TNA-Mediated Antisense Strategy to Knockdown Akt Genes for Triple-Negative Breast Cancer Therapy.

Triple-negative breast cancer (TNBC) remains a significant challenge in terms of treatment, with limited efficacy of chemotherapy due to side effects and acquired drug resistance. In this study, a threose nucleic acid (TNA)-mediated antisense approach is employed to target therapeutic Akt genes for TNBC therapy. Specifically, two new TNA strands (anti-Akt2 and anti-Akt3) are designed and synthesized that specifically target Akt2 and Akt3 mRNAs. These TNAs exhibit exceptional enzymatic resistance, high specificity, enhance binding affinity with their target RNA molecules, and improve cellular uptake efficiency compared to natural nucleic acids. In both 2D and 3D TNBC cell models, the TNAs effectively inhibit the expression of their target mRNA and protein, surpassing the effects of scrambled TNAs. Moreover, when administered to TNBC-bearing animals in combination with lipid nanoparticles, the targeted anti-Akt TNAs lead to reduced tumor sizes and decreased target protein expression compared to control groups. Silencing the corresponding Akt genes also promotes apoptotic responses in TNBC and suppresses tumor cell proliferation in vivo. This study introduces a novel approach to TNBC therapy utilizing TNA polymers as antisense materials. Compared to conventional miRNA- and siRNA-based treatments, the TNA system holds promise as a cost-effective and scalable platform for TNBC treatment, owing to its remarkable enzymatic resistance, inexpensive synthetic reagents, and simple production procedures. It is anticipated that this TNA-based polymeric system, which targets anti-apoptotic proteins involved in breast tumor development and progression, can represent a significant advancement in the clinical development of effective antisense materials for TNBC, a cancer type that lacks effective targeted therapy.

Chitiniphilus purpureus sp. nov., a novel chitin-degrading bacterium isolated from crawfish pond sediment.

A novel Gram-stain-negative, curved rod-shaped, motile and chitin-degrading strain, designated CD1T, was isolated from crawfish pond sediment in Caidian District (30° 58' N 114° 03' E), Wuhan City, Hubei Province, PR China. Growth of this strain was observed at 15-40°C (optimum between 28 and 30 °C), at pH 7.0-9.0 (optimum between pH 7.0 and 8.0) and with 0-1 % (w/v) NaCl (optimum at 0 %). With respect to the 16S rRNA gene sequences, strain CD1T had the highest similarity (96.91-97.25 %) to four type strains of the genera 'Chitinolyticbacter' and Chitiniphilus within the family Chitinibacteraceae. The phylogenetic trees based on genome sequences and 16S rRNA gene sequences indicated that strain CD1T was close to members of these two genera, in particular to the genus Chitiniphilus. The genomic DNA G+C content of strain CD1T was 64.8 mol%. The average nucleotide identity and the Genome-to-Genome Distance Calculator results showed low relatedness (below 95 and 70 %, respectively) between strain CD1T and the closely related type strains. Ubiquinone-8 was the predominant quinone. The major cellular fatty acids were C10 : 0, C16 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipid profile was composed of a mixture of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified lipids, two unidentified phospholipids, two unidentified aminolipids and an unidentified aminoglycolipid. On the basis of the evidences presented in this study, strain CD1T represents a novel species of the genus Chitiniphilus, for which the name Chitiniphilus purpureus sp. nov. is proposed, with strain CD1T (=CCTCC AB 2022395T=KCTC 92850T) as the type strain.

Contributions of selenium-oxidizing bacteria to selenium biofortification and cadmium bioremediation in a native seleniferous Cd-polluted sandy loam soil.

Selenium (Se) is a trace element that is essential for human health. Daily dietary Se intake is governed by the food chain through soil-plant systems. However, the cadmium (Cd) content tends to be excessive in seleniferous soil, in which Se and Cd have complex interactions. Therefore, it is a great challenge to grow crops containing appreciable amounts of Se but low amounts of Cd. We compared the effects of five Se-transforming bacteria on Se and Cd uptake by Brassica rapa L. in a native seleniferous Cd-polluted soil. The results showed that three Se-oxidizing bacteria (LX-1, LX-100, and T3F4) increased the Se content of the aboveground part of the plant by 330.8%, 309.5%, and 724.3%, respectively, compared to the control (p < 0.05). The three bacteria also reduced the aboveground Cd content by 15.1%, 40.4%, and 16.4%, respectively (p < 0.05). In contrast, the Se(IV)-reducing bacterium ES2-45 and weakly Se-transforming bacterium LX-4 had no effect on plant Se uptake, although they did decrease the aboveground Cd content. In addition, the three Se-oxidizing bacteria increased the Se available in the soil by 38.4%, 20.4%, and 24.0%, respectively, compared to the control (p < 0.05). The study results confirm the feasibility of using Se-oxidizing bacteria to simultaneously enhance plant Se content and reduce plant Cd content in seleniferous Cd-polluted soil.

Cultivation and application of nicotine-degrading bacteria and environmental functioning in tobacco planting soil.

Nicotine, a toxic and addictive alkaloid from tobacco, is an environmental pollutant. However, nicotine-degrading bacteria (NDB) and their function in tobacco planting soil are not fully understood. First, 52 NDB strains belonging to seven genera were isolated from tobacco soil. The most dominant genera were Flavobacterium (36.5%), Pseudomonas (30.8%), and Arthrobacter (15.4%), and Chitinophaga and Flavobacterium have not been previously reported. Then, two efficient NDB strains, Arthrobacter nitrophenolicus ND6 and Stenotrophomonas geniculata ND16, were screened and inoculated in the compost fertilizer from tobacco waste. The nicotine concentrations were reduced from 1.5 mg/g (DW) to below the safety threshold of 0.5 mg/g. Furthermore, strain ND6 followed the pyridine pathway of nicotine degradation, but the degrading pathway in strain ND16 could not be determined according to genomic analysis and color change. Finally, the abundance of nicotine-degrading genes in tobacco rhizosphere soil was investigated via metagenomic analysis. Five key genes, ndhA, nctB, kdhL, nboR, and dhponh, represent the whole process of nicotine degradation, and their abundance positively correlated with soil nicotine concentrations (p < 0.05). In conclusion, various NDB including unknown species live in tobacco soil and degrade nicotine efficiently. Some key nicotine-degrading genes could be used in monitoring nicotine degradation in the environment. The fermentation of compost from tobacco waste is a promising application of efficient NDB.

Fibrisoma montanum sp. nov., isolated from soil of Mountain Danxia, China.

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterium, designated HYT19T, was isolated from soil of Mountain Danxia in southern China. It showed the highest similarity of 16S rRNA gene sequence (97.0%) and formed a monophyletic clade with Fibrisoma limi BUZ 3T. Strain HYT19T grew at 16-37 °C (optimum 28-30 °C) and at pH 6-7. The draft genome size of strain HYT19T was 7.8 Mb with a DNA G+C content of 54.0 mol%. The digital DDH and average nucleotide identity values between strain HYT19T and F. limi BUZ 3T were 28.8% and 85.1%, respectively. MK-7 was the sole respiratory quinone. The major polar lipids were phosphatidylethanolamine, unidentified aminophospholipid, two unidentified aminolipids, unidentified phospholipid and unidentified lipid. The strain contained C16:1ω5c, iso-C15:0, summed feature 3 (C16:1ω6c and/or C16:1ω7c), C16:0, iso-C17:0 3-OH and anteiso-C15:0 as the major fatty acids. On the basis of phylogenetic, genomic, phenotypic and chemotaxonomic analysis, we propose a new species Fibrisoma montanum sp. nov. of genus Fibrisoma. The type strain is HYT19T (= CCTCC AB 2018342T = JCM 33105T).

Sphingomonas gilva sp. nov., isolated from mountain soil.

A Gram-stain-negative, strictly aerobic, motile, yellow, rod-shaped bacterium, designated ZDH117T, was isolated from soilsampled atthe Danxialandformin Guangdong Province, PR China. The 16S rRNA gene sequence of strain ZDH117T had highest similarityvalues to Sphingomonas adhaesivaDSM 7418T (97.5 %), SphingomonasdesiccabilisCP1DT (97.3 %) and Sphingomonas ginsenosidimutans KACC 14949T (97.2 %). However, phylogenetic analyses based on 16S rRNA gene sequences demonstrated that strain ZDH117T clustered with Sphingomonas zeicaulis 541T (96.17 %) and Sphingomonas sanxanigenens DSM 19645T (95.95 %). The genomic average nucleotide identity values of ZDH117T with S. adhaesiva DSM 7418T, S. desiccabilis CP1DTand S. ginsenosidimutans KACC TT were 75.1, 75.2 and 75.0 %, respectively. The G+C content of the genomic DNA was 67.6 mol%. Strain ZDH117T was characterized to have ubiquinone-10 as the predominant respiratory quinone, sym-homospermidine as the major polyamine and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), C14 : 0-2OH, C16 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the major cellular fatty acids (>5 % of total). The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, an unidentified phospholipid and three unidentified lipids. On the basis of its phenotypic, chemotaxonomic and phylogenetic characteristics, strain ZDH117T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas gilva sp. nov. is proposed. The type strain is ZDH117T (=KCTC 62894T=CCTCCAB 2018262T).

The essentialness of glutathione reductase GorA for biosynthesis of Se(0)-nanoparticles and GSH for CdSe quantum dot formation in Pseudomonas stutzeri TS44.

Pseudomonas stutzeri TS44 was able to aerobically reduce Se(IV) into SeNPs and transform Se(IV)/Cd(II) mixture into CdSe-QDs. The SeNPs and CdSe-QDs were systematically characterized by surface feature analyses, and the molecular mechanisms of SeNPs and CdSe-QD formation in P. stutzeri TS44 were characterized in detail. In vivo, under 2.5 mmol/L Se(IV) exposure, GorA was essential for catalyzing of Se(IV) reduction rate decreased by 67% when the glutathione reductase gene gorA was disrupted, but it was not decreased in the glutathione synthesis rate-limiting gene gshA mutated strain compared to the wild type. The complemented strains restored the phenotypes. While under low amount of Se(IV) (0.5 mmol/L), GSH played an important role for Se(IV) reduction. In vitro, GorA catalyzed Se(IV) reduction with NADPH as the electron donor (Vmax of 3.947 ± 0.1061 µmol/min/mg protein under pH 7.0 and 28℃). In addition, CdSe-QDs were successfully synthesized by a one-step method in which Se(IV) and Cd(II) were added to bacterial culture simultaneously. GSH rather than GorA is necessary for CdSe-QD formation in vivo and in vitro. In conclusion, the results provide new findings showing that GorA functions as a selenite reductase under high amount Se(IV) and GSH is essential for bacterial CdSe-QD synthesis.

Nocardioides litorisoli sp. nov., isolated from lakeside soil.

A Gram-stain-positive, rod-shaped, non-spore-forming bacterium, designated as x-2T, was isolated from lakeside soil of Sayram in the Xinjiang Uygur Autonomous Region, PR China. On the basis of 16S rRNA gene sequences, strain x-2T belongs to the genus Nocardioides in the family Nocardioidaceae, being most closely related to Nocardioides panacisoli Gsoil 346T (97.36 % 16S rRNA gene sequence similarity). Strain x-2T was characterized chemotaxonomically and found to have ll-diaminopimelic acid in the cell-wall peptidoglycan, phosphatidylglycerol, diphosphatidylglycerol, glycolipids and another three unknown phospholipids as the major polar lipids, MK-8(H4) as the predominant menaquinone and C18 : 1ω9c, iso-C16 : 0, C17 : 1ω8c and C16 : 0 as the major fatty acids. The genomic DNA G+C content of the novel strain was 71.1 mol%. The level of DNA-DNA relatedness between strain x-2T and N. panacisoli KCTC 19470T (=Gsoil 346T) was 29.8 %. These chemotaxonomic characters support the position of strain x-2T within the genus Nocardioides. The results of physiological and biochemical tests, as well as phylogenetic analysis, suggest that strain x-2T represents a novel species of the genus Nocardioides, for which the name Nocardioides litorisoli sp. nov. is proposed. The type strain is x-2T (=KCTC 39845T=CCTCCAB 2016255T).

Reduction of selenite to Se(0) nanoparticles by filamentous bacterium Streptomyces sp. ES2-5 isolated from a selenium mining soil.

BACKGROUND: Selenium (Se) is an essential trace element in living systems. Microorganisms play a pivotal role in the selenium cycle both in life and in environment. Different bacterial strains are able to reduce Se(IV) (selenite) and (or) Se(VI) (selenate) to less toxic Se(0) with the formation of Se nanoparticles (SeNPs). The biogenic SeNPs have exhibited promising application prospects in medicine, biosensors and environmental remediation. These microorganisms might be explored as potential biofactories for synthesis of metal(loid) nanoparticles. RESULTS: A strictly aerobic, branched actinomycete strain, ES2-5, was isolated from a selenium mining soil in southwest China, identified as Streptomyces sp. based on 16S rRNA gene sequence, physiologic and morphologic characteristics. Both SEM and TEM-EDX analysis showed that Se(IV) was reduced to Se(0) with the formation of SeNPs as a linear chain in the cytoplasm. The sizes of the SeNPs were in the range of 50-500 nm. The cellular concentration of glutathione per biomass decreased along with Se(IV) reduction, and no SeNPs were observed in different sub-cellular fractions in presence of NADPH or NADH as an electron donor, indicating glutathione is most possibly involved in vivo Se(IV) reduction. Strain ES2-5 was resistant to some heavy metal(loid)s such as Se(IV), Cr(VI) and Zn(II) with minimal inhibitory concentration of 50, 80 and 1.5 mM, respectively. CONCLUSIONS: The reducing mechanism of Se(IV) to elemental SeNPs under aerobic condition was investigated in a filamentous strain of Streptomyces. Se(IV) reduction is mediated by glutathione and then SeNPs synthesis happens inside of the cells. The SeNPs are released via hypha lysis or fragmentation. It would be very useful in Se bioremediation if Streptomyces sp. ES2-5 is applied to the contaminated site because of its ability of spore reproduction, Se(IV) reduction, and adaptation in soil.

Sphingoaurantiacus capsulatus sp. nov., isolated from mountain soil, and emended description of the genus Sphingoaurantiacus.

A novel Gram-stain-negative, strictly aerobic, non-motile, rod-shaped, capsule-forming bacterium, designated strain YLT33T, that formed orange-red colonies was isolated from mountain cliff soil from Enshi Grand Canyon, southwest China. Growth occurred at 4-35 °C (optimum 28 °C) and at pH 6.0-10.0 (optimum 7.0). It showed maximum (99.3 %) 16S rRNA gene sequence similarity and formed a monophyletic clade with Sphingoaurantiacus polygranulatusMC 3718T (=CCTCC 2014274T). The DNA G+C content was 68.5 mol% and strain YLT33T showed a 50.5 % DNA-DNA relatedness value to S. polygranulatusMC 3718T. The major fatty acids (>5 %) were C17 : 1ω6c (40.7 %), C15 : 0 (10.4 %), C15 : 1ω6c (9.4 %), summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH; 8.6 %), C17 : 1ω8c (7.1 %), C18 : 1ω7c (6.1 %), and C15 : 0 2-OH (5.7 %). Ubiquinone-10 was the sole respiratory quinone. The polar lipids of strain YLT33T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, two unknown glycolipids and one unknown phospholipid. Carotenoids were present in cells. Homospermidine was the major polyamine. In addition, strain YLT33T showed obvious differences from the closely related strain S. polygranulatusMC 3718T with respect to major polar lipids, fatty acids and other morphological, physiological and biochemical characteristics. These results from polyphasic taxonomic studies reveal that strain YLT33T represents a novel species of the genus Sphingoaurantiacus, for which the name Sphingoaurantiacuscapsulatus sp. nov. is proposed. The type strain is YLT33T (=CCTCC AB 2015150T=KCTC 42644T).

Domibacillus antri sp. nov., isolated from the soil of a cave.

A Gram-reaction-positive, strictly aerobic, capsule-forming, motile and rod-shaped bacterium, designated strain XD80T, was isolated from the soil of a native cave in Lichuan, Hubei province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XD80T was most closely related to Domibacillus iocasae CCTCC AB 2015183T (98.66 % sequence similarity), followed by Domibacillus robiginosus DSM 25058T(97.83 %), Domibacillus tundrae KCTC 33549T (97.70 %), Domibacillus enclensis CCTCC AB 2011121T (97.21 %) and Domibacillus indicus DSM 28032T (96.96 %). Levels of DNA-DNA relatedness between strain XD80T and D. iocasae CCTCC AB 2015183T, D. robiginosusDSM 25058T, D. tundrae KCTC 33549T and D. enclensis CCTCC AB 2011121T were 37.4 %, 53.8 %, 53.6 % and 52.7 %, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, aminophospholipid and two unknown phospholipids. The predominant fatty acids (>5 %) were iso-C15 : 0 (37.3 %), anteiso-C15 : 0 (10.8 %), C16 : 0 (10.4 %), iso-C17 : 0 (10.3 %), C16 : 1ω11c (9.6 %) and anteiso-C17 : 0 (7.4 %). MK-6 (86.4 %) was the major respiratory quinone. The DNA G+C content was 46.4 mol%. The cell-wall peptidoglycan contained meso-diaminopimelic acid (type A1γ). Ribose and glucose were the major whole-cell sugars. In addition, strain XD80T showed differential physiological characteristics from most members of the genus Domibacillus, encompassing hydrolysis of starch, acid production from inositol and raffinose, and production of valine arylamidase. The results of this polyphasic study indicated that strain XD80T represents a novel species of the genus Domibacillus, for which the name Domibacillus antri sp. nov. is proposed. The type strain is XD80T (=CCTCC AB 2015053T=KCTC 33636T).

Hymenobacter monticola sp. nov., isolated from mountain soil.

A Gram-reaction-negative, aerobic, non-motile, red-pigmented and rod-shaped bacterium, designated XF-6RT, was isolated from mountain soil in the Sichuan province of China. Phylogenetic trees based on 16S rRNA gene sequence analysis showed that XF-6RT belonged to the genus Hymenobacter. The greatest 16S rRNA gene sequence similarities of strain XF-6RT were with Hymenobacter soli PB17T (96.4 %) and Hymenobacter saemangeumensis GSR0100T (95.8 %). Summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0, C16 : 1ω5c and anteiso-C15 : 0 were the major fatty acids (>10 %). The only menaquinone was menaquinone-7. The major polar lipids were phosphatidylethanolamine, four aminolipids, four phosphoaminolipids and three lipids. The DNA G+C content was 62 mol%. On the basis of the polyphasic taxonomic analysis, strain XF-6RT is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter monticola sp. nov. is proposed. The type strain is XF-6RT ( = KCTC 42733T = CCTCC AB 2015206T).

Chitinophaga barathri sp. nov., isolated from mountain soil.

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterium, designated strain YLT18T, was isolated from mountain cliff soil of Enshi Grand Canyon in China. The major menaquinone was menaquinone 7 (MK-7) and the predominant fatty acids (>5 %) were iso-C15 : 0, C16 : 1ω5c, iso-C17 : 0 3-OH, summed feature 3 (C16 : 1ω7c/iso-C15 : 0 2-OH) and iso-C15 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, two unknown aminophospholipids, two unknown aminolipids and two unknown polar lipids. The DNA G+C content was 55.4 mol%. According to phylogenetic analysis based on 16S rRNA gene sequences, strain YLT18T was related most closely to Chitinophaga niabensis JS13-10T ( = DSM 24787T) and Chitinophaga cymbidii R156-2T ( = KCTC 23738T), with similarities of 96.7 and 96.2 %, respectively. In addition, strain YLT18T showed obvious differences from the closely related species in terms of esterase (C4) activity, acid production from fructose and rhamnose, and sole carbon source utilization by arabinose and rhamnose. The results from this polyphasic taxonomic study revealed that strain YLT18T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga barathri sp. nov. is proposed. The type strain is YLT18T ( = KCTC 42472T = CCTCC AB 2015054T).

Paenibacillus selenitireducens sp. nov., a selenite-reducing bacterium isolated from a selenium mineral soil.

A Gram-stain-positive, rod-shaped, facultatively anaerobic bacterium, designated strain ES3-24(T), was isolated from a selenium mineral soil. The isolate was endospore-forming, nitrate-reducing and motile by means of peritrichous flagella. The major menaquinone was menaquinone 7 (MK-7) and the predominant fatty acids (>5%) were anteiso-C15:0, iso-C16:0, C16:0 and anteiso-C17:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and two unknown aminophospholipids. Strain ES3-24(T) contained meso-diaminopimelic acid in the cell-wall peptidoglycan and the DNA G+C content was 49.6 mol%. According to phylogenetic analysis based on the 16S rRNA gene sequence, strain ES3-24(T) was most closely related to Paenibacillus terrigena A35(T), with 16S rRNA gene sequence identity of 98.3%, while the other members of the genus Paenibacillus had 16S rRNA gene sequence identities of less than 95.0%. DNA-DNA relatedness between strain ES3-24(T) and P. terrigena CCTCC AB206026(T) was 39.3 %. In addition, strain ES3-24(T) showed obvious differences from closely related species in major polar lipids, nitrate reduction and other physiological and biochemical characteristics. The data from our polyphasic taxonomic study reveal that strain ES3-24(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus selenitireducens sp. nov. is proposed. The type strain is ES3-24(T) ( = KCTC 33157(T) = CCTCC AB2013097(T)).

Paenirhodobacter enshiensis gen. nov., sp. nov., a non-photosynthetic bacterium isolated from soil, and emended descriptions of the genera Rhodobacter and Haematobacter.

A Gram-reaction-negative, facultatively anaerobic, non-motile, rod-shaped, non-photosynthetic bacterial strain, DW2-9(T), was isolated from soil. The highest 16S rRNA gene sequence similarities were found to Rhodobacter capsulatus ATCC 11166(T) (97.1%), Rhodobacter viridis JA737(T) (96.4%), Rhodobacter maris JA276(T) (96.2%), Rhodobacter veldkampii ATCC 35703(T) (96.0%), Haematobacter massiliensis CCUG 47968(T) (96.0%), Haematobacter missouriensis CCUG 52307(T) (95.9%) and Rhodobacter aestuarii JA296(T) (95.7%). The genomic DNA G+C content was 67.2 mol% and the major respiratory quinone was ubiquinone 10 (Q-10). The major cellular fatty acids (>5%) were C(18 : 1)ω7c, C(16 : 0), C(19 : 0) cyclo ω8c and summed feature 3 (one or more of iso-C(15 : 0) 2-OH, C(16 : 1)ω6c and C(16 : 1)ω7c). However, unlike species of the genus Rhodobacter, strain DW2-9(T) neither formed internal photosynthetic membranes nor produced photosynthetic pigments. DNA-DNA hybridization between strain DW2-9(T) and R. capsulatus JCM 21090(T) showed a relatedness of 33%. Strain DW2-9(T) contained phosphatidylethanolamine, phosphatidylglycerol and an unknown aminophospholipid as major polar lipids, which differed from those of species of the genera Rhodobacter and Haematobacter. In addition to the differences in phylogenetic position and polar lipid types, strain DW2-9(T) could be distinguished from species of the genus Haematobacter by the cultivation conditions. On the basis of our polyphasic taxonomic analysis, strain DW2-9(T) is considered to represent a novel genus and species, for which the name Paenirhodobacter enshiensis gen. nov., sp. nov. is proposed. The type strain of Paenirhodobacter enshiensis is DW2-9(T) ( = CCTCC AB 2011145(T) = KCTC 15169(T)). Emended descriptions of the genera Rhodobacter and Haematobacter are also proposed.