Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Mariana CĂLIN, Iuliana RĂUT, Diana CONSTANTINESCU-ARUXANDEI, Mihaela BADEA DONI, Melania-Liliana ARSENE, Nicoleta-Olguţa CORNELI, Gelu VASILESCU, Luiza JECU, Mariana Ştefania BUCUR, Veronica LAZĂR

The aim of this study was to investigate the influence of culture conditions on growth of keratinophilic fungal strain of Chrysosporium sp. in the presence or absence of keratin substrate. The effect of pH, temperature, carbon and nitrogen sources on fungal growth and sporulation was evaluated. The pH values ranged from 4 to 9.5 and the incubation temperature ranged from 20°C to 35°C. Glucose, fructose, maltose, sucrose, starch and cellulose were used as carbon sources. As nitrogen source, yeast extract, ammonium salts, urea and vitamin B12 were tested. All tests were also performed with basal mineral culture medium supplemented with keratin powder from chicken feathers. The feathers were cleaned with ethylic alcohol, washed with distilled water, dried at 60°C and finally grounded several times with a Retsch ball mill until a fine powder was obtained. The influence of the culture conditions on growth was assessed by measuring the diameter of the colonies grown on the solid medium after 5 and 10 days of incubation. The colony sporulation degree was appreciated macroscopically and microscopically. The presence of keratin in the culture media stimulated distinctly the fungal growth as compared to the culture media without keratin. Alkaline pH and temperatures between 27 and 30°C are optimal for its growth. Certain C and N sources can stimulate the fungal growth, but this seems to be influenced by the incubation time.

[Read full article] [Citation]

SPUPOPUPNO1