Phylogeny and structural insights of lipase from Halopseudomonas maritima sp. nov., isolated from sea sand.

A Gram-negative, aerobic bacterial strain RR6T was isolated from the sea sand to produce lipase and proposed as a novel species of Halopseudomonas. The optimum growth occurred at 28-37 °C, and the pH was 6.0-8.0. The optimum growth occurred at 3.0 -6.5% (w/v) NaCl. The major cellular fatty acids were C10:0 3OH, C12:0, C16:1 ω7c/16:1 ω6c, 18:1 ω7c and/or 18:1 ω6c, and C16:0. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid, and unidentified lipids. The genome is 3.93 Mb, and the G + C content is 61.3%. The 16S rRNA gene sequences shared 99.73-99.87% sequence similarity with the closely related type strains of Halopseudomonas. The average nucleotide identity and average amino acid identity of strain RR6T with reference type strains were below 95-96%, and the corresponding in-silico DNA-DNA hybridization values were below 70%. Strain RR6T clustered with Halopseudomonas gallaeciensis V113T and Halopseudomonas pachastrellae CCUG 46540 T in the phylogenetic tree. Further, lipase produced by this bacterium belongs to α/ß hydrolase lipase family and exhibits structural similarity to the lactonizing lipase. Based on the polyphasic analysis, the new isolates RR6T represent a novel species of Halopseudomonas for which Halopseudomonas maritima sp. nov. is proposed. The type strain is RR6T (= NBRC 115418 T = TBRC 15628 T).

Pseudomonas phenolilytica sp. nov., a novel phenol-degrading bacterium.

This study describes a bacterium strain RBPA9 isolated from a municipality waste dumping area capable of degrading phenol, proposed as a novel species of Pseudomonas. Cells are Gram-negative, rod shaped, aerobic and motile. The genome is 3.92 Mb, and the G + C content is 64.64%. The overall genome relatedness indices such as in silico DNA-DNA hybridization (isDDH), average nucleotide identity (ANI), and average amino acid identity (AAI) values were below 70% and 95-96%, respectively. Phylogenetic analysis based on genome-wide core genes and 16S rRNA gene sequences revealed that strain RBPA9 clustered with Pseudomonas stutzeri ATCC 17588 T in both the phylogenetic trees. Maximum growth was recorded at 200 mg /L concentration of phenol which was consumed within 24 h. A gene cluster of phenol degradation pathway was detected. The quantitative real-time PCR (RT-PCR) demonstrated the expression of all the genes required in the meta-cleavage pathway of phenol in RBPA9. Our results reveal that strain RBPA9 represents a novel species for which Pseudomonas phenolilytica sp. nov. is proposed. The type strain is RBPA9T (= TBRC 15231 T = NBRC 115284 T).

Genome analysis of Pseudomonas species reveals that Pseudomonas panacis Park et al. 2005 is a later heterotypic synonym of Pseudomonas marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980).

We described the comparative genomic analysis of Pseudomonas panacis DSM 18529T and Pseudomonas marginalis DSM 13124T of the genus Pseudomonas to define the taxonomic assignment. When conducting this analysis, genomic information for 203 type strains was available in the NCBI genome database. The ANI, AAI and isDDH data were higher than the threshold values between Pseudomonas panacis DSM 18529T and Pseudomonas marginalis DSM 13124T. Whole-genome comparisons show 97 % average nucleotide identity, 98 % average amino acid identity and 75 % in silico DNA-DNA hybridization values. Pseudomonas marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980) have priority over the name Pseudomonas panacis Park et al. 2005, therefore nomenclatural authorities propose that Pseudomonas panacis Park et al. 2005 is a later heterotypic synonym of Pseudomonas marginalis (Brown 1918) Stevens 1925 (Approved Lists 1980). The type strain is ATCC 10844T (=DSM 13124T=NCPPB 667T).

Genome analysis deciphered Chryseobacterium indicum is a distinct species associated with freshwater pufferfish.

A bacterium, strain PS-8T of the genus Chryseobacterium, was isolated from the skin of freshwater pufferfish (Tetraodon cutcutia). Strain PS-8T is a Gram-negative, aerobic, non-motile, and rod-shaped bacterium. Colonies appear in yellowish-orange colors. The major cellular fatty acids were C15:0 iso, C17:0 iso 3OH, C15:0 iso 3OH, and C11:0 anteiso. The predominant polar lipids were phosphatidylethanolamine and amino lipids. The genome size is 4.83 Mb. The G + C content was 35.6%. The in silico dDDH homology, ANI, and AAI were below the cutoff value, 70% and 95% to 96%, respectively, suggesting that strain PS-8T represents a defined species. The phylogenetic tree based on core and the non-recombinant genes showed the strain PS-8T clustered with Chryseobacterium gambrini DSM 18014T. Genome-wide analysis decodes several virulence factors of the genus Chryseobacterium, including genes for adherence, biofilm and stability, proliferation, resistance to immune response, and host-defense evasion system. The cladogram of the virulence genes showed a phylogenetic relationship among the Chryseobacterium species. Knowledge of the association of Chryseobacterium with freshwater pufferfish adds a new ecological niche to this bacterium.

Phylogeny and genomic analysis of Shewanella cutis sp. nov., isolated from freshwater pufferfish.

Three closely related, aerobic, Gram-stain-negative, motile, rod-shaped bacterial strains (PS-2T, PS-17, and PS-19) were isolated from the skin of freshwater pufferfish (Tetraodon cutcutia). Colonies are pinkish-colored. The optimum growth occurred at 28-30 °C, and the pH was 6.5-7. The major cellular fatty acids were C16:1 ω7c, iso-C15.0, C17:1 ω8c, C18:1 ω7c, and C16:0. The predominant polar lipids were phosphatidylglycerol, phosphatidylethanolamine, and amino lipids. The genome size of strain PS-2T is 4.8 Mbp, and the G + C content was 46.0%. The major fraction of genes were associated with biological processes (45.64%), followed by molecular function (29.86%) and cellular components (24.49%). The unique genes identified in strain PS-2T secreted cyanophycinase, UDP-N-acetylglucosamine 2-epimerase, methyltransferase, kynureninase, ADA regulatory protein, biphenyl degradation, thermostable carboxypeptidase 1, tetrathionate respiration, etc. In addition, alanine and glutamate racemases were present. The 16S rRNA gene sequences shared 98.83-99.24% similarity with the closely related type strains of Shewanella. The ANI and AAI of strain PS-2T with reference type strains of the genus Shewanella were below 95-96%, and the corresponding dDDH values were below 70%. A phylogenetic tree based on 16S rRNA gene sequences and genome-wide core genes revealed that strain PS-2T clustered with Shewanella oneidensis LMG 19005T in both phylogenetic trees. Based on the polyphasic analysis, the new isolates (PS-2T, PS-17, and PS-19) represent a novel species of Shewanella, for which Shewanella cutis sp. nov. is proposed. The type strain is PS-2T (= TBRC 15838T = NBRC 115342T).