Sub-lethal concentrations of Colombian Austroeupatorium inulifolium (HBK) essential oil and its effect on fungal growth and the production of enzymes

this work, we studied the effects of Austroeupatorium inulifolium (H.B.K.) essential oil on the growth and the enzyme production of phyto-pathogens species such as Aspergillus spp., Penicillium spp. and Fusarium spp. in vitro. Fungal growth was inhibited up to 70%, with P. brevicompactum and F. oxysporum being the most sensitive strains, while Aspergillus parasiticus and Penicillium nalgiovense were the most resistant. Sublethal concentrations of A. inulifolium essential oil increased pectinase, cellulase, protease and amylase activities in P. brevicompactum, A. flavus and F. oxysporum, with a concentration-dependent induction. Among the 71 compounds revealed by GC-MS analysis, trans beta - caryophyllene and ledene oxide (II) were the most abundant molecules. The antioxidant potential was measured using four in vitro assays, revealing a good antioxidant activity. The obtained results suggested the importance of the assessment of enzyme production involved in plant wall cell degradation, when the antifungal activity is evaluated. In addition, the use of sub-lethal concentrations of A. inulifolium essential oil to increase enzymatic activities in fungi can have great potential in the field of bioprospecting and biotechnology. (C) 2016 Elsevier B.V. All rights reserved.