2. Materials and methods
2.1. Preparation of starter culture
Pure culture of L. curvatus was obtained from the BIOTEC Culture Collection, Thailand. One loopful of a stock culture of L. curvatus kept in 20/100 g glycerol at
80 1C was cross-streaked on deMan Rogosa Sharpe (MRS) agar and then incubated at 30 1C for 48 h. A single colony of L. curvatus on MRS agar was transferred into 5 ml of MRS broth and incubated at
30 1C for 18–24 h. Cells were harvested by centrifugation at 4 1C at 10,300 g for 5 min using a Model 5403