Synthesis of homoserine lactone from Aspartic acid and induction of quorum sensing by E. coli isolates:-

Homoserine L-lactone was synthesized by E. coli through using aspartic acid which was added to the culture media at a final concentration 1%. Homoserine lactone production was checked at different intervals of incubation (after 2, 3, 4, 5, 6 and 24 hr.) where 0.01% of KCN is added to show the time of HSL appearance in the bacterial growth. It was found that the best interval for accumulation of homoserine lactone was after 4 hours. of incubation in which the homoserine lactone reached at optimal level. When one drop of culture supernatant was added to fresh growth of E. coli on slide, aggregation or quorum sensing was seen as indicator of HSL production.