EFFECT OF MUSHROOM EXTRACT ON THE GROWTH OF ISOLATED LACTIC ACID BACTERIA AND IMMOBILIZATION AS BIO−BEADS GEL

Abstract

Bacteria membered in lactic acid producing group containing many dominant properties can be applied in diverse fields. This research was aimed to select effective lactic acid bacterial strains and enhanced their growth with mushroom extracts. Fermented vegetable samples were used as a source to achieve lactic acid bacteria by isolating on MRS medium. Fifteen isolates were lactic producing bacteria that exhibited clear zone around their colony on medium. Bacterial isolates FV2, FV4, and FV14 have produced the highest lactic acid content in quantitative investigation. In addition, FV2 and FV4 have been found the ability to suppress growth of pathogenic bacteria Salmonella Typhimurium and Staphylococcus aureus, with the highest inhibitory activity at 200 AU/mL. Isolates FV2 and FV4 have been classified as Lactiplantibacillus plantarum FV2 and Pediococcus pentosaceus FV4 based on their 16S rRNA gene sequences. Mushroom extracts of Pleurotus pulmonarius and Lentinus squarrosulus (Mont.) have been discovered oligosaccharide, and antioxidants activity, including the property to support the growth and lactic acid production of L. plantarum FV2 and P. pentosaceus FV4. High survival of lactic acid bacteria within bio−bead gel structure have been found more than naked cell under strong acid condition, including storage at 4 ^°C up to 28 days. Bio−bead gels containing lactic acid bacteria and mushroom extracts could be applied as the starter culture to produce fermented milk that they promoted coagulation of milk protein, high lactic acid bacteria, and antioxidant activity.