Meta-analysis cum machine learning approaches address the structure and
biogeochemical potential of marine copepods associated bacteriobiome
Abstract
Copepods are dominant members of the zooplankton and the most abundant
forms of life. Studying the bacterial diversity associated with copepods
will helps in understanding the impact of global climate change on these
organisms. It is important to address the core microbiome of copepods
which has a key role in their host health and ocean biogeochemical
cycle. Early studies have identified few bacterial phyla and orders as
core microbiome. So to predict the important Operational taxonomic units
(OTUs), we used meta-analysis, and machine learning (RandomForest
Classifier) approaches. Also, we explore the biogeochemical potential of
copepods associated bacteriobiome (CAB). Overall, 50 important s-OTUs
were predicted by machine learning; among them, 38 s-OTUs were specific
to Calanus spp. and 17 s-OTUs were specific to Acartia spp. Six
bacterial genera were identified as important core sub-OTUs in copepods
for the first time, i.e. Micrococcus luteus, Krokinobacter eikastus,
Vibrio shilonii, Acinetobacter johnsonii Burkholderia and Sphingobium.
From the PICRUST2 analysis, the potential genes responsible for
methanogenesis (aerobic and anaerobic), methanotrophy and iron
fertilization were high in the CAB of Pleuromamma spp.. The potential
nitrogen-fixing genes were relatively high in the CAB of Pleuromamma
spp.. Whereas the potential genes for denitrification were relatively
high in the CAB of Temora spp., and the potential Dissimilatory Nitrate
Reduction (DRNA) genes were relatively high in Acartia spp.. All the CAB
of the copepod genera investigated in the present study has potential
genes for cobalamin synthesis.