Showing papers on "Keratinase published in 2001"

Purification and characterization of a 43.5 kDa keratinolytic metalloprotease from Microsporum canis.

Abstract: A keratinolytic protease secreted by a feline clinical isolate of Microsporum canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43.5 kDa and the pI was 7.7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50 degrees C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43.5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiological mechanisms of M. canis dermatophytosis.

Secretion of a trypsin-like thiol protease by a new keratinolytic strain of Bacillus licheniformis.

Abstract: When cultured in feather-containing broth with a growth optimum of pH 7.0 and 47 degrees C, a Bacillus licheniformis strain exhibited a high chicken feather-degrading activity. A trypsin-like protease was isolated from its ferment broth and was partially characterized. The enzyme was constitutively secreted and was highly active towards N-benzoyl-Phe-Val-Arg-p-nitroanilide as chromogenic substrate. Its pH optimum was 8.5 and it exhibited the highest activity at 52 degrees C. Fractionation on Sephadex G-100 column revealed that its molecular mass was about 42 kDa. The enzyme, which is new for the genus Bacillus, is a thiol protease, as tosyl-L-phenylalanine chloromethyl ketone, tosyl-L-lysine chloromethyl ketone, phenylmethylsulfonyl fluoride and ethylenediamine tetraacetate did not inhibit it, while HgCl2 and para-chloromercuribenzoate lowered its activity.

Production of extracellular enzymes by Microsporum canis and their role in its virulence

Abstract: Microsporum canis is the most prevalent dermatophyte of domestic animals. Several enzymes produced by dermatophytes, particularly keratinases, are considered to play a role in the virulence of this fungus. To investigate the possible relationship between the clinical status of M. canis infection and enzymatic activity of isolates, we studied the relationship between keratinase, elastase, lipase and DNase levels produced in vitro by different isolates and virulence as expressed in a guinea pig model. Samples isolated from symptomatic dogs and cats showed a statistically significantly (P < 0.05) higher keratinase activity than samples isolated from asymptomatic animals. Experimental infection of guinea pigs showed that a strain with high in vitro keratinase activity induced acute infection, which resolved clinically and mycologically faster than the infection induced by a strain with low keratinase activity. This suggested a strong correlation between high keratinase activity and the development of symptoms. The same correlation was not observed for other enzymes tested.

Partial purification and some biochemical characteristics of exocellular keratinase from Trichophyton mentagrophytes var. erinacei.

Abstract: The dermatophyte Trichophyton mentagrophytes var. erinacei isolated from patients infected with tinea cruris was cultured in Sabouraud dextrose broth, from which an exocellular kenitinase extract was obtained. The keratinase was partially purified with sephadix G-100 gel filtration. Some biochemical characteristics of the purified enzyme were examined. Its molecular weight was estimated to be 38000 dalton on sodium dodecyle sulfate polyacrylmide gel electrophoresis (SDS-PAGE). The optimal pH was 5.5 and optimal temperature for the highest keratinase activity was 50°C. The enzyme activity was specifically increased against guinea pig hair and fibrous protein and inhibited by phenylmethylsulfonylfloride.

Exocellular enzyme activity of dermatophytes and other fungi isolated from ruminants in Southern Iraq.

Abstract: Sixteen fungal species were isolated from 182 specimens collected from four ruminants (buffalo, camel, cattle and sheep) in Southern Iraq. Fungi represented by five species of dermatophytes and eleven species of other fungi were screened for the activity of four enzymes; keratinase, proteinase, lipase and amylase. Keratinase was found to be produced by all of the dermatophytes and non-dermatophytes, except for Paecillomyces variottii and Scytalidium lignicola. However, high keratinase activity was expressed by the dermatophytic species particularly by Trichophyton mentagrophytes var. erinacei and Microsporum gypseum. Three dermatophytes viz. M. gypseum, T. verrucosum and T. mentagrophytes var. nodulare were capable of producing protease, lipase and amylase. Although, T. mentagrophytes var. erinacei showed high protease activity, it did not produce lipase and amylase. On the contrary most of the non-dermatophytic species revealed protease and lipase activities higher than the dermatophytes. The Curvularia spp. isolates showed the highest protease and amylase activity, while Aspergillus parasiticus revealed the highest activity of lipase and amylase. No correlation was observed between enzyme activity and the growth rate of the examined fungi.

Fermentation characteristics and secretion of proteases of a new keratinolytic strain of Bacillus licheniformis

Abstract: A keratin-degrading strain of Bacillus licheniformis (K-508) was isolated from partially-degraded feathers and characterised. It had high chicken feather-degrading activity when cultured in feather-containing broth, with a growth optimum at pH 7 and 47 °C. Broth filtrates were active towards N-Bz-Phe-Val-Arg-p-nitroanilide and N-Suc-Ala-Ala-Pro-Phe-p-nitroanilide, as chromogenic protease substrates at pH 8. Strain K-508 displays keratinolytic activity against native feather keratin (without any pretreatment) in the presence of SH-reducing compounds. It constitutively secreted both trypsin-like and chymotrypsin-like proteases.

New bacterial strain with high keratinase activity

Abstract: PROBLEM TO BE SOLVED: To provide a new bacterial strain having high keratinase activity, and to provide a method for utilizing the strain. SOLUTION: This new bacterial strain is obtained by screening a plurality of colonies which are obtained on an agar medium by enrichment culture from soil including animal feather and/or hair. The strain thus obtained has been named as D1 strain (Bacterium D1, deposition number FERM P-18481), being morphologically an orange-red-colored Gram-negative bacillus and having motility; further, as a result of OF (oxidation-fermentation) test, the strain has been proved to be of oxidative type, being aerobic in chemical properties and characterized in being capable of producing urease, gelatinase and oxidase; as a result of purifying the strain by column chromatography, it has been proved that a keratinase was produced.

A Review of Microbial Degradation of Keratin and Its Application

Abstract: The progress of studies on keratin,keratinase and keratin degrading microorganisms were reviewed. A large amount of keratin contained wastes were produced in poultry farm,they could be a new resource of protein if treated properly.Some keratin degrading microorganisms and keratinase were isolated and studied.The application of keratinase to the treatment of keratin contained wastes should be a cost effective biotechnology for environmental protection.

Studies on screening of the feather keratin-degrading microorganisms and the producing of keratinase

Abstract: A feather-degrading culture was enriched with isolates from a poultry waste digester and adapted to grow with feathers as its primary source of Carbon, Nitrogen and energy. The strain is Bacillus with endosperm and Gram stain is positive. The optimum rate of growth is at 42 ℃ and at pH7.5 (with shaking 125 rpm). The maximal activity of keratinase is 25.20U/L. The productione of keratinase is repressed by supplementation of glucose and ammonium.

Bacillus sp. hb-5 generating keratinase

Abstract: PURPOSE: Provided is Bacillus sp HB-5 (KCTC 8959P) generating keratinase whose molecular weight is 60,000Da and which shows stability at pH 6-11 and 30-60 degC, decomposes insoluble proteins such as keratin, and is useful in manufacturing cosmetics as an active ingredient CONSTITUTION: Bacillus sp HB-5 (KCTC 8959P) and keratinase generated therefrom are obtained by the next steps of: i) selecting bacteria having activity of keratinase from soil and cultivating the bacteria at 37 degC for 72 hours to get as many enzymes as possible; ii) in order to measure the activation of the enzymes, reacting l ml of enzyme solution with 5 ml of casein at 37 degC for 10 minutes and adding TCA solution to stop the reaction for 30 minutes; iii) centrifuging the solution and mixing 1 ml of supernatant, 5 ml of sodium carbonate, and 1 ml of poline for 30 minutes; iv) measuring absorbency of the solution at 660nm; v) in order to separate the enzymes, filtering the solution with 045 μm filter paper and condensing and separating the enzymes from the filtered solution through membrane ultrafiltration system and gel column chromatography; and vi) performing SDS-polyacrylamide gel electrophoresis to identify the enzymes