Terrirubrum flagellatum gen. nov., sp. nov. of Terrirubraceae fam. nov. and Lichenibacterium dinghuense sp. nov. from forest soil and proposal of Rhodoblastaceae fam. nov.

Two Gram-negative, aerobic, rod-shaped bacterial strains, 7MK25T and 6Y81T, were isolated from forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Based on the results of 16S rRNA gene sequence analysis, strain 7MK25T showed the highest similarity (93.6 %) to Methyloferula stellata AR4T, followed by Bosea thiooxidans DSM 9653T (93.3 %). Strain 6Y81T had the highest similarity of 97.9 % to Lichenibacterium minor RmlP026T, followed by Lichenibacterium ramalinae RmlP001T (97.2 %). Phylogenomic analysis using the UBCG and PhyloPhlAn methods consistently showed that strain 7MK25T formed a sister clade to Boseaceae, while strain 6Y81T formed an independent clade within the genus Lichenibacterium, both in the order Hyphomicrobiales. The digital DNA-DNA hybridization and average nucleotide identity values between strains 7MK25T, 6Y81T and their close relatives were in the ranges of 19.1-29.9 % and 72.5-85.5 %, respectively. The major fatty acids of 7MK25T were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c), C19 : 0 cyclo ω8c, C16 : 0 and C17 : 0 cyclo, while those of 6Y81T were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c), C16 : 0 and C16 : 0 3-OH. Strains 7MK25T and 6Y81T took diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine as their dominant polar lipids, and Q-10 as their major respiratory quinone. On the basis of phenotypic and phylogenetic data, strain 7MK25T is proposed to represent a novel species of a novel genus with name Terrirubrum flagellatum gen. nov., sp. nov., within a novel family Terrirubraceae fam. nov., with 7MK25T (=KCTC 62738T=GDMCC 1.1452T) as its type strain. Strain 6Y81T represents a novel species in the genus Lichenibacterium, for which the name Lichenibacterium dinghuense sp. nov. (type strain 6Y81T=KACC 21 727T=GDMCC 1.2176T) is proposed. Rhodoblastaceae fam. nov. with Rhodoblastus as the type genus is also proposed to solve the non-monophylectic problem of the family Roseiarcaceae.

Paracidobacterium acidisoli gen. nov., sp. nov. and Alloacidobacterium dinghuense gen. nov., sp. nov., two acidobacteria isolated from forest soil, and reclassification of Acidobacterium ailaaui and Acidipila dinghuensis as Pseudacidobacterium ailaaui gen. nov., comb. nov. and Silvibacterium dinghuense comb. nov.

Two aerobic and obligately acidophilic bacteria, designated 4G-K13T and 4Y35T, were isolated from the forest soil sampled at Dinghushan Biosphere Reserve, Guangdong Province, PR China. These two strains were Gram-stain-negative, non-motile and short rods that multiplied by binary division. Strains 4G-K13T and 4Y35T had the highest 16S rRNA gene sequence similarity of 97.0 and 97.2 % to Silvibacterium bohemicum DSM 103733T and Acidisarcina polymorpha SBC82T, respectively. Phylogenetic trees based on the 16S rRNA gene and whole genome sequences showed consistently that these two strains formed a major clade with members of the genera Acidipila, Acidisarcina, Silvibacterium and Acidobacterium in the family Acidobacteriaceae, but each occupied an unique position. In both the UBCG and the PhyloPhlAn phylogenomic trees, strains 4G-K13T and 4Y35T congruently formed a highly supported subclade with Acidobacterium capsulatum DSM 11244T and Acidobacterium ailaaui DSM 27394T, respectively. The major fatty acids (>5 %) of strain 4G-K13T were iso-C15 : 0, iso-C17 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl), while that of strain 4Y35T were C16 : 0, C18 : 1 ω9c, iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl). Strain 4G-K13T contained phosphatidylethanolamine, four unidentified phospholipids, four glycolipids, two unidentified aminolipids and two unknown lipids, while strain 4Y35T had phosphatidylethanolamine, three unidentified phospholipids, two glycolipids, five unidentified aminolipids and one unknown polar lipid. The DNA G+C contents of 4G-K13T and 4Y35T were 60.5 and 55.8 mol%, respectively. Based on all these phylogenetic, physiological and chemotaxonomic data, we suggest that strains 4G-K13T and 4Y35T represent two novel species of two novel genera in the family Acidobacteriaceae, for which the names Paracidobacterium acidisoli gen. nov., sp. nov. (type strain: 4G-K13T=GDMCC 1.1195T=NBRC 113249T) and Alloacidobacterium dinghuense gen. nov., sp. nov. (type strain: 4Y35T=KACC 21728T=NBRC 114261T) are proposed. We also propose to reclassify Acidobacterium ailaaui and Acidipila dinghuensis as Pseudacidobacterium ailaaui gen. nov., comb. nov. and Silvibacterium dinghuense comb. nov., respectively, based mainly on the results of phylogenomic analysis.

Dyella telluris sp. nov. and Dyella acidiphila sp. nov., isolated from forest soil of Dinghushan Biosphere Reserve, China.

Cells of bacterial strains G9T and 7MK23T, isolated from forest soil samples collected from the Dinghushan Biosphere Reserve, Guangdong Province, PR China, were Gram-stain-negative, aerobic and rod-shaped. Strain G9T was motile with single polar flagellum and grew at 12-37 °C (optimum, 28 °C), pH 4.5-8.0 (optimum, pH 6.0-7.5) and in the presence of 0-3.5 % NaCl (optimum, 1.5%, w/v); while strain 7MK23T was non-motile and grew at 12-42 °C (optimum, 28-33 °C), pH 2.5-8.5 (optimum, pH 4.5-6.5) and NaCl levels of 0-1.0 % (optimum, 0-0.5 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that both isolates fell within the cluster of the genus Dyella. The closely related species (with a 16S rRNA gene sequence similarity >98.65%) of strain G9T were Dyella terrae JS14-6T (99.0 %), D. kyungheensis THG-B117T (98.8 %) and D. amyloliquefaciens DHC06T (98.7 %) while that of strain 7MK23T were D. mobilis DHON07T (99.2 %) and D. flava DHOC52T (99.1 %), but the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strains G9T, 7MK23T and the closely related Dyella species listed above were in the ranges of 77.5-83.8 % and 22.0-27.0 %, much lower than the species demarcation lines of 95.5 and 70 %, respectively. Phylogenomic analyses using UBCG and Phylophlan also supported that these two strains represent two novel species of Dyella. The major fatty acids of strain G9T were iso-C15 : 0, iso-C17 : 1 ω9c and iso-C17 : 0 while that of strain 7MK23T were iso-C15 : 0 and anteiso-C15 : 0. Ubiquinone-8 was the only respiratory quinone detected in both strains. The polar lipids of strain G9T consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and several unknown phospholipids, aminophospholipids, aminolipids and lipid while strain 7MK23T contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine and several unknown phospholipids and aminophospholipids. The DNA G+C contents of strains G9T and 7MK23T were 64.7 and 63.4 mol%, respectively. On the basis of 16S rRNA gene sequence phylogenetic and phylogenomic analyses as well as phenotypic data obtained, we propose that strains G9T and 7MK23T represent two novel species of the genus Dyella, for which the names Dyella telluris sp. nov. (type strain G9T=KACC 21725T=GDMCC 1.2132T) and Dyella acidiphila sp. nov. (type strain 7MK23T=KCTC 62739T=GDMCC 1.1446T) are proposed.

Dyella amyloliquefaciens sp. nov., isolated from forest soil.

A Gram-stain-negative, aerobic, yellow-pigmented, rod-shaped and motile with single polar flagellum bacterial strain, designated DHC06T, was isolated from forest soil sampled at Dinghushan Biosphere Reserve, Guangdong Province, PR China. The strain grew at 4-37 °C (optimum, 28 °C), pH 4.5-8.0 (pH 6.0-7.5) and in the presence of 0-4.0 % (2.0 %, w/v) NaCl. In the 16S rRNA gene sequence phylogram, strain DHC06T formed a clade with Dyella solisilvae DHG54T and Dyella terrae KACC 12748T within the genus of Dyella. Strain DHC06T had 16S rRNA gene sequence similarities of 98.6, 98.3, 98.3 and 98.2 % to Dyella japonica DSM 16301T, Dyella terrae JS14-6T, Dyella soli KACC 12747T and Dyella solisilvae DHG54T, respectively. The distinctiveness of strain DHC06Tfrom all described Dyellaspecies was also supported by the results of phylogenomic analysis based on 92 single-copy gene sequences. The DDH values among strain DHC06T and closely related Dyella species were all lower than 70 %. Strain DHC06T contained Q-8 as the only respiratory quinone. Its main fatty acids were iso-C15 : 0, iso-C17 : 1 ω9c and summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c). The DNA G+C content of strain DHC06T was 64.6 mol%. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. On the basis of phenotypic, 16S rRNA gene sequence and genomic analyses and chemotaxonomic data, strain DHC06T represents a novel species of the genus Dyella, for which the name Dyella amyloliquefaciens sp. nov. (type strain DHC06T=GDMCC 1.1186T=LMG 30090T) is proposed.

Paraburkholderia dinghuensis sp. nov., isolated from soil.

A novel Gram-stain-negative, aerobic, non-spore-forming, non-motile and rod-shaped bacterial strain, designated DHOA04T, was isolated from a forest soil sample collected at Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). It grew optimally at 28-33 °C and pH 6.5-7.0. Strain DHOA04T contained Q-8 as the major respiratory quinone. Its main fatty acids were C16 : 0, C17 : 0cyclo, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content of DHOA04T was 63.0 mol%, which is in the range of the genus Paraburkholderia. The average nucleotide identity and digital DNA-DNA hybridization values for the complete genomes were 81.6-83.0 and 25.5-27.0 % between strain DHOA04T and five closely related type strains. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and two unidentified aminophospholipids. On the basis of 16S rRNA gene sequence analysis, the strain was found to be closely related to members of the genus Paraburkholderia, but clearly separated from the established species. Phylogenetic analysis based on the 16S rRNA gene sequences using the maximum-likelihood algorithm indicated that strain DHOA04T was most closely related to Paraburkholderia ferrariae NBRC 106233T. The phenotypic, chemotaxonomic and phylogenetic data, and genome analysis showed that strain DHOA04T represents a novel species of the genus Paraburkholderia, for which the name Paraburkholderia dinghuensis sp. nov. is proposed. The type strain is DHOA04T (=KCTC 42627T=LMG 28839T).

Effects of chitooligosaccharide-zinc on the ovarian function of mice with premature ovarian failure via the SESN2/NRF2 signaling pathway.

Chitooligosaccharide-zinc (COS·Zn) is a powerful anti-oxidant and anti-aging scavenger, whose anti-oxidative ability immensely exceeds vitamin C. Therefore, this study was aimed to investigate the protective effects of COS·Zn against premature ovarian failure (POF) and potential mechanisms. Female KM adult mice were divided into the following groups: a treatment group (150 mg·kg-1·d-1 COS·Zn), a treatment group (300 mg·kg-1·d-1 COS·Zn), a prevention group, two control groups and two CY/BUS groups. COS·Zn (150, 300 mg·kg-1·d-1) and COS·Zn (300 mg·kg-1·d-1) were therapeutically and preventatively administered to POF mice in the treatment and prevention studies, respectively. All the groups were administered for 21 days. Fewer primary and secondary follicles were observed in the COS·Zn-treated groups (including the treatment and prevention groups) than those of the control groups. Meanwhile, the ovarian index and the levels of FSH and LH notably increased in the treatment and prevention groups compared with those in the CY/BUS group. The levels of MVH, OCT4 and PCNA in the treatment group (300·kg-1·d-1 COS·Zn) and MVH in the prevention group remarkably increased compared with those in the CY/BUS groups. Meanwhile, the levels of P53 and P16 protein were down-regulated in the treatment and prevention groups compared with those in the CY/BUS groups. Additionally, the amounts of Sestrin2 (SESN2) and SOD2 protein were obviously higher in the treatment group (150 mg·kg-1·d-1 COS·Zn) than those in the CY/BUS groups. Similarly, the amounts of NRF2 and SESN2 protein were up-regulated in the prevention group. Besides, an increased GSH level was observed in the two treatment groups, compared with that in the CY/BUS groups, and the same trend was also present in the prevention group. Taken together, COS·Zn improves the ovarian and follicular development through regulating the SESN2/NRF2 signaling pathway. These results suggest the role of COS·Zn as a novel agent for the treatment and prevention of POF.