Optimization of Growth of Lactobacillus acidophilus FTCC 0291 and Evaluation of Growth Characteristics in Soy Whey Medium:A Response Surface Methodology Approach

摘要

Four strains of probiotics were evaluated for their a-galactosidase activity.Lactobacillus acidophilus FTCC 0291 displayed the highest specific alpha-galactosidase activity and was thus selected to be optimized in soy whey medium supplemented with seven nitrogen sources.The first-order model showed that meat extract,vegetable extract,and peptone significantly(P<0.05)influenced the growth of L.acidophilus.The second-order polynomial regression estimated that maximum growth was obtained from the combination of 7.25%(w/v)meat extract,4.7%(w/v)vegetable extract,and 6.85%(w/v)peptone.The validation experiment showed that response surface methodology was reliable with a variation of only 1.14% from the actual experimental data.Increased utilization of oligosaccharides and reducing sugars contributed to increased growth of L.acidophilus in the soy whey medium.This was accompanied by increased production of short-chain fatty acids and a decrease in pH.