Composting and Bioremediation
The King Stropharia captures surface run-off of phosphorous and consumes E. coli, making it a potential species to use for watershed protection near animal operations.
Composting and Bioremediation
The primary interest at Sharondale is in using food mushrooms to break down and convert agricultural waste. The idea that waste from one use equals food or energy for another use in a continuous cycle is prominent in ecological design and is the basic premise for growing mushrooms and composting. Using substrates such as straw, manures, yard debris and other organic wastes, mushrooms grow for our food use and leave an enhanced nutrient base for other organisms to grow. Composting is the simplist way for you to use mushrooms on your property to break down the waste carbon sources you have available and create soil. By retaining and recycling carbon with naturally occurring microorganisms, you conserve an important and useful natural resource that would otherwise cost money and fuel to remove.
Many of the woodland mushrooms that we grow and consume as food are excellent candidates for bioremediation of environmental toxins. These mushrooms are able to breakdown lignin and cellulose, the primary structural components of wood. These wood molecules are very large and difficult to break down. The fungi excrete enzymes into the environment that break down these large organic molecules into smaller molecules which are then able to be absorbed as food by the mushroom and other microorganisms. In a similar way, large toxic molecules are broken down into
Pleurotus ostreatus: breaks down polyaromatic hydrocarbons(PAH’s), and helps to remediate petroleum products in soil
smaller less toxic or nontoxic parts which are then consumed or broken down further by the fungi and other microorganisms. There has been success in using some of these fungi to break down petroleum products and other persistent organic molecules in soils, decolorize industrial dyes and effluents, degrade pesticides, and breakdown explosives and chemical weapons.
Using the spent mushroom substrates which still contain living mushroom mycelium as filters or incorporated into soil is the most promising low-tech way to introduce these fungi into the environment to break down toxins. As toxic molecules are broken into smaller units and become benign and biologically available, bacteria, protozoa, insects, birds, plants and small animals join the growing multispecies ecosystem. The design of such a remediation project can include a planned or directed species succession, but much of the stabilization of the system that occurs is serendipitous according to the wild species which come to inhabit it. Mushrooms are grown on compost with a similar design. For example, the common button mushroom is grown on composted horse manure and cereal straws. This semi-selective compost is used for mushroom growing once many of the competitive microorganisms are killed by heating of the pile. Composting favors thermophilic (heat-tolerant) species, and kills heat sensitive species which are potential competition for Agaricus. Composting drives off ammonia, toxic to Agaricus. Low molecular weight compounds readily utilized by many microorganisms disappear, and high molecular weight compounds, cellulose and lignin, supplemented by microbial cell wall material remain to be exploited by Agaricus.
Agaricus subrufescens: excellent candidate to grow outdoors on composted manure substrates
At Sharondale, many local strains of mushrooms with composting and bioremediation potential are being collected. Check back occasionally for reports of ongoing experiments in bioremediation here at Sharondale Farm.
