Title |
Uncultured bacterial diversity in a seawater recirculating aquaculture system revealed by 16S rRNA gene amplicon sequencing |
Author |
Da-Eun Lee1, Jinhwan Lee2, Young-Mog Kim3, Jeong-In Myeong2, and Kyoung-Ho Kim1 |
Address |
1Department of Microbiology, Pukyong National University, Busan 48513, Republic of Korea, 2Aquaculture Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea, 3Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea |
Bibliography |
Journal of Microbiology, 54(4),296-304, 2016,
|
DOI |
10.1007/s12275-016-5571-4
|
Key Words |
bacterial diversity, recirculating aquaculture system, biofilter, amplicon sequencing, 16S rRNA gene |
Abstract |
Bacterial diversity in a seawater recirculating aquaculture
system (RAS) was investigated using 16S rRNA amplicon
sequencing to understand the roles of bacterial communities
in the system. The RAS was operated at nine different combinations
of temperature (15°C, 20°C, and 25°C) and salinity
(20‰, 25‰, and 32.5‰). Samples were collected from five
or six RAS tanks (biofilters) for each condition. Fifty samples
were analyzed. Proteobacteria and Bacteroidetes were most
common (sum of both phyla: 67.2% to 99.4%) and were inversely
proportional to each other. Bacteria that were present
at an average of ≥ 1% included Actinobacteria (2.9%) Planctomycetes
(2.0%), Nitrospirae (1.5%), and Acidobacteria (1.0%);
they were preferentially present in packed bed biofilters, mesh
biofilters, and maturation biofilters. The three biofilters showed
higher diversity than other RAS tanks (aerated biofilters, floating
bed biofilters, and fish tanks) from phylum to operational
taxonomic unit (OTU) level. Samples were clustered
into several groups based on the bacterial communities. Major
taxonomic groups related to family Rhodobacteraceae and
Flavobacteriaceae were distributed widely in the samples. Several
taxonomic groups like [Saprospiraceae], Cytophagaceae,
Octadecabacter, and Marivita showed a cluster-oriented distribution.
Phaeobacter and Sediminicola-related reads were
detected frequently and abundantly at low temperature. Nitrifying
bacteria were detected frequently and abundantly in
the three biofilters. Phylogenetic analysis of the nitrifying bacteria
showed several similar OTUs were observed widely
through the biofilters. The diverse bacterial communities and
the minor taxonomic groups, except for Proteobacteria and
Bacteroidetes, seemed to play important roles and seemed
necessary for nitrifying activity in the RAS, especially in packed
bed biofilters, mesh biofilters, and maturation biofilters. |