Deciphering the probiotic properties and safety assessment of a novel multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 from marine mangroves

With the increasing demand for diversified health, the characteristic probiotics species resources need to be expanded. Here, a novel marine multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 was identified from marine mangrove. Based on the characterization of probiotic properties in vivo and in vitro, the yeast could assimilate multiple carbon sources, and generate volatile flavor metabolites, achieved a 79.98% cholesterol removal rate with efficient in vivo survival and adhesion capabilities, and showed a strong antioxidant capacity. HJ2 also released hydrolase and fermented dietary fiber to yield SCFAs, contributing to disease prevention and treatment. Then, the safety was assessed according to phenotype and whole genome-sequencing analysis. No virulence genes or ARGs were annotated in the HJ2 genome. A few biogenic amines (BA)-related genes were observed, but the production of various BA and total BA were far below the food-defined thresholds. HJ2 did not produce virulence enzymes such as DNase, phospholipase, gelatinase, or coagulase, and exhibited sensitivity to amphotericin B and anidulafungin without β-hemolysis. An in vivo acute toxicity test conducted on mice demonstrated that HJ2 is safe. In conclusion, HJ2 could be considered safe and be further used as a potential probiotic candidate for further clinical trials.