Psychrobacter raelei sp. nov., isolated from a dog with peritonitis.

A strain belonging to the genus Psychrobacter, named PraFG1T, was isolated from the peritoneal effusion of a stray dog during necropsy procedures. The strain was characterized by the phylogenetic analyses based on the nucleotide sequences of 16S and 23S rRNA genes and of gyrB, which placed the strain in the genus Psychrobacter. The nucleotide sequence of the chromosome confirmed the placement, showing an average nucleotide identity of 72.1, 77.7, and 77.5 % with the closest related species, namely Psychrobacter sanguinis, Psychrobacter piechaudii, and Psychrobacter phenylpyruvicus, respectively, thus indicating a novel species. The polyphasic characterization by biochemical and fatty acid profiling as well as MALDI-TOF supported those findings. The strain was halotolerant, capable of growing within a temperature range between 4 and 37 °C, it was positive for catalase and oxidase, indole producing, nitrate reducing, and not able to use 5-keto-d-gluconic acid as a carbon source. Taken together, the data suggest that strain PraFG1T could be considered as representing a novel species, with the name Psychrobacter raelei sp. nov. (type strain PraFG1T=CIP 111873T=LMG 32233T).

Psychrobacter halodurans sp. nov. and Psychrobacter coccoides sp. nov., two new slightly halophilic bacteria isolated from marine sediment.

In this study, two bacterial strains designated F2608T and F1192T, isolated from marine sediment sampled in Weihai, PR China, were characterized using a polyphasic approach. Strains were aerobic, Gram-stain-negative and motile. According to the results of phylogenetic analyses based on their 16S rRNA genes, these two strains should be classified under the genus Psychrobacter and they both show <98.5% sequence similarity to their closest relative, Psychrobacter celer JCM 12601T. Moreover, strain F2608T showed 97.5% sequence similarity to strain F1192T. Strain F2608T grew at 4-37 °C (optimum, 30-33 °C) and at pH 6.0-9.0 (optimum, pH 6.5-7.0) in the presence of 0-12% (w/v) NaCl (optimum, 4.0-5.0%). Strain F1192T grew at 4-37 °C (optimum, 30 °C) and at pH 5.5-9.0 (optimum, pH 7.0-7.5) in the presence of 0.5-12% (w/v) NaCl (optimum, 3.0-4.0%). The genomic DNA G+C contents of strain F2608T and strain F1192T were 47.4 and 44.9 %, respectively. Genomic characteristics including average nucleotide identity and digital DNA-DNA hybridization values clearly separated strain F2608T from strain F1192T. The sole isoprenoid quinone in these two strains was ubiquinone 8 and the major cellular fatty acids (>10.0%) were C18:1 ω9c and C17:1 ω8c. The major polar lipids of these two strains were phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Based on the results of polyphasic analysis, the two strains represent two novel species of the genus Psychrobacter, for which the names Psychrobacter halodurans sp. nov. and Psychrobacter coccoides sp. nov. are proposed. The type strains are F2608T (=MCCC 1K05774T=KCTC 82766T) and F1192T (=MCCC 1K05775T=KCTC 82765T), respectively.

Psychrobacter pocilloporae sp. nov., isolated from a coral, Pocillopora eydouxi.

Two closely related aerobic, Gram-stain-negative, rod-shaped bacteria (S6-60T and S6-67) were isolated from the mucus of the coral, Pocilloporaeydouxi, from the Andaman Sea, India. Heterotrophic growth on marine agar was observed at 4-37 °C and at pH 6.5-10.0; optimum growth occurred at 25-30 °C and at pH 7-9. 16S rRNA gene sequence analysis confirmed that the isolates belong to the genus Psychrobacter; the two isolates shared more than 99.5 % pairwise sequence similarity. Strain S6-60T showed a maximum 16S rRNA similarity of 98.92 % with Psychrobacter pacificensis DSM 23406T. DNA-DNA homology between the two isolates, S6-60T and S6-67, was above 90 %, whereas strain S6-60T showed less than 70 % homology with closely related type species. The DNA G+C content was 47.7 mol%. It contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phospholipid as the major polar lipids. C10 : 0, C12 : 0 3OH, C16 : 0, C18 : 1ω9c, C17 : 1ω8c and C16 : 1ω7c were found to be the predominant fatty acids. Based on a polyphasic analysis, the isolates (S6-60T and S6-67) represent a novel species of the genus Psychrobacter for which the name Psychrobacter pocilloporae sp. nov. is proposed with S6-60T(=JCM 31058T=LMG 29157T) as the type strain.

Psychrobacter fjordensis sp. nov., a psychrotolerant bacterium isolated from an Arctic fjord in Svalbard.

A Gram-negative, non-motile, non-spore-forming, psychrotolerant and halotolerant bacterium designated BSw21516B(T), was obtained from seawater in Kongsfjorden, a glacial fjord in the Arctic Svalbard and subjected to taxonomic analysis using a polyphasic approach. This bacterium was observed to optimally grow at 25-29 °C; between at 4 and 34 °C, but not at >35 °C; and in the presence of 0-8 % (w/v) NaCl at an optimum concentration of 2-5 % (w/v) NaCl. Strain BSw21516B(T) was found to contain Ubiquinone-8 (Q-8) as a predominant respiratory lipoquinone and C18:1 ω9c and summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) as predominant cellular fatty acids. Phylogenetic analysis of 16S rRNA and gyrB gene sequences showed that this isolate belongs to the genus Psychrobacter and is closely related to Psychrobacter fozii LMG 21280(T), which was isolated from a sediment sample in Antarctica. DNA hybridization experiments revealed a low level of DNA-DNA relatedness (less than 58.6 %) between strain BSw21516B(T) and its closest relatives. Based on these results a new species Psychrobacter fjordensis sp. nov. is proposed (type strain BSw21516B(T) = KCTC 42279(T) = CCTCC AB 2014020(T)).

Psychrobacillus soli sp. nov., capable of degrading oil, isolated from oil-contaminated soil.

A novel, aerobic, psychrotolerant, Gram-stain-positive, endospore-forming strain, NHI-2(T), was isolated from oil-contaminated soil near a gas station in Mongolia. This strain was characterized by motile rods and grew over a wide range of temperatures ( -2 to 40 °C) with optimal growth at 28-30 °C. It tolerated salt concentrations of up to 7% over a five-day incubation period. Analysis of 16S rRNA gene sequence indicated that strain NHI-2(T) belongs to the genus Psychrobacillus. Sequence similarity between NHI-2(T) and members of the genus Psychrobacillus with validly published names ranged from 97.83 to 98.18%. DNA-DNA hybridization indicated less than 70% relatedness to reference strains within the genus. The G+C content of the genomic DNA was 36 mol%. This strain contained MK-8 as a predominant isoprenoid menaquinone. NHI-2(T) had ornithine in the cell wall similar to reference strains of the genus Psychrobacillus. The major fatty acids present in NHI-2(T )were anteiso-C15 : 0 (51.0%), iso-C15 : 0 (9.1%) and anteiso-C17 : 0 (8.0%). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. These data highlight that the phenotype of strain NHI-2(T) differs from that of related species in terms of chemotaxonomic properties and genotype characteristics. Therefore, this strain is proposed as a representative of a novel species, named Psychrobacillus soli. The type strain is NHI-2(T) ( = KEMB 9005-135(T) = KACC 18243(T) = NBRC 110600(T)).

Psychrobacter ciconiae sp. nov., isolated from white storks (Ciconia ciconia).

Five beige bacterial strains (176/10(T), 178/10, 182/10, 185/7 and 193/8) were isolated from white storks in Poland and found to share identical 16S rRNA gene sequences; they were also investigated in a polyphasic taxonomic study. The cells of all isolates were rod-shaped and Gram-stain-negative. A comparison of the 16S rRNA gene sequences of these organisms with the sequences of the type strains of the most closely related species of the genus Psychrobacter showed highest sequence similarities to the type strains of Psychrobacter pulmonis and Psychrobacter faecalis (both 97.1 %). The 16S rRNA gene sequence similarities to all other species of the genus Psychrobacter were below 96.3 %. All five isolates showed an identical profile of physiological reactions and almost identical fatty acid profiles consisting of mainly C18 : 1ω9c, but also C12 : 0 3-OH as a characteristic hydroxylated fatty acid. A quinone system with mainly ubiquinone Q-8 was detected and the polar lipid profile of the type strain, 176/10(T), was mainly composed of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine and diphosphatidylglycerol, plus some hitherto uncharacterized phospholipids and one aminolipid. The major polyamines were spermidine and putrescine. DNA-DNA hybridizations between 176/10(T) and the type strains of P. pulmonis and P. faecialis resulted in relatedness values below 70 %. These results indicate that the strains represent a novel species, for which the name Psychrobacter ciconiae sp. nov. (type strain 176/10(T) = CIP 110777(T) = LMG 28175(T) = CCM 8519(T)) is proposed.

Sponge-associated microbial Antarctic communities exhibiting antimicrobial activity against Burkholderia cepacia complex bacteria.

The aerobic heterotrophic bacterial communities isolated from three different Antarctic sponge species were analyzed for their ability to produce antimicrobial compounds active toward Cystic Fibrosis opportunistic pathogens belonging to the Burkholderia cepacia complex (Bcc). The phylogenetic analysis performed on the 16S rRNA genes affiliated the 140 bacterial strains analyzed to 15 genera. Just three of them (Psychrobacter, Pseudoalteromonas and Arthrobacter) were shared by the three sponges. The further Random Amplified Polymorphic DNA analysis allowed to demonstrate that microbial communities are highly sponge-specific and a very low degree of genus/species/strain sharing was detected. Data obtained revealed that most of these sponge-associated Antarctic bacteria and belonging to different genera were able to completely inhibit the growth of bacteria belonging to the Bcc. On the other hand, the same Antarctic strains did not have any effect on the growth of other pathogenic bacteria, strongly suggesting that the inhibition is specific for Bcc bacteria. Moreover, the antimicrobial compounds synthesized by the most active Antarctic bacteria are very likely Volatile Organic Compounds (VOCs), a finding that was confirmed by the SPME-GC-MS technique, which revealed the production of a large set of VOCs by a representative set of Antarctic bacteria. The synthesis of these VOCs appeared to be related neither to the presence of pks genes nor the presence of plasmid molecules. The whole body of data obtained in this work indicates that sponge-associated bacteria represent an untapped source for the identification of new antimicrobial compounds and are paving the way for the discovery of new drugs that can be efficiently and successfully used for the treatment of CF infections.

Psychrobacter aestuarii sp. nov., isolated from a tidal flat sediment.

A Gram-negative-staining, non-motile, non-spore-forming and strictly aerobic bacterial strain, SC35(T), was isolated from tidal flat sediment collected from the South Sea, Korea, and subjected to a taxonomic study using a polyphasic approach. The organism grew optimally at 20-30 degrees C and with 1-2 % (w/v) NaCl. Strain SC35(T) contained ubiquinone-8 as the predominant respiratory lipoquinone and C(18 : 1)omega9c as the major fatty acid. The DNA G+C content was 48.5 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain SC35(T) formed a lineage within the genus Psychrobacter (94.3-96.5 % sequence similarity), forming a distinct branch in a clade also containing Psychrobacter pacificensis NIBH P2K6(T) and Psychrobacter celer SW-238(T). On the basis of phenotypic and phylogenetic data, strain SC35(T) (=KCTC 22503(T)=JCM 16343(T)) was placed in the genus Psychrobacter as the type strain of a novel species, for which the name Psychrobacter aestuarii sp. nov. is proposed.

Psychrobacter lutiphocae sp. nov., isolated from the faeces of a seal.

The taxonomic status of a Gram-negative-staining bacterium, isolated from the faeces of a seal, was investigated using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that the novel isolate formed a distinct phyletic line within the genus Psychrobacter, displaying >3.3% sequence divergence with other known Psychrobacter species. The generic assignment was confirmed by chemotaxonomic data, which revealed a fatty acid profile that included straight-chain saturated, unsaturated and 3-hydroxylated fatty acids, with C18:1omega9c as the major fatty acid. A ubiquinone with eight isoprene units (Q-8) was the predominant respiratory quinone and spermidine was the predominant polyamine. The novel isolate was distinguished from other members of the genus Psychrobacter by using a set of phenotypic properties. On the basis of phenotypic and phylogenetic considerations, it is proposed that the new isolate represents a novel species, for which the name Psychrobacter lutiphocae sp. nov. is proposed. Strain IMMIB L-1110T (=DSM 21542T=CCUG 56590T) is the type strain.

Psychrobacter fulvigenes sp. nov., isolated from a marine crustacean from the Sea of Japan.

Two novel Psychrobacter-like bacteria, strains KC 40(T) and KC 65, were isolated from a marine crustacean specimen collected from the Sea of Japan, and were characterized by using a polyphasic approach. Strains were selected on the basis of their ability to produce black-brown diffusible pigments on commonly used organic media, which appears to be a unique characteristic of recognized members of the genus Psychrobacter. Phylogenetic analyses based on both 16S rRNA and gyrB gene sequences showed that the novel isolates formed a separate cluster within the genus Psychrobacter. Strains KC 40(T) and KC 65 shared highest levels of 16S rRNA gene sequence similarity with Psychrobacter urativorans DSM 14009(T) (98.0 %), Psychrobacter pulmonis CCUG 46240(T) (97.9 %), Psychrobacter cibarius JG-219(T) (97.9 %), Psychrobacter faecalis Iso-46(T) (97.8 %), Psychrobacter aquimaris SW-210(T) (97.6 %), Psychrobacter namhaensis SW-242(T) (97.6 %) and Psychrobacter nivimaris 88/2-7(T) (97.6 %). DNA-DNA hybridization experiments revealed 84 % DNA-DNA relatedness between strains KC 40(T) and KC 65 but much lower levels of relatedness (7-35 %) between the novel strains and the type strains of recognized Psychrobacter species, confirming their assignment to a single novel species of the genus Psychrobacter. The two novel strains could be distinguished from recognized species of the genus Psychrobacter based on a combination of physiological and biochemical characteristics. On the basis of phenotypic and molecular properties, strains KC 40(T) and KC 65 are considered to represent a novel species of the genus Psychrobacter, for which the name Psychrobacter fulvigenes sp. nov. is proposed. The type strain is KC 40(T) (=KMM 3954(T)=NRIC 0746(T)=JCM 15525(T)).

Oil-utilizing bacteria associated with fish from the Arabian Gulf.

AIMS: The objectives were to count and identify the oil-utilizing bacteria associated with fish, and to study their hydrocarbon-degradation potential. METHODS AND RESULTS: The standard dilution-plate method using a medium with crude oil as a sole source of carbon and energy revealed that 10 different fish sorts from the Arabian Gulf and two from fish farms accommodated millions of oil-utilizing bacteria per square centimetre of fish surface and per gram of gills and guts. According to their 16S rRNA sequences, those bacteria were affiliated to Psychrobacter, Vibrio, Planococcus, Pseudomonas and Actinobacterium. Planktonic and benthic biomass samples from the Gulf were also rich in oil-utilizing bacteria, but with different composition. All isolates could grow on n-alkanes from C(8) to C(40) and three representative aromatics as individual sole sources of carbon and energy. Quantitative analysis of hydrocarbons by gas-liquid chromatography revealed that the biomass samples of the individual bacteria could consume crude oil, n-octadecane and phenanthrene in liquid media. CONCLUSIONS: The abundant oil-utilizing bacterial associated with fish have the potential for cleaning oily waters. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: Aquatic fauna accommodates rich consortia of oil-utilizing bacteria.

Psychrobacter celer sp. nov., isolated from sea water of the South Sea in Korea.

A Gram-negative, non-motile, non-spore-forming, slightly halophilic bacterial strain, SW-238(T), was isolated from sea water collected from the South Sea in Korea, and subjected to a polyphasic taxonomic study. The organism grew optimally at 25-30 degrees C and in the presence of 2-3% (w/v) NaCl. Strain SW-238(T) was characterized chemotaxonomically as containing ubiquinone (Q-8) as the predominant respiratory lipoquinone and C(18:1)omega9c as the major fatty acid. Its DNA G+C content was 47.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SW-238(T) fell within the radiation of the cluster comprising Psychrobacter species. The 16S rRNA gene sequence of strain SW-238(T) had similarity levels of 94.8-97.9% to sequences of the type strains of recognized Psychrobacter species. Levels of DNA-DNA relatedness between strain SW-238(T) and the type strains of 10 phylogenetically related Psychrobacter species were below 70%. On the basis of phenotypic and phylogenetic data and genetic distinctiveness, strain SW-238(T) (=KCTC 12313(T)=JCM 12601(T)) was placed in the genus Psychrobacter as the type strain of a novel species, for which the name Psychrobacter celer sp. nov. is proposed.

Psychrobacter aquimaris sp. nov. and Psychrobacter namhaensis sp. nov., isolated from sea water of the South Sea in Korea.

Two Gram-negative, non-motile, non-spore-forming, slightly halophilic bacterial strains, SW-210(T) and SW-242(T), were isolated from sea water of the South Sea in Korea, and were characterized taxonomically by means of a polyphasic approach. The two isolates grew optimally at 25-30 degrees C and in the presence of 2-3 % (w/v) NaCl. Strains SW-210(T) and SW-242(T) contained Q-8 as the predominant respiratory lipoquinone and C(18 : 1)omega9c as the major fatty acid. The DNA G+C contents of strains SW-210(T) and SW-242(T) were 43.2 and 45.3 mol%, respectively. The 16S rRNA gene sequences of strains SW-210(T) and SW-242(T) were 98.9 % similar, and the mean DNA-DNA relatedness value between them was 24 %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains SW-210(T) and SW-242(T) form distinct phylogenetic lineages within the radiation of the cluster comprising Psychrobacter species, having 16S rRNA gene sequence similarity levels of 95.9-99.2 % with respect to the type strains of Psychrobacter species. The levels of DNA-DNA relatedness between the two isolates and the type strains of 15 phylogenetically related Psychrobacter species were well below 70 %. On the basis of phenotypic and phylogenetic data and genomic distinctiveness, strains SW-210(T) and SW-242(T) were classified in the genus Psychrobacter as representing two distinct novel species, for which the names Psychrobacter aquimaris sp. nov. (type strain, SW-210(T) = KCTC 12254(T) = DSM 16329(T)) and Psychrobacter namhaensis sp. nov. (type strain, SW-242(T) = KCTC 12255(T) = DSM 16330(T)) are proposed, respectively.