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Varela, Hermosinda; Ferrari, Mario Daniel; Belobrajdic, L; Vazquez, Adriana; Loperena, Milka Lyliam

doi:10.1023/a:1018384025181

Cited by 59 publications

(9 citation statements)

References 5 publications

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“…Alkaline proteases find a number of applications in food industry (Neklyudov et al 2000), leather processing industry (Varela et al 1997), waste management (Dalev 1994), medical applications (Kudrya and Simonenko 1994). Proteases are used in detergents and cleaning agent for a long time (Sakiyama et al 1998; Showell 1999).…”

Section: Discussionmentioning

confidence: 99%

Identification and characterization of alkaline serine protease from goat skin surface metagenome

2011

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Metagenomic DNA isolated from goat skin surface was used to construct plasmid DNA library in Escherichia coli DH10B. Recombinant clones were screened for functional protease activity on skim milk agar plates. Upon screening 70,000 clones, a clone carrying recombinant plasmid pSP1 exhibited protease activity. In vitro transposon mutagenesis and sequencing of the insert DNA in this clone revealed an ORF of 1890 bp encoding a protein with 630 amino acids which showed significant sequence homology to the peptidase S8 and S53 subtilisin kexin sedolisin of Shewanella sp. This ORF was cloned in pET30b and expressed in E. coli BL21 (DE3). Although the cloned Alkaline Serine protease (AS-protease) was overexpressed, it was inactive as a result of forming inclusion bodies. After solubilisation, the protease was purified using Ni-NTA chromatography and then refolded properly to retain protease activity. The purified AS-protease with a molecular mass of ~63 kDa required a divalent cation (Co2+ or Mn2+) for its improved activity. The pH and temperature optima for this protease were 10.5 and 42°C respectively.

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Section: Discussionmentioning

confidence: 99%

Identification and characterization of alkaline serine protease from goat skin surface metagenome

2011

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“…For enzyme production, a modified production medium A [16] was used, which contained the following: 0.5% whole chicken feather, 0.2% glucose, 0.5% peptone, 0.5% yeast extract, 0.1% K 2 HPO 4 , 0.3% KH 2 PO 4 , 0.1% CaCl 2 and 0.1% MgSO 4 . The above medium (50 ml, pH 7) was dispensed in 250 ml Erlenmeyer flasks and sterilized by autoclaving at 121 °C for 20 min.…”

Section: Methodsmentioning

confidence: 99%

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Ramnani

Gupta

2004

Biotech and App Biochem

110

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A 3.5-fold increase in keratinase production by Bacillus licheniformis RG1 was achieved by using statistical methods involving Plackett-Burman design and response surface methodology. Eight variables were screened using Plackett-Burman design. Of these, glucose, peptone and glutathione were found to affect the response signal positively, whereas CaCl(2) had a negative effect. Further interaction of these factors, along with phosphate and incubation time, was studied using response surface methodology. An optimum keratinase production of 1295 units/mg dry weight was obtained with the following medium composition: 1% glucose, 1% peptone, 1% phosphate, 0.05% glutathione, 0.5% feather and 2% inoculum under shaking at 250 rev./min with an incubation period of 72 h at 37 degrees C. Keratinase production was found to be a function of biomass and maximum production occurred during the stationary phase.

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“…Proteases are used during the soaking, dehairing and bating states of preparing skins and hides. Pancreatic proteases are used in the bating process and the use of microbial alkaline proteases are popular (Varela et al 1997 ). Alkaline proteases swell hair roots and attack hair follicle proteins, resulting in the easy removal of hair.…”

Section: Introductionmentioning

confidence: 99%

“…Dehairing proteases have been characterized from various Bacillus sp., e.g. B. subtilis 11QDB32 (Varela et al 1997 ), B. amyloliquefaciens (George et al 1995 ), B. subtilis K2 (Hameed et al 1996 ; Hameed et al 1999 ) and B. circulans (Subba Rao et al 2009 ).…”

Section: Introductionmentioning

confidence: 99%

Cow dung: a potential biomass substrate for the production of detergent-stable dehairing protease by alkaliphilic Bacillus subtilis strain VV

et al. 2012

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Cow dung, a cheap and easily available source of energy, was used as the substrate for the production of alkaline protease by solid-state fermentation using the Bacillus subtilis strain VV. In order to achieve the maximum yield of this enzyme, the following optimum process parameters are needed: fermentation period (72 h), pH (10.0), moisture content (140%), inoculum (25%), temperature (30–40°C), carbon source (2% (w/w) maltose) and nitrogen source (1% (w/w) urea). The protease was stable over a broad temperature range (30–50°C) and pH (8.0-10.0), with maximum activity at 50°C and pH 10.0. Among the divalent ions tested, Ca2+ (0.01 M) increased enzyme activity. The purified protease, after being subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was found to have a molecular mass of 38.5 kDa. The enzyme was solvent-and surfactant-stable and showed activity even after 24 h incubation along with various commercially available detergents. This enzyme possessed dehairing properties for animal hide after 16 h of incubation at room temperature. From these results it is evident that cow dung is a potential substrate for the production of a detergent-stable, dehairing protease by B. subtilis. This enzyme has a lot of potential applications in the detergent and leather-processing industries.

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Cited by 59 publications

References 5 publications

Identification and characterization of alkaline serine protease from goat skin surface metagenome

Identification and characterization of alkaline serine protease from goat skin surface metagenome

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Cow dung: a potential biomass substrate for the production of detergent-stable dehairing protease by alkaliphilic Bacillus subtilis strain VV

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