Search

Sufu is a cheese-like product fermented with soybean curd in China, widely consumed for its unique nutritional and flavor properties. To investigate the associations among microbial communities, chemical properties, producing regions and dressing flavors of sufu , the high-throughput sequencing for 16 sufu products from different regions based on the bacterial 16S rRNA and fungal internal transcribed spacer 2 gene was performed. A sum of 368 bacterial genera and 299 fungal genera were identified. The fungal microflora in sufu samples contained many symbiont fungi of soybean. Aspergillus and Actinomucor were abundant in the sufu products as hydrolase-producing genera. The bacterial diversity result showed that lactic acid bacteria (LAB) were very abundant in all these sufu products and the Lactococcus was the most abundant genus. According to the principal coordinate analysis and hierarchical clustering analysis, the bacterial communities of sufu samples could be generally clustered into the LAB clade and Bacillus clade. Moreover, the fungal communities of sufu samples from eastern China could be generally clustered into one group, while the dressing flavor of sufu samples during post-fermentation was not a major factor for microbial communities shaping. This study could potentially serve as a reference for a rational design of microbial communities to improve the sufu quality. • Microbial compositions in different sufu products varied significantly. • Lactic acid bacteria were abundant and the Lactococcus was the most abundant genus. • The bacterial communities could be clustered into the LBA clade and Bacillus clade. • The fungal communities of sufu samples could be shaped by geographical factors. • The bacterial communities were variable and could be modulated by many factors. [ABSTRACT FROM AUTHOR]

A total of 88 lactic acid bacteria (LAB) strains were isolated from Chinese traditional sourdough and five of them were selected based on their bile resistance. All the five strains were identified as Lactobacillus plantarum by 16S rRNA gene sequencing. In vitro probiotic properties of the L. plantarum strains including tolerance to simulated gastrointestinal conditions, aggregation activity, and cholesterol removal ability were assessed. Two representatives, L. plantarum ZJUFT34 and L. plantarum ZJUFT17, were intragastrically administered to male C57BL/6J mice of 4-week age for 6 weeks to evaluate their in vivo health-promoting effects. The results indicated that L. plantarum ZJUFT34, L. plantarum ZJUFHN9, and L. plantarum ZJUFAH5 could survive the 3-h incubation in simulated gastric juice with a pH value of 2.0, while L. plantarum ZJUFT32 and L. plantarum ZJUFT17 exhibited better autoaggregation activities and coaggregation activities with pathogens. All the strains showed a cholesterol removal ability in vitro. However, L. plantarum ZJUFT34 or L. plantarum ZJUFT17 administration did not significantly change the serum total cholesterol in vivo. But the ratio of high-density lipoprotein cholesterol to low-density lipoprotein cholesterol was significantly increased by the L. plantarum administration. Besides, L. plantarum ZJUFT17 significantly lowered serum tumor necrosis factor (TNF)-α concentrations. Furthermore, the administration of the LAB strains showed significant influences on lipid metabolism-related gut microbiota. These findings suggested that the L. plantarum strains may benefit the prevention of metabolic syndrome.