Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Discussion papers
https://doi.org/10.5194/bg-2016-147
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-2016-147
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Submitted as: research article 03 May 2016

Submitted as: research article | 03 May 2016

Review status
This discussion paper is a preprint. It has been under review for the journal Biogeosciences (BG). The revised manuscript was not accepted.

Distinctly different bacterial communities in surface and oxygen minimum layers in the Arabian Sea

Mandar Bandekar1, Nagappa Ramaiah1, Anand Jain1,2, and Ram Murti Meena1 Mandar Bandekar et al.
  • 1Microbial Ecology Laboratory, Biological Oceanography Division, CSIR - National Institute of Oceanography, Dona P aula, Goa, 403004
  • 2Present address: Arctic group, National Center for Antarctic and Ocean Research, Sada Headland, Vasco - da - Gama, Goa , 403804

Abstract. Contributions of microbial communities to biogeochemical processes in oxygen minimum oceanic zones are being realized through the applications of molecular techniques. To understand seasonal and depth-wise variations in bacterial community structure (BCS) in the Arabian Sea oxygen minimum region, extensive sampling and molecular analyses were carried out. 16S rRNA gene sequencing was done to profile the BCS from five depths, surface (5 m), deep chorophyll maximum (43–50 m, DCM), 250 m, 500 m and 1000 m during Spring intermonsoon (SIM), Fall intermonsoon (FIM), and Northeast monsoon (NEM) seasons. Sequencing of 743 chimera-free clones revealed a clear vertical partitioning of BCS between the surface (surface + DCM) and OMZ (250 + 500 + 1000 m) layers. There was no distinct seasonal difference in the BCS. Most 16S rRNA gene sequences were affiliated to Gammaproteobacteria (39.31 %), Alphaproteobacteria (23.56 %) and Cyanobacteria (20.2 %). Higher diversity and OTUs in OMZ predominantly consisting of Alteromonodales, Sphinogomonadales, Rhodobacterales, Burkholderales, and Acidimicrobiales we observed might be due to their microaerophilic metabolism, ability to degrade recalcitrant substrates and assimilate sinking particulate matter. Further hitherto undescribed diversity both in surface and OMZ layers was evidenced. Implicit role of extant bacterial community in denitrification and anammox and in sulphur oxidation is highlighted.

Mandar Bandekar et al.
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Mandar Bandekar et al.
Mandar Bandekar et al.
Viewed  
Total article views: 500 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
337 126 37 500 2 25
  • HTML: 337
  • PDF: 126
  • XML: 37
  • Total: 500
  • BibTeX: 2
  • EndNote: 25
Views and downloads (calculated since 03 May 2016)
Cumulative views and downloads (calculated since 03 May 2016)
Cited  
Saved  
No saved metrics found.
Discussed  
Latest update: 21 Sep 2019
Publications Copernicus
Download
Short summary
Oxygen minimum zones occur mostly in nutrient rich upwelling regions. They are sprawling intensifying due to anthropogenic impacts. In denitrification depths of 200–1000 m in Arabian Sea (AS) DO is < 20 M making it the largest anoxic region. We aimed to delineate phylogenetic diversity of bacterial community and find it to be diverse yet distinctively different communities predominate surface and OMZ layers. Prokaryote types adapted to low DO likely play vital roles in C, N & S cycling in AS OMZ.
Oxygen minimum zones occur mostly in nutrient rich upwelling regions. They are sprawling...
Citation