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Leucine, starch and bicarbonate utilization by specific bacterial groups in surface shelf waters off G alicia ( NW S pain)
Author(s) -
Teira E.,
HernandoMorales V.,
GuerreroFeijóo E.,
Varela M. M.
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13748
Subject(s) - biology , gammaproteobacteria , starch , bacteroidetes , bacteria , alphaproteobacteria , food science , roseobacter , biochemistry , axenic , polysaccharide , microbiology and biotechnology , 16s ribosomal rna , gene , clade , genetics , phylogenetic tree
Summary The capability of different bacterial populations to degrade abundant polymers, such as algal‐derived polysaccharides, or to utilize preferentially polymers over monomers, remains largely unknown. In this study, microautoradiography was combined with fluorescence in situ hybridization (MAR‐FISH) to evaluate the ability of Bacteroidetes, SAR11, Roseobacter spp., Gammaproteobacteria and SAR86 cells to use bicarbonate, leucine and starch under natural light conditions at two locations in shelf surface waters off NW Spain. The percentage of cells incorporating bicarbonate was relatively high (mean 32% ± 4%) and was positively correlated with the intensity of solar radiation. The proportion of cells using starch (mean 56% ± 4%) or leucine (mean 47% ± 4%) was significantly higher than that using bicarbonate. On average, SAR11, Roseobacter spp. and Gammaproteobacteria showed a similarly high percentage of cells using leucine (47%–65% of hybridized cells) than using starch (51%–64% of hybridized cells), while Bacteroidetes and SAR86 cells preferentially used starch (53% of hybridized cells) over leucine (34%–40% of hybridized cells). We suggest that the great percentage of bacteria using starch is related to a high ambient availability of polymers associated to algal cell lysis, which, in turn, weakens the short‐term coupling between phytoplankton release and bacterial production.