Design and construction of chemical-biological module clusters for degradation and assimilation of poly(ethylene terephthalate) waste.

The rising accumulation of poly(ethylene terephthalate) (PET) waste presents an urgent ecological challenge, necessitating an efficient and economical treatment technology. Here, we developed chemical-biological module clusters that perform chemical pretreatment, enzymatic degradation, and microbial assimilation for the large-scale treatment of PET waste. This module cluster included (i) a chemical pretreatment that involves incorporating polycaprolactone (PCL) at a weight ratio of 2% (PET:PCL = 98:2) into PET via mechanical blending, which effectively reduces the crystallinity and enhances degradation; (ii) enzymatic degradation using Thermobifida fusca cutinase variant (4Mz), that achieves complete degradation of pretreated PET at 300 g/L PET, with an enzymatic loading of 1 mg protein per gram of PET; and (iii) microbial assimilation, where Rhodococcus jostii RHA1 metabolizes the degradation products, assimilating each monomer at a rate above 90%. A comparative life cycle assessment demonstrated that the carbon emissions from our module clusters (0.25 kg CO2-eq/kg PET) are lower than those from other established approaches. This study pioneers a closed-loop system that seamlessly incorporates pretreatment, degradation, and assimilation processes, thus mitigating the environmental impacts of PET waste and propelling the development of a circular PET economy.

Complete degradation of PET waste using a thermophilic microbe-enzyme system.

Enzymatic degradation has been proposed as a suitable solution for addressing PET pollution, but approximately 10 % of PET is left as nonbiodegradable. Microbes can completely degrade PET at the gram level per year. Based on the complementary benefits of microbes and enzymes, a microbe-enzyme system was created to completely degrade PET. Here, a thermophilic microbe-enzyme (TME) system composed of Bacillus thermoamylovorans JQ3 and leaf-branch compost cutinase variant (ICCG) was used to demonstrate the synergistic degradation of PET, enabling 100 % degradation of PET waste at a high PET loading level (360 g/L). Six endogenous PET hydrolases of strain JQ3 were discovered by employing an ester bond hydrolysis function-first genome mining (EGM) strategy and first successfully expressed in E. coli. These hydrolases could release TPA as the final product from PET and preferentially degraded BHET instead of MHET. Of these, carboxylesterase 39_5 and ICCG could degrade PET in a synergistic manner to generate 50 µM of TPA, which was greater than the sum of the individual treatments. Finally, the degradation pathway of the TME system was speculated to include biofilm formation, PET degradation and utilization. The successful implementation of this study rendered a scale-up degradation feasible of PET at a lower cost.

Current Fungal Taxonomy and Developments in the Identification System.

A functional identification system is the core and basis of fungal taxonomy, which provides sufficient diagnostic characteristics for species delimitation. Phenotype-based identification systems have exhibited significant drawbacks, such as being laborious and time-consuming. Thus, a molecular-based identification system (rDNA, DNA fingerprint, etc.) is proposed for application to fungi that lack reliable morphological characteristics. High Throughput Sequencing also makes great contributions to fungal taxonomy. However, the formal naming of nonculturable fungi from environmental sequencing is a significant challenge. Biochemical profile-based identification systems have outstanding value in fungal taxonomy and can occasionally be indispensable. This method utilizes biomarker metabolites and proteins that are expected to be unequivocal and stable. Of these, Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry has become the method of choice for chemotaxonomy. In sum, these described identification systems cannot solve all problems of species delimitation, and considerable attention to the updating of fungal nomenclature, standardization of techniques, knowledge sharing, and dissemination will be necessary.

Synergism Between Multi-Pseudomonas and Cutinase for Biodegradation of Crude Oil-Based Derivatives.

Polyethylene terephthalate (PET) as one of the main crude oil-based derivatives, produces a significant amount of waste that is difficult to degrade. Currently, microbial degradation of PET is an eco-friendly, efficient, and economical method. This study was conducted to propose a novel screening strategy for PET-degrading bacteria, and evaluate their degradation efficiency of PET. Two strains, Pseudomonas nitroreducens S8 and Pseudomonas monteilii S17, were isolated and could utilize PET as a carbon source by co-culture. The combined use of both bacteria gave a synergistic effect on the disruption of the PET surface through colonization behavior, which could enhance the subsequent degradation of PET. Its time of reaching a peak value of PET degradation rate (94.5% at 6 d) was 2 days earlier than these of single bacteria. A similar synergistic effect was also observed in the metabolization of PET monomers, and the metabolic rate was expressed as 82.4% of bis (2-hydroxyethyl) terephthalate (BHET), 64.0% of mono (2-hydroxyethyl) terephthalate (MHET), and 20.0% of terephthalic acid (TPA), respectively. This study is novel in showing the degradation of PET waste by combinations of bacterial pretreatment and enzymatic treatment, which can be a promising method.

Directional-path modification strategy enhances PET hydrolase catalysis of plastic degradation.

Poly (ethylene terephthalate) (PET) is a widely used type of general plastic that produces a significant amount of waste due to its non-degradable properties. We propose a novel directional-path modification (DPM) strategy, involving positive charge amino acid introduction and binding groove remodeling, and apply it to Thermobifida fusca cutinase to enhance PET degradation. The highest value of PET degradation (90%) was achieved in variant 4Mz (H184S/Q92G/F209I/I213K), exhibiting values almost 30-fold that of the wild-type. We employed molecular docking, molecular dynamics simulations, and QM/MM MD for the degradation process of PET, accompanied by acylation and deacylation. We found that the distance of nucleophilic attack was reduced from about 4.6 Å in the wild type to 3.8 Å in 4Mz, and the free energy barrier of 4Mz dropped from 14.3 kcal/mol to 7.1 kcal/mol at the acylation which was the rate-limiting step. Subsequently, the high efficiency and universality of the DPM strategy were successfully demonstrated in LCC, Est119, and BhrPETase enhancing the degradation activity of PET. Finally, the highest degradation rate of the pretreated commercial plastic bottles had reached to 73%. The present study provides insight into the molecular binding mechanism of PET into the PET hydrolases structure and proposes a novel DPM strategy that will be useful for the engineering of more efficient enzymes for PET degradation.

Genetic and Chemical Diversity of Edible Mushroom Pleurotus Species.

The genus Pleurotus is one of the most widely cultivated and edible mushrooms with various cultivators. Three molecular characteristics were used to evaluate the genetic diversity of 132 tested samples. Phylogenetic analysis showed five clades for tested samples of the genus Pleurotus by the combined ITS and LSU sequences with strong bootstraps and Bayesian posterior probability supports. A total of 94 polymorphic fragments ranging from 10 to 100 bp were observed by using an intersimple sequence repeat (ISSR) marker. The DNA fragment pattern showed that P. ostreatus cultivator (strain P9) was clearly distinguished from wild strain based on their clear banding profiles produced. DNA GC content of the genus Pleurotus varied from 55.6 mol% to 43.3 mol%. Their chemical composition was also determined, including sugar, amino acid, polar lipid, mycolic acid, quinone, and fatty acid, which presented some high homogeneity. Most of the tested samples contained mycolic acid; glucose and arabinose as the main sugars; aspartic acid, arginine, lysine, tyrosine, and alanine as the main amino acids; and C16:0, C18:0, C18:2 cis-9,12, anteiso-C14:0, and summed feature 8 as the main fatty acids. In addition, their polar lipid profiles were investigated for the first time, which significantly varied among Pleurotus species. The genus Pleurotus contained menaquinone-6 as the sole respiratory quinone, which showed a significant difference with that of its closely related genera. These results of this study demonstrated that the combined method above could efficiently differentiate each Pleurotus species and thus be considered an efficient tool for surveying the genetic diversity of the genus Pleurotus.

Accelerated biodegradation of polyethylene terephthalate by Thermobifida fusca cutinase mediated by Stenotrophomonas pavanii.

Polyethylene terephthalate (PET) is a general plastic that produces a significant amount of waste due to its non-biodagradable properties. We obtained four bacteria (Stenotrophomonas pavanii JWG-G1, Comamonas thiooxydans CG-1, Comamonas koreensis CG-2 and Fulvimonas soli GM-1) that utilize PET as a sole carbon source through a novel stepwise screening and verification strategy. PET films pretreated with S. pavanii JWG-G1 exhibited weight loss of 91.4% following subsequent degradation by Thermobifida fusca cutinase (TfC). S. pavanii JWG-G1 was able to colonize the PET surface and maintain high cell viability (over 50%) in biofilm, accelerating PET degradation. Compared with PET films with no pretreatment, pretreatment with S. pavanii JWG-G1 caused the PET surface to be significantly rougher with greater hydrophilicity (contact angle of 86.3 ± 2° vs. 96.6 ± 2°), providing better opportunities for TfC to contact and act on PET. Our study indicates that S. pavanii JWG-G1 could be used as a novel pretreatment for efficiently accelerating PET biodegradation by TfC.

Synergistic biodegradation of poly(ethylene terephthalate) using Microbacterium oleivorans and Thermobifida fusca cutinase.

Poly(ethylene terephthalate) (PET) is a major source of plastic pollution. Biodegradation technologies are of paramount interest in reducing or recycling PET waste. In particular, a synergistic microbe-enzyme treatment may prove to be a promising approach. In this study, a synergistic system composed of Microbacterium oleivorans JWG-G2 and Thermobifida fusca cutinase (referred to as TfC) was employed to degrade bis(hydroxyethyl) terephthalate (BHET) oligomers and a high crystalline PET film. A novel degradation product that was obtained by M. oleivorans JWG-G2 treatment alone was identified as ethylene glycol terephthalate (EGT). With the addition of TfC as a second biocatalyst, the highest synergy degrees for BHET oligomers and PET film degradation were 2.79 and 2.26, respectively. The largest amounts of terephthalic acid (TPA) and mono(2-hydroxyethyl) terephthalate (MHET) (47 nM and 330 nM, respectively) were detected after combined treatment of PET film with M. oleivorans JWG-G2 at 5 × 103 µL/cm2 and TfC at 120 µg/cm2, and the degree of PET film surface destruction was more significant than those produced by each treatment alone. The presence of extracellular PET hydrolases in M. oleivorans JWG-G2, including three carboxylesterases, an esterase and a lipase, was predicted by whole genome sequencing analysis, and a predicted PET degradation pathway was proposed for the synergistic microbe-enzyme treatment. The results indicated that synergistic microbe-enzyme treatment may serve as a potentially promising tool for the future development of effective PET degradation. KEY POINTS: • An ecofriendly synergistic microbe-enzyme PET degradation system operating at room temperature was first introduced for degrading PET. • A novel product (EGT) was first identified during PET degradation. • Potential PET hydrolases in M. oleivorans JWG-G2 were predicted by whole genome sequencing analysis.

Arthrobacter sedimenti sp. nov., isolated from river sediment in Yuantouzhu park, China.

A Gram-stain positive, motile, aerobic and rod-shaped strain (MIC A30T) was isolated from river sediment in Yuantouzhu park, Wuxi City, China. Growth occurred at 20-40 °C, at pH 6.0-9.0 and at 0-5.0% NaCl. Strain MIC A30T was moderately related to Arthrobacter liuii CGMCC 1.12778T (97.9%), Arthrobacter pokkaliiT (97.9%) and Arthrobacter globiformis NBRC 12137T (96.7%) by 16S rRNA analysis. The DNA-DNA relatedness values between strain MIC A30T and these reference strains were below 30%. The DNA G+C content was 63.1 mol%. Average nucleotide identity (ANI) and genome-to-genome distance (GGD) values between strain MIC A30T and A. liuii CGMCC 1.12778T were 60.34% and 29.39%, respectively. Quinone was identified as MK-9(H2). Major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. Major fatty acids were iso-C15:0, anteiso-C15:0 and anteiso-C17:0. Whole-cell sugars were galactose, mannose and rhamnose. The cell wall peptidoglycan contained A4α peptidoglycan type with lysine as the diagnostic diamino acid. Based on several taxonomic results, strain MIC A30T is identified as a novel species in genus Arthrobacter, whose name is proposed as Arthrobacter sedimenti sp. nov. The type strain is MIC A30T (= KACC 19599T = CGMCC 1.13474T).

Luteimonas cellulosilyticus sp. nov., Cellulose-Degrading Bacterium Isolated from Soil in Changguangxi National Wetland Park, China.

A Gram-negative, motile, aerobic, and rod-shaped strain (MIC 1.5T) was isolated from soil in Changguangxi national wetland park. Growth occurred at 20-45 °C, at pH 6.0-8.0, and at 0-4.0% NaCl. Based on 16S rRNA gene sequence analysis, strain MIC 1.5T was related to were identified as Luteimonas dalianensis CGMCC 1.12191T (95.3%), Luteimonas padinae DSM 101536T (94.5%), Luteimonas huabeiensis DSM 26429T (94.1%), and Luteimonas mephitis DSM 12574T (92.5%). The DNA-DNA relatedness values between strain MIC 1.5T , and these strains were well below 31%. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The DNA G+C content of strain MIC 1.5T was 66.3 mol%. Average nucleotide identity (ANI) and genome-to-genome distance (GGD) values between strain MIC 1.5T and L. dalianensis CGMCC 1.12191T were 65.39% and 29.52%, respectively. The quinone was identified as Q-8. The major fatty acids were iso-C15:0, iso-C15:0 3OH, and iso-C17:0 3OH and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH). Based on the phylogenetic, physiological, and chemotaxonomic results, strain MIC 1.5T represents a novel species of the genus Luteimonas, for which the name Luteimonas cellulosilyticus sp. nov. is proposed. The type strain is MIC 1.5T (= KACC 19469T = CCTCC AB 2017256T).

Cellulomonas aurantiaca sp. nov., isolated from a soil sample from a tangerine field.

A Gram-stain positive, facultatively aerobic, motile and rod-shaped bacterial strain, designated THG-SMD2.3T, was isolated from a soil sample collected in a tangerine field, Republic of Korea. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Cellulomonas and to be closely related to Cellulomonas fimi ATCC 484T (98.5%), Cellulomonas biazotea DSM 20112T (98.3%), Cellulomonas chitinilytica X.bu-bT (98.0%), Cellulomonas xylanilytica XIL11T (97.2%), Cellulomonas humilata ATCC 25174T (97.1%) and Cellulomonas composti TR7-06T (97.0%). The 16S rRNA gene sequence similarities with other current species of the genus Cellulomonas were in the range 95.4-96.6%. Catalase and oxidase tests were found to be positive. The DNA G+C content was determined to be 73.0 mol%. DNA-DNA hybridization values between strain THG-SMD2.3T and C. fimi ATCC 484T, C. biazotea DSM 20112T, C. chitinilytica X.bu-bT, C. xylanilytica XIL11T, C. humilata ATCC 25174T and C. composti TR7-06T were 58.1 ± 1.6%, 56.7 ± 0.8%, 30.3 ± 1.6%, 22.8 ± 1.6%, 19.9 ± 1.6%, and 13.5 ± 3.0%, respectively. Strain THG-SMD2.3T was also found to be able to grow at 20-42 °C, at 0-3% NaCl and at pH 5.5-10. The major fatty acids were identified as anteiso-C15:0, iso-C15:0, anteiso-C17:0 and iso-C14:0. The predominant menaquinone was identified as tetrahydrogenated menaquinones with nine isoprene units [MK-9(H4)]. The polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. Based on these phenotypic, genotypic and phylogenetic characterisations strain THG-SMD2.3T (= KACC 19341T = CGMCC 1.16303T) is concluded to represent a novel species of the genus Cellulomonas, for which the name Cellulomonas aurantiaca sp. nov. is proposed.

Chitinophaga aurantiaca sp. nov., isolated from a soil sample from a tangerine field.

A Gram-stain-negative, facultatively anaerobic, non-motile and rod-shaped bacterial strain, designated THG-SD5.5T, was isolated from a soil sample collected in a tangerine field, Republic of Korea. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Chitinophaga and to be closely related to Chitinophaga ginsengihumi KACC 17604T (97.9%) and Chitinophaga rupis KACC 14521T (97.5%). The 16S rRNA gene sequence similarities with other species of the genus Chitinophaga were in the range 92.8-95.5%. Catalase test was positive. Oxidase test was negative. The DNA G + C content was determined to be 46.1 mol%. DNA-DNA hybridization values between strain THG-SD5.5T and C. ginsengihumi KACC 17604T and C. rupis KACC 14521T were 45.1% and 15.6%, respectively. Strain THG-SD5.5T was also found to be able to grow at 24-33 °C, at 0-5% NaCl and at pH 5.5-9.0. The major fatty acids were identified as anteiso-C15:0, C16:0, anteiso-C17:0 and C18:0. The dominant respiratory quinone was identified as menaquinone-7 (MK-7). The polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid, two unidentified phospholipids and three unidentified lipids. Based on these phenotypic, genotypic and phylogenetic characterisations, strain THG-SD5.5T (= KACC 19338T = CGMCC 1.16304T) is concluded to represent a novel species of the genus Chitinophaga, for which the name Chitinophaga aurantiaca sp. nov. is proposed.

Glaciecola amylolytica sp. nov., an amylase-producing bacterium isolated from seawater.

A Gram-stain-negative, aerobic, non-motile and coccus-shaped bacterium (THG-3.7T) was isolated from seawater. Growth occurred at 10-30 °C (optimum 25 °C), at pH 6-8 (optimum 7) and in the presence of 1-8 % (w/v) NaCl (optimum 4 %). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-3.7T were identified as Paraglaciecola mesophila DSM 15026T (95.3 % similarity), Glaciecola pallidula DSM 14239T (95.2 %), Paraglaciecola aquimarina KCTC 32108T (95.1 %), Paraglaciecola arctica KACC 14537T (94.9 %), Glaciecola nitratireducens KCTC 12276T (94.7 %) and Paraglaciecola psychrophila CGMCC 1.6130T (94.7 %). 16S rRNA gene sequence similarities among strain THG-3.7T and other species were lower than 94.7 %. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified lipid and one unidentified aminolipid. The quinone system was composed of Q-8. The major fatty acids were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The DNA G+C content of strain THG-3.7T was 47.9 mol%. On the basis of the data presented, strain THG-3.7T represents a novel species of the genus Glaciecola, for which the name Glaciecola amylolytica sp. nov. is proposed. The type strain is THG-3.7T (=KACC 19478T=CCTCC AB 2017258T).

Scopulibacillus cellulosilyticus sp. nov., a cellulose-degrading bacterium isolated from tea.

A Gram-stain positive, aerobic, non-motile, endospore-forming and rod-shaped strain (THG-NT9T) was isolated from a green tea sample. Growth occurred at 20-45 °C (optimum 28-35 °C), at pH 6.0-8.0 (optimum 7.0) and at 0-2.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-NT9T were identified as Scopulibacillus daqui DSM 28236T (98.6%), Scopulibacillus darangshiensis DSM 19377T (97.4%), Pullulanibacillus pueri CGMCC 1.12777T (96.7%) and Pullulanibacillus camelliae CGMCC 1.15371T (96.3%). The DNA G + C content of strain THG-NT9T was determined to be 47.5 mol %. DNA-DNA hybridization values between strain THG-NT9T and S. daqui DSM 28236T, S. darangshiensis DSM 19377T, P. pueri CGMCC 1.12777T, P. camelliae CGMCC 1.15371T and Pullulanibacillus naganoensis DSM 10191T were 41.3 ± 0.1 (39.4 ± 0.4% reciprocal analysis), 39.1 ± 0.1 (37.3 ± 0.1%), 21.4 ± 0.7 (20.1 ± 0.3%), 20.7 ± 0.1 (20.1 ± 0.4%) and 12.1 ± 0.2% (8.3 ± 0.2%). The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified lipids. The quinone was identified as MK-7. The major fatty acids were C18:3 ω7c, iso-C15:0, iso-C16:0, iso-C17:0 and anteiso-C17:0. The cell wall type was determined to be A1γ peptidoglycan with meso-diaminopimelic acid as the diagnostic diamino acid plus alanine and glutamic acid and glucose as the cell wall sugar. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA-DNA hybridization data, strain THG-NT9T represents a novel species of the genus Scopulibacillus, for which the name Scopulibacillus cellulosilyticus sp. nov. is proposed. The type strain is THG-NT9T (= KCTC 33918T = CGMCC 1.16305T).

Camelliibacillus cellulosilyticus gen. nov., sp. nov., a cellulose-degrading bacterium isolated from tea.

A Gram-stain-positive, oxidase- and catalase-positive, endospore-forming, aerobic, non-motile and rod-shaped bacterium (THG-YT1T) was isolated from green tea. Growth occurred at 10-40 °C (optimum, 25-30 °C), at pH 6-8 (optimum, 7) and at 0-2 % NaCl (optimum, 0 %). Based on 16S rRNA gene sequences, phylogenetic analyses showed that strain THG-YT1T formed a distinct lineage with respect to closely related genera in the family Bacillaceae. Strain THG-YT1T was most closely related to the genera within the families Pullulanibacillus, Scopulibacillus, Tuberibacillus and Caenibacillu, with levels of 16S rRNA gene sequence similarity to the type species of members of these genera of less than 95.0 %. The menaquinone was MK-7. The polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified aminolipids and two unidentified glycolipids. The major fatty acids of strain THG-YT1T were C18 : 3ω7c and anteiso-C17 : 0. The cell-wall peptidoglycan type was A1γ with meso-diaminopimelic acid as the diagnostic diamino acid plus alanine and glutamic acid. The cell-wall sugar was glucose. The DNA G+C content of strain THG-YT1T was determined to be 53.5 mol%. Based on the data presented here, strain THG-YT1T represents a novel species of a new genus of the family Bacillaceae, for which the name Camelliibacillus cellulosilyticus gen. nov., sp. nov. is proposed. The type strain is Camelliibacillus cellulosilyticus THG-YT1T(=KACC 19471T=CGMCC 1.16306T).

Nocardioides pelophilus sp. nov., isolated from freshwater mud.

A Gram-stain-positive, aerobic, motile, rod- or cocci-shaped bacterium with flagella bacterium (THG-T63T) was isolated from freshwater mud. Growth occurred at 10-40 °C (optimum, 28-35 °C), at pH 6-8 (optimum, 7) and at 0-6 % NaCl (optimum, 2 %). Based on 16S rRNA sequence analysis, the nearest phylogenetic neighbours of strain THG-T63T were identified as Nocardioides panacisoli KCTC 19470T (97.5 %), Nocardioides caeni KCTC 19600T (96.4 %), Nocardioides humi KCTC 19265T (96.3 %), Nocardioides kongjuensis KCTC 19054T (96.1 %) and Nocardioides nitrophenolicus KCTC 457BPT (96.1 %). 16S rRNA sequence similarities among strain THG-T63T and other species were lower than 96.0 %. The polar lipids were phosphatidylglycerol, phosphatidylinositol and one unidentified phospholipid. The quinone system was composed of MK-8 (H4). The major fatty acids were C16 : 0, C17 : 1ω6c, C17 : 1ω8c, C18 : 0 10-methyl, C18 : 1ω9c and iso-C16 : 0. The cell-wall peptidoglycan contained ll-2,6-diaminopimelic acid. The DNA G+C content of strain THG-T63T was 74.6 mol%. Strain THG-T63T exhibited levels of DNA-DNA relatedness of 20-44 % to the type strains of phylogenetically related Nocardioides species and could be differentiated from these species based on differences in phenotypic characteristics. On the basis of the data presented here, strain THG-T63T represents a novel species of the genus Nocardioides, for which the name Nocardioides pelophilus sp. nov. is proposed. The type strain is THG-T63T(=KACC 19192T=CGMCC 4.7388T).

Nibribacter flagellatus sp. nov., isolated from rhizosphere of Hibiscus syriacus and emended description of the genus Nibribacter.

A Gram-stain negative, aerobic, motile by flagella, rod-shaped strain (THG-T16T) was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10-40 °C (optimum 28-30 °C), at pH 6.0-8.0 (optimum 7.0) and at 0-1.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-T16T were identified as Nibribacter koreensis KACC 16450T (98.6%), Rufibacter roseus KCTC 42217T (94.7%), Rufibacter immobilis CCTCC AB 2013351T (94.5%) and Rufibacter tibetensis CCTCC AB 208084T (94.4%). The DNA G+C content of strain THG-T16T was determined to be 46.7 mol%. DNA-DNA hybridization values between strain THG-T16T and N. koreensis KACC 16450T, R. roseus KCTC 42217T, R. immobilis CCTCC AB 2013351T, R.tibetensis CCTCC AB 208084T were 33.5 ± 0.5% (31.7 ± 0.7% reciprocal analysis), 28.1 ± 0.2% (25.2 ± 0.2%), 17.1 ± 0.9% (10.2 ± 0.6%) and 8.1 ± 0.3% (5.2 ± 0.1%). The polar lipids were identified as phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and three unidentified lipids. The quinone was identified as MK-7 and the polyamine as sym-homospermidine. The major fatty acids were identified as C16:1 ω5c, C17:1 ω6c, iso-C15:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA-DNA hybridization data, strain THG-T16T represents a novel species of the genus Nibribacter, for which the name Nibribacter flagellatus sp. nov. is proposed. The type strain is THG-T16T(= KACC 19188T = CCTCC AB 2016246T).

Sphingomonas rhizophila sp. nov., isolated from rhizosphere of Hibiscus syriacus.

A Gram-stain-negative, aerobic, non-motile, rod-shaped, catalase-positive and oxidase-positive bacteria (THG-T61T), was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10-37 °C (optimum 25-30 °C), at pH 5.0-9.0 (optimum 7.0) and in the presence of 0-2.0 % NaCl (optimum without NaCl supplement). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-T61T were identified as Sphingomonas ginsengisoli KCTC 12630T (97.9 %), Sphingomonas jaspsi DSM 18422T (97.8 %), Sphingomonas astaxanthinifaciens NBRC 102146T (97.4 %), Sphingomonassediminicola KCTC 12629T (97.2 %), 'Sphingomonas swuensis' KCTC 12336 (97.1 %) and Sphingomonas daechungensis KCTC 23718T (96.9 %). The isoprenoid quinone was ubiquinone-10 (Q-10). The major fatty acids were C16 : 0, C17 : 1ω6c, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and summed feature 7 (C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, one unidentified lipid, one unidentified phospholipid, one unidentified glycolipid and one unidentified phosphoglycolipid. The polyamine was homospermidine. The DNA G+C content of strain THG-T61T was 65.6 mol%. The DNA-DNA relatedness values between strain THG-T61T and its closest reference strains were less than 49.2 %, which is lower than the threshold value of 70 %. Therefore, strain THG-T61T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas rhizophila sp. nov. is proposed. The type strain is THG-T61T (=KACC 19189T=CCTCC AB 2016245T).

Paracoccus pueri sp. nov., isolated from Pu'er tea.

A Gram-stain negative, aerobic, short rod-shaped, motile by flagella bacterial strain (THG-N2.35T), was isolated from Pu'er tea. Growth occurred at 10-40 °C (optimum 28 °C), at pH 4-7 (optimum 7) and at 0-5% NaCl (optimum 1%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-N2.35T were identified as Paracoccus hibisci KACC 18632T (99.0%), Paracoccus tibetensis CGMCC 1.8925T (98.7%), Paracoccus beibuensis CGMCC 1.7295T (98.2%), Paracoccus aestuarii KCTC 22049T (98.2%), Paracoccus rhizosphaerae LMG 26205T (98.1%), Paracoccus zeaxanthinifaciens ATCC 21588T (97.1%), Paracoccus marcusii DSM 11574T (97.0%). Levels of similarity between strain THG-N2.35T and other Paracoccus species were lower than 97.0%. DNA-DNA hybridization values between strain THG-N2.35T and P. hibisci KACC 18632T, P. tibetensis CGMCC 1.8925T, P. beibuensis CGMCC 1.7295T, P. aestuarii KCTC 22049T, P. rhizosphaerae LMG 26205T, P. zeaxanthinifaciens ATCC 21588T, P.marcusii DSM 11574T were 47.5% (42.3%, reciprocal analysis), 36.1% (32.3%), 24.7% (22.1%), 19.2% (16.3%), 11.3% (8.8%), 11.1% (10.8%), 6.1% (5.8%), respectively. The DNA G+C content of strain THG-N2.35T was 62.3 mol%. The polar lipids were diphosphatidylglycerol, phosphatidyl-N-methylethanolamine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The quinone was ubiquinone-10 (Q-10). The major fatty acids were C10:0 3OH, C16:0, C18:0 and C18:1 ω7ϲ. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-N2.35T represent a novel species of the genus Paracoccus, for which the name Paracoccus pueri sp. nov. is proposed. The type strain is THG-N2.35T (= KACC 18934T = CCTCC AB 2016177T).

Actinotalea solisilvae sp. nov., isolated from forest soil and emended description of the genus Actinotalea.

A Gram-stain-positive, aerobic, non-motile and short-rod-shaped actinobacterium, designated THG-T121T, was isolated from forest soil. Growth occurred at 10-40 °C (optimum 28-30 °C), at pH 6-8 (optimum 7) and at 0-4 % NaCl (optimum 1 %). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-T121T were identified as Actinotalea ferrariae KCTC 29134T (97.9 %), Actinotalea fermentans KCTC 3251T (97.3 %), Cellulomonas carbonis KCTC 19824T (97.2 %). 16S rRNA gene sequence similarities among strain THG-T121T and other recognized species were lower than 97.0 %. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two phosphatidylinositol mannosides, one unidentified phospholipid, three unidentified glycolipids and one unidentified lipid. The isoprenoid quinone was menaquinone (MK-10(H4)). The major fatty acids were anteiso-C15 : 0, anteiso-C15 : 1 A, C16 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C17 : 0. The whole-cell sugars of strain THG-T121T were rhamnose, ribose, mannose and glucose. The peptidoglycan type of strain THG-T121T is A4ß, containing l-Orn-D-Ser-L-Asp. The DNA G+C content of strain THG-T121T was 72.4 mol%. DNA-DNA hybridization values between strain THG-T121T and A. ferrariae KCTC 29134T, A. fermentans KCTC 3251T and C. carbonis KCTC 19824T were 30.2 % (27.3 %, reciprocal analysis), 28.4 %, (17.3 %) and 16.9 %, (9.3 %), respectively. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-T121T represents a novel species of the genus Actinotalea, for which the name Actinotaleasolisilvae sp. nov. is proposed. The type strain is THG-T121T (=KACC 19191T=CGMCC 4.7389T).