Abstract
In recent year food industry trend to reduce the using of preservative, and change to use lactic acid bacteria or enzyme to preserved food, so we could go a step further to raise its additional value. Diacetyl is one kind of aromatic product in the metabolic process of lactic acid bacteria, which has the fragrance and also has inhibition effect to some bacteria. According to the past research, overexpression of ilvBN gene in lactic acid bacteria may effectively increase diacetyl of lactic acid bacteria. Therefore, this research we will isolate the enzymatic gene from a new strain Lactobacillus rhamnosus TCELL-1 by overlapping PCR method, ligated with a shuttle vector pHY300PLK via electroporation into Lb. rhamnosus TCELL-1. The results of GC/MS show that the encoding ilvBN gene is overexpressive and has been observed higher production about four fold of diacetyl than without the enzymatic gene does in Lb. rhamnosus TCELL-1. In deferred agar spot assay, we observed that overexpression ilvBN gene in TCELL-1 can inhibit food pathogens effectively.