RESULTS: During a 7-month study of bacterial communities comparing free-living and aggregate-associated bacteria in Lake Taihu, China, we found that aerobic anoxygenic phototrophic (AAP) bacteria were significantly more abundant within Microcystis aggregates than in free-living samples, suggesting a possible functional role for AAP bacteria in overall aggregate community function. We then analyzed gene composition in 102 high-quality metagenome-assembled genomes (MAGs) of bloom-microbiome bacteria from 10 lakes spanning four continents, compared with 12 complete Microcystis genomes which revealed that microbiome bacteria and Microcystis possessed complementary biochemical pathways that could serve in C, N, S, and P cycling. Mapping published transcripts from Microcystis blooms onto a comprehensive AAP and non-AAP bacteria MAG database (226 MAGs) indicated that observed high levels of expression of genes involved in nutrient cycling pathways were in AAP bacteria.
CONCLUSIONS: Our results provide strong corroboration of the hypothesized Microcystis interactome and the first evidence that AAP bacteria may play an important role in nutrient cycling within Microcystis aggregate microbiomes. Video Abstract.
结果:在一项为期7个月的细菌群落研究中,比较了太湖的自由生活和聚集相关细菌,中国,我们发现,需氧缺氧光养(AAP)细菌在微囊藻聚集体中比在自由生活样品中明显更丰富,提示AAP细菌在总体聚集群落功能中可能发挥的功能作用。然后,我们分析了来自四大洲10个湖泊的102个高质量宏基因组组装基因组(MAG)中的基因组成,与12个完整的微囊藻基因组相比,这些基因组表明微生物组细菌和微囊藻具有互补的生化途径,N,S,和P循环。将微囊藻繁殖的已发表转录本映射到全面的AAP和非AAP细菌MAG数据库(226MAG)上,表明在AAP细菌中观察到与营养循环途径有关的基因的高水平表达。
结论:我们的结果为假设的微囊藻相互作用组提供了有力的佐证,并首次证明AAP细菌可能在微囊藻聚集微生物群中的营养循环中起重要作用。视频摘要。