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Phenotypic and Genomic Properties of Chitinispirillum alkaliphilum gen. nov., sp. nov., A Haloalkaliphilic Anaerobic Chitinolytic Bacterium Representing a Novel Class in the Phylum Fibrobacteres.

Sorokin DY, Rakitin AL, Gumerov VM, Beletsky AV, Sinninghe Damsté JS, Mardanov AV, Ravin NV - Front Microbiol (2016)

Bottom Line: The chitinolytic activity was associated with cells.Analysis of the 4.4 Mb draft genome identified pathways for chitin utilization, particularly, secreted chitinases linked to the cell surface, as well as genes for the hydrolysis of other polysaccharides and fermentation of sugars, while the genes needed for aerobic and anaerobic respiration were absent.The phylogenetic analysis using 16S rRNA gene and ribosomal proteins indicated that ACht6-1 forms a novel deep lineage at the class level within the bacterial candidate division TG3.

View Article: PubMed Central - PubMed

Affiliation: Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of SciencesMoscow, Russia; Department of Biotechnology, Delft University of TechnologyDelft, Netherlands.

ABSTRACT
Anaerobic enrichment from sediments of hypersaline alkaline lakes in Wadi el Natrun (Egypt) with chitin resulted in the isolation of a fermentative haloalkaliphilic bacterium, strain ACht6-1, growing exclusively with insoluble chitin as the substrate in a sodium carbonate-based medium at pH 8.5-10.5 and total Na(+) concentrations from 0.4 to 1.75 M. The isolate had a Gram-negative cell wall and formed lipid cysts in old cultures. The chitinolytic activity was associated with cells. Analysis of the 4.4 Mb draft genome identified pathways for chitin utilization, particularly, secreted chitinases linked to the cell surface, as well as genes for the hydrolysis of other polysaccharides and fermentation of sugars, while the genes needed for aerobic and anaerobic respiration were absent. Adaptation to a haloalkaliphilic lifestyle was reflected by the gene repertoire encoding sodium rather than proton-dependent membrane-bound ion pumps, including the Rnf-type complex, oxaloacetate decarboxylase, V-type ATPase, and pyrophosphatase. The phylogenetic analysis using 16S rRNA gene and ribosomal proteins indicated that ACht6-1 forms a novel deep lineage at the class level within the bacterial candidate division TG3. Based on phylogenetic, phenotypic and genomic analyses, the novel chitinolytic bacterium is described as Chitinispirillum alkaliphilum gen. nov., sp. nov., within a novel class Chitinispirillia that could be included into the phylum Fibrobacteres.

No MeSH data available.


Related in: MedlinePlus

Hydrolytic activities of ACht6-1 crude cell extract towards different polysaccharides. The following substrates were tested: 1, chitin; 2, chitosan; 3, carboxymethyl cellulose; 4, microcrystalline cellulose; 5, starch; 6, beech-wood xylan; 7, birch-wood xylan.
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Figure 5: Hydrolytic activities of ACht6-1 crude cell extract towards different polysaccharides. The following substrates were tested: 1, chitin; 2, chitosan; 3, carboxymethyl cellulose; 4, microcrystalline cellulose; 5, starch; 6, beech-wood xylan; 7, birch-wood xylan.

Mentions: The capacities of ACht6-1 to degrade different polysaccharides were evaluated by assaying the digestion of cellulose, amorphous chitosan, starch, and xylan by ACht6-1 cell extracts. Carboxymethyl cellulose (test substrate for the β-1,4-endoglucanase activity) was most efficiently hydrolyzed, and lower activities were observed towards starch, microcrystalline cellulose and chitosan (Figure 5). Despite the fact that ACht6-1 failed to grow with all these polymers, the cells grown with chitin showed positive results for amylase and β-1,4-endoglucanase in agar-diffusion assay (see Figure S3 in the Supplemental Material). This assay also revealed proteolytic activity, although the organism was not able to grow on proteinaceous substrates.


Phenotypic and Genomic Properties of Chitinispirillum alkaliphilum gen. nov., sp. nov., A Haloalkaliphilic Anaerobic Chitinolytic Bacterium Representing a Novel Class in the Phylum Fibrobacteres.

Sorokin DY, Rakitin AL, Gumerov VM, Beletsky AV, Sinninghe Damsté JS, Mardanov AV, Ravin NV - Front Microbiol (2016)

Hydrolytic activities of ACht6-1 crude cell extract towards different polysaccharides. The following substrates were tested: 1, chitin; 2, chitosan; 3, carboxymethyl cellulose; 4, microcrystalline cellulose; 5, starch; 6, beech-wood xylan; 7, birch-wood xylan.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814513&req=5

Figure 5: Hydrolytic activities of ACht6-1 crude cell extract towards different polysaccharides. The following substrates were tested: 1, chitin; 2, chitosan; 3, carboxymethyl cellulose; 4, microcrystalline cellulose; 5, starch; 6, beech-wood xylan; 7, birch-wood xylan.
Mentions: The capacities of ACht6-1 to degrade different polysaccharides were evaluated by assaying the digestion of cellulose, amorphous chitosan, starch, and xylan by ACht6-1 cell extracts. Carboxymethyl cellulose (test substrate for the β-1,4-endoglucanase activity) was most efficiently hydrolyzed, and lower activities were observed towards starch, microcrystalline cellulose and chitosan (Figure 5). Despite the fact that ACht6-1 failed to grow with all these polymers, the cells grown with chitin showed positive results for amylase and β-1,4-endoglucanase in agar-diffusion assay (see Figure S3 in the Supplemental Material). This assay also revealed proteolytic activity, although the organism was not able to grow on proteinaceous substrates.

Bottom Line: The chitinolytic activity was associated with cells.Analysis of the 4.4 Mb draft genome identified pathways for chitin utilization, particularly, secreted chitinases linked to the cell surface, as well as genes for the hydrolysis of other polysaccharides and fermentation of sugars, while the genes needed for aerobic and anaerobic respiration were absent.The phylogenetic analysis using 16S rRNA gene and ribosomal proteins indicated that ACht6-1 forms a novel deep lineage at the class level within the bacterial candidate division TG3.

View Article: PubMed Central - PubMed

Affiliation: Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of SciencesMoscow, Russia; Department of Biotechnology, Delft University of TechnologyDelft, Netherlands.

ABSTRACT
Anaerobic enrichment from sediments of hypersaline alkaline lakes in Wadi el Natrun (Egypt) with chitin resulted in the isolation of a fermentative haloalkaliphilic bacterium, strain ACht6-1, growing exclusively with insoluble chitin as the substrate in a sodium carbonate-based medium at pH 8.5-10.5 and total Na(+) concentrations from 0.4 to 1.75 M. The isolate had a Gram-negative cell wall and formed lipid cysts in old cultures. The chitinolytic activity was associated with cells. Analysis of the 4.4 Mb draft genome identified pathways for chitin utilization, particularly, secreted chitinases linked to the cell surface, as well as genes for the hydrolysis of other polysaccharides and fermentation of sugars, while the genes needed for aerobic and anaerobic respiration were absent. Adaptation to a haloalkaliphilic lifestyle was reflected by the gene repertoire encoding sodium rather than proton-dependent membrane-bound ion pumps, including the Rnf-type complex, oxaloacetate decarboxylase, V-type ATPase, and pyrophosphatase. The phylogenetic analysis using 16S rRNA gene and ribosomal proteins indicated that ACht6-1 forms a novel deep lineage at the class level within the bacterial candidate division TG3. Based on phylogenetic, phenotypic and genomic analyses, the novel chitinolytic bacterium is described as Chitinispirillum alkaliphilum gen. nov., sp. nov., within a novel class Chitinispirillia that could be included into the phylum Fibrobacteres.

No MeSH data available.


Related in: MedlinePlus