Antioxidant and biotechnological potential of Pediococcus pentosaceus RZ01 and Lacticaseibacillus paracasei RZ02 in a millet-based fermented substrate

Abstract

Lactobacillus and Bifidobacterium are the most known genera of the therapeutic niche of organisms that have developed various defense mechanisms through their antioxidative activity which help mitigate the abnormality caused by reactive oxygen species to cell components. Nevertheless, for these probiotic organisms to exert their beneficial effects, the need to enhance functionality and protect bacterial cells in the gastrointestinal tract requires an efficient method for a better selection of favorable fermentation conditions with a sufficient yield of desired property or product. Here we reported the potential and antioxidant activities of isolated probiotic strains, with a considerable viable cell count between 10⁸ and 10⁹ CFU/mL, as the pH of both fermented millet substrate decreased from 6.13 to 3.62 at 35 °C within 14 h using a statistical optimization approach. The identified strains Pediococcus pentosaceus RZ01 and Lacticaseibacillus paracasei RZ02 alongside the reference strain had an overall gastrointestinal tolerance of 60% under simulated conditions, with Pediococcus pentosaceus RZ01 showing the highest bile salt survival rate (123.07%). Lactobacillus paracasei RZ02 indicates a high hydrophobicity potential (86.48%), suggesting a better adhesion ability to the gastrointestinal tract. Concurrently, Pediococcus pentosaceus RZ01 and Lactobacillus paracasei RZ02 fermented substrate had 39.69 and 44.51% of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the release of bioactive compounds of health importance. These provide important references for formulating novel probiotic fermented cereal product, understanding of probiotic-prebiotic relationship, as well as pave way for biotechnological application of identified and related probiotics.

Funding

Key Technologies Research and Development Program,(2021YFC2100900); National Natural Science Foundation of China,(32071470); Science and Technology Bureau of Xinjiang Production and Construction Corps,(2019AB009)