Influence of hydrological factors on bacterial community structure in a tropical monsoonal estuary in India

Abstract

In the present study, we analysed variations in bacterial community structure along a salinity gradient in a tropical monsoonal estuary (Cochin estuary, CE), on the southwest coast of India, using Illumina nextgeneration sequencing (NGS). Water samples were collected from eight different locations thrice a year, to assess the variability in the bacterial community structure and to determine the physico-chemical factors in uencing the bacterial diversity. Proteobacteria was the most dominant phyla in the estuary followed by Bacteroidetes, Cyanobacteria, Actinobacteria, and Firmicutes. Statistical analysis indicated signi cant variations in bacterial communities between freshwater, mesohaline and euryhaline regions, as well as between the monsoon (wet) and non-monsoon (dry) periods. Non-metric multidimensional scaling (NMDS) analysis demonstrated that the bacterial communities cluster according to different salinity regimes of the estuary. Canonical Correspondence analysis (CCA) showed a clear spatial and temporal variation in the distribution of bacterial communities in the CE. Abundance of Betaproteobacteria was high in the freshwater regions, while Gammaproteobacteria, Alphaproteobacteria and Epsilonproteobactera were more abundant in mesohaline and euryhaline regions of the estuary.Correlagram based on Pearson correlation analysis demonstrated the impact of different physicochemical variables on the distribution of dominant phyla, class and genera. Spatial and temporal variations in bacterial community structure could be due to regional variations in environmental conditions imparted by allochthonous inputs, monsoonal rainfall, and tidal in uence.

Influence of environmental settings in geographically distinct ports on the protein profiles of cultivable bacteria using MALDI–TOF mass spectrometry

“…The species present in older ballast water are tougher and thus could have the potential to proliferate in non‐native environments (Ardura et al., 2021). Various factors such as salinity, temperature, dissolved inorganic nutrients, trophic conditions, anthropogenic input, nature of organic matter present in the habitat, substrate availability, abundance of planktons and grazing pressure influence the bacterial production, their diversity, and distribution of dominant phyla, class and genera (Eswaran & Khandeparker, 2017; Parvathi et al., 2021 and references therein). Bacillus spp.…”

Bacterial diversity in the aquatic system in India based on metagenome analysis—a critical review

“…Gammaproteobacteria was more abundant in regions with high nutrient concentrations. Salinity and other inorganic nutrients in the CE are primarily responsible for seasonal and geographic fluctuations in bacterial community structure (Parvathi et al 2021 ) (Table 4 ).…”

“…The majority of the metagenome of Zuari, Mandovi, Chaliyar, Anjarakkandi and Cochin estuary comprises Proteobacteria. Consequently, the structure of communities and ecosystem functioning appears to be influenced by habitats and anthropogenic effects (Parvathi et al 2021 ; Khandeparker et al 2017 ) (Table 4 ). The studies from Indian estuarine systems corroborated with recent studies on distinct bacterial communities in estuarine environments of Sydney Harbor estuary—Australia (Jeffries et al 2016 ), Changjiang estuary—China (Wu et al 2019 ), Pearl estuary, a subtropical estuary—China (Mai et al 2022 ), and Yaquina Bay estuary—USA (Kieft et al 2018 ).…”

Pyroptosis-Related Gene Markers Can Effectively Diagnose Endometriosis and Predict Prognosis

“…The"limma" package [22] was used to identify the differentially expressed genes (DEGs) between EM and normal tissues with the FDR-adjusted p value < 0.05 and | log2FC|> 2.5 [23]. The correlation of DEGs was analyzed and demonstrated by using the R package "corrplot"package [24]. The protein-protein interaction (PPI) network of DEGs was obtained from the Search Tool for the Retrieval of Interacting Genes (STRING, https://string-db.org/) database [25].…”