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. 2021 Sep;28(36):50579-50592.
doi: 10.1007/s11356-021-14263-0. Epub 2021 May 8.

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

Ammini Parvathi  1 , Michela Catena  2 , Vijayan Jasna  2   3 , Nikhil Phadke  4 , Nikhita Gogate  4
Affiliations

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

Ammini Parvathi et al. Environ Sci Pollut Res Int. 2021 Sep.

Abstract

In the present study, we analyzed 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 next-generation 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 influencing the bacterial diversity. Proteobacteria was the most dominant phyla in the estuary followed by Bacteroidetes, Cyanobacteria, Actinobacteria, and Firmicutes. Statistical analysis indicated significant variations in bacterial communities between freshwater and mesohaline and euryhaline regions, as well as between the monsoon (wet) and nonmonsoon (dry) periods. The abundance of Betaproteobacteria was higher in the freshwater regions, while Alphaproteobacteria and Epsilonproteobactera were more abundant in mesohaline and euryhaline regions of the estuary. Gammaproteobacteria was more abundant in regions with high nutrient concentrations. Various bacterial genera indicating the presence of fecal contamination and eutrophication were detected. Corrplot based on Pearson correlation analysis demonstrated the important physico-chemical variables (temperature, salinity, dissolved oxygen, and inorganic nutrients) that influence the distribution of dominant phyla, class, and genera. The observed spatio-temporal variations in bacterial community structure in the CE were governed by regional variations in anthropogenic inputs and seasonal variations in monsoonal rainfall and tidal influx.

Keywords: Bacterial diversity; Cochin estuary; Estuaries; Monsoonal estuaries; Next-generation sequencing (NGS); Proteobacteria.

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References

    1. Acinas SG, Klepac-Ceraj V, Hunt DE, Pharino C, Ceraj I, Distel DL, Polz MF (2004) Fine-scale phylogenetic architecture of a complex bacterial community. Nature 430:551–554. https://doi.org/10.1038/nature02649 - DOI
    1. Bernhard AE, Donn T, Giblin AE, Stahl DA (2005) Loss of diversity of ammonia-oxidizing bacteria correlates with increasing salinity in an estuary system. Environ Microbiol 7:1289–1297. https://doi.org/10.1111/j.1462-2920.2005.00808.x - DOI
    1. Bhavya PS, Kumar S, Gupta GVM, Sudheesh V, Sudharma KV, Varrier DS, Dhanya KR, Saravanane N (2016) Nitrogen uptake dynamics in a tropical eutrophic estuary (Cochin, India) and adjacent coastal waters. Estuar Coasts 39(1):54–67. https://doi.org/10.1007/s12237-015-9982-y - DOI
    1. Bobrova O, Kristoffersen JB, Oulas A, Ivanytsia V (2016) Metagenomic 16s rRNA investigation of microbial communities in the Black Sea estuaries in south-west of Ukraine. Acta Biochim Pol 63(2):315–319. https://doi.org/10.18388/abp.2015_1145 - DOI
    1. Boehm AB, Sassoubre LM. (2014). Enterococci as indicators of environmental fecal contamination. Enterococci: from commensals to leading causes of drug resistant infection [Internet].

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