Anna Kancelista

Biotransformation of dehydroepiandrosterone (DHEA) by environmental strains of filamentous fungi

Microbial transformations of steroids are an important method of obtaining new steroid derivatives of potential pharmaceutical activity, which follows the principles of green chemistry. We studied the ability of selected filamentous fungus species to transform dehydroepiandrosterone (DHEA) and interesting DHEA derivatives were obtained. Twenty-five strains of filamentous fungi were isolated from soil and air in Wroclaw and they were used as biocatalysts. Strains of the genus Penicillium transformed the substrate into the products of Baeyer–Villiger lactonization in the D ring. Biotransformation of DHEA by Fusarium acuminatum KCh S1 strain led to a stereoselective hydroxylation at 7α (the product was obtained with 97% conversion). Androst-5-ene-3β,7α,17α-triol, compound with high anticancer activity towards glioblastoma and lymphoma cell lines was obtained with 65% yield in the culture of Mucor hiemalis KCh W2 strain. In the culture of Aspergillus versicolor KCh TJ1 strain, DHEA was transformed into androst-1,4-diene-3,17-dione (ADD) with high isolated yield.

Survivability and storage stability of Trichoderma atroviride TRS40 preserved by fluidised bed drying on various agriculture by-products

ABSTRACT Agriculture by-products were applied to proliferate biomass of Trichoderma atroviride TRS40 in solid state fermentation (SSF) cultures. The culture media overgrown with mycelium together with conidia were preserved by fluidised bed drying at various temperatures (50°C, 60°C and 70°C) and the received biopreparations were stored for 12 months. In order to determine the suitability of TRS40 in the production of biopreparations, the influence of preservation process and storage time on their survivability was examined. The three-component mixture proved more effective in the SSF cultures, ensuring TRS40 count at 6.07 × 109 CFU/g dm, which was ca. 6 times higher than in the mono-component medium. TRS40 survivability after preservation at various temperatures ranged from 40.4% to 100%, regardless of carrier type. In turn, after 12-month storage of the biopreparations produced on the three-component medium, regardless of drying temperature, the number of viable cells ranged from 2.43 × 108 to 2.49 × 108 CFU/g dm. Furthermore, selected parameters of growth kinetics in the Bioscreen C system were determined. The storage time of biopreparations had various effects on growth kinetic parameters. In addition, the preserved preparations based on the TRS40 retained their capability for biosynthesis of hydrolases, even after 12 months of storage.

MOESM6 of New keratinolytic bacteria in valorization of chicken feather waste

Additional file 6: Table S5. Concentration of dominant amino acids in feather hydrolysates prior to and after treatments.

Effect of Lyophilization on Survivability and Growth Kinetic of Trichoderma Strains Preserved on Various Agriculture By-Products

Growth of four Trichoderma strains were tested on lignocellulosic by-products in solid state fermentation (SSF). The strains were also analyzed for their survival rate and growth after lyophilization on these carriers. All applied monocomponent and bicomponent media were substrates for the production and preservation of Trichoderma biomass. However, the maximum number of colony forming units (CFU/g dm) was acquired on bicomponent media based on dried grass and beet pulp or grass with corn cobs, when compared to monocomponent media. Although the process of lyophilization reduced the survival rate by 50%-60%, the actual number of viable cells in obtained biopreparations remained relatively high (0.58 × 108-1.68 × 108 CFU/g dm). The studied strains in the preserved biopreparations were characterized by a high growth rate, as evaluated in microcultures using the Bioscreen C system.