Microbial community structural characteristics and associated relationships with environmental factors in different ecological habitats

Abstract

Aquatic ecological habitats are widely distributed and essential for the development of microorganisms, yet little is known about the community structures of prokaryotes and eukaryotes of periphytic biofilms under different habitats. The microbial community thus among five distinct ecological habitats were investigated in winter from 14 periphytic biofilms samples using 16S rRNA and 18S rRNA genes sequencing, the relationships between microbial community and environmental factors were illustrated simultaneously. The results revealed that several dominant microorganisms within periphytic biofilms were Proteobacteria (42.56%), Bacteroidota (21.57%), Cyanobacteria (9.22%) and Verrucomicrobiota (9.18%) in prokaryotes, similar to the planktonic compositions. Whereas Bacillariophyta (29.64%), Chlorophyta (19.38%), Annelida (12.77%) and Ciliophora (9.17%) in eukaryotes were dominated. The prokaryotic biodiversity in natural periphyton was obviously higher than their corresponding water columns. Several specific genera such as Flavobacterium (20.67%), Luteolibacter (11.35%), Surirella, Gomphonema (9.44%) and Nais (7.81%) were enriched in the periphytic biofilms. Besides, the structural equation model indicated that TP, \({\text{N}\text{O}}_{3}^{-}-\text{N}\) and pH significantly affected the biomass. Further, pH, TP and TN significantly influenced microbial genera which mainly belonging to Proteobacteria and Chlorophyta phyla through network analysis and random forest analysis. Meanwhile, the network analysis potentially revealed higher stability and interconnection between prokaryotes and eukaryotes in periphytic biofilms. Microbial functional predictions types were not significantly differently distributed within varied habitats. These findings highlighted that microbial communities exhibited spatial ecological variations due to the joint influence of environmental variables. This study provided useful information for understanding the variations in prokaryotes and eukaryotes of periphytic biofilms among different ecological habitats.