Two-stop Fermentation Of ?-arbutin And Xanthan Gum

?-Arbutin is natural,emerging and activity skin whitening agents.It is non-irritability,non-irritating and high compatibility.It has better ability of inhibiting tyrosinase activity than ?-Arbutin.This essay explored biosynthesis of a-Arbutin and xanthan gum with Xanthomona maltophilia BT-112.This paper systematically expounded the change of a-Arbutin yield and xanthan gum yield under the condtions of free substrate and immobilized substrate,and explored the influence of ultrasound to the yield of a-Arbutin and xanthan gum,and researched yield of a-Arbutin and xanthan gum under the condtions of rice hull hydroiysate as the carbon source.The optimization of fermentation conditions were biomass 1.2 g·L-1,the second step temperature 28 ?,180 rpm shaker culture 48h and adding 250 mg·L-1 peptone,with out adding glucose.The ?-Arbutin yield was 16.2 g·L-1,and xanthan gum yield was 17.8 g·L-1.The conditions of alkaline pretreatment were 1.25%NaOH for 60 min.The rice hull hydrolysate had 21.12 g·L-1 reducing sugar after enzymatic hydrolysis.The yield of a-arbutin and xanthan gum could get 6.8 g·L-1 and 11.87 g·L-1 with the rice hull hydrolysate adsorbed by 2%activated carbon for 60 min as medium.The optimization of two-step fermentation conditions of a-arbutin and xanthan gum using immobilized substrate were biomass 1.48 g·L-1,the second step shaker culture 48h and adding 250 mg·L-1 peptone,with out adding glucose and bacteria.The a-arbutin yield was 18.2 g·L-1,and xanthan gum yield was 12.8 g·L-1.?-arbutin production was prepared by using immobilized hydroquinone as a glucosyl acceptor which was guided by a three-factor,three-level Box-Behnken design.The design factors were the ultrasound cycle9(A),ultrasound time(B),and ultrasound frequency(C)and the response values was ?-arbutin yield(Y).The optimized formulation was as follows:A,B and C levels of 18.94%,10.47 min and 9 times.The results of the study showed that under the optimized formulation conditions,the a-arbutin yield could get 11.18 g·L-1 which was exceed non-ultrasound team for 11.2%.