The gut microbiome and its potential role in paradoxical anaerobism in pupfishes of the Mojave Desert

Abstract

Background: Pupfishes frequently enter paradoxical anaerobism in response to endogenously produced or exogenously supplied ethanol in a dose-dependent manner. To decipher the role of the gut microbiota in ethanolassociated paradoxical anaerobism, gut microbial communities were depleted using a cocktail of antibiotics and profiled using 16S rRNA gene sequencing. Results: Compared to the control group (n = 12), microbiota-depleted fish (n = 12) spent more time in paradoxical anaerobism. Our analysis indicated that the bacterial phyla Proteobacteria, Fusobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Patescibacteria, and Dependentiae dominated the pupfish gut, which is consistent with other fish gut microbiota. Although the gut microbial communities with and without antibiotic treatment were similarly diverse, they were distinct and the greatest contribution to the dissimilarity (27.38%) was the common fish commensal Cetobacterium. Conclusions: This study reports the first characterization of gut microbial communities of pupfish and suggests the microbiome may play a critical role in regulating metabolic strategies that are critical for survival in extremes of temperature and oxygen concentration. We speculate that Cetobacterium, a primary fermenter, also consumes ethanol through secondary fermentation via an alcohol dehydrogenase and therefore regulates the transition from paradoxical anaerobism to aerobic respiration in fish. Given the wide distribution and abundance of Cetobacterium in warm-water fishes, this process may be of broad importance, and suggests that the microbiome be carefully considered for both conservation and aquaculture.

Bioelectrochemically enhanced degradation of bisphenol S: mechanistic insights from stable isotope-assisted investigations

“…Bacteroides have also been previously identified as degradators of BPA or other aromatic hydrocarbon degradation ( Comte et al., 2006 ; Yang et al., 2019 ). Cetobacterium most frequently occurs as gut microbes ( Sheng et al., 2010 ) and sludge microbes ( Song et al., 2015a ; Tian et al., 2020 ), which were previously found to be involved in the consumption of alcohols ( Bhute et al., 2020 ), fatty acids, and protein ( Hao et al., 2017 ). Recent studies also found the existence of Cetobacterium in sludge and landfill sites ( Song et al., 2015a ; Tian et al., 2020 ) and their abilities in degradation of surfactants ( Motteran et al.…”

The gut bacterial microbiome of Nile tilapia (Oreochromis niloticus) from lakes across an altitudinal gradient

“…These results imply that the intestine of Nile tilapia might harbour more diversified microbial communities in addition to the microbial communities reported thus far. Patescibacteria and Dependentiae dominated the pupfish gut [ 44 ]. Patescibacteria is associated with biodegradable plastics such as polylactic acid [ 45 ], and has also been reported as a potential microbial bioindicator of phosphorus mining [ 46 ].…”

The gut bacterial microbiome of Nile tilapia (Oreochromis niloticus) from lakes across an altitudinal gradient

“…These results imply that the intestine of Nile tilapia might harbour more diversi ed microbial communities in addition to the microbial communities reported thus far. Patescibacteria and Dependentiae dominated the pup sh gut [44]. Patescibacteria is associated with biodegradable plastics such as polylactic acid [45], and has also been reported as a potential microbial bioindicator of phosphorus mining [46].…”