品中，我们观察到与嗜碱纤维杆菌和铁还原嗜酸菌相关的OTU发生了重大变化，同时其他几个OTU明显减少。最终阶段样品保持了稳定的细菌群落，主要OTU与杆状嗜热栖热菌、嗜碱纤维杆菌和近似华丽线菌的相似性有限。总之，在ATAD过程中观察到的细菌群落变化可能部分归因于中间和最终阶段对革兰氏阴性菌的细胞裂解活性。微观试验表明，某些物理因素，如高氧气供应和剪切力，也可能导致ATAD初始和中间阶段细菌群落的变化以及最终阶段稳定的细菌群落的形成。
