Specialty mushrooms are primary decomposers and can grow and reproduce on a variety of natural, agricultural, and post-consumer waste substrates. These mushrooms include common species such as oyster (Pleurotus spp.), shiitake (Lentinula edodes), lions' mane (Hericium erinaceus), maitake (Grifola frondosa), and beech (Hypsizygus tessulatus). Much of our research focusses on Pleurotus spp., especially on Pleurotus ostreatus, the pearl oyster mushroom, because it is perhaps the most robust species in terms of aggressiveness and ability to outcompete contaminants, and it can grow and reproduce on just about any substrate available. This make it a fine platform for research and most of our other species tested are compared to pearl oyster production.
Most commercial production of specialty mushrooms occurs on a combination of straw or sawdust, with a percentage of cotton mean or soybean hulls added in to increase nitrogen content. Our lab explores a variety of less common and novel organic material as substrates for mushroom production and compare this production on standard commercial material. Our work has examine differences in production, measured as bioefficiency, when the principal substrate, the carbon base, is modified. Comparing wheat straw, with other waste streams such as corn cobs, sorghum stubble, and buffle grass, an invasive weed of the southwest,and using delinted contton seed as the nitrogen amembment, we found only moderate changes in bioefficiency when the carbon base was modified.
However, when we changed the high nitrogen amendment to this carbon base, amendments such as whole cotton seed (delinted), mesquite pods (a natural waste stream in the southwest), and alfalfa (in the form of pellets), we found production on cotton seed significantly higher than that of the other substrate mixes when keeping the carbon base the same (straw). This suggests the source of the nitrogen amendment is an important decision when maximizing production in a commercial operation.