Penaeicolahalotolerans gen. nov., sp. nov., a novel bacterium of the family Cyclobacteriaceae isolated from a shrimp pond

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterium (designated as LMIT005^T) was isolated from shrimp ponds in Shantou, China. The new isolate was characterized taxonomically using a polyphasic approach. Based on 16S rRNA gene sequence analysis, strain LMIT005^T was found to be affiliated with the family Cyclobacteriaceae of the order Cytophagales while appearing as a distinct lineage. The 16S rRNA gene sequence similarity between strain LMIT005^T and Algoriphagus yeomjeoni KCTC 12309^T, the closest type strain in the family, was 91.3 %. Strain LMIT005^T grew optimally at 25 °C, pH 7 and in the presence of 2.0 % (w/v) NaCl. The DNA G+C content (data from genome sequence) was 40.5 mol%. Compared with reference strain A. yeomjeoni KCTC 12309^T, the average nucleotide identity (ANI) of LMIT005^T was 70 %. The sole respiratory quinone of LMIT005^T was menaquinone (MK-7), and the major fatty acids were summed feature 3 (C_16 : 1 ω6c / C_16 : 1 ω7c). The polar lipids of strain LMIT005^T were mainly composed of phosphatidylethanolamine, phosphatidylcholine, two unidentified amino lipids, two unidentified lipids, one unidentified glycolipid and one unidentified phospholipid. The draft genome of strain LMIT005^T comprised 3 089 781 bp (3.09 Mb) nucleotides and 2773 genes. Antimicrobial resistant-related genes (blal, mexA, and mexb) were annotated in the genome of strain LMIT005^T, which indicated that it might be able to resist β-lactam antibiotics. This was further verified by antimicrobial resistant test. Given its distinct genomic, morphological, and physiological differences from previously described type strains, strain LMIT005^T is proposed as a representative of a novel genus of the family Cyclobacteriaceae, with the name Penaeicola halotolerans gen. nov., sp. nov. The type strain is LMIT005^T (=KCTC 82616^T=CICC 25047^T).

Litoribacter populi sp. nov., isolated from the soil of a Populus euphratica forest

A Gram-stain-negative, rod-shaped, and orange-pigmented bacterium, designated XAAS-A1^T, was isolated from the soil of a Populus euphratica forest. The main respiratory quinone of XAAS-A1^T is MK-7, and the principal cellular fatty acids are iso-C_15:0, C_17:1 ω6c, Iso-C_17:0 3OH, and summed feature 3 (C_16:1ω6c and/or C_16:1ω7c). The major polar lipids are phosphatidylethanolamine, phosphatidylcholine, and two unidentified lipids. The 16S rRNA gene sequence analysis indicated that XAAS-A1^T belongs to the genus Litoribacter within the family Cyclobacteriaceae, having the highest sequence similarities to Litoribacter ruber KCTC 22899^T (97.1%) and L. alkaliphilus KCTC 32217^T (96.9%). XAAS-A1^T has a DNA G + C content of 42.1 mol%. The orthoANI and the digital DNA-DNA hybridization values were markedly lower than the recommended threshold values of 96% and 70%. Phenotypic and genotypic data suggest that XAAS-A1^T represents a novel species of the genus Litoribacter, for which we propose the name Litoribacter populi sp. nov. and XAAS-A1^T (= CCTCC AB 2017159^T = KCTC 62045^T) as the type strain.

Lunatibacter salilacus gen. nov., sp. nov., a member of the family Cyclobacteriaceae, isolated from a saline and alkaline lake sediment

A non-motile, Gram-staining negative, catalase- and oxidase-positive, crescent-rod shaped bacterium, designated strain CUG 91308^T, was isolated from a sediment sample of Qinghai Lake, Qinghai Province, China. Colonies on OSM agar were round, smooth, flat and pinkish-orange in colour. Strain CUG 91308^T could grow at 15-37 °C, pH 6-12 and in the presence of up to 7.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CUG 91308^T belonged to the family Cyclobacteriaceae and formed a clade with the genus Lunatimonas in the phylogenetic tree, but separated from any species of the known genera within the family. The genomic DNA G+C content is about 42.1 %. The predominant fatty acids (>10 %) were iso-C_15 : 0 (21.1 %), summed feature 3 (C_16 : 1  ω7c / C_16 : 1  ω6c / iso-C_15 : 0 2OH) (14.3 %), iso-C_17 : 0 3OH (12.3 %) and summed feature 9 (iso-C_17 : 1  ω9c / C_16 : 0 10-methyl) (10.6 %). The polar lipids of strain CUG 91308^T were phosphatidylethanolamine (PE) and four unidentified polar lipids. Strain CUG 91308^T contained MK-7 as the major respiratory quinone. On the basis of phenotypic, genotypic and phylogenetic data, strain CUG 91308^T represents a novel species of a novel genus in the family Cyclobacteriaceae, for which the name Lunatibacter salilacus gen. nov., sp. nov. is proposed. The type strain of the proposed new isolate is CUG 91308^T (=KCTC 62636^T=CGMCC 1.13593^T).

Soda pans of the Pannonian steppe harbor unique bacterial communities adapted to multiple extreme conditions

Soda pans of the Pannonian steppe are unique environments regarding their physical and chemical characteristics: shallowness, high turbidity, intermittent character, alkaline pH, polyhumic organic carbon concentration, hypertrophic condition, moderately high salinity, sodium and carbonate ion dominance. The pans are highly productive environments with picophytoplankton predominance. Little is known about the planktonic bacterial communities inhabiting these aquatic habitats; therefore, amplicon sequencing and shotgun metagenomics were applied to reveal their composition and functional properties. Results showed a taxonomically complex bacterial community which was distinct from other soda lakes regarding its composition, e.g. the dominance of class Alphaproteobacteria was observed within phylum Proteobacteria. The shotgun metagenomic analysis revealed several functional gene components related to the harsh and at the same time hypertrophic environmental conditions, e.g. proteins involved in stress response, transport and hydrolase systems targeting phytoplankton-derived organic matter. This is the first detailed report on the indigenous planktonic bacterial communities coping with the multiple extreme conditions present in the unique soda pans of the Pannonian steppe.

Negadavirga shengliensis gen. nov., sp. nov., a novel member of the family Cyclobacteriaceae isolated from oil-contaminated saline soil

Four novel Gram-stain-negative, rod-shaped, and non-motile bacterial strains, SLG210-21(T), SLG210-4, SLG210-5 and SLG210-14, were isolated from oil-contaminated saline soil in Shengli Oilfield, China. Growth were observed at 25-42 °C (optimum 37 °C), in the presence of 0-10 % (w/v) NaCl (optimum 0-1 %) and at pH 4.0-10.0 (optimum pH 7.6-8.6). All the strains were positive for catalase and α, β-galactosidase activities and nitrogen reduction, and negative for oxidase activity, glucose fermentation and hydrolysis of agar, starch, gelatin, Tween 40, 60 and 80. The DNA G+C contents of the four strains were 41.3-43.0 mol% and the predominant respiratory quinones were all menaquinone-7. The major fatty acids were iso-C15:0, anteiso-C15:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:1 ω5c and summed feature 9 (iso-C17:1 ω9c and/or 10-methyl C16:0), while the polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, glycolipid, two unidentified phospholipids and two unidentified amino lipids. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the four strains clustered together to form a stable branch in the family Cyclobacteriaceae, and were most closely related to the genera Cyclobacterium and Echinicola with the 16S rRNA gene sequence similarities being 88.6-90.3 and 89.6-91.4 %, respectively. DNA-DNA hybridization between SLG210-21(T) and the other three strains showed the relatedness of 93.8 ± 4.5, 96.2 ± 4.2 and 82.3 ± 4.8 %, respectively. Based on the polyphasic analysis, a novel species in a new genus, Negadavirga Shengliensis gen. nov., sp. nov., is proposed with SLG210-21(T) (=LMG 27737(T) = CGMCC1.12768(T)) [corrected] as the type strain.

Mongoliicoccus alkaliphilus sp. nov. and Litoribacter alkaliphilus sp. nov., isolated from salt pans

Four bacterial strains (JC165T, JC166T, JC169 and JC170) were isolated from salt pan soils from a coastal region of Tamilnadu, India. They were obligately aerobic, pink- to red-pigmented, mesophilic, haloalkaliphiles having chemoorganoheterotrophic growth on various carbon sources and were catalase- and oxidase-positive. Phototrophic growth and bacteriochlorophyll a were absent in all four strains. Major carotenoids present were β-carotene and rhodoxanthin. The main fatty acid in all strains was iso-C15 : 0. The main polar lipids were phosphatidylethanolamine (PE) and phosphatidylcholine (PC) as well as a few unidentified lipids. Bacterial hopane derivatives and diplopterol (DPL) were detected in all four strains. Based on the 16S rRNA gene sequences, all four strains belong to the family Cyclobacteriaceae in the phylum Bacteroidetes . Strains JC165T and JC169 had a sequence similarity of 97.2 % with Mongoliicoccus roseus MIM28T, while strains JC166T and JC170 had a sequence similarity of 99.5 % with Litoribacter ruber YIM CH208T. Strains JC165T/JC169 and JC166T/JC170 had genomic DNA reassociation values (based on DNA–DNA hybridization) of 21±2 % and 23±1 % with M. roseus KCTC 19808T ( = MIM28T) and L. ruber KCTC 22899T ( = YIM CH208T), respectively, suggesting that they represented novel species. The reassociation values of >85 % between strains JC165T and JC169, and JC166T and JC170 suggested they were strains of the same species. The genomic information was supported by phenotypic observations leading to the proposal of two novel species, Mongoliicoccus alkaliphilus sp. nov. (type strain, JC165T = KCTC 32210T = LMG 27255T) and Litoribacter alkaliphilus sp. nov. (type strain, JC166T = KCTC 32217T = LMG 27256T).