1. Variable promotion of algae and macrophyte organic matter on methanogenesis in anaerobic lake sediment.
- Author
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Wang, Tong, Zhumabieke, Maidina, Zhang, Nan, Liu, Cheng, Zhong, Jicheng, Liao, Qianjiahua, and Zhang, Lei
- Subjects
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LAKE sediments , *ATMOSPHERIC methane , *ORGANIC compounds , *ALGAL blooms , *POTAMOGETON , *NUCLEOTIDE sequencing , *MACROPHYTES - Abstract
Shallow lakes are an important natural source of atmospheric methane (CH 4), and the input of autochthonous organic matter (OM) into their sediments encourages methanogenesis. Although algal- and macrophytic-originated OM in these lakes are expected to have different impacts on methanogenesis and methanogenic archaeal communities in lake sediments owing to their various properties, their specific influence and role in sediment remain unclear. In this study, a 148-day incubation was carried out by adding algal- and macrophytic-OM to the sediments of shallow eutrophic Lake Chaohu and Lake Taihu in China. CH 4 was periodically monitored, while the methanogens were examined via qPCR and high-throughput sequencing at the end of incubation. Algal-OM stimulated CH 4 production more than macrophytic-OM in both sediments, with the rates initially increasing and then decreasing before reaching a relative constant. Macrophytic-OM promoted CH 4 production to a comparable extent in both lakes, while algal-OM promoted greater CH 4 in Lake Chaohu than in Lake Taihu. However, algal-OM did not significantly increase mcrA gene copies, while macrophytic-OM did by 17.0–20.1-fold. Algal-OM potentially promoted the methylotrophic pathway in Lake Taihu but did not change the methanogenic structure in Lake Chaohu. Comparatively, macrophytic-OM promoted CH 4 production mainly by acetoclastic methanogen proliferation in both lakes. More CH 4 release with algal-OM compared to macrophytic-OM deserves further attention owing to the prevailing increasing algal blooms and the declining macrophyte population in lakes. [Display omitted] • Algal-OM and macrophytic-OM promoted methanogenesis in sediments. • Algal-OM promoted more methane than macrophytic-OM in sediments. • Algal-OM did not significantly increase mcr A gene copies but macrophytic-OM did. • Algal-OM increased the methylotrophic archaea in sediment from Lake Taihu. • Macrophytic-OM stimulated acetoclastic methanogen proliferation in both lakes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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