Analysis of microbial diversity in apple vinegar fermentation process through 16s rDNA sequencing.

Based on SPME-GC-MS analysis, it could be found that the production of acetic acid, phenethyl acetate, and isoamyl acetate gradually increased in the apple vinegar fermentation broth with the fermentation time. Consequently, in order to systematically explore the dynamic changes of microbial diversity and metabolites in the process of apple vinegar fermentation, 16S rDNA were sequenced and analyzed in this work. The present results showed that bacterial diversity was rich and exhibited a certain variation during the dynamic fermentation process of apple vinegar. Furthermore, Lactococcus and Oenococcus were the predominant bacteria in the pre-fermentation (alcoholic fermentation) of apple vinegar, while the dominant bacteria in the middle and late fermentation stages (acetic acid fermentation) were Lactococcus and Acetobacter. In addition, during the whole fermentation process of apple vinegar, Lactococcus was the most dominant bacteria, Oenococcus was the unique species in the stage of alcohol fermentation, and Acetobacter increased rapidly in the stage of acetic acid fermentation. In conclusion, our finding provided a theoretical basis for the processing technology of apple vinegar fermentation, and a theory evidence for the safety and health assessment of apple vinegar.

[Molecular evolution of the poplar MIR169 gene family].

MicroRNAs (miRNAs) are a class of short non-coding RNAs found widely in eukaryotic organisms. The ptc-MIR169 gene family, which consists of 33 members, is the largest miRNA gene family in poplar (Populus trichocarpa) It is significant to analyze the evolution of the ptc-MIR169 gene family in order to understand the evolutionary mechanisms of miRNAs in poplar. In the present study, we investigated the molecular phylogeny, duplication, expression and target genes of the MIR169 gene family in poplar. Both tandem duplications and chromosome segmental duplications contributed to the expanding of ptc-MIR169 gene family, and the expression patterns diversified obviously among the gene family. These findings suggest that the ptc-MIR169 gene family is involved in complex regulatory networks, and plays significant roles in development and stress response in poplar. This paper provides a reference for the evolutionary study of miRNAs in poplar and related species in Salicaceae.

[Investigation on the integrative course of genetics and genomics].

Genomics is an important subdiscipline of genetics, and it forms a complete research system based on novel theories and techniques. Incorporating genomics in undergraduate curriculum is a response to the need of the development of genetics. The teaching of genomics has significant advantages on developing scientific thinking, enhances bioethics accomplishment, and professional interests in undergraduate students. The integration of genomics into genetics is in accordance with the principles of subject development and education. Related textbooks for undergraduate education are currently available in China, and it is feasible to set up a genetics and genomics integrative course by modifying teaching contents of the genetics course, selecting appropriate teaching approaches, and optimal application of the computer-assisted instruction.