Pseudomonas tolaasii, P. reactans and Burkholderia gladioli pv. agaricicola, are responsible of diseases on some species of cultivated mushrooms. The main bioactive metabolites produced by both Pseudomonas strains are the lipodepsipeptides (LDPs) tolaasin I and II and the so called White Line Inducing Principle (WLIP), respectively, LDPs which have been extensively studied for their role in the disease process and for their biological properties. In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established. In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques. Recently, five news minor tolaasins, tolaasins A-E, were isolated from the culture filtrates of P. tolaasii and their chemical structure was determined by extensive use of NMR and MS spectroscopy. Furthermore, their antimicrobial activity was evaluated on target micro-organisms (fungi-including the cultivated mushrooms Agaricus bisporus, Lentinus edodes, and Pleurotus spp.-chromista, yeast and bacteria). The Gram positive bacteria resulted the most sensible and a significant structure-activity relationships was apparent. The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature. Furthermore, the exopolysaccharide (EPS) from the culture filtrates of B. gladioli pv. agaricicola, as well as the O-chain and lipid A, from the lipopolysaccharide (LPS) of the three bacteria, were isolated and the structures determined
lipopolysaccharides, exopolysaccharides, Pseudomonas tolaasii, bacterial diseases, cultivated mushrooms, Pseudomonas reactans, Burkholderia gladioli pv. agaricicola, antimicrobial activity, lipodepsipetides, mycopathogenic bacteria, permeabilising effects on membranes
NCBI PubMed ID: 19787100Journal NLM ID: 101322827Publisher: Thousand Oaks, CA: SAGE Publications
Correspondence: evidente@unina.it
Institutions: Dipartimento di Scienze del Suolo, della Pianta, dell’Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Portici, Italy, Dipartimento di Biologia, Difesa e Biotecnologie Agro-Forestali, Università degli Studi della Basilicata, Potenza, Italy
Methods: 13C NMR, 1H NMR, methylation, NMR-2D, GC-MS, 31P NMR, acid hydrolysis, extraction, acetylation, MALDI-TOF
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