Quantitative PCR study on the mode of action of oligosaccharide elicitors on penicillin G production by Penicillium chrysogenum.

Aim: To investigate the effects of single and multiple additions of the oligosaccharide elicitors, obtained from alginate and locust bean gum, on penicillin G production and the transcript level of penicillin G biosynthetic genes.

Methods And Results: The transcript copy numbers and penicillin G concentration in liquid cultures of Penicillium chrysogenum grown under control and elicited conditions were compared using quantitative PCR and HPLC assay respectively. An increase in the penicillin G production rate and transcript copy numbers of the three major penicillin G biosynthetic genes pcbAB, pcbC and penDE was observed in the elicited cultures compared to control cultures. The effects were observed to be higher in multiple elicitor added cultures compared to single elicitor supplemented and control cultures.

Conclusions: The results show, for the first time in bioreactor cultures, the enhancement of penicillin G transcript copy number of the penicillin biosynthetic genes using qPCR with a corresponding increase in the penicillin G production upon multiple elicitor addition of two different types of elicitors.

Significance And Impact Of The Study: Establishment of the effect of multiple elicitor addition on penicillin G production and investigating the role of oligosaccharide elicitors as transcriptional activators has wide spread impact for antibiotic industry.