Sediment microbial taxonomic and functional diversity in a natural salinity gradient challenge Remane’s “species minimum” concept

PeerJ

article

Christina Pavloudi¹  Jon B. Kristoffersen¹  Anastasis Oulas¹  Marleen De Troch²  Christos Arvanitidis¹ 

[1] Institute of Marine Biology, Biotechnology and Aquaculture ,(IMBBC), Hellenic Centre for Marine Research;Marine Biology Research Group, Department of Biology, Faculty of Sciences, Ghent University;Microbial Ecophysiology Group, Faculty of Biology/Chemistry and MARUM, University of Bremen;Bioinformatics Group, The Cyprus Institute of Neurology and Genetics

关键词: Amvrakikos Gulf;    Salinity gradient;    Illumina sequencing;    Prokaryotes;    Sediment;    16S rRNA;   

DOI  :  10.7717/peerj.3687

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Several models have been developed for the description of diversity in estuaries and other brackish habitats, with the most recognized being Remane’s Artenminimum (“species minimum”) concept. It was developed for the Baltic Sea, one of the world’s largest semi-enclosed brackish water body with a unique permanent salinity gradient, and it argues that taxonomic diversity of macrobenthic organisms is lowest within the horohalinicum (5 to 8 psu). The aim of the present study was to investigate the relationship between salinity and sediment microbial diversity at a freshwater-marine transect in Amvrakikos Gulf (Ionian Sea, Western Greece) and assess whether species composition and community function follow a generalized concept such as Remane’s. DNA was extracted from sediment samples from six stations along the aforementioned transect and sequenced for the 16S rRNA gene using high-throughput sequencing. The metabolic functions of the OTUs were predicted and the most abundant metabolic pathways were extracted. Key abiotic variables, i.e., salinity, temperature, chlorophyll-a and oxygen concentration etc., were measured and their relation with diversity and functional patterns was explored. Microbial communities were found to differ in the three habitats examined (river, lagoon and sea) with certain taxonomic groups being more abundant in the freshwater and less in the marine environment, and vice versa. Salinity was the environmental factor with the highest correlation to the microbial community pattern, while oxygen concentration was highly correlated to the metabolic functional pattern. The total number of OTUs showed a negative relationship with increasing salinity, thus the sediment microbial OTUs in this study area do not follow Remane’s concept.

【 授权许可】

CC BY