Volume 16 Part 1 Article 69
Title: Bacterial Rot of Shiitake (Lentinula edodes)
Authors: O.V. Shulga, B. Kirchhoff, N.A. Goncharenko and A.P. Gryganski
We have observed epidemics of bacterial rot often in association with bacterial blotch on shiitake mushrooms (Lentinula edodes) in Ukrainian and German farms. Reasons for these epidemics were a high humidity (~95%) and a rapid rise in temperature to 29-30°C in the cultivation room, and increased moisture at the surface of the sawdust blocks. The disease reduced the number of primordia, with a mean yield loss of 16.3% compared to healthy crops. Bacterial rot manifested as fruiting bodies having a slimy surface, enlarged and deformed soft stems that were covered with a green-brown colored slime and soft undeveloped caps, often with contorted margins and undeveloped gills. Sometimes caps were absent. A scale was developed relating the level of infection to marketability of the product. Sale of fresh fruiting bodies was possible only if infection was limited to <10% of the mushroom surface area. The gramnegative bacterium, Burkholderia (syn. Pseudomonas) cepacia, was isolated from symptomatic fruiting bodies. This bacterium was rod-shaped, had an optimal growth temperature of 30-35°C, was oxidasenegative, grew on nutrient medium with saccharose producing slime, was unable to hydrolyze starch, hydrolyzed Tween 80, lacked arginine-hydrolase and was a denitrificator. Different strains produced non-fluorescent pigments and had specific fatty acids in their cell walls. Triterpene derivatives were found in the membranes, which were similar to sterols in eukaryotes. B. cepacia is an opportunistic pathogen in humans. Occurrence of this bacterium in shiitake culture poses a threat to consumersPlease login to download the PDF for this proceeding.