Trichoderma Sp(Trichoderma reesei, Trichoderma virens)

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Trichoderma

Scientific Name: Trichoderma Sp(Trichoderma reesei, Trichoderma virens)

Domain : Prokaryotic

GRAS Organism used for industrial application

Biosafety Level: BSL1/BSL2, Varies depending on research context

Benefits and Applications

• There are around 90 species under the Trichoderma genus. Out of which, few species
  stand out for industrial applications.
• Members of the genus Trichoderma are also utilized in various industry branches –
  mainly in the production of enzymes, antibiotics, and other metabolites.
• Several Trichoderma spp. positively affect plants by stimulating plant growth, and
  protecting plants from fungal and bacterial pathogens. They are used in biological plant
  protection as fungicides as well as in bioremediation.
• Trichoderma reesei (Teleomorph Hypocrea jecorina) is one of the two major fungal
  platforms for industrial enzyme production, along with Aspergillus sp.
• Its use derives from its history as a model organism for studies on cellulose degradation
  and its cellulase enzyme complex since the 1940s, which suggested its use for industrial
  bioethanol manufacturing during the oil crisis in the mid 1970s. T. reesei has now
  maintained its position as a highly productive, easy-to-handle, robust and safe cell
  factory for more than 40 years.
• In addition to T. reese's role in bio-ethanol production, it is used to produce industrial
  enzymes with a broad range of applications supporting the bio-based economy. To date there are
  around 243 commercially available enzyme products manufactured by fermentation of
  microorganisms, 30 of these are made using Trichoderma as a host, 21 of which are
  recombinant products sold for use in food, feed, and technical applications including
  textiles and pulp and paper.
• T. Reesei is used for the industrial production of Cellulases and has been classified as a
  GRAS organism by FDA.The enzymes (cellobiohydrolase, beta-glucosidase and
  endo-glucanase) expressed by the production strain belong to the cellulase class of
  enzymes.
• Cellulases catalyze the hydrolysis of the 1,4-beta-D-glycosidic linkages in cellulose,
  hemicellulose, lichens and cereal beta-D-glucans to break down the cellulose present in
  plants.
• Cellulase enzymes are used as processing aids in a wide range of food products. The
  typical food applications where this cellulase will be used are:
  Fruit and vegetable processing, starch and grain processing, brewing and other cereal
  based beverages and potable/ fuel alcohol production. Brewing and Other Cereal Based
  Beverages.
• Brewing processes rely on cereals (malted or not) as the primary raw material. And, are
  the primary raw material in the production of beer and other cereal based beverages.
  Cellulase enzymes are typically added during the mashing step to reduce the viscosity of
  the wort and improve the separation of the wort from the spent grains.
• Also, the cellulase enzyme degrades the polymeric beta-glucans present in the
  endosperm cell wall of grain, into smaller less viscous molecules, thereby lessening the
  filtration time and Wine Processing: Cellulases are added during maceration, vinification
  (storage, aging) and/or before filtration. They catalyze the degradation of structural
  polysaccharides thereby, lowering the viscosity which results in improved juice yield,
  clarification and filterability.
• Cellulases also liberate and solubilize the phenolic compounds (tannins) and glycoside
  precursors from grape cells wall and flesh leading to better color intensity, stability and
  improved overall mouth feel and aroma. The enzymes may be inactivated by
  pasteurization or removed by bentonite addition and/or filtration. Therefore, the enzymes
  will not be present/active in the final food.
• Fruit and Vegetable Processing: In the juice industry, cellulases are applied in
  combination with other macerating enzymes. They are used to increase process
  performance and yield, improve extraction methods and clarify and stabilize juice.
  They can also reduce viscosity in nectars and purees. Here the enzymes are denatured
  during the pasteurization steps included in the processing, rendering the enzyme
  inactive.

• Starch/Grain processing:

  Complex structures in cereals can cause processing issues when the grain is milled and
  when fractionated into starch, gluten and fiber.
  The use of cellulases during grain milling can provide a smooth and efficient processing
  of that grain, enable separation of the grain structures and ensure quality polysaccharide
  and gluten fractions.
  Cellulases are typically added in grain processing during the milling, mixing and steeping
  processes.
  Enzymes are inactivated when used in further food processing, such as baking and
  starch liquefaction, and are considered non-functional.

• Trichoderma fungi use various complex direct or indirect mechanisms against fungal
  pathogens, which usually interact altogether in the biocontrol phenomenon.

• The direct impact on pathogens includes the production of cell wall degrading enzymes
  (CWDEs), synthesis of antibiotics, competition for space and nutrients (mainly carbon,
  nitrogen, and iron), and establishment of a direct parasitic relationship with the fungal
  pathogen.

• On the other hand, Trichoderma indirectly induces local or systemic plant resistance
  through products (elicitors) released from the cell walls of the plant host (endo elicitors)
  and the infecting microorganism (exo elicitors). The type of mechanisms involved is often
  a strain characteristic and depends on the interaction type between the antagonist
  microorganism, pathogen, and the host plant.Trichoderma seems to be the best
  candidate for use in green technologies due to its wide biofertilization and biostimulatory
  potential. Most of the species from the genus Trichoderma belong to the plant
  growth-promoting fungi that produce phytohormones and the
  1-aminocyclopropane-1-carboxylate (ACC) deaminase enzyme. The biocontrol and
  biostimulation properties of Trichoderma directly translate into its wide application in
  agriculture.
• Due to the largest number of isolated anti-fungal bioactive compounds, Currently, at
  least 77 commercial Trichoderma-based bio-fungicides are available on the global
  market, including 7 approved by the European Commission for use in the Member
  States of the European Union.

Maintenance

PDA (potato dextrose agar) is used for the revival and maintenance of Trichoderma

• Fresh cultures preservation:

  Single spores technique is used for Trichoderma viride to get a pure culture, from the
  mother culture a plug of media is taken and placed on fresh media.
  The plates are properly wrapped and incubated at 25 °C for 7 days and this is repeated
  after 7-10 days to maintain the culture for a longer period of time.

• Slants preservation:

  Autoclave PDA media at 121 °C for 15 min at 15psi. Pour autoclaved media in already
  sterilized test tubes/vials. Allow media to solidify in test tubes/vials at an angle of 65°.
  Loopful inoculums of Trichoderma viride are transferred to Potato Dextrose Agar (PDA)
  slants, keep the tubes in incubators at 25 °C for 7 days and maintain at 4 °C as pure
  culture.
  Recovery inoculums are placed on fresh PDA media and incubated for 7 days. They are
  then checked for the recovery and viability within a three month interval.

• Gene Manipulation:
  There are two potent methods of Trichoderma transformation mediated by either (a)
  polyethylene glycol or (b) Agrobacterium. Method used and protocol differs based on
  applications.

Genome

Trichoderma reesei QM6a - Link
Trichoderma virens Gv29-8 - Link