Optimal culture conditions for keratinase production by a novel thermophilicMyceliophthora thermophilastrain GZUIFR-H49-1

Abstract

Aims: To investigate the effect of medium compositions and culture conditions on keratinase production by a novel thermophilic fungus Myceliophthora thermophila (Apinis) Oorschot strain GZUIFR‐H49‐1. Methods and Results: The thermophilic strain GZUIFR‐H49‐1 with keratinolytic ability was characterized and identified as a strain of M. thermophila on the basis of its morphological characters and molecular analysis of ITS1‐5.8S‐ITS2 rDNA sequence. Among the medium compositions tested, the soluble starch (SS), urea, sodium thiosulfate and CaCl2 were the most effective C‐source, N‐source, S‐source and mineral ion, respectively, by employing the single‐factor experiment. The urea and pH value were the significant factors (P < 0·05) for the keratinase production in this experiment condition using Plackett–Burman factorial design. The conditions of keratinase production were further optimized by Box–Behnken design. Consequently, there was a 6·4‐fold increase (5100 U l−1) in the keratinase activity than the initial value (800 U l−1) by this optimal process. Conclusions: This study indicated that the optimization design proved a useful and powerful tool for the development of optimal medium compositions and culture conditions. Myceliophthora thermophila strain GZUIFR‐H49‐1 was a promising fungus strain for keratinase production. Significance and Impact of the Study: This study characterized a novel thermophilic M. thermophila strain GZUIFR‐H49‐1 with potential applications for keratinase production. These conditions of keratinase production obtained by means of optimization design will be accumulated as potential information for exploration and utilization to the new fungus isolate.

Microbial keratinases: industrial enzymes with waste management potential

“…[122] Studies regarding supplementation of keratincontaining media with different carbon and nitrogen sources usually enhances keratinase production. [23,47,51,57,95,106,107,[122][123][124][125] Additional nitrogen sources viz. urea, peptone, tryptone, yeast extract, ammonium chloride and sodium nitrate also results in increased enzyme titer.…”

“…Production of microbial keratinase is induced when keratin is used as substrate [47,[105][106][107] and, thus keratinous rich residues (e.g. chicken feathers, feather meal or, hairs) are often added to the cultivation medium.…”

Optimization of the culture condition of Bacillus mucilaginous using Agaricus bisporus industrial wastewater by Plackett–Burman combined with Box–Behnken response surface method

“…Second, Box–Behnken experimental design is less frequently, the cycle is short, and the regression equation obtained is highly precise. It is also an effective method to study interactions between several factors, which can be used to reduce development costs, optimize processing conditions, improve product quality, and solve practical production problems (Khoshayand et al 2011; Liang et al 2011). Third, SYTO 9 and PI were used for double staining of viable and dead cells.…”

Lecanicillium araneogenum sp. nov., a new araneogenous fungus

“…DNA extraction was carried out according to Liang et al (2009). The extracted DNA was stored at −20 °C.…”