China National Research Institute of Food & Fermentation

More and more Chinese families are using dishwashers, consumers have paid special attention to the sterilization and disinfection function of dishwashers in recent years. However, there is still a lack of research on the distribution of microorganisms in dishwashers nationwide in China. In order to better upgrade the sterilization and disinfection functions of dishwashers, the plate culture method and high-throughput sequencing technology were used to comprehensively analyze the microbiology of household dishwashers in different cities of China in spring, summer, autumn and winter in this study. A total of 1109 strains of bacteria were isolated from dishwashing machine samples by culturable method, including 706 strains of bacteria distributed in 72 genera, 403 strains of fungi distributed in 52 genera.The most frequently isolated bacteria were Bacillus, Pseudomonas, Brevibacillus, Exiguobacterium, and Acinetobacter. The most frequently isolated fungi were Aspergillus, Penicillium, Exophiala, Fusarium, and Candida. A total of 3779 OTUs were obtained from bacteria and 1541 OTUs were obtained from fungi by amplicon sequencing. The results of culture-independent analysis were consistent with those of culturable analysis. This study laid a foundation for the directional screening of superior microbial resources in dishwashers. It provided data support for the further upgrading of the sterilization and disinfection function of the dishwasher.

[Objective] The aim was to identify bacterial strain CICC 10822 isolated from Aldos life nutrition liquid and under the biol. characteristics.[Method] By using the traditional microbiol. separation and culture method, bacterial strain CICC 10822 isolated from Xinjiang Aldos life nutrition liquid in 30°C was classified and identified.[Result] Strain CICC 10822 contact enzyme reaction was neg., nitrate reduction was neg., starch hydrolysis was neg., and arginine was neg.It could utilize glucose, fructose, ribose and galactose, and could not use maltose, xylose, lactose, glycerol, mannitol, sorbitol, cellobiose, rhamnose, arabinose, liquefied gelatin.By using microbial taxonomy and identification technol. based on morphol. observation, physiol. and biochem. characteristics anal., phylogenetic anal. of 16 S rDNA and phe S gene sequences, strain CICC 10822 was identified as Lactobacillus acidipiscis.[Conclusion] The results lay a foundation for study on the bacterial biol. functions in the future.

The amino acid composition and mol. weight distribution of oyster whole powder and oyster peptide were analyzed.The effects of different concentrations of oyster powder and oyster peptide on the synthesis and secretion of testosterone, dihydrotestosterone and cyclic guanosine monophosphate(cGMP) in mouse leydig cells(TM3 cells) were studied to provide a basis for improving the sexual function of oyster peptides.The effects of oyster whole powder and oyster peptide on the survival rate of TM3 cells were determined by MTT colorimetric assay.The contents of testosterone, dihydrotestosterone and c GMP were detected by ELISA.Nitrate reductase method was used to determine the content of nitric oxide(NO) and the activity of SOD in the cells was detected by nitroblue tetrazolium(NBT) chromogenic assay.The results showed that the oyster whole powder and oyster peptide had rich amino acid composition, the oyster peptide contained more essential amino acids and arginine, and the oyster peptide had a mol. weight of less than 1 000 u as high as 92.1264%.Compared with oyster whole powder, oyster peptide could significantly promote the secretion of testosterone, dihydrotestosterone and cGMP in TM3 cells, significantly enhance the synthesis of NO in TM3 cells, and increase the SOD activity of TM3 cells, indicating that oyster peptides had promoting functions.The role of its mechanism may be related to the improvement of the NO-cGMP pathway by oyster peptides.