The Voracious Appetites of Fungi
As I'm sure you're all aware, fungi are incredibly diverse in terms of the roles that they play in a variety of systems. I'd like to take a moment to discuss a few of those roles that I've been learning a little about recently. The first is thanks to the efforts of the Radical Mycology collective. They've been conducting experiments to examine the possibilities of fungi being trained to eat cigarette butts. Cigarette butts are a leading constituent of pollution in the form of litter and are composed of an industrial plastic called cellulose acetate. Cellulose acetate also happens to be relatively similar to other forms of cellulose that mushrooms utilize as food. Long story short: they've been having marked success with training mushrooms to consume this overly abundant food source. I'll spare you the gory details here and let those on the leading edge provide you with a better picture. Here's a link to the article (with a great video describing the project) on Radical Mycology's site and here's a link to some coverage that the research got from getting to GREENR, a blog supporting sustainability studies and skills. For anyone in our area who's interested in exploring mycoremediation solutions, please feel free to get in touch with us to toss around some ideas. We're lucky to have a collaborator with a vested interest in bioremediation, including mycoremediation, and we'd be happy to see what we can do to help.
I've also recently attended a composting workshop hosted by Broken Ground. The workshop highlighted a few methods for composting that can be carried out in the winter months here in the Gallatin Valley. The section of the workshop that illustrated an aspect of fungal ecology that many people seem to overlook was the Bokashi talk, given by Kathleen Rauch of Bokashi Lotus. It seems that, with our association of fungi with their fruiting bodies, we often forget about their unicellular or asexual family members.
Bokashi is a system for anaerobically processing food waste into a wonderful, soil building compost. To do this, the waste is first fermented. Many of us experience fermented goods on a regular basis: sauerkraut, pickled foods, beer, sourdough, and kombucha are all fermented. In all of these processes, microorganisms are used to alter the structure and chemical properties of the materials being fermented.
In Bokashi, three groups of microorganisms contribute to the pickling of the waste: lactic acid forming bacteria (usually Lactobacillus sp.), phototrophic proteobacteria (usually Rhodopseudomonas palustris or Rhodobacter spheroides) and yeast (usually Saccharomyces cerevisiae, a common brewers yeast) Many commercially prepared formulas may contain other organisms as well but these three are the key players. Of course, from the mycological perspective we're excited about the yeasts but the other organisms are essential to pull off the proper fermentation without putrification.
The inoculant is created by culturing these organisms using rice water, milk, and molasses. The Saccharomyces species is cultured directly from the rice itself. Wild yeasts are everywhere which is why grapes can be turned directly to wine or grains fermented without the addition of yeast. The quality of these beverages is affected by the quality of the native strains of yeast in the region which is why vintners and brewers select their yeasts to complement their recipes. By adding rice to water and allowing it to ferment for 5-7 days, we can culture a strain of yeast that will pickle our food wastes without having purchase or add any yeast. After the rice has fermented, strain out the solids. Next, milk is added to the mixture to begin culturing the Lactobacillus bacteria. Whole, unpasteurized milk is recommended to ensure the presence of the microorganisms that we're after but there have been cases of success reported by using pasteurized milk. Allow the mixture to sit until the solids have separated out of the milk and then strain out the solids. A small quantity of molasses is added to provide a food source for the microorganisms. This mixture should have a shelf life of about a year! It can also be used to inoculate a carbon source such as wheat bran or coffee grounds which can then be dried to create a shelf stable source of inoculant. For more specific recipes or for help with anything Bokashi, send Kathleen a message via her Bokashi Lotus Facebook page or contact us to get connected.
So what's the big deal? Why'd you go to all of the trouble to spend weeks nurturing these microorganisms? Well, partially because we're friends of the fungi but also because this little concoction is some really incredible stuff! Basically, anything that you're not supposed to put in your traditional compost pile, you can put into your bokashi bins. The trick to successful bokashi is maintaining an anaerobic (airtight) environment for the initial pickling stage of roughly 2 weeks (often less if the conditions are optimal). After that, you have the choice of adding it to an aerobic (oxygen rich) compost system or keeping it anaerobic by burring it directly in the soil.
Since you're keeping the initial pickling stages in buckets (or other airtight containers), it allows you to maintain a sink for all of the food scraps in your winter routine. The inoculated buckets can even freeze (like if you store it in your garage or somewhere outside of the roughly 60-80ºF comfort zone of the culture) and it will continue pickling once it warms back up! Then, when spring rolls around, you've got a bunch of beautifully pickled waste to add to the compost or soil.
The pickling process itself renders many of the health concerns with putrification and the potential for pathogens by essentially outcompeting pathogenic bacteria and then rendering the final product inhospitable for those same pathogens. This is largely why the things that aren't supposed to be added to traditional compost can be applied to Bokashi. The other reason is that the voracity with which these organisms ferment the waste allows them to rather rapidly digest these substances, rendering them readily decomposable when added to the soil or compost. This characteristic also means that the liquid inoculant has other useful applications such as eating the buildup of organic matter in your drains or acting as a pro-biotic for your septic system!
And remember how excited I was about the ability to maintain Bokashi during the winter? Well it turns out that some healthy Bokashi can even invigorate your aerobic compost pile throughout the winter by adding it in layers to the pile. The intense microbial activity in the Bokashi and the influx of new organisms from the pile into the Bokashi releases enough heat to maintain the thermophyllic environment required for the organisms to continue decomposing the materials through the winter.
This is a limited insight into a few of the myriad uses for fungi. I'll try to post more interesting tidbits from time to time. As always, let us know if there's anything that we can help you with. We'd be happy to hear from people with an interest in any aspect of mycology so that we can put together materials tailored to what our community wants to learn. Until then, maybe give Bokashi a try, if it seems right for you!