Microbial Community Affects Daqu Quality and the Production of Ethanol and Flavor Compounds in Baijiu Fermentation.

Daqu is a traditional starter for Baijiu fermentation and is produced by spontaneous fermentation of ground and moistened barley or wheat. The quality of Daqu is traditionally evaluated based on physicochemical and subjective sensory parameters without microbiological analysis. Here, we compared the physicochemical characteristics of qualified (QD) and inferior (ID) Daqu, their microbial communities based on plate counting and PacBio SMRT sequencing of rRNA gene libraries, and their impacts on Baijiu fermentation. The results showed that the glucoamylase and α-amylase activities of QD were significantly higher than those of ID. The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium Bacillus licheniformis and fungi Saccharomycopsis fibuligera and Lichtheimia ramosa, were significantly higher in QD than in ID. The laboratory-scale Baijiu fermentation tests showed that the relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture content in the former. Consequently, more glycerol, acetic acid, ethanol, and other volatile compounds were produced in the QD than in the ID fermentation set. The results suggest that Daqu quality is determined by, and can be evaluated based on, its microbial community.

Two new forest pathogens in Phaeolus (Polyporales, Basidiomycota) on Chinese coniferous trees were confirmed by molecular phylogeny.

Phaeolus schweinitzii (Fr.) Pat. was originally described in Europe and is considered a common forest pathogen on conifers in the Northern Hemisphere. Our molecular phylogeny based on samples from China, Europe, and North America confirms that P. schweinitzii is a species complex, including six taxa. P. schweinitzii sensu stricto has a distribution in Eurasia; the samples from Northeast and Southwest China are distantly related to P. schweinitzii sensu stricto, and two new species are described after morphological, phylogenetic, and geographical analyses. The species growing on Larix, Picea, and Pinus in Northeast China is described as Phaeolus asiae-orientalis. Another species mostly occurring on Pinus yunnanensis in Southwest China is Phaeolus yunnanensis. In addition, three taxa distributed in North America differ from P. schweinitzii sensu stricto. Phaeolus tabulaeformis (Berk.) Pat. is in Southeast North America, "P. schweinitzii-1" in Northeast North America, and "P. schweinitzii-2" in western North America.

[Changes in physicochemical property and microbial community of Pseudostellaria heterophylla soil at diffe-rent fallow ages]. / 太子参不同休耕年限土壤理化特征和微生物群落变化.

Pseudostellaria heterophylla is authentic traditional Chinese herbal medicine in Fujian Province. P. hete-rophylla suffers from serious consecutive monoculture problems. Fallow can alleviate such problems, but the mecha-nism is still unclear. In this study, high-throughput sequencing was performed to analyze the changes in soil microbial community structure and diversity in the P. heterophylla soil at different fallow ages as well as their relationships with soil physicochemical properties and phenolic acids. The results showed that fungal community diversity decreased but bacterial community diversity increased in fallow soils compared with the control soil of P. heterophy-lla. For bacterial communities, the relative abundance of Acidobacteria increased, while that of Proteobacteria and Actinobacteria decreased in fallow soils. For fungal communities, the relative abundance of dominant phyla had no significant difference between fallow and control soils. Soil acidity and organic matter content showed a trend of weakening and decreasing, respectively, with the increases of fallow years. In addition, with the increases of fallow years, the content of phenolic acids in soil, including benzoic acid and salicylic acid, showed significant decrease, while some other phenolic acids such as p-coumaric acid were accumulated obviously. Taken together, fallow could efficiently ameliorate the structure of soil microbial community and soil properties of P. heterophylla, and thus alleviate the effects of continuous cropping.

Complete mitogenome of the entomopathogenic fungus Orbiocrella petchii.

In this study, the complete mitogenome of an entomopathogenic fungus Orbiocrella petchii (syn. Torrubiella petchii) was assembled and annotated. This circular mitogenome was 23,794 bp in length and consisted of 2 rRNA genes (rnl and rns), 25 tRNA genes, and 14 standard protein-coding genes of the oxidative phosphorylation system. Two group I introns were identified, and they encoded ribosomal protein S3 (in rnl) or a GIY-YIG endonuclease (in nad1). Phylogenetic analysis based on mitochondrial DNA sequences confirms O. petchii in the family of Clavicipitaceae.

Naumovozyma baii sp. nov., an ascomycetous yeast species isolated from rotten wood in a tropical forest.

Two strains isolated from rotten wood were included in the Saccharomyces group based on morphological characteristics. However, rRNA gene sequence analyses (including the 18S rRNA gene, 26S rRNA gene D1/D2 domain and internal transcribed spacer region) indicated that these two strains represent a novel species of Naumovozyma, for which the name Naumovozyma baii sp. nov. is proposed (type strain: BW 22(T) = CGMCC 2.04520(T) = CBS 12642(T)). The MycoBank number of the new species is MB800484.

Udeniomyces kanasensis sp. nov., a ballistoconidium-forming yeast species in the Cystofilobasidiales.

In a survey of ballistoconidium-forming yeast diversity in the phyllosphere, five strains from wilting plant leaves collected from Kanas Nature Reserve in Xinjiang province, China were selected based on morphological comparison. These strains formed pinkish-white colonies and large bilaterally symmetrical ballistoconidia. Molecular phylogenetic analyses based on the 26S rRNA D1/D2 domain and ITS region sequences showed that these strains belonged to the Udeniomyces clade in the Cystofilobasidiales. They differ from the described Udeniomyces species significantly in the rRNA sequences as well as physiological criteria. Therefore, a new species Udeniomyces kanasensis sp. nov. (type strain XJ 6E2(T)=CGMCC 2.02627 (T)=CBS 12488 (T)) is proposed to accommodate these strains. The MycoBank number of the new species is MB 563659.

microRNA-143 protects cells from DNA damage-induced killing by downregulating FHIT expression.

MicroRNAs (miRNAs) are posttranscriptional modulators of gene expression and play an important role in many developmental processes. Recent studies suggest roles of miRNAs in carcinogenesis. Fragile histidine triad (FHIT) gene deletion, methylation, and reduced Fhit protein expression occur in about 70% of human epithelial tumors and are clearly associated with tumor progression. Although it has been previously reported that Fhit(-/-)cells exhibit more resistance to multi-DNA damage inducers, including ionizing radiation, it remains unclear how miRNAs targeting FHIT in DNA damage response play the role. This study reports that miR-143 directly targets FHIT and that overexpression of miR-143 results in significant G2-phase arrest and protects cells from DNA damage-induced killing. These results indicate an association of FHIT gene inactivation with increased survival after DNA damage and also provide useful information for miRNA-based drug development in two directions: protect cells from DNA damage-induced killing and sensitize cells to radiation therapy.

Cloning and localization of vip3A gene of Bacillus thuringiensis.

An insecticidal protein gene, vip3A, was cloned from Bacillus thuringiensis strain WB50. The nucleotide sequence of 2,460 bp (GenBank acc. No. AY295778) showed 99% homology with the known vip3A genes. Using specific primers for vip3A gene, PCR was performed to demonstrate that the gene was not located on the bacterial chromosome and this was confirmed by Southern blotting using an internal fragment (486 bp) from vip3A gene as a probe. The gene was carried on a plasmid of 31.8 kb.