[Air Microbial Contamination and Risk of Respiratory Exposure of Workers in Chicken Farms].

Animal farms are important sources of microbial contamination in the air environment. However, there are few reports on the time-regularity characteristics of airborne microbial contamination in farms. In the context of this situation, a study was conducted for more than 80 weeks using 16S rRNA gene amplicon sequencing to characterize the bacterial distribution and respiratory exposure in the farm air and fecal environment, respectively, taking a layer farm as an example. The results showed that 16S rRNA concentrations in air and manure samples ranged from 6.08×105-4.90×106 copies·m-3 and 4.27×108-1.15×1010 copies·g-1, respectively. The mean values of airborne bacterial concentrations were significantly higher in winter than in summer, whereas the biodiversity showed the opposite trend. The dominant bacterial phylum in both air and manure in the layer farm was Firmicutes. During the investigated time, the top three dominant genera in the air were relatively stable, in the order of Lactobacillus, Bacteroides, and Faecalibacterium, whereas the dominant genera in feces fluctuated with the increase in breeding time. The correlation between the community structure of bacteria and pathogenic bacteria in both air and manure was not significant, but the concentrations of both target microorganisms in different media were significantly correlated. The bioaerosolization index of bacteria in manure showed an increasing trend with increasing breeding time, whereas the opposite trend was observed for pathogenic bacteria. In this case, [Ruminococcus]_torques_group, Bacteroides, and Faecalibacterium were the top three pathogenic genera that were the most prone to aerosolization. There were seasonal differences in bacterial respiratory exposures of chicken farm workers, with mean intake values of 2.54×107 copies·d-1 and 2.87×105 copies·d-1 for bacteria and pathogenic bacteria, respectively. The results of this study will provide a scientific basis for systematically assessing the contamination characteristics and potential health risks of airborne microorganisms on farms and for developing corresponding industry standards for occupational exposure and prevention and control measures.

[Diversity and Community Structure of Airborne Fungi in Different Working Areas of Composting Plants].

Composting plants are an important source of airborne fungi. At present, no research has been reported on differences in the types and abundance of escaped fungi in different working areas, which makes it very difficult to comprehensively assess the ecological health risks of the air in composting plants. In light of this situation, this study collected air samples from the composting, packaging, office, and downwind areas of the composting plants and used high-throughput sequencing technology to analyze and compare the biological diversity and community structure of airborne fungi in the four areas. The source of airborne fungi in offices and downwind areas was further traced. The results showed that the highest abundance and diversity of airborne fungi were found in the packing and composting areas of the composting plants. Ascomycota and Basidiomycota were two fungal phyla with the highest relative abundance in the four regions. Overall, the distribution of dominant fungal genera differed; Trichocomaceae and Davidiella were the dominant genera in three areas of the composting plants. Among the 136 detected fungal genera, the number of endemic airborne fungal genera in the composting and packaging area was the largest, and 52.94% of the fungal genera was shared by the four areas. At the level of fungal genera, the community structures in the air in three areas of the composting plants were similar. The statistical difference analysis results of the key genera in different areas of the composting plants showed that the number of different fungal genera between the downwind, packaging, and composting areas was the largest, and no statistically different fungal genera were detected in the air between the packaging and composting areas. The Source Tracker analysis results showed that the contribution percentage of the packaging and composting areas to the airborne fungi in the office and downwind areas was between 9.52%-15.85%. The results of this study will provide basic data for evaluating the relationship between airborne fungal exposure and human health in different areas of the composting plant, as well as its ecological impact on the surrounding air environment.

[Sources and Pollution Characteristics of Antibiotic Resistance Genes and Conditional Pathogenic Bacteria in Concentrated Poultry Feeding Operations].

Concentrated animal feeding operations (CAFOs) is considered a source of airborne human pathogens and antibiotic resistance genes. This study collected fecal samples and corresponding air samples from inside and outside atmospheric environments of layer and broiler feeding operations. We detected the types of 61 genes including five classes of antibiotics antibiotic resistance genes (23 genes of ampicillin, 23 genes of tetracycline, 5 genes of quinolones, 5 genes of sulfonamides and 2 genes of erythromycin), five conditional pathogenic bacteria (Enterococcus, Escherichia coli, Staphylococcus, Campylobacter and Clostridium perfringens) and class1 integron. Quantitative real time PCR was used to analyze concentrations of typical genes with relatively high detection rates. The results indicated that the detection rates of antibiotic resistance genes were 8,7,2,3 and 2. At the same time, two kinds of pathogenic bacteria were detected. The detection rates of the target genes in the air were lower than those of the fecal sample. The total bacterial gene (16S rDNA) concentration in the air of layer and broiler was 106 copies·m-3, and that of the other typical genes was about 104copies·m-3. And the outdoor concentration was much lower than the indoor concentration. The proportions of antibiotic resistance genes and conditional pathogenic bacteria in the air were higher than those in the fecal samples and the outdoor proportions were lower than the indoor proportions. Preliminary results of this study indicated that feces was an important source of antibiotic resistance genes, conditional pathogenic bacteria and class1 integron. Aerosolization degrees of genes in feces were different. This study will provide the basic data for both source tracking of antibiotic resistance genes and pathogens from CAFOs and risk assessment of pollution of CAFOs in the surrounding air environment.

[Ammonia Removal Rate and Microbial Community Structures in Different Biofilters for Treating Aquaculture Wastewater].

Three MBBRs and three curtain type trickling filters (CTFs) with different carriers were operated in lab-scale simulated RASs. The characteristics of biofilms, ammonia removal rates and microbial communities in six reactors were compared with each other. Compared with the biofilms of MBBRs, the biofilms of CTFs were heavier and grew faster. The weight of biofilms on CTFs with carbon fiber carriers was the maximum (45.97 g·m-2), and the ammonia nitrogen removal efficiency (86.76%) of this CTFs was higher than the other filters or reactors (61.96%~78.76%). In addition, the concentration of the accumulated nitrite in the carbon fiber CTFs was the lowest in all the six reactors. The microbial communities of biofilms in the six biofilters were evaluated by the high-throughput Illumina-MiSeq sequencing technology. The results showed that the microbial (bacteria and eukaryote) community in biofilms of CTFs was different from that in biofilms of MBBRs. At both bacteria and micro-eukaryote level, the species richness and biological diversity of biofilms in the trickling filters were higher than those in the MBBRs. On the contrary, the Simpson index of bacterial community in biofilms of MBBRs was higher than that in the trickling filters. In all the six biofilters, Nitrospira and Nakamurella were the dominated bacterial genera. Saprospiraceae was more abundant in CTFs than in MBBRs, but Comamonadaceae was enriched in the MBBRs. At the micro-eukaryote genus level, Rhabditida norank genus was more abundant in CTFs, while Chlorophyceae norank genus was more abundant in the MBBRs. The results provide useful information about microbial ecology that can be used for the application of CTFs in RAS.

Dyadobacter endophyticus sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, designated 65T, was isolated from surface-sterilized root tissue of maize, collected from Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 65T belonged to the genus Dyadobacter and had highest 16S rRNA gene sequence similarity to Dyadobacter jiangsuensis CGMCC 1.12969T (99.1 %), Dyadobacter beijingensis CGMCC 1.6375T (98.8 %), Dyadobacter fermentans DSM 18053T (98.6 %) and Dyadobacter soli KCTC 22481T (98.6 %). However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to D. jiangsuensis CGMCC 1.12969T (18.2±1.3 %), D. beijingensis CGMCC 1.6375T (14.2±2.0 %), D. fermentans DSM 18053T (14.1±2.0 %) and D. soli KCTC 22481T (13.8±0.6 %). The predominant respiratory quinone was menaquinone-7 (MK-7) and the major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω5c, iso-C15 : 0 3-OH, C16 : 0 3-OH and C16 : 0. The polar lipid profile of strain 65T revealed the presence of phosphatidylethanolamine, four aminolipids and two unidentified phospholipids. The DNA G+C content was 46.6 mol%. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 65T from closely related species of the genus Dyadobacter. Strain 65T thus represents a novel species within the genus Dyadobacter, for which the name Dyadobacterendophyticus sp. nov. is proposed. The type strain is 65T (=CGMCC 1.15288T=DSM 100786T).

Sphingomonaszeicaulis sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-staining-negative, aerobic and rod-shaped strain designated 541T was isolated from surface-sterilized root tissue of maize, collected from the Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study using a polyphasic approach. According to a phylogenetic tree based on 16S rRNA gene sequences, strain 541T represented a member of the genus Sphingomonas and clustered with Sphingomonas sanxanigenens DSM 19645T, with which it shared the highest 16S rRNA gene sequence similarity (98.8 %). The predominant respiratory quinone was ubiquinone-10 (Q-10), the major polyamine was sym-homospermidine and the major cellular fatty acids were C18 : 1ω7c (50.9 %), C16 : 0 (22.0 %) and C14 : 0 2-OH (11.4 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. The DNA G+C content was 64.7 mol%. DNA-DNA relatedness between strain 541T and its closest phylogenetic relative Sphingomonas sanxanigenens DSM 19645T was 50.8 %. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 541T from closely related species of the genus Sphingomonas. Strain 541T represents a novel species within the genus Sphingomonas, for which the nameSphingomonas zeicaulis sp. nov. is proposed, with the type strain 541T (=CGMCC 1.15008T=DSM 100587T).

Filimonas zeae sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic, motile by gliding and filamentous strain, designated 772T,was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, China. 16S rRNA gene sequence analysis indicated that strain 772T was closely related to Filimonas endophytica SR2-06T andFilimonas lacunae YT21T of the family Chitinophagaceae with sequence similarities of 99.0 and 96.9 %, respectively. However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to Filimonas. endophytica KCTC 42060T (18.7±1.8 %) and Filimonas. lacunae DSM 21054T (17.9±2.0%). The DNA G+C content of strain 772T was 44.9 mol%. The respiratory quinone was menaquinone-7 and the polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phospholipids and one unidentified lipid. The major fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 772T from the closely related species Filimonas. endophytica andF. lacunae. Strain 772T thus represents a novel species within the genus Filimonas, for which the name Filimonas zeae sp. nov. is proposed. The type strain is 772T (=CGMCC 1.15290T=DSM 100760T).

Paenibacillus radicis sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-positive, aerobic, endospore-forming, and rod-shaped strain designated 694T was isolated from surface-sterilized root tissue of a maize planted in the Fangshan District of Beijing, People's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain 694T and Paenibacillus xinjiangensis DSM 30034T (98.5 %) and Paenibacillus glycanilyticus (98.1 %), respectively. However, the DNA-DNA hybridization values between strain 694T and its close relatives P. xinjiangensis 16970T and Paenibacillus algorifonticola CGMCC 1.10223T were 30.0 % and 36.7 % respectively. The DNA G+C content of strain 694T was determined to be 46.9 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to be anteiso-C15 : 0 (42.1 %), iso-C15 : 0 (18.4 %), iso-C16 : 0 (11.2 %) and C16 : 0 (12.1 %). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 694T from the closely related species in the genus Paenibacillus. Strain 694T is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus radicis sp. nov. is proposed, with the type strain 694T ( = CGMCC 1.15286T = DSM 100762T).

[Distribution Characteristics of Antibiotic Resistance Genes in Vegetable Soils in Beijing].

In order to study the distribution characteristics and pollution status of antibiotic resistance genes (ARGs) in the vegetable soils, greenhouse and field soil samples in 11 organic vegetable bases with long-term manure amended in Beijing were collected. All samples were subjected to the determination of 13-type antibiotics and related ARGs. The experimental results showed that tetracycline residues were the highest among all antibiotics tested, followed by sulfanilamides. Antibiotic residues were higher in greenhouse soils than in field soils. For all soil samples, sulfanilamide resistance genes sul 1 and sul 2, as well as the tetracycline resistance gene tetL were observed with 100% detection frequencies. Detection frequency for class I integron (intI 1) in greenhouse soils was 1.5 times higher than that in field soils. The relative abundance for sul 2 and tetL in soil samples ranged 10-4-10-2 as found by quantitative PCR (qPCR) detection. The relative abundance of sul 2 was significantly positively correlated with the contents of sulfadimidine and doxycycline (P<0.05), and the relative abundance of tetL did not exhibit evident correlation with the contents of antibiotics tested. These results would contribute to understanding of the pollution status of ARGs in vegetable soils in Beijing, and to evaluation of currently agricultural practices based on ARGs.

[Pollution Characteristics of Antibiotic Resistant Bacteria from Atmospheric Environment of Animal Feeding Operations].

Animal feeding operations is considered as a source of airborne human pathogens and antibiotics genes. In this study, we investigated the concentration, size distribution and aerodynamic diameter of airborne bacteria, tetracycline resistant bacteria and erythromycin resistant bacteria from 22 animal feeding operations in three districts of Beijing. The results indicated that the highest and lowest concentrations of these three types of bioaerosol were detected in pig and cow house, respectively. The concentration of airborne bacteria was higher in layer house, whereas concentration of antibiotic resistant bacteria was higher in broiler house. Tetracycline and erythromycin resistant bacteria were detected from the atmospheric environment from out door of layer and broiler house with the percentages of 8.81%, 15.89% and 23.19%, 36.53%, respectively. The size distribution and aerodynamic diameter varied from inside and outside of pig, cow, and layer and broiler house. Most of tetracycline resistant bacteria and erythromycin resistant bacteria from current four types of animal feeding operations mainly deposited in pharynx, larynx and bronchus of respiratory system. This study would offer the base data for evaluating the detriment of bioaerosol from animal feeding operations to the worker and environment.

Paenibacillus wenxiniae sp. nov., a nifH gene -harbouring endophytic bacterium isolated from maize.

A novel Gram-positive, aerobic, motile, endospore-forming, rod-shaped bacterium, designated 373(T) was isolated from surface-sterilised root tissue of a maize planted in Fangshan District of Beijing, Peopole's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. The highest 16S rRNA gene sequence similarity was found between strain 373(T) and Paenibacillus hunanensis (98.1%), meanwhile the 16S rRNA gene sequence similarity between strain 373(T) and the type strains of other recognised members of the genus Paenibacillus were all below 95.6%. However, the DNA-DNA hybridization values between strain 373(T) and the type strain P. hunanensis DSM 22170(T) was 30.2%. The DNA G+C content of strain 373(T) was determined to be 46.0 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to consist of anteiso-C15: 0 (59.6%), anteiso-C17: 0 (12.8%) and C16: 0 (6.7%). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 373(T) from the closely related species in this genus Paenibacillus. Strain 373(T) is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus wenxiniae sp. nov. is proposed, with the type strain 373(T) (= CGMCC 1.15007 (T) = DSM100576 ).

Variovorax guangxiensis sp. nov., an aerobic, 1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from banana rhizosphere.

A 1-aminocyclopropane-1-carboxylate deaminase producing bacterium, designated GXGD002(T), was isolated from the rhizosphere of banana plants cultivated in Guangxi province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GXGD002(T) is a member of the genus Variovorax. High levels of 16S rRNA gene sequence similarity are found between strain GXGD002(T) and Variovorax paradoxus DSM 30034(T) (99.4 %), Variovorax ginsengisoli KCTC 12583(T) (99.1 %), Variovorax boronicumulans KCTC 22010(T) (99.0 %), Variovorax soli DSM18216(T) (98.7 %), Variovorax defluvii DSM 27259(T) (98.1 %) and Variovorax dokdonensis KCTC 12544(T) (97.4 %) respectively. However, the DNA-DNA hybridization values between strain GXGD002(T) and its closely related species V. paradoxus DSM 30034(T), V. ginsengisoli KCTC 12583(T) and V. boronicumulans KCTC 22010(T) were found to be 40.7, 30.9 and 23.7 %, respectively. The DNA G + C content of strain GXGD002(T) was found to be 67.8 mol%. The major fatty acids of strain GXGD002(T) are C16:0 (20.3 %), C10:0 3OH (18.4 %), C17:0 cyclo (18.9 %), C18:1w7c (12.3 %) and summed feature 3 (13.9 %). The predominant respiratory quinone was identified as ubiquinone-8 (Q-8) and the major polar lipids as phosphatidylethanolamine and phosphatidylglycerol. The results of polyphasic taxonomic study including physiological and biochemical tests, whole-cell SDS-PAGE profiles and chemotaxonomic analysis allowed a clear differentiation of strain GXGD002(T) from the other species in the genus Variovorax. Based on these results, a new species, Variovorax guangxiensis, is proposed. The type strain is GXGD002(T) (=DSM 27352(T) = ACCC 05911(T)).

[Concentration and size distribution of bioaerosols at non-haze and haze days in Beijing].

In recent years, haze has been observed frequently in Beijing. Haze was one of the atmospheric phenomena caused by the accumulation of particulate matter. As an important fraction of particular matter, bioaerosol could potentially cause significantly negative health effects. In this study, we detected the concentration and size distribution of viable bioaerosol during non-haze and haze days, analyzed correlation of viable bioaerosol with the ambient temperature and relative humidity using Spearman's correlation coefficient and finally detected the changing of size distribution of viable bioaerosol in summer and winter. Results indicated that concentrations of viable bioaerosol exhibited a negative correlation with Air Quality Index (AQI) of PM2.5 and positive correlation with temperature. Relative humidity had a negative correlation with airborne bacteria while positive correlation with airborne fungi. The highest concentration of airborne bacteria and fungi were detected at size arrange of 4.5-7.0 µm and 2. 1-3.3 µm in the winter, respectively. In the summer, both the highest concentration of airborne bacteria and fungi were observed at size arrange of 3.3-4.5 µm. The results of this study will provide the basis data for hazard evaluation of bioaerosol on human health at non-haze and haze days.

Hansschlegelia beijingensis sp. nov., an aerobic, pink-pigmented, facultatively methylotrophic bacterium isolated from watermelon rhizosphere soil.

A novel Gram-stain-negative, aerobic, rod-shaped strain designated PG04(T) was isolated from the rhizosphere of watermelon plants cultivated in Beijing, China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, isolate PG04(T) belonged clearly to the genus Hansschlegelia and was most closely related to Hansschlegelia zhihuaiae (97.3 % similarity to the type strain). The predominant respiratory quinone was ubiquinone 10 (Q-10) and the polar lipid profile was composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The major fatty acids were C18 : 1ω7c (41.3 %), C19 : 0 cyclo ω8c (30.6 %) and C16 : 0 (19.1 %). The G+C content of the DNA was about 64.4 mol%. DNA-DNA hybridization experiments showed 34.4 % relatedness between strain PG04(T) and H. zhihuaiae DSM 18984(T). The results of physiological and biochemical tests and differences in fatty acid profiles allowed clear phenotypic differentiation of strain PG04(T) from the most closely related species in the genus, H. zhihuaiae. Strain PG04(T) therefore represents a novel species within the genus Hansschlegelia, for which the name Hansschlegelia beijingensis sp. nov. is proposed, with the type strain PG04(T) ( = DSM 25481(T) = ACCC 05759(T)).

[Analysis of microbial community structure in lactic acid fermentation from kitchen waste].

In this study, PCR-DGGE was used to analyze the microbial community structure in lactic acid fermentation from kitchen waste. The results showed that with Lactobacillus amylophilus inoculation, both the microbial diversity and lactic acid production in the open fermentation system were higher than those in the sterilized fermentation system. These results indicated that the microbial diversity and the lactic acid production have great correlation in the kitchen waste fermentation system. Through analyzing the sequence of some DNA bands excised from the DGGE gel, it showed that in addition to the inoculation of Lactobacillus amylophilus there were some indigenous lactic acid bacteria, such as Lactobacillus sp., Lactobacillus casei, Lactobacillus plantarum and indigenous hydrolytic bacteria, such as Pseudomonas sp.. These indigenous bacteria can help to promote lactic acid production. PCR-DGGE is feasible for analyzing the dynamic changes of microbial community structure in kitchen waste with complicated composition.

Isolation and characterization of Methanoculleus receptaculi sp. nov. from Shengli oil field, China.

Three strictly anaerobic, thermophilic methanogens (ZC-2T, ZC-3 and ZC-6) were isolated from Shengli oil field, China. The 16S rRNA gene sequences of the three strains were nearly identical, possessing > 99.8% sequence similarity. They also possessed high sequence similarity, 97.4%, to Methanoculleus palmolei strain INSLUZ(T) (97.4% and 97.5%, respectively), indicating that they represented a novel species within the genus Methanoculleus. Cells of strain ZC-2T were nonmotile cocci, 0.8-1.7 microm in diameter, and always occurred singly or in pairs. The three strains used H2/CO2 or sodium formate as substrates for methanogenesis but not sodium acetate, trimethylamine, monomethylamine, ethanol, dimethyl sulfide, isopropanol, isobutanol, butan-2-ol or H2/CO. Optimum growth of strain ZC-2T occurred in the presence of 0.2 M NaCl, pH 7.5-7.8 and temperature 50-55 degrees C with a specific growth rate of 0.084 h(-1). The mol% G+C content of the genomic DNA was 55.2 mol%. Based on these phenotypic and phylogenetic characteristics, strains ZC-2T, ZC-3 and ZC-6 are proposed to represent a novel species in the genus Methanoculleus and named Methanoculleus receptaculi sp. nov. The type strain is ZC-2T (CGMCC 1.5087T=DSM 18860T).

Methermicoccus shengliensis gen. nov., sp. nov., a thermophilic, methylotrophic methanogen isolated from oil-production water, and proposal of Methermicoccaceae fam. nov.

A thermophilic, methylotrophic methanogen, strain ZC-1(T), was isolated from the Shengli oilfield, China. Cells of strain ZC-1(T) were motile cocci, 0.7-1.0 microm in diameter and always occurred in clusters of two to four cells. Lysis-susceptibility experiments and analysis of transmission electron micrographs of strain ZC-1(T) suggested the presence of a proteinaceous cell wall. Strain ZC-1(T) used methanol, methylamine and trimethylamine as substrates for methanogenesis. Optimal growth, with a doubling time of around 5 h, occurred at pH 6.0-6.5, 65 degrees C, 0.3-0.5 M NaCl and 0.05-0.20 M MgCl(2). The DNA G+C content of this organism was 56 mol%. Analysis of 16S rRNA gene sequence and the inferred amino acid sequence of the mcrA gene of strain ZC-1(T) indicated that it is related specifically to members of the family Methanosaetaceae (90.6 and 76.6 % sequence similarity, respectively). However, strain ZC-1(T) failed to grow with acetate as substrate for methanogenesis, which is a special characteristic of the family Methanosaetaceae. Based on these phenotypic and phylogenic characteristics, strain ZC-1(T) is proposed to represent a novel genus and species, for which the name Methermicoccus shengliensis gen. nov., sp. nov. is proposed. The type strain is ZC-1(T) (=CGMCC 1.5056(T)=DSM 18856(T)). Methermicoccaceae fam. nov. is also proposed.