{{short description|Enzymes produced by fungi and secreted outside their cells}} thumb|Birch polypore (Piptoporus betulinus) - geograph.org.uk - 1553987 '''Extracellular enzymes''' or exoenzymes are synthesized inside the cell and then secreted outside the cell, where their function is to break down complex macromolecules into smaller units to be taken up by the cell for growth and assimilation.<ref name="Sinsabaugh1994">{{cite journal|last1=Sinsabaugh|first1=R. S.|s2cid=20188510|title=Enzymic analysis of microbial pattern and process|journal=Biology and Fertility of Soils|volume=17|issue=1|year=1994|pages=69–74|issn=0178-2762|doi=10.1007/BF00418675}}</ref> These enzymes degrade complex organic matter such as cellulose and hemicellulose into simple sugars that enzyme-producing organisms use as a source of carbon, energy, and nutrients.<ref name="BurnsDeForest2013">{{cite journal|last1=Burns|first1=Richard G.|last2=DeForest|first2=Jared L.|last3=Marxsen|first3=Jürgen|last4=Sinsabaugh|first4=Robert L.|last5=Stromberger|first5=Mary E.|last6=Wallenstein|first6=Matthew D.|last7=Weintraub|first7=Michael N.|last8=Zoppini|first8=Annamaria|title=Soil enzymes in a changing environment: Current knowledge and future directions|journal=Soil Biology and Biochemistry|volume=58|year=2013|pages=216–234|issn=0038-0717|doi=10.1016/j.soilbio.2012.11.009}}</ref> Grouped as hydrolases, lyases, oxidoreductases and transferases,<ref name="Sinsabaugh1994"/> these extracellular enzymes control soil enzyme activity through efficient degradation of biopolymers.
Plant residues, animals and microorganisms enter the dead organic matter pool upon senescence<ref name="Cebrian1999">{{cite journal|last1=Cebrian|first1=Just|s2cid=4384243|title=Patterns in the Fate of Production in Plant Communities|journal=The American Naturalist|volume=154|issue=4|year=1999|pages=449–468|issn=0003-0147|doi=10.1086/303244|pmid=10523491}}</ref> and become a source of nutrients and energy for other organisms. Extracellular enzymes target macromolecules such as carbohydrates (cellulases), lignin (oxidases), organic phosphates (phosphatases), amino sugar polymers (chitinases) and proteins (proteases)<ref>{{cite book|title=Manual of environmental microbiology|year=2007|publisher=ASM|location=Washington, DC|isbn=978-1-55581-379-6|pages=704–711|author=Allison, S.D.|edition=3rd|editor=Hurst, CJ. |editor2=Crawford, RL. |editor3=Garland, JL. |editor4=Lipson DA. |editor5=Mills, AL |editor6=Stetzenbach, LD|chapter=Soil enzymes: linking proteomics and ecological processes|display-authors=etal}}</ref> and break them down into soluble sugars that are subsequently transported into cells to support heterotrophic metabolism.<ref name="Sinsabaugh1994"/>
Biopolymers are structurally complex and require the combined actions of a community of diverse microorganisms and their secreted exoenzymes to depolymerize the polysaccharides into easily assimilable monomers. These microbial communities are ubiquitous in nature, inhabiting both terrestrial and aquatic ecosystems. The cycling of elements from dead organic matter by heterotrophic soil microorganisms is essential for nutrient turnover and energy transfer in terrestrial ecosystems.<ref name="GessnerSwan2010">{{cite journal|last1=Gessner|first1=Mark O.|last2=Swan|first2=Christopher M.|last3=Dang|first3=Christian K.|last4=McKie|first4=Brendan G.|last5=Bardgett|first5=Richard D.|last6=Wall|first6=Diana H.|last7=Hättenschwiler|first7=Stephan|title=Diversity meets decomposition|journal=Trends in Ecology & Evolution|volume=25|issue=6|year=2010|pages=372–380|issn=0169-5347|doi=10.1016/j.tree.2010.01.010|pmid=20189677}}</ref> Exoenzymes also aid digestion in the guts of ruminants,<ref name="KrauseDenman2003">{{cite journal|last1=Krause|first1=Denis O|last2=Denman|first2=Stuart E|last3=Mackie|first3=Roderick I|last4=Morrison|first4=Mark|last5=Rae|first5=Ann L|last6=Attwood|first6=Graeme T|last7=McSweeney|first7=Christopher S|title=Opportunities to improve fiber degradation in the rumen: microbiology, ecology, and genomics|journal=FEMS Microbiology Reviews|volume=27|issue=5|year=2003|pages=663–693|issn=0168-6445|doi=10.1016/S0168-6445(03)00072-X|pmid=14638418|doi-access=free}}</ref> termites,<ref>{{cite journal |last = Warnecke |first= F|title= Metagenomic and functional analysis of hindgut microbiota of a wood-feeding higher termite |journal=Nature |year=2007|volume=450 |issue= 7169|pages=560–565|doi=10.1038/nature06269 |pmid= 18033299|display-authors=etal|bibcode= 2007Natur.450..560W|s2cid= 4420494|url= https://authors.library.caltech.edu/37425/7/nature06269-s1.pdf}}</ref> humans and herbivores. By hydrolyzing plant cell wall polymers, microbes release energy that has the potential to be used by humans as biofuel.<ref name="Ragauskas2006">{{cite journal |author1-link=Arthur Ragauskas |last1=Ragauskas|first1=A. J.|s2cid=9213544|title=The Path Forward for Biofuels and Biomaterials|journal=Science|volume=311|issue=5760|year=2006|pages=484–489|issn=0036-8075|doi=10.1126/science.1114736|pmid=16439654|bibcode=2006Sci...311..484R}}</ref> Other human uses include waste water treatment,<ref name="ShackleFreeman2006">{{cite journal|last1=Shackle|first1=V.|last2=Freeman|first2=C.|last3=Reynolds|first3=B.|title=Exogenous enzyme supplements to promote treatment efficiency in constructed wetlands|journal=Science of the Total Environment|volume=361|issue=1–3|year=2006|pages=18–24|issn=0048-9697|doi=10.1016/j.scitotenv.2005.09.032|pmid=16213577|bibcode=2006ScTEn.361...18S}}</ref> composting<ref name="CrecchioCurci2004">{{cite journal|last1=Crecchio|first1=Carmine|last2=Curci|first2=Magda|last3=Pizzigallo|first3=Maria D.R.|last4=Ricciuti|first4=Patrizia|last5=Ruggiero|first5=Pacifico|title=Effects of municipal solid waste compost amendments on soil enzyme activities and bacterial genetic diversity|journal=Soil Biology and Biochemistry|volume=36|issue=10|year=2004|pages=1595–1605|issn=0038-0717|doi=10.1016/j.soilbio.2004.07.016}}</ref> and bioethanol production.<ref name="Wackett2008">{{cite journal|last1=Wackett|first1=Lawrence P|title=Biomass to fuels via microbial transformations|journal=Current Opinion in Chemical Biology|volume=12|issue=2|year=2008|pages=187–193|issn=1367-5931|doi=10.1016/j.cbpa.2008.01.025|pmid=18275861}}</ref>
==Factors influencing extracellular enzyme activity== Extracellular enzyme production supplements the direct uptake of nutrients by microorganisms and is linked to nutrient availability and environmental conditions. The varied chemical structure of organic matter requires a suite of extracellular enzymes to access the carbon and nutrients embedded in detritus. Microorganisms differ in their ability to break down these different substrates and few organisms have the potential to degrade all the available plant cell wall materials.<ref name="AllisonLeBauer2009">{{cite journal|last1=Allison|first1=Steven D.|last2=LeBauer|first2=David S.|last3=Ofrecio|first3=M. Rosario|last4=Reyes|first4=Randy|last5=Ta|first5=Anh-Minh|last6=Tran|first6=Tri M.|title=Low levels of nitrogen addition stimulate decomposition by boreal forest fungi|journal=Soil Biology and Biochemistry|volume=41|issue=2|year=2009|pages=293–302|issn=0038-0717|doi=10.1016/j.soilbio.2008.10.032}}</ref> To detect the presence of complex polymers, some exoenzymes are produced constitutively at low levels, and expression is upregulated when the substrate is abundant.<ref name="KlonowskaGaudin2002">{{cite journal|last1=Klonowska|first1=Agnieszka|last2=Gaudin|first2=Christian|last3=Fournel|first3=André|last4=Asso|first4=Marcel|last5=Le Petit|first5=Jean|last6=Giorgi|first6=Michel|last7=Tron|first7=Thierry|title=Characterization of a low redox potential laccase from the basidiomycete C30|journal=European Journal of Biochemistry|volume=269|issue=24|year=2002|pages=6119–6125|issn=0014-2956|doi=10.1046/j.1432-1033.2002.03324.x|pmid=12473107|doi-access=free}}</ref> This sensitivity to the presence of varying concentrations of substrate allows fungi to respond dynamically to the changing availability of specific resources. Benefits of exoenzyme production can also be lost after secretion because the enzymes are liable to denature, degrade or diffuse away from the producer cell.
Enzyme production and secretion is an energy intensive process<ref name="Schimel2003">{{cite journal|last1=Schimel|first1=J|title=The implications of exoenzyme activity on microbial carbon and nitrogen limitation in soil: a theoretical model|journal=Soil Biology and Biochemistry|volume=35|issue=4|year=2003|pages=549–563|issn=0038-0717|doi=10.1016/S0038-0717(03)00015-4}}</ref> and, because it consumes resources otherwise available for reproduction, there is evolutionary pressure to conserve those resources by limiting production.<ref name="AllisonWeintraub2010">{{cite book|last1=Allison|first1=Steven D.|last2=Weintraub|first2=Michael N.|last3=Gartner|first3=Tracy B.|last4=Waldrop|first4=Mark P.|title=Soil Enzymology |chapter=Evolutionary-Economic Principles as Regulators of Soil Enzyme Production and Ecosystem Function |series=Soil Biology |volume=22|year=2010|pages=229–243|issn=1613-3382|doi=10.1007/978-3-642-14225-3_12|isbn=978-3-642-14224-6|citeseerx=10.1.1.689.2292}}</ref> Thus, while most microorganisms can assimilate simple monomers, degradation of polymers is specialized, and few organisms can degrade recalcitrant polymers like cellulose and lignin.<ref name="BaldrianKolařík2011">{{cite journal|last1=Baldrian|first1=Petr|last2=Kolařík|first2=Miroslav|last3=Štursová|first3=Martina|last4=Kopecký|first4=Jan|last5=Valášková|first5=Vendula|last6=Větrovský|first6=Tomáš|last7=Žifčáková|first7=Lucia|last8=Šnajdr|first8=Jaroslav|last9=Rídl|first9=Jakub|last10=Vlček|first10=Čestmír|last11=Voříšková|first11=Jana|title=Active and total microbial communities in forest soil are largely different and highly stratified during decomposition|journal=The ISME Journal|volume=6|issue=2|year=2011|pages=248–258|issn=1751-7362|doi=10.1038/ismej.2011.95|pmid=21776033|pmc=3260513}}</ref> Each microbial species carries specific combinations of genes for extracellular enzymes and is adapted to degrade specific substrates.<ref name="AllisonLeBauer2009"/> In addition, the expression of genes that encode for enzymes is typically regulated by the availability of a given substrate. For example, presence of a low-molecular weight soluble substrate such as glucose will inhibit enzyme production by repressing the transcription of associated cellulose-degrading enzymes.<ref name="Hanif2004">{{cite journal|last1=Hanif|first1=A|title=Induction, production, repression, and de-repression of exoglucanase synthesis in Aspergillus niger|journal=Bioresource Technology|volume=94|issue=3|year=2004|pages=311–319|issn=0960-8524|doi=10.1016/j.biortech.2003.12.013|pmid=15182839}}</ref>
Environmental conditions such as soil pH,<ref name="DeForestSmemo2011">{{cite journal|last1=DeForest|first1=Jared L.|last2=Smemo|first2=Kurt A.|last3=Burke|first3=David J.|last4=Elliott|first4=Homer L.|last5=Becker|first5=Jane C.|s2cid=97965526|title=Soil microbial responses to elevated phosphorus and pH in acidic temperate deciduous forests|journal=Biogeochemistry|volume=109|issue=1–3|year=2011|pages=189–202|issn=0168-2563|doi=10.1007/s10533-011-9619-6}}</ref> soil temperature,<ref name="WallensteinHaddix2012">{{cite journal|last1=Wallenstein|first1=Matthew D.|last2=Haddix|first2=Michelle L.|last3=Lee|first3=Daniel D.|last4=Conant|first4=Richard T.|last5=Paul|first5=Eldor A.|title=A litter-slurry technique elucidates the key role of enzyme production and microbial dynamics in temperature sensitivity of organic matter decomposition|journal=Soil Biology and Biochemistry|volume=47|year=2012|pages=18–26|issn=0038-0717|doi=10.1016/j.soilbio.2011.12.009}}</ref> moisture content,<ref name="FiorettoPapa2000">{{cite journal|last1=Fioretto|first1=A.|last2=Papa|first2=S.|last3=Curcio|first3=E.|last4=Sorrentino|first4=G.|last5=Fuggi|first5=A.|title=Enzyme dynamics on decomposing leaf litter of Cistus incanus and Myrtus communis in a Mediterranean ecosystem|journal=Soil Biology and Biochemistry|volume=32|issue=13|year=2000|pages=1847–1855|issn=0038-0717|doi=10.1016/S0038-0717(00)00158-9}}</ref> and plant litter type and quality<ref name="WaldropZak2006">{{cite journal|last1=Waldrop|first1=Mark P.|last2=Zak|first2=Donald R.|s2cid=10919578|title=Response of Oxidative Enzyme Activities to Nitrogen Deposition Affects Soil Concentrations of Dissolved Organic Carbon|journal=Ecosystems|volume=9|issue=6|year=2006|pages=921–933|issn=1432-9840|doi=10.1007/s10021-004-0149-0}}</ref> have the potential to alter exoenzyme expression and activity. Variations in seasonal temperatures can shift metabolic needs of microorganisms in synchrony with shifts in plant nutrient requirements.<ref name="FinziAustin2011">{{cite journal|last1=Finzi|first1=Adrien C|last2=Austin|first2=Amy T|last3=Cleland|first3=Elsa E|last4=Frey|first4=Serita D|author-link4=Serita Frey|last5=Houlton|first5=Benjamin Z|author5-link=Benjamin Z. Houlton|last6=Wallenstein|first6=Matthew D|s2cid=2862965|title=Responses and feedbacks of coupled biogeochemical cycles to climate change: examples from terrestrial ecosystems|journal=Frontiers in Ecology and the Environment|volume=9|issue=1|year=2011|pages=61–67|issn=1540-9295|doi=10.1890/100001|hdl=11336/84335 |hdl-access=free}}</ref> Agricultural practices such as fertilizer amendments and tillage can change the spatial distribution of resources, resulting in altered exoenzyme activity in the soil profile.<ref name="PollThiede2003">{{cite journal|last1=Poll|first1=C.|last2=Thiede|first2=A.|last3=Wermbter|first3=N.|last4=Sessitsch|first4=A.|last5=Kandeler|first5=E.|title=Micro-scale distribution of microorganisms and microbial enzyme activities in a soil with long-term organic amendment|journal=European Journal of Soil Science|volume=54|issue=4|year=2003|pages=715–724|issn=1351-0754|doi=10.1046/j.1351-0754.2003.0569.x|s2cid=97005809 }}</ref> Introduction of moisture exposes soil organic matter to enzyme catalysis<ref>{{cite journal|last=Fierer|first=N|author2=Schimel, JP|s2cid=2815843|title=A proposed mechanism for the pulse of carbon dioxide production commonly observed following the rapid rewetting of a dry soil|journal= Soil Science Society of America Journal|year=2003|volume=67|issue=3|pages=798–805|doi=10.2136/sssaj2003.0798|bibcode=2003SSASJ..67..798F}}</ref> and also increases loss of soluble monomers via diffusion. Additionally, osmotic shock resulting from water potential changes can impact enzyme activities as microbes redirect energy from enzyme production to synthesizing osmolytes to maintain cellular structures.
==Extracellular enzyme activity in fungi during plant decomposition== thumb|Plant cell showing primary and secondary wall by CarolineDahl Most of the extracellular enzymes involved in polymer degradation in leaf litter and soil have been ascribed to fungi.<ref name="BoerFolman2005">{{cite journal|last1=Boer|first1=Wietse de|last2=Folman|first2=Larissa B.|last3=Summerbell|first3=Richard C.|last4=Boddy|first4=Lynne|title=Living in a fungal world: impact of fungi on soil bacterial niche development|journal=FEMS Microbiology Reviews|volume=29|issue=4|year=2005|pages=795–811|issn=0168-6445|doi=10.1016/j.femsre.2004.11.005|pmid=16102603|doi-access=free}}</ref><ref name="HättenschwilerTiunov2005">{{cite journal|last1=Hättenschwiler|first1=Stephan|title=Biodiversity and Litter Decomposition in Terrestrial Ecosystems|last2=Tiunov|first2=Alexei V.|last3=Scheu|first3=Stefan|journal=Annual Review of Ecology, Evolution, and Systematics|volume=36|issue=1|year=2005|pages=191–218|issn=1543-592X|doi=10.1146/annurev.ecolsys.36.112904.151932}}</ref><ref>{{cite journal|last=Baldrian|first=P|title=Microbial enzyme-catalyzed processes in soils and their analysis|journal= Plant, Soil and Environment|year=2009|volume=55|issue=9|pages=370–378|doi=10.17221/134/2009-PSE|doi-access=free}}</ref> By adapting their metabolism to the availability of varying amounts of carbon and nitrogen in the environment, fungi produce a mixture of oxidative and hydrolytic enzymes to efficiently break down lignocelluloses like wood. During plant litter degradation, cellulose and other labile substrates are degraded first<ref name="Berg2000">{{cite journal|last1=Berg|first1=Björn|title=Litter decomposition and organic matter turnover in northern forest soils|journal=Forest Ecology and Management|volume=133|issue=1–2|year=2000|pages=13–22|issn=0378-1127|doi=10.1016/S0378-1127(99)00294-7}}</ref> followed by lignin depolymerization with increased oxidative enzyme activity and shifts in microbial community composition.
In plant cell walls, cellulose and hemicellulose is embedded in a pectin scaffold<ref name="RidleyO'Neill2001">{{cite journal|last1=Ridley|first1=Brent L|last2=O'Neill|first2=Malcolm A|last3=Mohnen|first3=Debra|title=Pectins: structure, biosynthesis, and oligogalacturonide-related signaling|journal=Phytochemistry|volume=57|issue=6|year=2001|pages=929–967|issn=0031-9422|doi=10.1016/S0031-9422(01)00113-3|pmid=11423142|bibcode=2001PChem..57..929R }}</ref> that requires pectin degrading enzymes, such as polygalacturonases and pectin lyases to weaken the plant cell wall and uncover hemicellulose and cellulose to further enzymatic degradation.<ref name="LagaertBeliën2009">{{cite journal|last1=Lagaert|first1=Stijn|last2=Beliën|first2=Tim|last3=Volckaert|first3=Guido|title=Plant cell walls: Protecting the barrier from degradation by microbial enzymes|journal=Seminars in Cell & Developmental Biology|volume=20|issue=9|year=2009|pages=1064–1073|issn=1084-9521|doi=10.1016/j.semcdb.2009.05.008|pmid=19497379}}</ref> Degradation of lignin is catalyzed by enzymes that oxidase aromatic compounds, such as phenol oxidases, peroxidases and laccases. Many fungi have multiple genes encoding lignin-degrading exoenzymes.<ref name="CourtyHoegger2009">{{cite journal|last1=Courty|first1=P. E.|last2=Hoegger|first2=P. J.|last3=Kilaru|first3=S.|last4=Kohler|first4=A.|last5=Buée|first5=M.|last6=Garbaye|first6=J.|last7=Martin|first7=F.|last8=Kües|first8=U.|title=Phylogenetic analysis, genomic organization, and expression analysis of multi-copper oxidases in the ectomycorrhizal basidiomyceteLaccaria bicolor|journal=New Phytologist|volume=182|issue=3|year=2009|pages=736–750|issn=0028-646X|doi=10.1111/j.1469-8137.2009.02774.x|pmid=19243515|s2cid=23324645 |doi-access=}}</ref>
Most efficient wood degraders are saprotrophic ascomycetes and basidiomycetes. Traditionally, these fungi are classified as brown rot (Ascomycota and Basidiomycota), white rot (Basidiomycota) and soft rot (Ascomycota) based on the appearance of the decaying material.<ref name="BurnsDeForest2013"/> Brown rot fungi preferentially attack cellulose and hemicellulose;<ref>{{cite journal|last=Martinez|first=AT|title=Biodegradation of lignocellulosics: microbial, chemical, and enzymatic aspects of the fungal attack of lignin|journal=International Microbiology|year=2005|volume=8|pages=195–204|pmid=16200498|issue=3|display-authors=etal}}</ref> while white rot fungi degrade cellulose and lignin. To degrade cellulose, basidiomycetes employ hydrolytic enzymes, such as endoglucanases, cellobiohydrolase and β-glucosidase.<ref name="BaldrianValášková2008">{{cite journal|last1=Baldrian|first1=Petr|last2=Valášková|first2=Vendula|title=Degradation of cellulose by basidiomycetous fungi|journal=FEMS Microbiology Reviews|volume=32|issue=3|year=2008|pages=501–521|issn=0168-6445|doi=10.1111/j.1574-6976.2008.00106.x|pmid=18371173|doi-access=free}}</ref> Production of endoglucanases is widely distributed among fungi and cellobiohydrolases have been isolated in multiple white-rot fungi and in plant pathogens.<ref name="BaldrianValášková2008"/> β-glucosidases are secreted by many wood-rotting fungi, both white and brown rot fungi, mycorrhizal fungi<ref name="KusudaUeda2006">{{cite journal|last1=Kusuda|first1=Mizuho|last2=Ueda|first2=Mitsuhiro|last3=Konishi|first3=Yasuhito|last4=Araki|first4=Yoshihito|last5=Yamanaka|first5=Katsuji|last6=Nakazawa|first6=Masami|last7=Miyatake|first7=Kazutaka|last8=Terashita|first8=Takao|s2cid=84906200|title=Detection of β-glucosidase as saprotrophic ability from an ectomycorrhizal mushroom, Tricholoma matsutake|journal=Mycoscience|volume=47|issue=4|year=2006|pages=184–189|issn=1340-3540|doi=10.1007/s10267-005-0289-x|doi-access=free}}</ref> and in plant pathogens. In addition to cellulose, β-glucosidases can cleave xylose, mannose and galactose.<ref name="ValaskovaBaldrian2006">{{cite journal|last1=Valaskova|first1=V.|last2=Baldrian|first2=P.|title=Degradation of cellulose and hemicelluloses by the brown rot fungus Piptoporus betulinus - production of extracellular enzymes and characterization of the major cellulases|journal=Microbiology|volume=152|issue=12|year=2006|pages=3613–3622|issn=1350-0872|doi=10.1099/mic.0.29149-0|pmid=17159214|doi-access=free}}</ref>
In white-rot fungi such as ''Phanerochaete chrysosporium'', expression of manganese-peroxidase is induced by the presence of manganese, hydrogen peroxide and lignin,<ref>{{cite journal |vauthors=Li D, Alic M, Brown JA, Gold MH |title=Regulation of manganese peroxidase gene transcription by hydrogen peroxide, chemical stress, and molecular oxygen |journal=Appl. Environ. Microbiol. |volume=61 |issue=1 |pages=341–5 |date=January 1995 |pmid=7887613 |pmc=167287 |doi= 10.1128/AEM.61.1.341-345.1995|bibcode=1995ApEnM..61..341L }}</ref> while laccase is induced by availability of phenolic compounds.<ref>{{cite journal|last=Leonowicz|first=A|title=Fungal laccases: properties and activity on lignin|journal=Journal of Basic Microbiology|year=2001|volume=41|pages=185–227|pmid=11512451|issue=3–4|doi=10.1002/1521-4028(200107)41:3/4<185::aid-jobm185>3.0.co;2-t|s2cid=23523898|display-authors=etal}}</ref> Production of lignin-peroxidase and manganese-peroxidase is the hallmark of basidiomycetes and is often used to assess basidiomycete activity, especially in biotechnology applications.<ref name="Hofrichter2002">{{cite journal|last1=Hofrichter|first1=Martin|title=Review: lignin conversion by manganese peroxidase (MnP)|journal=Enzyme and Microbial Technology|volume=30|issue=4|year=2002|pages=454–466|issn=0141-0229|doi=10.1016/S0141-0229(01)00528-2}}</ref> Most white-rot species also produce laccase, a copper-containing enzyme that degrades polymeric lignin and humic substances.<ref name="Baldrian2006">{{cite journal|last1=Baldrian|first1=Petr|title=Fungal laccases – occurrence and properties|journal=FEMS Microbiology Reviews|volume=30|issue=2|year=2006|pages=215–242|issn=0168-6445|doi=10.1111/j.1574-4976.2005.00010.x|pmid=16472305|doi-access=free}}</ref>
Brown-rot basidiomycetes are most commonly found in coniferous forests, and are so named because they degrade wood to leave a brown residue that crumbles easily. Preferentially attacking hemicellulose in wood, followed by cellulose, these fungi leave lignin largely untouched.<ref name="HammelKapich2002">{{cite journal|last1=Hammel|first1=Kenneth E.|last2=Kapich|first2=Alexander N.|last3=Jensen|first3=Kenneth A.|last4=Ryan|first4=Zachary C.|title=Reactive oxygen species as agents of wood decay by fungi|journal=Enzyme and Microbial Technology|volume=30|issue=4|year=2002|pages=445–453|issn=0141-0229|doi=10.1016/S0141-0229(02)00011-X|s2cid=96847091 }}</ref> The decayed wood of soft-rot Ascomycetes is brown and soft. One soft-rot Ascomycete, ''Trichoderma reesei'', is used extensively in industrial applications as a source for cellulases and hemicellulases.<ref name="KumarSingh2008">{{cite journal|last1=Kumar|first1=Raj|last2=Singh|first2=Sompal|last3=Singh|first3=Om V.|s2cid=4830678|title=Bioconversion of lignocellulosic biomass: biochemical and molecular perspectives|journal=Journal of Industrial Microbiology & Biotechnology|volume=35|issue=5|year=2008|pages=377–391|issn=1367-5435|doi=10.1007/s10295-008-0327-8|pmid=18338189|doi-access=free}}</ref> Laccase activity has been documented in ''T. reesei'', in some species in the Aspergillus genus<ref name="Tamayo-Ramosvan Berkel2012">{{cite journal|last1=Tamayo-Ramos|first1=Juan Antonio|last2=van Berkel|first2=Willem JH|last3=de Graaff|first3=Leo H|title=Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger|journal=Microbial Cell Factories|volume=11|issue=1|year=2012|pages=165|issn=1475-2859|doi=10.1186/1475-2859-11-165|pmid=23270588|pmc=3548707 |doi-access=free }}</ref> and in freshwater ascomycetes.<ref name="Junghanns2005">{{cite journal|last1=Junghanns|first1=C.|title=Degradation of the xenoestrogen nonylphenol by aquatic fungi and their laccases|journal=Microbiology|volume=151|issue=1|year=2005|pages=45–57|issn=1350-0872|doi=10.1099/mic.0.27431-0|pmid=15632424|doi-access=free}}</ref>
==Measuring fungal extracellular enzyme activity in soil, plant litter, and other environmental samples== 128px|left|Electronic PH meter Methods for estimating soil enzyme activities involve sample harvesting prior to analysis, mixing of samples with buffers and the use of substrate. Results can be influenced by: sample transport from field-site, storage methods, pH conditions for assay, substrate concentrations, temperature at which the assay is run, sample mixing and preparation.<ref name="GermanWeintraub2011">{{cite journal|last1=German|first1=Donovan P.|last2=Weintraub|first2=Michael N.|last3=Grandy|first3=A. Stuart|last4=Lauber|first4=Christian L.|last5=Rinkes|first5=Zachary L.|last6=Allison|first6=Steven D.|title=Optimization of hydrolytic and oxidative enzyme methods for ecosystem studies|journal=Soil Biology and Biochemistry|volume=43|issue=7|year=2011|pages=1387–1397|issn=0038-0717|doi=10.1016/j.soilbio.2011.03.017}}</ref>
For hydrolytic enzymes, colorimetric assays are required that use a p-nitrophenol (p-NP)-linked substrate,<ref name="SinsabaughLinkins1990">{{cite journal|last1=Sinsabaugh|first1=Robert L.|last2=Linkins|first2=Arthur E.|title=Enzymic and chemical analysis of particulate organic matter from a boreal river|journal=Freshwater Biology|volume=23|issue=2|year=1990|pages=301–309|issn=0046-5070|doi=10.1111/j.1365-2427.1990.tb00273.x}}</ref> or fluorometric assays that use a 4-methylumbelliferone (MUF)-linked substrate.<ref name="MarxWood2001">{{cite journal|last1=Marx|first1=M.-C|last2=Wood|first2=M|last3=Jarvis|first3=S.C|title=A microplate fluorimetric assay for the study of enzyme diversity in soils|journal=Soil Biology and Biochemistry|volume=33|issue=12–13|year=2001|pages=1633–1640|issn=0038-0717|doi=10.1016/S0038-0717(01)00079-7}}</ref>
Oxidative enzymes such as phenol oxidase and peroxidase mediate lignin degradation and humification.<ref name="Sinsabaugh2010">{{cite journal|last1=Sinsabaugh|first1=Robert L.|title=Phenol oxidase, peroxidase and organic matter dynamics of soil|journal=Soil Biology and Biochemistry|volume=42|issue=3|year=2010|pages=391–404|issn=0038-0717|doi=10.1016/j.soilbio.2009.10.014}}</ref> Phenol oxidase activity is quantified by oxidation of L-3, 4-dihydoxyphenylalanine (L-DOPA), pyrogallol (1, 2, 3-trihydroxybenzene), or ABTS (2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid). Peroxidase activity is measured by running the phenol oxidase assay concurrently with another assay with L-DOPA and hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) added to every sample.<ref name="DeForest2009">{{cite journal|last1=DeForest|first1=Jared L.|title=The influence of time, storage temperature, and substrate age on potential soil enzyme activity in acidic forest soils using MUB-linked substrates and l-DOPA|journal=Soil Biology and Biochemistry|volume=41|issue=6|year=2009|pages=1180–1186|issn=0038-0717|doi=10.1016/j.soilbio.2009.02.029}}</ref> The difference in measurements between the two assays is indicative of peroxidase activity. Enzyme assays typically apply proxies that reveal exo-acting activities of enzymes. Exo-acting enzymes hydrolyze substrates from the terminal position. While activity of endo-acting enzymes which break down polymers midchain need to be represented by other substrate proxies. New enzyme assays aim to capture the diversity of enzymes and assess the potential activity of them in a more clear way.<ref>{{Cite journal|last1=Arnosti|first1=C.|last2=Bell|first2=C.|last3=Moorhead|first3=D. L.|last4=Sinsabaugh|first4=R. L.|last5=Steen|first5=A. D.|last6=Stromberger|first6=M.|last7=Wallenstein|first7=M.|last8=Weintraub|first8=M. N.|date=January 2014|title=Extracellular enzymes in terrestrial, freshwater, and marine environments: perspectives on system variability and common research needs|url=http://link.springer.com/10.1007/s10533-013-9906-5|journal=Biogeochemistry|language=en|volume=117|issue=1|pages=5–21|doi=10.1007/s10533-013-9906-5|s2cid=83660222 |issn=0168-2563|url-access=subscription}}</ref><ref>{{Cite journal|last=Arnosti|first=Carol|date=2011-01-15|title=Microbial Extracellular Enzymes and the Marine Carbon Cycle|url=http://www.annualreviews.org/doi/10.1146/annurev-marine-120709-142731|journal=Annual Review of Marine Science|language=en|volume=3|issue=1|pages=401–425|doi=10.1146/annurev-marine-120709-142731|pmid=21329211 |bibcode=2011ARMS....3..401A |issn=1941-1405|url-access=subscription}}</ref><ref>{{Cite journal|last1=Obayashi|first1=Y|last2=Suzuki|first2=S|date=2008-03-26|title=Occurrence of exo- and endopeptidases in dissolved and particulate fractions of coastal seawater|url=http://www.int-res.com/abstracts/ame/v50/n3/p231-237/|journal=Aquatic Microbial Ecology|language=en|volume=50|pages=231–237|doi=10.3354/ame01169|issn=0948-3055|doi-access=free}}</ref>
With newer technologies available, molecular methods to quantify abundance of enzyme-coding genes are used to link enzymes with their producers in soil environments.<ref name="HassettZak2008">{{cite journal|last1=Hassett|first1=John E.|last2=Zak|first2=Donald R.|last3=Blackwood|first3=Christopher B.|last4=Pregitzer|first4=Kurt S.|s2cid=39272773|title=Are Basidiomycete Laccase Gene Abundance and Composition Related to Reduced Lignolytic Activity Under Elevated Atmospheric NO3 − Deposition in a Northern Hardwood Forest?|journal=Microbial Ecology|volume=57|issue=4|year=2008|pages=728–739|issn=0095-3628|doi=10.1007/s00248-008-9440-5|pmid=18791762}}</ref><ref name="LauberSinsabaugh2008">{{cite journal|last1=Lauber|first1=Christian L.|last2=Sinsabaugh|first2=Robert L.|last3=Zak|first3=Donald R.|s2cid=15755901|title=Laccase Gene Composition and Relative Abundance in Oak Forest Soil is not Affected by Short-Term Nitrogen Fertilization|journal=Microbial Ecology|volume=57|issue=1|year=2008|pages=50–57|issn=0095-3628|doi=10.1007/s00248-008-9437-0|pmid=18758844}}</ref> Transcriptome analyses are now employed to examine genetic controls of enzyme expression,<ref name="MorozovaHirst2009">{{cite journal|last1=Morozova|first1=Olena|last2=Hirst|first2=Martin|last3=Marra|first3=Marco A.|s2cid=26713396|title=Applications of New Sequencing Technologies for Transcriptome Analysis|journal=Annual Review of Genomics and Human Genetics|volume=10|issue=1|year=2009|pages=135–151|issn=1527-8204|doi=10.1146/annurev-genom-082908-145957|pmid=19715439}}</ref> while proteomic methods can reveal the presence of enzymes in the environment and link to the organisms producing them.<ref name="WallensteinWeintraub2008">{{cite journal|last1=Wallenstein|first1=Matthew D.|last2=Weintraub|first2=Michael N.|title=Emerging tools for measuring and modeling the in situ activity of soil extracellular enzymes|journal=Soil Biology and Biochemistry|volume=40|issue=9|year=2008|pages=2098–2106|issn=0038-0717|doi=10.1016/j.soilbio.2008.01.024}}</ref>
{| class="wikitable" style=white-space:nowrap" |- ! '''Process''' !! '''Enzyme''' !! '''Substrate''' |- | Cellulose-degradation || Cellobiohydrolase β-glucosidase || pNP, MUF<ref name="BaldrianValášková2008"/><ref name="LyndWeimer2002">{{cite journal|last1=Lynd|first1=L. R.|last2=Weimer|first2=P. J.|last3=van Zyl|first3=W. H.|last4=Pretorius|first4=I. S.|title=Microbial Cellulose Utilization: Fundamentals and Biotechnology|journal=Microbiology and Molecular Biology Reviews|volume=66|issue=3|year=2002|pages=506–577|issn=1092-2172|doi=10.1128/MMBR.66.3.506-577.2002|pmid=12209002|pmc=120791}}</ref> |- | Hemicellulose-degradation || β-glucosidases Esterases || pNP, MUF<ref name="CollinsGerday2005">{{cite journal|last1=Collins|first1=Tony|last2=Gerday|first2=Charles|last3=Feller|first3=Georges|title=Xylanases, xylanase families and extremophilic xylanases|journal=FEMS Microbiology Reviews|volume=29|issue=1|year=2005|pages=3–23|issn=0168-6445|doi=10.1016/j.femsre.2004.06.005|pmid=15652973|doi-access=free}}</ref><ref name="BielyPuchart2006">{{cite journal|last1=Biely|first1=Peter|last2=Puchart|first2=Vladimír|title=Recent progress in the assays of xylanolytic enzymes|journal=Journal of the Science of Food and Agriculture|volume=86|issue=11|year=2006|pages=1636–1647|issn=0022-5142|doi=10.1002/jsfa.2519|bibcode=2006JSFA...86.1636B }}</ref> |- | Polysaccharide-degradation || α-glucosidases N-acetylglucosaminidase || pNP, MUF<ref name="Seidl2008">{{cite journal|last1=Seidl|first1=Verena|title=Chitinases of filamentous fungi: a large group of diverse proteins with multiple physiological functions|journal=Fungal Biology Reviews|volume=22|issue=1|year=2008|pages=36–42|issn=1749-4613|doi=10.1016/j.fbr.2008.03.002}}</ref> |- | Lignin-degradation || Mn-peroxidase Laccase (polyphenol oxidase)
Peroxidase || Pyrogallol, L-DOPA, ABTS<ref name="Hofrichter2002"/> L-DOPA, ABTS<ref name="Baldrian2006"/> |}
==Applications of fungal extracellular enzymes ==
{| class="wikitable" |- ! Application !! Enzymes & their uses |-
|'''Paper production'''
|| '''Cellulases''' – improve paper quality and smooth fibers<ref name="RavalasonJan2008">{{cite journal|last1=Ravalason|first1=Holy|last2=Jan|first2=Gwénaël|last3=Mollé|first3=Daniel|last4=Pasco|first4=Maryvonne|last5=Coutinho|first5=Pedro M.|last6=Lapierre|first6=Catherine|last7=Pollet|first7=Brigitte|last8=Bertaud|first8=Frédérique|last9=Petit-Conil|first9=Michel|last10=Grisel|first10=Sacha|last11=Sigoillot|first11=Jean-Claude|last12=Asther|first12=Marcel|last13=Herpoël-Gimbert|first13=Isabelle|s2cid=24813930|title=Secretome analysis of Phanerochaete chrysosporium strain CIRM-BRFM41 grown on softwood|journal=Applied Microbiology and Biotechnology|volume=80|issue=4|year=2008|pages=719–733|issn=0175-7598|doi=10.1007/s00253-008-1596-x|pmid=18654772}}</ref> '''Laccases''' – soften paper and improving bleaching<ref name="WitayakranRagauskas2009">{{cite journal|last1=Witayakran|first1=Suteera|last2=Ragauskas|first2=Arthur J.|title=Modification of high-lignin softwood kraft pulp with laccase and amino acids|journal=Enzyme and Microbial Technology|volume=44|issue=3|year=2009|pages=176–181|issn=0141-0229|doi=10.1016/j.enzmictec.2008.10.011}}</ref>
|- | '''Biofuel generation''' || '''Cellulases''' – for production of renewable liquid fuels<ref name="Wilson2009">{{cite journal|last1=Wilson|first1=David B|title=Cellulases and biofuels|journal=Current Opinion in Biotechnology|volume=20|issue=3|year=2009|pages=295–299|issn=0958-1669|doi=10.1016/j.copbio.2009.05.007|pmid=19502046 |bibcode=2009COBt...20..295W }}</ref> |- | '''Dairy industry''' || '''Lactase''' – part of β-glucosidase family of enzymes and can break down lactose to glucose and galactose '''Pectinases''' – in the manufacture of yogurt
|- | '''Brewing industry'''
120px|left|Black Sheep Brewery Tour || '''Beer production and malting'''<ref name="LalorGoode2009">{{cite book|last1=Lalor|first1=Eoin|last2=Goode|first2=Declan |title=Enzymes in Food Technology |chapter=Brewing with Enzymes |year=2009|pages=163–194|doi=10.1002/9781444309935.ch8 |isbn=9781444309935}}</ref> |- | '''Fruit and jam manufacturing'''
100px|Jelly Jars - Tanglewood Gardens - Nova Scotia, Canada || '''Pectinases''', '''cellulases''' – to clarify fruit juices and form jams
|- |Bioremediation||'''Laccases''' – as biotransformers to remove nonionic surfactants<ref name="MartinCorvini2009">{{cite journal|last1=Martin|first1=C.|last2=Corvini|first2=P. F. X.|last3=Vinken|first3=R.|last4=Junghanns|first4=C.|last5=Krauss|first5=G.|last6=Schlosser|first6=D.|title=Quantification of the Influence of Extracellular Laccase and Intracellular Reactions on the Isomer-Specific Biotransformation of the Xenoestrogen Technical Nonylphenol by the Aquatic Hyphomycete Clavariopsis aquatica|journal=Applied and Environmental Microbiology|volume=75|issue=13|year=2009|pages=4398–4409|issn=0099-2240|doi=10.1128/AEM.00139-09|pmid=19429559|pmc=2704831|bibcode=2009ApEnM..75.4398M }}</ref><ref name="StrongClaus2011">{{cite journal|last1=Strong|first1=P. J.|last2=Claus|first2=H.|title=Laccase: A Review of Its Past and Its Future in Bioremediation|journal=Critical Reviews in Environmental Science and Technology|volume=41|issue=4|year=2011|pages=373–434|issn=1064-3389|doi=10.1080/10643380902945706|bibcode=2011CREST..41..373S |s2cid=96397441 }}</ref> |- | '''Waste water treatment'''|| '''Peroxidases''' - removal of pollutants by precipitation<ref name="DuránEsposito2000">{{cite journal|last1=Durán|first1=Nelson|last2=Esposito|first2=Elisa|title=Potential applications of oxidative enzymes and phenoloxidase-like compounds in wastewater and soil treatment: a review|journal=Applied Catalysis B: Environmental|volume=28|issue=2|year=2000|pages=83–99|issn=0926-3373|doi=10.1016/S0926-3373(00)00168-5 |bibcode=2000AppCB..28...83D }}</ref><ref name="M.M.2001">{{cite journal|last1=M.|first1=Kissi|last2=M.|first2=Mountadar|last3=O.|first3=Assobhei|last4=E.|first4=Gargiulo|last5=G.|first5=Palmieri|last6=P.|first6=Giardina|last7=G.|first7=Sannia|s2cid=1662318|title=Roles of two white-rot basidiomycete fungi in decolorisation and detoxification of olive mill waste water|journal=Applied Microbiology and Biotechnology|volume=57|issue=1–2|year=2001|pages=221–226|issn=0175-7598|doi=10.1007/s002530100712|pmid=11693925}}</ref> |- | '''Sludge treatment''' || '''Lipases''' - used in degradation of particulate organic matter<ref name="WhiteleyBurgess2003">{{cite journal|last1=Whiteley|first1=C.G.|last2=Burgess|first2=J.E.|last3=Melamane|first3=X.|last4=Pletschke|first4=B.|last5=Rose|first5=P.D.|title=The enzymology of sludge solubilisation utilising sulphate-reducing systems: the properties of lipases|journal=Water Research|volume=37|issue=2|year=2003|pages=289–296|issn=0043-1354|doi=10.1016/S0043-1354(02)00281-6|pmid=12502058|bibcode=2003WatRe..37..289W }}</ref> |- | '''Phytopathogen management''' || '''Hydrolytic enzymes''' produced by fungi, e.g. ''Fusarium graminearum'', pathogen on cereal grains resulting in economic losses in agriculture <ref>{{cite journal|last=Kikot|first=G.E.|title=Contributions of cell wall degrading enzymes to pathogenesis of Fusarium graminearum: a review|journal=Journal of Basic Microbiology|year=2009|volume=49|issue=3|pages=231–241|doi=10.1002/jobm.200800231|pmid=19025875|s2cid=45168988 |display-authors=etal |bibcode=2009JBMic..49..231K }}</ref> |- | '''Resource management''' '''Water retention''' || Soil aggregates and water infiltration influence enzyme activity<ref name="UdawattaKremer2009">{{cite journal|last1=Udawatta|first1=Ranjith P.|last2=Kremer|first2=Robert J.|last3=Garrett|first3=Harold E.|last4=Anderson|first4=Stephen H.|title=Soil enzyme activities and physical properties in a watershed managed under agroforestry and row-crop systems|journal=Agriculture, Ecosystems & Environment|volume=131|issue=1–2|year=2009|pages=98–104|issn=0167-8809|doi=10.1016/j.agee.2008.06.001 |bibcode=2009AgEE..131...98U }}</ref><ref name="PowlsonGregory2011">{{cite journal|last1=Powlson|first1=D.S.|last2=Gregory|first2=P.J.|last3=Whalley|first3=W.R.|last4=Quinton|first4=J.N.|last5=Hopkins|first5=D.W.|last6=Whitmore|first6=A.P.|last7=Hirsch|first7=P.R.|last8=Goulding|first8=K.W.T.|title=Soil management in relation to sustainable agriculture and ecosystem services|journal=Food Policy|volume=36|year=2011|pages=S72–S87|issn=0306-9192|doi=10.1016/j.foodpol.2010.11.025}}</ref> |- | '''Soil fertility and plant production''' || Use of enzyme activity as indicator of soil quality<ref name="PowlsonGregory2011"/><ref name="Trasar-CepedaLeirós2008">{{cite journal|last1=Trasar-Cepeda|first1=C.|last2=Leirós|first2=M.C.|last3=Gil-Sotres|first3=F.|title=Hydrolytic enzyme activities in agricultural and forest soils. Some implications for their use as indicators of soil quality|journal=Soil Biology and Biochemistry|volume=40|issue=9|year=2008|pages=2146–2155|issn=0038-0717|doi=10.1016/j.soilbio.2008.03.015|bibcode=2008SBiBi..40.2146T |hdl=10261/49118|hdl-access=free}}</ref> |- | '''Composting'''
128px|Drums with septic tank sludge with different amounts of urea added (6881892839) || Impacts of composting municipal solid waste on soil microbial activity<ref name="CrecchioCurci2004"/>
|- | '''Soil organic matter stability''' || Impact of temperature and soil respiration on enzymatic activity and its effect on soil fertility<ref name="JonesCox2003">{{cite journal|last1=Jones|first1=Chris D.|last2=Cox|first2=Peter|last3=Huntingford|first3=Chris|title=Uncertainty in climate-carbon-cycle projections associated with the sensitivity of soil respiration to temperature|journal=Tellus B|volume=55|issue=2|year=2003|pages=642–648|issn=0280-6509|doi=10.1034/j.1600-0889.2003.01440.x|bibcode=2003TellB..55..642J}}</ref> |- | '''Climate change indicators''' '''Impact on soil processes''' ||Potential increase in enzymatic activity leading to elevated CO2 emissions<ref name="Kirschbaum2004">{{cite journal|last1=Kirschbaum|first1=Miko U. F.|title=Soil respiration under prolonged soil warming: are rate reductions caused by acclimation or substrate loss?|journal=Global Change Biology|volume=10|issue=11|year=2004|pages=1870–1877|issn=1354-1013|doi=10.1111/j.1365-2486.2004.00852.x|bibcode=2004GCBio..10.1870K|s2cid=86293310 }}</ref> |-
|'''Quantifying global warming outcomes''' || Predictions based on soil organic matter decomposition<ref name="GillabelCebrian-Lopez2010">{{cite journal|last1=Gillabel|first1=Jeroen|last2=Cebrian-Lopez|first2=Beatriz|last3=Six|first3=Johan|last4=Merckx|first4=Roel|title=Experimental evidence for the attenuating effect of SOM protection on temperature sensitivity of SOM decomposition|journal=Global Change Biology|volume=16|issue=10|year=2010|pages=2789–2798|issn=1354-1013|doi=10.1111/j.1365-2486.2009.02132.x|bibcode=2010GCBio..16.2789G|s2cid=86672269 }}</ref> and strategies for mitigation<ref name="MacíasCamps Arbestain2010">{{cite journal|last1=Macías|first1=Felipe|last2=Camps Arbestain|first2=Marta|s2cid=153406514|authorlink2=Marta Camps Arbestain|title=Soil carbon sequestration in a changing global environment|journal=Mitigation and Adaptation Strategies for Global Change|volume=15|issue=6|year=2010|pages=511–529|issn=1381-2386|doi=10.1007/s11027-010-9231-4 |bibcode=2010MASGC..15..511M }}</ref> |- |'''Impact of elevated CO2 on enzyme activity & decomposition''' || Understanding the implication of microbial responses and its impact on terrestrial ecosystem functioning<ref name="ZakPregitzer2011">{{cite journal|last1=Zak|first1=Donald R.|last2=Pregitzer|first2=Kurt S.|last3=Burton|first3=Andrew J.|last4=Edwards|first4=Ivan P.|last5=Kellner|first5=Harald|title=Microbial responses to a changing environment: implications for the future functioning of terrestrial ecosystems|journal=Fungal Ecology|volume=4|issue=6|year=2011|pages=386–395|issn=1754-5048|doi=10.1016/j.funeco.2011.04.001 |bibcode=2011FunE....4..386Z }}</ref> |}
==See also==
*Enzymes *Enzyme kinetics *Enzyme assay *List of enzymes *Decomposition *Plant litter *Nutrient cycle
==References==
{{Reflist|3}}
==Further reading== *[http://www.chem.qmul.ac.uk/iubmb/enzyme/ Enzyme nomenclature] * [https://web.archive.org/web/20121228002422/http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookenzym.html Reactions and enzymes] *Richard P. Dick (ed.) 2011. Methods in Soil Enzymology. ''Soil Science Society of America'', Wisconsin, USA {{ISBN|978-0-89118-854-4}}
==External links== *[http://www.enzyme-database.org ExplorEnz]- searchable enzyme database to access the IUBMB Enzyme Nomenclature List *[http://www.brenda-enzymes.org BRENDA] – database and related literature of known enzymes *[http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/enzyme Enzyme structures] *[http://enzyme.expasy.org ExPASy] database for sequence data *[http://www.genome.jp/kegg KEGG: Kyoto Encyclopedia of Genes and Genomes] biochemical pathways and enzymes database *[https://mycoclap.fungalgenomics.ca/mycoCLAP/ MycoCLAP] searchable database of fungal enzyme genes *[http://metacyc.org MetaCyc] metabolic pathways of different organisms *[http://pec.biodbs.info Pectinase] {{Webarchive|url=https://web.archive.org/web/20190915075210/http://pec.biodbs.info/ |date=2019-09-15 }} database for pectinase enzymes and their inhibitors
Category:Mycology