title: Diversity of ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes in the MgCl2-dominated deep hypersaline anoxic basin discovery.
abstract: Partial sequences of the form I (cbbL) and form II (cbbM) of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit genes were obtained from the brine and interface of the MgCl2-dominated deep hypersaline anoxic basin Discovery. CbbL and cbbM genes were found in both brine and interface of the Discovery Basin but were absent in the overlying seawater. The diversity of both genes in the brine and interface was low, which might caused by the extreme saline conditions in Discovery of approximately 5 M MgCl2. None of the retrieved sequences were closely related to sequences deposited in the GenBank database. A phylogenetic analysis demonstrated that the cbbL sequences were affiliated with a Thiobacillus sp. or with one of the RuBisCO genes from Hydrogenovibrio marinus. The cbbM sequences clustered with thiobacilli or formed a new group with no close relatives. The results implicate that bacteria with the potential for carbon dioxide fixation and chemoautotrophy are present in the Discovery Basin. This is the first report demonstrating that RuBisCO genes are present under hypersaline conditions of 5 M MgCl2.
authors.affiliation: Laboratory of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands. paul.van.der.wielen@kiwa.nl
authors.forename: Paul W J J
authors.initials: PW
authors.lastname: van der Wielen
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005798:Genes, Bacterial; D014644:Genetic Variation; D015636:Magnesium Chloride; D008522:Mediterranean Sea; D010802:Phylogeny; D044147:Piscirickettsiaceae / Q000201:enzymology / Q000235:genetics; D021122:Protein Subunits; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000235:genetics*; D012623:Seawater / Q000382:microbiology; D012965:Sodium Chloride; D013855:Thiobacillus / Q000201:enzymology / Q000235:genetics; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D021122:Protein Subunits; D015636:Magnesium Chloride; D012965:Sodium Chloride; D012273:Ribulose-Bisphosphate Carboxylase