红树林沉积物中天然多聚有机物厌氧降解菌多样性与细菌新类群分离

[目的]红树林沉积物中有机物丰富,通过研究认识参与难降解天然有机多聚物的微生物降解过程及其环境作用,并获得新颖的难培养厌氧微生物.[方法]对漳州九龙江河口红树林沉积物中降解纤维素、几丁质和木质素的厌氧细菌定向富集和平板分离纯化,并对其多样性进行分析.[结果]共筛选分离获得202株厌氧细菌(82株专性厌氧细菌,120株兼...

Diversity of anaerobic degrading bacteria for natural organic polymers in mangrove sediments and isolation of novel groups of bacteria

[Objective] Organic matters are rich in the mangrove sediments. This research was aimed to understand the community structure and degradation process of microorganisms involved in natural organic polymers and their environmental roles. [Methods] Using anaerobic microbial culture technology to enrich, isolate and analyze the microbial diversity of anaerobic bacteria that involved in degrading cellulose, chitin and lignin in the mangrove sediments of the Jiulong River Estuary in Zhangzhou. [Results] A total of 202 anaerobes (82 obligate anaerobes and 120 facultative anaerobes) were isolated. Among those strains, four candidate novel genera (named Lachnotalea sp. MCCC 1A16036, Varunaivibrio sp. MCCC 1A15903, Clostridium sp. MCCC 1A15884 and Caminicella sp. MCCC 1A17445, respectively) and four candidate novel species (named Sunxiuqinia sp. MCCC 1A15904, Pseudodesulfovibrio sp. MCCC 1A16040, Pseudodesulfovibrio sp. MCCC 1A16038 and Mangrovibacterium lignilyticum MCCC 1A15882, respectively) were isolated. The dominant cultivable bacteria isolated from different substrate enrichments mainly belong to phyla Proteobacteria, Bacteroides and Firmicutes, but the population is slightly different. The species Prolixibacter bellariivorans and Mangrovibacterium lignilyticum, which belong to the phylum Bacteroides, and the species Desulfovibrio salexigenes and Vibrio alginolyticus, which belong to the phylum Proteobacteria, are most dominant in cellulose and chitin-enriched microbial communities. The strains Demequina salsinemoris MCCC 1A15890 and Brevibacterium celere MCCC 1A17451 (in the phylum Actinobacteria) showed the highest degradation activity to cellulose, while the strains Propionigenium maris MCCC 1A15874 and Ilyobacter polytropus MCCC 1A15889 (in the phylum Fusobacteria) showed the highest degradation activity to chitin. Among the lignin enriched bacteria, Mangrovebacterium lignlyticum (in the phylum Bacteroides) and Clostridium amygdalinum (in the phylum Firmicutes) had high relative abundance. The strains Desulfomicrobium apsheronum MCCC 1A15932 (in the phylum Proteobacteria) and Mangrovibacterium lignilyticum MCCC 1A15882 (in the phylum Bacteroides) have significant efficiency on lignin degradation. [Conclusion] There are diverse, novel and difficult-to-cultivable anaerobic bacteria in mangrove sediments, and most of them have the ability to degrade cellulose, chitin or lignin in anaerobic condition. The results will provide relevant theoretical basis and bacterial resources to explore the biogeochemical cycle of organic polymer carbon in environment of mangrove sediments in situ.