Characterization of functional activity in composted casing amendments used in cultivation of Agaricus bisporus (Lange) Imbach

97-109In cultivation of button mushroom [Agaricus bisporus (Lange) Imbach], casing layer that is nutritionally deficient to compost is believed to trigger the fruit body formation and this is conducted by the bacterial community residing in casing layer. The change in nutritional status of the casing is highly correlated with microbial flora. Therefore, an attempt was made to characterize the bacterial flora in casing layer, i.e., Farm Yard Manure and Spent Mushroom Substrate (FYM+SMS, 3:1) and Farm Yard Manure and Vermi Compost (FYM+VC, 3:1), employing phenetic approaches. Morphotypically different and functionally characterized bacterial isolates were identified by partial 16S rDNA gene fragment sequencing. Available data showed a significant variety of organisms that included Acinetobacter and Pseudomonas of the γ-proteobacteria, that were most frequently encountered genera. Amongst Gram-positive bacteria, Bacillus was the most highly represented genus that was derived from the agaric fruit bodies. In addition, FYM+SMS was found to be a high yielding casing mixture, which took minimum case run period together with superior fruit body quality as compared to FYM+VC