Effects of three different PAHs on nitrogen-fixing bacterial diversity in mangrove sediment

ABSTRACTAlthough mangroves represent ecosystems of global importance, the genetic diversity and abundance of functional genes that are key to their functioning scarcely have been explored. Here, we present a survey based on thenifHgene across transects of sediments of two mangrove systems located along the coast line of São Paulo state (Brazil) which differed by degree of disturbance, i.e., an oil-spill-affected and an unaffected mangrove. The diazotrophic communities were assessed by denaturing gradient gel electrophoresis (DGGE), quantitative PCR (qPCR), and clone libraries. ThenifHgene abundance was similar across the two mangrove sediment systems, as evidenced by qPCR. However, thenifH-based PCR-DGGE profiles revealed clear differences between the mangroves. Moreover, shifts in thenifHgene diversities were noted along the land-sea transect within the previously oiled mangrove. ThenifHgene diversity depicted the presence of nitrogen-fixing bacteria affiliated with a wide range of taxa, encompassing members of theAlphaproteobacteria,Betaproteobacteria,Gammaproteobacteria,Firmicutes, and also a group of anaerobic sulfate-reducing bacteria. We also detected a unique mangrove-specific cluster of sequences denoted Mgv-nifH. Our results indicate that nitrogen-fixing bacterial guilds can be partially endemic to mangroves, and these communities are modulated by oil contamination, which has important implications for conservation strategies.

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The bacterial diversity in a Brazilian non-disturbed mangrove sediment

Antonie van Leeuwenhoek ◽

10.1007/s10482-010-9471-z ◽

2010 ◽

Vol 98 (4) ◽

pp. 541-551 ◽

Cited By ~ 43

Author(s):

Armando C. F. Dias ◽

Fernando D. Andreote ◽

Janaina Rigonato ◽

Marli Fátima Fiore ◽

Itamar S. Melo ◽

...

Keyword(s):

Bacterial Diversity ◽

Mangrove Sediment

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Mangrovibacterium diazotrophicum gen. nov., sp. nov., a nitrogen-fixing bacterium isolated from a mangrove sediment, and proposal of Prolixibacteraceae fam. nov.

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.052779-0 ◽

2014 ◽

Vol 64 (Pt_3) ◽

pp. 875-881 ◽

Cited By ~ 34

Author(s):

Xiao-Fang Huang ◽

Yu Juan Liu ◽

Jun-De Dong ◽

Ling-Yun Qu ◽

Yan-Ying Zhang ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Gene Signature ◽

Mangrove Sediment ◽

Rrna Gene ◽

Nitrogen Fixing ◽

Uncultured Bacterium ◽

Content Type ◽

Link Type ◽

Close Relationship

A nitrogen-fixing bacterium, designated strain SCSIO N0430T, was isolated from a mangrove sediment sample. Analysis of the sequence of the nifH gene responsible for nitrogen fixation in this strain indicated a close relationship to an uncultured bacterium ZNZ-D11 (GenBank accession no. JF896696). 16S rRNA gene sequence analysis revealed that this isolate had less than 93 % similarity to its closest relative, Sunxiuqinia elliptica DQHS4T. A phylogenetic tree reconstructed based on 16S rRNA gene sequences revealed that strain SCSIO N0430T was a member of the phylum Bacteroidetes . Chemotaxonomic and physiological characteristics, including phospholipids and major fatty acids, readily distinguished the isolate from established members of the phylum Bacteroidetes . It is concluded that strain SCSIO N0430T represents a novel genus and species, for which the name Mangrovibacterium diazotrophicum gen. nov., sp. nov. is proposed, with the type strain of the species SCSIO N0430T ( = KCTC 32129T = DSM 27148T = JCM 19152T). Based on phylogenetic characteristics and 16S rRNA gene signature nucleotide patterns, the three genera Sunxiuqinia , Prolixibacter and Mangrovibacterium are proposed to make up a novel family, Prolixibacteraceae fam. nov., in the order Bacteroidales .

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