Abstract:

In order to improve conversion rate of osteocalcin, bovine bone powder was subjected to symbiotic fermentation of Lactobacillus acidophilus GG (LGG) and Lactobacillus rhamnosus (LA). A series of single-factor experiments were conducted to investigate the effects of symbiotic fermentation parameters, including LGG/LA ratio, fermentation time, bovine bone powder amount and glucose amount on conversion rate of osteocalcin. Based on this, the optimal values of these parameters were determined using central composite design combined with response surface analysis. Results indicated that a symbiotic phenomena between both the probiotics was observed, which could convert calcium from bound state to free state. Fermentation time and bone powder concentration were among the most important affecting factors. A maximum calcium conversion rate of 32.21% was obtained under the following optimized fermentation conditions: LGG/LA ratio 1:4.67, fermentation time 69.96 h, bone powder 4.45%, and glucose 12.26%.

Key words: Lactobacillus rhamnosus, Lactobacillus acidophilus, bovine bone powder, calcium conversion rate