Screening of microfungi for lipolytic activity and optimization of process parameters in lipase production by solid substrate fermentation using selected microfungi (Penicillium aurantiogriseum)

In the present study, eighty-four strains of microfungi were screened for lipolytic activity, and Penicillium aurantiogriseum showing the highest enzyme activity was selected. Then extracellular lipase production from this species was carried out using the solid state fermentation (SSF) method, in which various agricultural wastes were used as substrates. Among the various agricultural wastes used in SSF, sunflower pulp was determined as the best solid substrate. Optimum fermentation conditions were found as follows: 6-day incubation time at 25 oC and moisturizing liquid pH: 5.5 (distilled water), initial moisture level 75% (w/v), initial inoculum concentration 1 ml (1x106 spores/ml), and 1% sesame oil as a carbon source. As a result of the optimum conditions, the volume activity was recorded as 0.4 U/ml, and the specific enzyme activity was obtained as 1.13 U/mg.

Micromycetes-resistant colored cotton is promising material to reduce mycotoxins amounts in textiles

The aim of research was to characterize epiphyte micromycetes observed on variable cotton fibers accessions, to estimate the range of fiber destruction and select cotton, which were the most resistant to fungus damage. The accessions of differently colored Upland Cotton varieties (Gossypium hirsutum L.) evaluated: eleven cotton of natural green, twelve – of brown and eleven of conventional white color. Cotton plants have been grown in Sothern Federal District, RF. The fiber samples for the study were placed into a thermostat in sterile Petri dishes on moistened filter paper in order to stimulate the development of mycelium or sporulation of fungi naturally occurred on fibers. Incubation carried out in a thermostat at a +24-28 °C, humidity of 90-100% and exposed for 28 days. The samples examined with a microscope or binocular magnifier. Aspergillus ustus (Bainier), A. fumigatus Fresen., A. niger v. Tiegh., A. flavus Link, Penicillium aurantiogriseum Dierckx, P. notatum Westling, Rhizopus nigricans Ehrenb. and Alternaria alternata (Fuier) Keissler were detected. Compared with exposed white, accession of green and brown colors were significantly resistant to fungus. The mean of destruction (K) of white cotton varied up to 0.95, but colored accessions not exceeded 0.3 (initial destruction of the surface, not affecting internal fiber’s structure).