Biology and biotechnology of Trichoderma

Fungi of the genus Trichoderma are soilborne, green-spored ascomycetes that can be found all over the world. They have been studied with respect to various characteristics and applications and are known as successful colonizers of their habitats, efficiently fighting their competitors. Once established, they launch their potent degradative machinery for decomposition of the often heterogeneous substrate at hand. Therefore, distribution and phylogeny, defense mechanisms, beneficial as well as deleterious interaction with hosts, enzyme production and secretion, sexual development, and response to environmental conditions such as nutrients and light have been studied in great detail with many species of this genus, thus rendering Trichoderma one of the best studied fungi with the genome of three species currently available. Efficient biocontrol strains of the genus are being developed as promising biological fungicides, and their weaponry for this function also includes secondary metabolites with potential applications as novel antibiotics. The cellulases produced by Trichoderma reesei, the biotechnological workhorse of the genus, are important industrial products, especially with respect to production of second generation biofuels from cellulosic waste. Genetic engineering not only led to significant improvements in industrial processes but also to intriguing insights into the biology of these fungi and is now complemented by the availability of a sexual cycle in T. reesei/Hypocrea jecorina, which significantly facilitates both industrial and basic research. This review aims to give a broad overview on the qualities and versatility of the best studied Trichoderma species and to highlight intriguing findings as well as promising applications

Tailoring Cocrystal and Salt Formation and Controlling the Crystal Habit of Diflunisal

Crystal habit modification of the drug diflunisal that normally grows into extremely thin, long needles has been achieved by breaking the stacking effect with the help of coformers. Eight new cocrystals are reported, along with three crystal structures. In all cases, ortho F disorder, often a feature in diflunisal structures was absent due to the presence of CH···F interactions. Co-milling diflunisal with oxalic acid produced 1:1 and 2:1 cocrystals. In contrast, in solution crystallization, oxalic acid played the role of an additive resulting in the crystallization of diflunisal form I rather than form III. To rationalize cocrystal formation, a statistical analysis of the Cambridge Crystallographic Data Centre database for aromatic o-hydroxy carboxylic acids was carried out. All cocrystals of o-hydroxy carboxylic acids with the COOH dimer motif have an electron-withdrawing group on one of the acids. COOH···Nar motifs are formed preferentially over carboxylic homodimers in the presence of an Nar coformer