In vitro and in vivo impact of some Pseudomonas spp. on the growth and yield of cultivated mushroom (Agaricus bisporus)

The aim of this study was to determine the in vitro and in vivo actions of isolated Pseudomonas spp. from casing soil on the hyphal growth and yield of Agaricus bisporus. It was found that only Pseudomonas putida increased the hyphae extension rate and also mushroom yield up to 26.6% when compared to the non-inoculated control. Pseudomonas tolaasii markedly inhibited growth, lysis of A. bisporus mycelium, and there were also significant reduction in mushroom yield (-72.5%). Mycelial growth was also inhibited by Pseudomonas aeruginosa, but the inhibition only occurred when the fungus hypha contact with the bacterial colony, this inhibition reduced the mushroom yield by 70.5%. Furthermore, Pseudomonas fluorescens had no statistically positive effects on mushroom mycelium growth and yield compared to control treatments. Until now, most research and applications of Pseudomonas aeruginosa have been conducted with animal disease. Findings of this research showed that this bacterium inhibits the mushroom hyphal growth and significantly reduces the harvested mushroom.