Biodiversity of Trichoderma in Neotropics

Trichoderma species frequently are predominant over wide geographic regions in all climatic zones, where they are significant decomposers of woody and herbaceous materials. They are characterized by rapid growth, an ability to assimilate a diverse array of substrates, and by their production of an range of antimicrobials. Strains have been exploited for production of enzymes and antibiotics, bioremediation of xenobiotic substances, and as biological control agents against plant pathogenic fungi and nematodes. The main use of Trichoderma in global trade is derived from its high production of enzymes. Trichoderma reesei (teleomorph: Hypocrea jecorina) is the most widely employed cellulolytic organism in the world, although high levels of cellulase production are also seen in other species of this genus (Baig et al., 2003, Watanabe et al., 2006). Worldwide sales of enzymes had reached the figure of $ 1.6 billion by the year 2000 (Demain 2000, cited by Karmakar and Ray, 2011), with an annual growth of 6.5 to 10% not including pharmaceutical enzymes (Stagehands, 2008). Of these, cellulases comprise approximately 20% of the enzymes marketed worldwide (Tramoy et al., 2009). Cellulases of microbial origin are used to process food and animal feed, biofuel production, baking, textiles, detergents, paper pulp, agriculture and research areas at all levels (Karmakar and Ray, 2011). Most cellulases are derived from Trichoderma (section Longibrachiatum in particular) and Aspergillus (Begum et al., 2009). Trichoderma is also an efficient degrader of heteropolysaccharides such as xylan, and xylanases and mannanases are of importance in the production of fine paper (Watanabe et al., 2006). In addition, some strains of Trichoderma are agents of bioremediation, capable of assimilating heavy metals (Akhtar et al., 2009; Guillermina et al., 2002) and of degrading cyanide (Ezzi and Lynch, 2005) and pesticides with high persistence in the environment (Cross, 1999, Tang et al., 2009). The genus Trichoderma includes strains altogether producing an extremely wide range of metabolites, including compounds with antifungal activities (phenolic compounds, 6-┙pentyl-pyrone, viridofunginas, harzianopiridona), antibiotics (anthraquinone, harzianodiona, gliotoxin), plant growth regulators (ciclonerodiol, ┙-harzianopiridonapentyl-pyrone), antimicrobial peptides including more than 200 peptaibols, and even viridiol phytotoxic compounds with potential pharmaceutical uses as anti-tumor and immunomodulatory compounds (harzianodiona and gliotoxin). These and other metabolites that are unclassified inhibitors and anti-virus agents expand the prospects of industrial, pharmaceutical or other commercial uses of this organism (Sivasithanparam and Ghisalberti, 1998, Supothina et al., 2007, Vinal et al., 2006, Xiao-Yan et al., 2006).