Induction of antibacterial activity by alpha-D-oligogalacturonides in Nephrolepis sp. (pteridophyta)

This paper presents data on the induction by alpha-D-oligogalacturonides (OG) of antibiotic activity in vitro by the fern Nephrolepis sp. The extracts from the fern grown aseptically, partly in a medium containing a mixture of OG and partly in a medium lacking OG, as control, were tested against several bacterial strains. The results show that the OG mixture promotes the production of antibiotic compounds. Comparing the present results with those on the antimicrobial properties of the same fern grown in a greenhouse, we discuss the hypothesis that the production of antibiotic substances can be elicited by different factors, such as products of synthesis or degradation of the biotic component of the soil or by OG (in axenic culture) that can mimic the effect of natural elicitors. (C) 1997 Elsevier Science B.V.