Untitled

Singh, Chandra Jeet

doi:10.1023/a:1006844201399

Cited by 26 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In addition, the biomass increased steadily with incubation time. Similar production kinetics of keratinase has been reported for fungi such as Endothia parastica (Melzer and Boland, 1999), Trichophyton simii (Singh, 1997), Malbranchea gypsea (Singh, 1998), and Trichophyton vanbreuseghemii (Moallaei et al, 2006). In A. fumigatus (Do et al, 2004) and A. oryzae (Jousson et al, 2004), the rate of keratinase production reached a maximum concentration after 21 days of incubation and the concentration of extracellular keratinase produced by Lysobacter NCIMB 9497 (Allpress et al, 2002) was maximal after 29 days of growth.…”

Section: Resultssupporting

confidence: 78%

See 1 more Smart Citation

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus,Aspergillus flavusStrain K-03

Kim

2007

Mycobiology

View full text Add to dashboard Cite

A keratinolytic enzyme secreted by Aspergillus flavus K-03 cultured in feather meal basal medium (FMBM) containing 2% (w/v) chicken feather was purified and characterized. Keratinolytic enzyme secretion was the maximal at day 16 of the incubation period at pH 8 and 28℃. No relationship was detected between enzyme yield and increase of fungal biomass. The fraction obtained at 80% ammonium sulfate saturation showed 2.39-fold purification and was further purified by gel filtration in Sephadex G-100 followed by ion exchange chromatography on DEAE-Sephadex A-50, yielding an active protein peak showing 11.53-fold purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymograms indicated that the purified keratinase is a monomeric enzyme with 31 kDa molecular weight. The extracellular keratinase of A. flavus was active in a board range of pH (7~10) and temperature (30℃~70℃) profiles with the optimal for keratinase activity at pH 8 and 45℃. The keratinase activity was totally inhibited by protease inhibitors such as phenylmethylsulfonyl fluoride (PMSF), iodoacetic acid, and ethylenediaminetetraacetate (EDTA) while no reduction of activity by the addition of dithiothreitol (DTT) was observed. N-terminal amino acid sequences were up to 80% homologous with the fungal subtilisins produced by Fusarium culmorum. Therefore, on the basis of these characteristics, the keratinase of A. flavus K-03 is determined to be subtilisins-like.

show abstract

Section: Resultssupporting

confidence: 78%

“…Most of the other keratinases from bacteria and fungi (Cheng et al, 1995; Gradisar et al, 2005; Santos et al, 1996; Singh, 1997) are active at alkaline pH but show optimal activity at roughly 40℃, which is lower than the optimum temperature of the enzyme from the fungus A. flavus K-03.…”

Section: Resultsmentioning

confidence: 95%

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus,Aspergillus flavusStrain K-03

Kim

2007

Mycobiology

View full text Add to dashboard Cite

show abstract

“…However, these eVects are not common for all microorganisms. For example, the supplementation of the culture medium with both, carbon and nitrogen sources had a positive eVect on the production of keratinase by Scopulariopsis brevicaulis [1], while in cultures of Trichophyton simii, exogenous sugars suppressed keratinase production [34].…”

Section: Discussionmentioning

confidence: 99%

Influence of the carbon and nitrogen sources on keratinase production by Myrothecium verrucaria in submerged and solid state cultures

Gioppo¹,

Moreira-Gasparin²,

Costa³

et al. 2009

J Ind Microbiol Biotechnol

View full text Add to dashboard Cite

Myrothecium verrucaria is a nondermatophytic filamentous fungus able to grow and to produce keratinase in submerged (93.0 +/- 19 U/ml) and solid state (98.8 +/- 7.9 U/ml) cultures in which poultry feather powder (PFP) is the only substrate. The purpose of the present work was to verify how different carbon and nitrogen sources can influence the production of keratinase by this fungus. Addition of carbohydrates, such as glucose and sucrose, caused only slight improvements in keratinase production, but the addition of starch caused a significant improvement (135.0 +/- 25 U/ml). The highest levels of keratinase activity, however, were obtained by supplementing the PFP cultures with cassava bagasse, 168.0 +/- 28 U/ml and 189.0 +/- 26 U/ml in submerged and solid state cultures, respectively. Contrarily, the supplementation of PFP medium with organic or inorganic nitrogen sources, such as casein, soy bean protein, gelatin, ammonium nitrate and alanine, decreased the production of keratinase in both types of cultures (around 20 U/ml), showing that the production of keratinase by M. verrucaria is repressed by nitrogen sources. The results obtained in this work suggest that the association of the two residues PFP plus cassava bagasse could be an excellent option as a cheap culture medium for the production of keratinase in submerged and solid state cultures.

show abstract

“…This fact is obviously associated with a better investigation of these organisms as objects of scientific research and biotechnological processes in comparison with fungal models, although filamentous fungi are also capable of secreting hydrolases that destroy keratin [ 21 ]. Most of the accumulated knowledge about fungal keratinases relates to enzymes synthesized by dermatophytes [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ], while data on keratinolytic enzymes of micromycetes that do not cause dermatophytosis remain scarce [ 9 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Keratinolytic Properties of Aspergillus clavatus Promising for Biodegradation

Timorshina

Popova

Kreyer

et al. 2022

IJERPH

View full text Add to dashboard Cite

The high demand for keratinolytic enzymes and the modest presentation of fungal keratinase diversity studies in scientific sources cause a significant interest in identifying new fungal strains of keratinase producers, isolating new enzymes and studying their properties. Four out of the 32 cultures showed a promising target activity on protein-containing agar plates—Aspergillus amstelodami A6, A. clavatus VKPM F-1593, A. ochraceus 247, and Cladosporium sphaerospermum 1779. The highest values of keratinolytic activity were demonstrated by extracellular proteins synthesized by Aspergillus clavatus VKPM F-1593 cultivated under submerged conditions on a medium containing milled chicken feathers. The enzyme complex preparation was obtained by protein precipitation from the culture liquid with ammonium sulfate, subsequent dialysis, and lyophilization. The fraction of a pure enzyme with keratinolytic activity (pI 9.3) was isolated by separating the extracellular proteins of A. clavatus VKPM F-1593 via isoelectric focusing. The studied keratinase was an alkaline subtilisin-like non-glycosylated protease active over a wide pH range with optimum keratinolysis at pH 8 and 50 °C.

show abstract

Untitled

Cited by 26 publications

References 17 publications

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus,Aspergillus flavusStrain K-03

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus,Aspergillus flavusStrain K-03

Influence of the carbon and nitrogen sources on keratinase production by Myrothecium verrucaria in submerged and solid state cultures

Keratinolytic Properties of Aspergillus clavatus Promising for Biodegradation

Contact Info

Product

Resources

About