Effect of salinity on denitrification under limited single carbon source by Marinobacter sp. isolated from marine sediment.
Marinobacter comprises Gram-negative, aerobic, motile, and rod-shaped bacteria within the gamma-subclass of the Proteobacteria and is known to be halophilic or halotolerant, heterotrophic neutrophile. Two strains classified as belonging to Marinobacter, named PAD-2 and SeT-1, were isolated from marine sediment. The most closely related species of PAD-2 and SeT-1 are M. alkaliphilus and M. guinea, respectively. The strain PAD-2 exhibited remarkably higher denitrification at concentrations of 0.5 to 1 M NaCl (3-6% w/w) than at other salinities (2 and 3 M NaCl, 12-18% w/w), and optimal denitrification was observed in media with 0.5 M NaCl. The effect of pH on denitrification by strain PAD-2 was also examined, and the optimum denitrification occurred at neutral pH rather than under alkaline conditions. Overall, strain PAD-2 appears to be a novel halotolerant species belonging to the genus Marinobacter that shares many characteristics, such as substrate utilization profile and optimum NaCl concentration for growth with M. alkaliphilus.
Marine Microbiology, Faculty of Bioresources, Mie University, Kurimamachiya-cho, Tsu, Mie, Japan.
Miyo
M
Nakano
Tadashi
T
Inagaki
Suguru
S
Okunishi
Reiji
R
Tanaka
Hiroto
H
Maeda
D002244:Carbon / Q000378:metabolism*; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D053520:Marinobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D017422:Sequence Analysis, DNA
D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D009566:Nitrates; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D002244:Carbon; D009584:Nitrogen