Fungi camembertii Fungi are also essential for chocolate: the naturally bitter cocoa beans are processed into a sweet tasty candy by a "fermentation" (sensu food-scientists) using Candida krusei and Geotrichum Biopulping and Bioremediation Several important industrial process, which have the potential to be great boons to ecosystem health, are in the pilot stage: biopulping and bioremediation The lignin-degrading enzyme system of Phanerochaete chrysosporium is special for these two uses One of the biggest energy and pollution expenditures in paper making comes from removal of the brown lignin from wood so that the white cellulose is all that is left to make paper What if paper companies could use the enzymes of a fungus to remove the lignin? This could result in a savings in both energy and time and avoid the polluting wastes that are commonly dumped out of the mills This process is known as biopulping There are several products in the pilot stage, but no large-scale biopulping is yet being done To understand this system, you must know that wood consists primarily of cellulose, which is white, and lignin, which is brown Members of Phanerochaete and other genera cause a white rot of wood That is, the fungus decays the lignin and leaves the cellulose behind There are also fungi that cause a brown rot, digesting the cellulose and leaving the lignin behind Many kinds of fungi cause a white rot, but P chrysosporium has several features that might make it very useful First of all, unlike some white rotters, it leaves the cellulose of the wood virtually untouched Second, it has a high optimum temperature (about 40 1C), which means it can grow on wood chips in compost piles, which attain a high temperature These characteristics point to some possible roles for this fungus in biotechnology applications The basis for all of Phanerocaete’s powers come from its enzymes that can degrade lignin This same enzyme system can also degrade chemicals that are chemically similar to lignin Some of the lignin-degrading enzymes of P chrysosporium will also degrade toxic wastes, such as PCBs (polychlorinated biphenyls), PCPs (phencyclidines), TNT (trinitrotoluene), and similar chemicals The structure of these chemicals is similar to that of lignin, and the ligninase enzymes will work on them The fungus performs well on the laboratory bench, but as with many industrial bioprocesses, there are difficulties in scaling up the process Nonetheless, this procedure has the potential to clean up some industrial and toxic waste sites In my lab, Adam Gusse, Paul Miller and Volk (2006) published a paper on the biodegradation of phenolic resin plastics with Phanerochaete chrysosporium We demonstrated the ability of this white-rot fungus to degrade phenolic resin, a previously nonbiodegradable industrial polymer (plastic-like) that is not commercially recycled These phenolic resin polymers, first known as Bakelite, are found gluing layers of plywood together, providing the binding matrix to particleboard, or laminating the surface of FormicaTM counter tops They are also used in constructing rotary telephone casings, bowling balls, toilet seats, motor casings, and many other everyday products The annual production of phenolic resin is 2.2 million tons per year Formerly considered to be nonbiodegradable and contributing greatly to landfills, our work 639 has demonstrated, through three lines of independent evidence, that phenolic resin polymers can be degraded by Phanerochaete chrysosporium (See TomVolkFungi.net for further information.) Threatened or Endangered Fungi Like the proverbial canary in the coal mine, fungi may be the first indicators of things going wrong in ecosystems Remember that fungi are the threads that tie the whole food web together, since they are the primary decomposers and aid most plants as mycorrhizae in the absorption of minerals and water Thus if something goes wrong with the fungi – if they disappear – there may be dire consequences for any plants and animals that are dependent on them Lichens have already been proven to be accurate indicators of air quality, in both their quantity and diversity Several European countries maintain ‘‘red lists’’ of threatened or endangered fungi One fungus that may be a candidate for the endangered species list in the United States is Bridgeoporus nobilissimus, a polypore fungus with a very large, perennial fruiting body (Figure 20) For a long time this fungus was in the Guinness Book of World Records as the largest known fruiting body of a fungus, at over 160 kg (300 pounds)! There are just eight known sites in Oregon, Washington, and California at which B nobilissimus is now known to occur It is considered by many to be a rare and probably endangered fungus The main reason for this designation is that it is restricted to very large specimens of noble fir (Abies procera) and occasionally Pacific silver fir (Abies amabilis) with a diameter at breast height (dbh) of 1–2 m Trees of this diameter are not very common This fungus is considered endangered because its habitat is endangered Unfortunately, it is not clear whether the U.S Endangered Species Act applies to fungi In this zoocentric world, most people are more interested in the ‘‘charismatic megafauna’’ than in some ‘‘lowly’’ fungus However, the fungi have many important roles to play in the ecosystem and should not be ignored No ecosystem could exist for long without fungi! Figure 20 The author with Bridgeoporus nobilissimus on a large host tree of Abies procera (noble fir)