Primary production in a subtropical stratified coastal lagoon--contribution of anoxygenic phototrophic bacteria.
Anaerobic anoxygenic phototrophic bacteria can be found in the suboxic waters of shallow stratified coastal systems, and may play important roles in the total primary production of subtropical stratified coastal lagoons. We investigated the spatiotemporal variability of light CO(2) fixation and net oxygen production in the stratified Conceição Lagoon (Brazil) in summer and fall of 2007, as well as the contribution of bacteriochlorophyll a (BChl a)-containing bacteria to photosynthetically driven electron transfer. Both chlorophyll a (Chl a) and BChl a varied in space, while only BChl a varied in time (three-fold increase from summer to fall). In summer, net oxygen production and light CO(2) fixation were correlated, with both having higher rates with higher Chl a concentrations in the enclosed region of the lagoon. In fall, CO(2) fixation was decoupled from oxygen production. Denaturing gradient gel electrophoresis revealed that bacterial communities of oxic site 12 and suboxic site 33 formed one cluster, different from other oxic samples within the lagoon. In addition, BChl a/Chl a ratios at these sites were high, 40% and 45%, respectively. Light acted as the main factor controlling the BChl a concentration and CO(2) fixation rates. High turbidity within the enclosed area of the lagoon explained high BChl a and decoupling between CO(2) fixation and oxygen production in oxygenated waters. Contribution of purple sulfur bacteria to total bacterial density in suboxic waters was 1.2%, and their biomass contributed to a much higher percentage (12.2%) due to their large biovolume. Our results indicate a significant contribution of anaerobic anoxygenic bacteria to the primary production of the "dead zone" of Conceição Lagoon.
Fontes
Maria Luiza S
ML
Institute of Oceanography, Federal University of Rio Grande, Av. Itália km 8, Campus Carreiros, Rio Grande, Rio Grande do Sul, Brazil. fontesml@ccb.ufsc.br
Suzuki
Marcelino T
MT
Cottrell
Matthew T
MT
Abreu
Paulo C
PC
D001419:Bacteria / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D058491:Bacterial Load; D025541:Bacteriochlorophyll A / Q000032:analysis; D018533:Biomass; D001938:Brazil; D002734:Chlorophyll / Q000032:analysis; D016000:Cluster Analysis; D017753:Ecosystem; D010100:Oxygen / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology*; D010933:Plankton / Q000378:metabolism; D025341:Principal Component Analysis; D012621:Seasons; D012623:Seawater / Q000737:chemistry; D014871:Water Microbiology
D025541:Bacteriochlorophyll A; D002734:Chlorophyll; D010100:Oxygen
Nature. 2000 Sep 14;407(6801):177-9
11001053
Science. 2009 Apr 17;324(5925):347-8
19372421
Microbiol Mol Biol Rev. 1998 Sep;62(3):695-724
9729607
Trends Genet. 1993 Feb;9(2):56-60
8456503
Proc Natl Acad Sci U S A. 2008 Oct 7;105(40):15452-7
18824689
Appl Environ Microbiol. 2007 Nov;73(21):6802-10
17766441
Appl Environ Microbiol. 2007 Jun;73(12):3936-44
17468276
FEMS Microbiol Ecol. 2005 Feb 1;51(3):353-61
16329883
Appl Environ Microbiol. 2008 Jul;74(13):4012-21
18469118
Appl Environ Microbiol. 1977 May;33(5):1225-8
327932
Appl Environ Microbiol. 1989 Jan;55(1):78-85
16347839
Environ Microbiol. 2007 Oct;9(10):2401-6
17803766
C R Biol. 2008 Sep;331(9):668-77
18722986
Biochim Biophys Acta. 2005 Feb 17;1706(3):220-31
15694350
Science. 2001 Jun 29;292(5526):2492-5
11431568
Oecologia. 2001 Nov;129(3):395-406
28547195
Appl Environ Microbiol. 1993 Mar;59(3):695-700
7683183
J Environ Qual. 2001 Mar-Apr;30(2):275-81
11285887
Microb Ecol. 2009 Jul;58(1):140-52
18953593
Microb Ecol. 2005 Aug;50(2):230-41
16184336
Appl Environ Microbiol. 2006 Jan;72(1):557-64
16391092
Science. 2008 Aug 15;321(5891):926-9
18703733