''Trichoderma reesei'' is a

mesophilic A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum growth range from . The optimum growth temperature for these organisms is 37°C. The term is mainly applied to microorganisms. Organi ...

and

filamentous The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

. It is an

anamorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an ase ...

of the fungus ''Hypocrea jecorina''. ''T. reesei'' can secrete large amounts of cellulolytic

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

s (

cellulase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharide ...

s and

hemicellulase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysacchar ...

s). Microbial cellulases have industrial application in the conversion of

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

, a major component of plant

biomass Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...

, into

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...

. ''T. reesei'' isolate QM6a was originally isolated from the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

because of its degradation of canvas and garments of the

US army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

. All strains currently used in biotechnology and basic research were derived from this isolate. Recent advances in the

biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...

of cellulase

enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, the mechanism of cellulose

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

(

cellulolysis Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

), strain improvement, molecular cloning and process engineering are bringing ''T. reesei'' cellulases closer to being a commercially viable route to cellulose hydrolysis. Several industrially useful strains have been developed and characterised, e.g. Rut-C30, RL-P37 and MCG-80. The genome was released in 2008. ''T. reesei'' has a mating type-dependent characterised sexual cycle.

Sexual development

''T. reesei'' QM6a has a ''MAT1-2'' mating type locus. The opposite mating type, ''MAT1-1'', was recently found, proving that ''T. reesei'' is a heterothallic species. After being regarded as asexual since its discovery more than 50 years ago, sexual reproduction can now be induced in ''T. reesei'' QM6a leading to formation of fertilized stromata and mature ascospores.

Use in industry

''T. reesei'' is an important commercial and industrial micro-organism due to its cellulase production ability. Many strains of ''T. reesei'' have been developed since its discovery, with heavy emphasis on increasing cellulase production. These improvement programs originally consisted of classical (ionising-radiation-based and chemical-based) mutagenesis, which led to strains capable of producing 20 times as much cellulase as QM6a. The ultimate aim in the creation of hypercellulolytic strains was to obtain a carbon catabolite derepressed strain. This derepression would allow the ''T. reesei'' strain to produce cellulases under any set of growth conditions, even in the presence of glucose. However, with the advent of modern genetic engineering tools such as targeted deletion, targeted knockout, and more, a new generation of strains dubbed "hyperproducers" has emerged. Some of the highest performing industrial strains produce up to 100 grams of cellulases per litre, more than 3 times as much as the RUT-C30 strain (which itself produces twice as much as the parent strain NG14 from which it was derived). ''T. reesei'' is used in the creation of stonewashed jeans. The cellulase produced by the fungus partially degrades the cotton material in places, making it soft and causing the jeans to look as if they had been washed using stones.Tom Volk's Fungus of the Month
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Sexual development

Use in industry

See also

References

External links