Utility of Saccharomyces cerevisiae As Probiotics to Induce Protease Production for Worms Feed Improvement

Saccharomyces cerevisiae is a potential yeast used as probiotic in animal feeds, due to it has several enzymes such as protease that needed to degrade protein material in feed to small molecule in order to easy adsorbed by cells. The research was constructed to determine the protease expression from the S. cerevisiae yeast that presented in tofu dregs as feed for Lumbricus rubellus worm, the concentration optimum and fermentation time of probiotic to degrade the residual protein in tofu dregs, and the effect of tofu dregs fermented by S. cerevisiae to support the growth of Lumbricus rubellus worm. The results showed that S. cerevisiae significantly expressed protease in medium containing tofu dregs with activty of 59.93 U/ml. The addition of S. cerevisiae 10% (v/w) in various optical density in tofu dregs medium showed the present of probiotic with OD600 0.6 for 12 hours of fermentation time exhibited the optimum degradation of residual protein in medium. The tofu dregs feed fermented by yeast probiotic for 15 days could increase the weight growth of Lumbricus rubellus as 51.32% (w/w) compared to control without probiotic that only 14% (w/w). Also it increased pulp resistance from the decay process compared to pulp without probiotic.