Novel Clostridium populations involved in the anaerobic degradation of Microcystis blooms

Abstract

Understanding the microbial degradation of Microcystis biomass is crucial for determining the ecological consequences of Microcystis blooms in freshwater lakes. The purpose of this study was to identify bacteria involved in the anaerobic degradation of Microcystis blooms. Microcystis scum was anaerobically incubated for 90 days at three temperatures (15 1C, 25 1C and 35 1C). We used terminal restriction fragment length polymorphism (T-RFLP) analysis of bacterial 16S rRNA genes, followed by cloning and sequencing of selected samples, to reveal the community composition of bacteria and their dynamics during decomposition. Clostridium spp. were found to be the most dominant bacteria in the incubations, accounting for 72% of the sequenced clones. Eight new clusters or subclusters (designated CLOS.1-8) were identified in the Clostridium phylogenetic tree. The bacterial populations displayed distinct successions during Microcystis decomposition. Temperature had a strong effect on the dynamics of the bacterial populations. At 15 1C, the initial dominance of a 207-bp T-RF (Betaproteobacteria) was largely substituted by a 227-bp T-RF (Clostridium, new cluster CLOS.2) at 30 days. In contrast, at 25 1C and 35 1C, we observed an alternating succession of the 227-bp T-RF and a 231-bp T-RF (Clostridium, new cluster CLOS.1) that occurred more than four times; no one species dominated the flora for the entire experiment. Our study shows that novel Clostridium clusters and their diverse consortiums dominate the bacterial communities during anaerobic degradation of Microcystis, suggesting that these microbes' function in the degradation process.

The Influence of Glyphosate on the Microbiota and Production of Botulinum Neurotoxin During Ruminal Fermentation

“…2). The C. histolyticum group consists of cluster I and II of the Clostridiaceae including many species with pathogenic potential [47]. Therefore, the glyphosate-induced dysbiosis of crude fiberrich diets during the dry period of cows could induce a higher susceptibility for pathogens or support such microorganisms that normally occur in small numbers.…”

Paenibacillus taihuensis sp. nov., isolated from an eutrophic lake

“…During the post-blooming stage, large quantities of algae cells accumulate and decompose, resulting in serious environmental and ecological consequences (Li et al, 2012). Recent studies have shown that various heterotrophic bacteria are associated with algal blooms and decomposition in eutrophic lakes (Berg et al, 2009;Grossart et al, 2006;Xing et al, 2011). Taihu lake, located in Jiangsu Province of China (30 u 559 400-31 u 329 580 N 119 u 529 320-120 u 369 100 E), has suffered from repeated algal blooms in the past years (Paerl et al, 2011).…”

“…Taihu lake, located in Jiangsu Province of China (30 u 559 400-31 u 329 580 N 119 u 529 320-120 u 369 100 E), has suffered from repeated algal blooms in the past years (Paerl et al, 2011). Previous studies on the microbial diversity and population dynamics during algal decomposition with molecular tools such as 16S rRNA gene sequencing showed that Clostridium-affiliated 16S rRNA gene sequences from members of the phylum Firmicutes were highly abundant in decomposing algal slurry (Xing et al, 2011). We attempted to cultivate bacterial isolates, and bacterial strains that are phylogenetically related to the genus Paenibacillus of the phylum Firmicutes were obtained.…”

To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell

“…Besides, redox potential also affected anaerobic fermentation process [32]. It was reported that CBB was anaerobically degraded mainly through fermentation by the genus Clostridium [33]. In fact, the genus Clostridium is widely regarded as important fermentative bacteria [34].…”