Effect of edible mushroom on the growth of some lactobacillus spp.

In this study, the effect of Cordyceps militaris extract on the development of Lactobacillus acidophilus and Lactobacillus casei species was determined in vitro. Lactobacillus acidophilus and Lactobacillus casei species used in the study were activated using MRS and 2.5% solutions of mushroom extract were prepared and filter sterilization process was applied. Sterile substrate solutions were added to the MRS at a final concentration of 0,5%, 1%, 2% and Lactobacillus spp. As a control sample; carbohydrate-free samples, containing 1% glucose and inulin were used. The samples were then incubated at 37°C for 48 hours. During fermentation (at 0, 12, 24, 36 and 48 hours), cell density (OD600), pH, number of microorganisms, growth rate, prebiotic activity score (PAS), lactic acid and short chain fatty acids (SCFA) amount (g/L) were determined. According to the results of this study, it was found that mushroom extract positively affected the development of Lactobacillus acidophilus and Lactobacillus casei species and pH values decreased during fermentation. In addition, an increase in cell density was observed in the medium. The average OD values for Lb. casei in the medium containing different substrate sources during fermentation were ranged from 0,452 to 1,454; for Lb. acidophilus the OD values ranged from 0,383 to 1,193. The average Lb. casei counts during fermentation ranged from 7,80 to 8,22 log10 cfu/mL and the average Lb. acidophilus counts ranged from 7,78 to 7,82 log10 cfu/mL. During fermentation, OD values and average number of microorganisms increased in the samples containing mushroom extract. Lactic acid and acetic acid were mostly formed by acids produced during fermentation. These acids were followed by propionic and butyric acid. When the total amount of SCFA produced as a result of fermentation was examined, the highest values were determined in fattening media containing Lb. casei. As a result, it has been determined that mushroom extract has positive effects on the development of Lactobacillus species and can be used as a component with prebiotic potential, supported by different studies.