Agromyces chromiiresistens sp. nov., Novosphingobium album sp. nov., Sphingobium arseniciresistens sp. nov., Sphingomonas pollutisoli sp. nov., and Salinibacterium metalliresistens sp. nov.: five new members of Microbacteriaceae and Sphingomonadaceae from polluted soil.

There are many unidentified microbes in polluted soil needing to be explored and nominated to benefit the study of microbial ecology. In this study, a taxonomic research was carried out on five bacterial strains which were isolated and cultivated from polycyclic aromatic hydrocarbons, and heavy metals polluted soil of an abandoned coking plant. Phylogenetical analysis showed that they belonged to the phyla Proteobacteria and Actinobacteria, and their 16S rRNA gene sequence identities were lower than 98.5% to any known and validly nominated bacterial species, suggesting that they were potentially representing new species. Using polyphasic taxonomic approaches, the five strains were classified as new species of the families Microbacteriaceae and Sphingomonadaceae. Genome sizes of the five strains ranged from 3.07 to 6.60 Mb, with overall DNA G+C contents of 63.57-71.22 mol%. The five strains had average nucleotide identity of 72.38-87.38% and digital DNA-DNA hybridization of 14.0-34.2% comparing with their closely related type strains, which were all below the thresholds for species delineation, supporting these five strains as novel species. Based on the phylogenetic, phylogenomic, and phenotypic characterizations, the five novel species are proposed as Agromyces chromiiresistens (type strain H3Y2-19aT = CGMCC 1.61332T), Salinibacterium metalliresistens (type strain H3M29-4T = CGMCC 1.61335T), Novosphingobium album (type strain H3SJ31-1T = CGMCC 1.61329T), Sphingomonas pollutisoli (type strain H39-1-10T = CGMCC 1.61325T), and Sphingobium arseniciresistens (type strain H39-3-25T = CGMCC 1.61326T). Comparative genome analysis revealed that the species of the family Sphingomonadaceae represented by H39-1-10T, H39-3-25T, and H3SJ31-1T possessed more functional protein-coding genes for the degradation of aromatic pollutants than the species of the family Microbacteriaceae represented by H3Y2-19aT and H3M29-4T. Furthermore, their capacities of resisting heavy metals and metabolizing aromatic compounds were investigated. The results indicated that strains H3Y2-19aT and H39-3-25T were robustly resistant to chromate (VI) and/or arsenite (III). Strains H39-1-10T and H39-3-25T grew on aromatic compounds, including naphthalene, as carbon sources even in the presence of chromate (VI) and arsenite (III). These features reflected their adaptation to the polluted soil environment.

Solibacillus daqui sp. nov., isolated from high-temperature Daqu.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterial strain, designated ZS111008T, was isolated from high-temperature Daqu, a starter for production of Chinese Jiang-flavour Baijiu, and was characterized by polyphasic taxonomy. This novel isolate grew in the presence of 0-5 % (w/v) NaCl, at pH 6.0-9.0 and 25-45 °C; optimum growth was observed with 1 % (w/v) NaCl, at pH 8.0 and 30 °C. A comparative analysis of the 16S rRNA gene sequence (1461 bp) of strain ZS111008T showed highest similarity to Solibacillus silvestris DSM12223T (96.7%), followed by Solibacillus cecembensis PN5T (96.6%) and Solibacillus isronensis AMCK01000046 (96.5%). The DNA G+C content of strain ZS111008T was 37.21 mol%. The respiratory quinone was identified as menaquinone-7 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and one unknown phospholipid. Lys was detected as the diagnostic diamino acid in the cell wall. Based on morphological characteristics, chemotaxonomic characteristics and physiological properties, strain ZS111008T represents a novel species of the genus Solibacillus, for which the name Solibacillus daqui sp. nov. is proposed. The type strain for this proposed species is ZS111008T (=CGMCC 1.19455T=JCM 35214T).

Lentibacillus daqui sp. nov., isolated from high-temperature Daqu, a starter for production of Chinese Jiang-flavour Baijiu.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterial strain, designated ZS110521T, was isolated from high-temperature Daqu, a starter for production of Chinese Jiang-flavour Baijiu and was characterised by polyphasic taxonomy. This novel isolate grew in the presence of 0-20 % (w/v) NaCl, at pH 6.0-9.0 and 20-50 °C; optimum growth was observed with 8-10 % (w/v) NaCl, at pH 7.0 and 37 °C. A comparative analysis of the 16S rRNA gene sequence (1460 bp) of ZS110521T revealed that it displayed the highest similarity to Lentibacillus populi WD4L-1T (95.5 %), followed by Lentibacillus garicola SL-MJ1T (95.4 %) and Lentibacillus lacisalsi BH260T (95.2 %). ANI and dDDH values between ZS110521T and other strains of species of the genus Lentibacillus were less than 78 and 28 %, respectively. The predominant cellular fatty acids (> 10 %) of ZS110521T were anteiso-C17 : 0 (37.8 %), anteiso-C15 : 0 (28.1 %) and iso-C16 : 0 (15.5 %). The respiratory quinone was identified as menaquinone-7 (MK-7) and the major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The polyphasic taxonomic data and the results of chemotaxonomic analysis confirmed that ZS110521T represents a novel species, for which the name Lentibacillus daqui sp. nov. is proposed. The type strain of this proposed species is ZS110521T (=CGMCC 1.19456T =JCM 35213T).

Comparative Genomics Unveils the Habitat Adaptation and Metabolic Profiles of Clostridium in an Artificial Ecosystem for Liquor Production.

Clostridium inhabiting pit mud (PM) is one of the important bacterial populations for synthesizing flavor compounds of Chinese strong-flavor baijiu. The long-term cereal fermentation with sorghum as the main raw material creates an environment rich in starch, ethanol, and organic acids (mainly lactic acid). However, the genetic factors underpinning Clostridium's adaptation to PM remain poorly understood. Here, we performed comparative genomic analysis between 30 pit mud-associated (PMA) and 100 non-pit mud-associated (NPMA) Clostridium strains. Comparison analysis of the enrichment of KEGG pathways between PMA and NPMA Clostridium strains showed two-component system, flagellar assembly, and bacterial chemotaxis pathways related to environmental adaptation were enriched in PMA strains. The number of genes encoding alcohol dehydrogenase and l-lactate dehydrogenase in PMA Clostridium strains was significantly higher than that in NPMA, which is helpful for them to adapt to the ethanol- and lactic acid-rich environment. The analysis of carbohydrate-active enzymes demonstrated that glycoside hydrolases (GHs) was the most abundant family in all Clostridium strains, and genes encoding GH4 and GH13, involved in starch and sucrose metabolism, were enriched in PMA Clostridium. Horizontal gene transfer analysis revealed that multiple genes encoding the enzymes involved in carbohydrate and amino acid metabolism were transferred from Bacillus to Clostridium in pit mud. Most of the PMA Clostridium strains had good potential for butyric acid synthesis from ethanol, lactic acid, and starch. Collectively, this study furthers our understanding of the habitat adaptation and metabolic potential of PMA Clostridium strains. IMPORTANCE Pit mud is a typical artificial ecosystem for Chinese liquor production. Clostridium inhabiting pit mud plays essential roles in the flavor formation of strong-flavor baijiu. The relative abundance of Clostridium increased with pit mud quality, further influencing the quality of baijiu. So far, the ecological adaptation of Clostridium to a pit mud-associated lifestyle is largely unknown. Here, comparative genomic analysis of pit mud-associated (PMA) and non-pit mud-associated (NPMA) Clostridium strains was performed. We found genes related to the metabolism of starch, ethanol, and lactic acid were enriched in PMA Clostridium strains, which facilitated their adaptation to the unique brewing environment. In addition, horizontal gene transfer contributed to the adaptation of Clostridium to pit mud. Our findings provide genetic insights on PMA Clostridium strains' ecological adaptation and metabolic characteristics.

Research Progress of Near-Infrared Fluorescence Immunoassay.

Near-infrared fluorescence probes (NIFPs) have been widely used in immunoassay, bio-imaging and medical diagnosis. We review the basic principles of near-infrared fluorescence and near-infrared detection technology, and summarize structures, properties and characteristics of NIFPs (i.e., cyanines, xanthenes fluorescent dyes, phthalocyanines, porphyrin derivates, single-walled carbon nanotubes (SWCNTs), quantum dots and rare earth compounds). We next analyze applications of NIFPs in immunoassays, and prospect the application potential of lateral flow assay (LFA) in rapid detection of pathogens. At present, our team intends to establish a new platform that has highly sensitive NIFPs combined with portable and simple immunochromatographic test strips (ICTSs) for rapid detection of food-borne viruses. This will provide technical support for rapid detection on the port.

Metagenomics reveals flavour metabolic network of cereal vinegar microbiota.

Multispecies microbial community formed through centuries of repeated batch acetic acid fermentation (AAF) is crucial for the flavour quality of traditional vinegar produced from cereals. However, the metabolism to generate and/or formulate the essential flavours by the multispecies microbial community is hardly understood. Here we used metagenomic approach to clarify in situ metabolic network of key microbes responsible for flavour synthesis of a typical cereal vinegar, Zhenjiang aromatic vinegar, produced by solid-state fermentation. First, we identified 3 organic acids, 7 amino acids, and 20 volatiles as dominant vinegar metabolites. Second, we revealed taxonomic and functional composition of the microbiota by metagenomic shotgun sequencing. A total of 86 201 predicted protein-coding genes from 35 phyla (951 genera) were involved in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of Metabolism (42.3%), Genetic Information Processing (28.3%), and Environmental Information Processing (10.1%). Furthermore, a metabolic network for substrate breakdown and dominant flavour formation in vinegar microbiota was constructed, and microbial distribution discrepancy in different metabolic pathways was charted. This study helps elucidating different metabolic roles of microbes during flavour formation in vinegar microbiota.

Elucidating and Regulating the Acetoin Production Role of Microbial Functional Groups in Multispecies Acetic Acid Fermentation.

UNLABELLED: Acetoin (3-hydroxy-2-butanone) formation in vinegar microbiota is crucial for the flavor quality of Zhenjiang aromatic vinegar, a traditional vinegar produced from cereals. However, the specific microorganisms responsible for acetoin formation in this centuries-long repeated batch fermentation have not yet been clearly identified. Here, the microbial distribution discrepancy in the diacetyl/acetoin metabolic pathway of vinegar microbiota was revealed at the species level by a combination of metagenomic sequencing and clone library analysis. The results showed that Acetobacter pasteurianus and 4 Lactobacillus species (Lactobacillus buchneri, Lactobacillus reuteri, Lactobacillus fermentum, and Lactobacillus brevis) might be functional producers of acetoin from 2-acetolactate in vinegar microbiota. Furthermore, A. pasteurianus G3-2, L. brevis 4-22, L. fermentum M10-3, and L. buchneri F2-5 were isolated from vinegar microbiota by a culture-dependent method. The acetoin concentrations in two cocultures (L. brevis 4-22 plus A. pasteurianus G3-2 and L. fermentum M10-3 plus A. pasteurianus G3-2) were obviously higher than those in monocultures of lactic acid bacteria (LAB), while L. buchneri F2-5 did not produce more acetoin when coinoculated with A. pasteurianus G3-2. Last, the acetoin-producing function of vinegar microbiota was regulated in situ via augmentation with functional species in vinegar Pei After 72 h of fermentation, augmentation with A. pasteurianus G3-2 plus L. brevis 4-22, L. fermentum M10-3, or L. buchneri F2-5 significantly increased the acetoin content in vinegar Pei compared with the control group. This study provides a perspective on elucidating and manipulating different metabolic roles of microbes during flavor formation in vinegar microbiota. IMPORTANCE: Acetoin (3-hydroxy-2-butanone) formation in vinegar microbiota is crucial for the flavor quality of Zhenjiang aromatic vinegar, a traditional vinegar produced from cereals. Thus, it is of interest to understand which microbes are driving the formation of acetoin to elucidate the microbial distribution discrepancy in the acetoin metabolic pathway and to regulate the metabolic function of functional microbial groups in vinegar microbiota. Our study provides a perspective on elucidating and manipulating different metabolic roles of microbes during flavor formation in vinegar microbiota.

Website for avian flu information and bioinformatics.

Highly pathogenic influenza A virus H5N1 has spread out worldwide and raised the public concerns. This increased the output of influenza virus sequence data as well as the research publication and other reports. In order to fight against H5N1 avian flu in a comprehensive way, we designed and started to set up the Website for Avian Flu Information ( http://www.avian-flu.info ) from 2004. Other than the influenza virus database available, the website is aiming to integrate diversified information for both researchers and the public. From 2004 to 2009, we collected information from all aspects, i.e. reports of outbreaks, scientific publications and editorials, policies for prevention, medicines and vaccines, clinic and diagnosis. Except for publications, all information is in Chinese. Till April 15, 2009, the cumulative news entries had been over 2000 and research papers were approaching 5000. By using the curated data from Influenza Virus Resource, we have set up an influenza virus sequence database and a bioinformatic platform, providing the basic functions for the sequence analysis of influenza virus. We will focus on the collection of experimental data and results as well as the integration of the data from the geological information system and avian influenza epidemiology.