Strain identification, probiotic potential evaluation, and mannanase production optimisation of Lactiplantibacillus plantarum HDM10.

Lactiplantibacillus plantarum (L. plantarum) HDM10, isolated from fermented winter jujube (Ziziphus jujuba) juice, was identified by biochemical and molecular analyses. The strain exhibited γ-haemolysis, susceptibility to several tested antibiotics, and strong gastrointestinal tolerance, with survival rates of 72.63% and 80.00% at pH 2.0 and 3.0, respectively. Survival remained above 70% in 0.05-0.5% bile salts and reached 67.82% at 1.0%. More than 80% of cells survived simulated gastric and intestinal conditions. Response surface methodology optimised mannanase production to 87.73 U/mL, representing a 27.1% increase over the initial activity. Congo red staining confirmed enhanced polysaccharide hydrolysis. HDM10 also showed strong mucin adhesion (>70%) and slight growth promotion in the presence of mucin. These results demonstrate its safety, probiotic potential, and suitability for -synbiotic applications.