BIOL2038 Fungi - Past Lecture Notes PDF

Fungi 2 – beneficial fungi BIOL2038 Vladimir Jiranek February 19, 2024 © University of Southampton, 2024 Aims/LOs Benefits of fungi to humans: Food (the fungal biomass itself) Food (fungus aids processing or alters the substrate) Recreation Biope...

Fungi 2 – beneficial fungi BIOL2038 Vladimir Jiranek February 19, 2024 © University of Southampton, 2024 Aims/LOs Benefits of fungi to humans: Food (the fungal biomass itself) Food (fungus aids processing or alters the substrate) Recreation Biopesticides Crop yield boosting Mycoremediation Enzyme production Medicines 2 Research  Food – fungal biomass High nutritional value (e.g., Fusarium venenatum) High in protein Low in fat, no cholesterol High fibre High minerals, vitamins and anti-oxidants Formulated into meat alternatives 3 Food – fungal biomass Food – familiar fungal biomass Agaricus (‘B’) Morchella (‘A’) White/button mushroom Morels Cantharellus (‘B’) Tuber (‘A’) Pleurotus (‘B’) Chanterelles Truffle Oyster mushroom Boletus (‘B’) Lentinula (‘B’) Termitomyces titanicus (‘B’) e.g., Porcini e.g., Shiitake chi-ngulu-ngulu (‘discovered’ in 1980) 5 Food – yeast biomass mainly Saccharomyces cerevisiae Saccharomyces (“sugar-fungus”) cerevisiae (“of beer”) is a highly efficient fermenter of sugars Preferring fermentation (2 ATP + ethanol) rather than respiration (36 ATP), despite the energy trade-off…..why? Biomass is an important product or waste too Sugar      Ethanol + CO2 + Flavour compounds + Biomass fermentation Extract Flavour enhancer Spent brewer’s yeast Nutrients Washed to de-bitter Heat + salt Heat inactivated Cell lysis Nutrients Molecules breakdown Food – processing mainly Saccharomyces cerevisiae Sugar      Ethanol + CO2 + Flavour compounds + Biomass fermentation Distillation Food – processing Aspergillus oryzae (‘A’) Fermentation of soy bean paste + roasted wheat + water + salt = soy sauce Some yeast involvement yields a bit if ethanol too A. oryzae used for making sake (Japanese rice ‘wine’, ~18% ABV) A. oryzae added to steamed rice, enzyme convert starch to sugars More steamed rice in water + S. cerevisiae combined with above (only) simultaneous saccharification and fermentation (~30 days) Aging occurs in cedar wood barrels Distillation produces shochu 8 Food – processing Penicillium camemberti (‘A’) and P. roqueforti (‘A’) Added to substrate in cheese-making process Either grows on the surface or penetrates into the cheese Gives unique flavour and texture to the finish product e.g., P. camemberti - lipolysis, proteolysis,  lactose, lactate, citrate, metabolise fatty & amino acids to yield volatile flavour and aroma compounds - ammonia, methyl-ketones, 1°and 2°alcohols, esters, aldehydes, lactones and sulfur compounds Cheeseman et al., (2014) Multiple recent horizontal transfers of a large genomic region in cheese making fungi. Nat. Commun. 5. 9 Food – action on substrate Botrytis cinerea (‘A’) Grey or ‘Noble rot’ Highly valued in for some wine styles (£ 350) Spores may be sprayed on grapes to encourage development Mould penetrates grapes, dehydrates, converts some sugars to glycerol Individual berries hand-picked from bunches – may take 6+ passes Juice (syrup) undergoes partial fermentation by yeast to produce a sweet dessert wines 10 Recreation Magic mushrooms Many species, all Basidiomycota (illegal!) Active ingredients: psilocybin, psilocin - hallucinogenic Possibly evolved as a defence mechanism against insects (‘change their minds’) Psilocybin similar to serotonin Interferes with serotonin receptors in brain Range of effects on body 11 12 Biopesticides – entomopathogenic fungi Beauveria bassiana (‘A’) Metarhizium anisopliae (‘A’) 13 14 Biopesticides – entomopathogenic fungi Common soil fungi (so not obligate parasitic) Mass production on whey-based culture media Control of locusts, aphids, bedbugs, thrips, whiteflies, termites 15 Biopesticides – nematophagous fungi Nematodes (worms) attack roots of crop plants Attempts to use fungi to control nematodes Nematode-trapping, endoparasitic, attack eggs/cysts e.g. Drechslerella spp (‘A’) Hyphae can also be adhesive https://youtu.be/hWdmL8sGCB4?t=11 16 Crop yield boosting Many crop plant species are in symbiosis with mycorrhizal fungi Inoculating soil with spores of mycorrhizal fungi increases yield 17 Mycoremediation Use of fungi in decontamination of environment Heavy metals: Pleurotes (‘B’), Aspergillus (‘A’), Trichoderma (‘A’) Organic pollutants (Polycyclic aromatic hydrocarbons, petroleum, Polychlorinated biphenyls, etc): wood- decay fungi, Pleurotes (‘B’), Pestalopiosis (‘A’) Other pesticides, dyes, etc Absorb (thus discard the fungus) or break down pollutants 18 Enzyme production ~50% of industrial enzymes are from fungi E.g., Aspergillus (‘A’), Penicillium (‘A’), Rhizopus (‘Z’), Trichoderma (‘A’), etc Examples: Proteases (proteins) – in food, leather, detergents Cellulases (cellulose) – textiles, paper, laundry, brewing, agriculture, biofuel, food Xylanases (xylan) – food, agriculture Lipases (lipids) – detergents, biofuels, ester production Amylases (starch) – food, biofuels Phytases (phytic acid) – enhance digestibility of animal feed 19 Medicines Inhibition zone around Penicillium chrysogenum (‘A’) Caused by an antibiotic - penicillin Evolved as a way for Conidiophores with conidia (asexual) fungi to compete with bacteria Original isolates underwent selection, mutagenesis, breeding, etc. Titre increased by 1000. Other species and antibiotics utilised – different target species 20 Medicines Statins (cholesterol control): Penicillium spp (‘A’), Aspergillus terreus (‘A’), Monascus purpureus (‘A’), etc. Actually inhibit other fungi by interfering in sterol synthesis Same effect in humans Anti-cancer drugs: Penicillium spp (‘A’) Immuno-suppressants: Penicillium spp (‘A’), Tolypocladium inflatum (‘A’), etc. Drugs against malaria, diabetes, … 21 Production of D vitamins Research Saccharomyces cerevisiae (‘A’) Model organism in cell biology, genetics, DNA repair, aging, etc. One of the best studied eukaryotes First eukaryote to have its genome sequenced (1996) by an international consortium of several labs – took 6 yrs Followed by a deletion library, over-expression library, etc SGS – Saccharomyces genome database: curated repository of gene function, linkages, pathways, publications, etc., etc. Proven to be an incredibly powerful system 22 To sum up... You should … … be aware of the many ways that fungi are beneficial to humans: … food (biomass or processing), recreation, biopesticides, crop yield boosting, enzyme production, mycoremediation, medicines, research … look further into this if you’re interested; I gave you just a quick overview! 23 Aesthetics 24