Quorum sensing as a method for improving sclerotiorin production in Penicillium sclerotiorum

Quorum sensing has been extensively studied in the bacterial kingdom but little is known about it in filamentous fungi. gamma-Butyrolactones have been established as quorum sensing molecules in Gram-negative bacteria (as acyl-homoserine lactones) and Gram-positive bacteria (as A-factor) and they are present in many filamentous fungi (e.g. as butyrolactone I in Aspergillus terreus). This study investigates possible role of multicolic acid (and related derivates) as quorum sensing molecule(s) in P. sclerotiorum and its effect on the production of secondary metabolite sclerotiorin. Exogenous addition of an ethyl acetate extract of supernatants from P. sclerotiorum IMI 104602 (Strain M) at 48 h of growth resulted in maximum sclerotiorin yield of 8.5 mg g(-1) in Strain M at 168 h post-inoculation, a 1.8-fold increase as compared to the control. Addition of spent medium containing gamma-butyrolactone molecules from this strain to P. sclerotiorum IMI 040574 (Strain S) resulted in 6.4-fold increase in sclerotiorin yield at 168 h post-inoculation without causing a significant change in the biomass production (p>0.05) or carbohydrate consumption rate (p>0.05). The results presented here suggest that multicolic acid (and related derivatives) function as quorum sensing molecules in the filamentous fungus P. sclerotiorum.