Bioutilization of Arca subcrenata Myofibrillar Protein by Four Probiotics

Using Arca subcrenata as the research object, this study explored the differences in the utilization of simulated digestion products of Arca subcrenata myofibrillar protein by probiotics, namely Lactiplantibacillus plantarun, Bifidobacterium bifidobacterial, Lacticaseibacillus rhamnosus and Bifidobacterium animalis subsp. Lactis Probio-M8. The study first simulated the in vitro digestion of myofibrillar protein from Arca subcrenata and used it as a nitrogen source to co-culture with probiotics by nitrogen source replacement and nitrogen source addition, respectively. Subsequently, the utilization characteristics by the probiotics on the digestion products of myofibrillar protein from Arca subcrenata were evaluated by monitoring the growth curve, pH and colony number among others. The results showed that, compared to the de Man-Rogosa-Sharpe group, the nitrogen source replacement group could significantly inhibit the proliferation of the four probiotic species (P<0.05), but the inhibitory effect on Probio-M8 was weak. When the simulated digestion products of Arca subcrenata myofibrillar protein were added to the medium as the nitrogen source, the protein products could significantly promote the proliferation of Probio-M8. At the protein concentration of 0.03 mg/mL, the number of Probio-M8 viable bacteria was 1.2 times higher than that of the control group, implying the protein significantly promoted the growth of Probio-M8 (P<0.05). However, Arca subcrenata myofibrillar protein products had no significant effect on extracellular polymer substances. The results showed that, when the nitrogen source was replaced, simulated digestion products of Arca subcrenata myofibrillar protein inhibited the proliferation of probiotics. When the nitrogen source was added, the simulated digestion products of Arca subcrenata myofibrillar protein at low concentrations had probiotic-specific growth-promoting effect on the four probiotics. It indicated that different probiotics have different nitrogen source requirements. These results would provide theoretical guidance for the bio-utilization of nitrogen sources by probiotics.