Skip to main content

Table 1 Effect of protease inhibitors, organic solvents, metal ions, and detergents on the activity of the keratinolytic extracts obtained with Bacillus cytotoxicus LT-1 and Bacillus cytotoxicus Oll-15. Each determination was performed in triplicate. Residual activity is expressed as a percentage, comparing with the activity measured in the absence of any compound. Asterisks show the differences with a P < 0.05 (LSD test, ANOVA).

From: The keratinolytic bacteria Bacillus cytotoxicus as a source of novel proteases and feather protein hydrolysates with antioxidant activities

Chemical Concentration Residual activity (%)
LT-1 Oll-15
 Inhibitors
  PMSF 1 mM 87.8 ± 3.0* 95.8 ± 4.4*
  Iodoacetamide 1 mM 89.7 ± 4.2* 56.9 ± 3.2*
  EDTA 1 mM 4.5 ± 1.9* 0.6 ± 0.1*
  Phenantroline 1 mM 1.8 ± 0.5* 0.8 ± 0.5*
  Pepstatin A 5 μM 98.5 ± 1.2 111.1 ± 0.4*
 Metal ions
  Mg+2 1 mM 121.8 ± 2.2* 130.1 ± 2.9*
  Zn+2 1 mM 107.5 ± 5.3* 112.2 ± 10.0*
  Ca+2 1 mM 143.8 ± 2.3* 147.2 ± 0.8*
  Mn+2 1 mM 117.5 ± 3.1* 116.2 ± 13.8*
  Co+2 1 mM 41.3 ± 4.4* 46.4 ± 3.3*
  Na+ 1 mM 94.9 ± 6.7 82.7 ± 6.5*
  K+ 1 mM 89.1 ± 4.2* 107.1 ± 6.4
  Hg+2 1 mM 28.5 ± 3.1* 27.9 ± 2.3*
 Organic solvents
  Methanol 1% v/v 98.3 ± 1.5 102.6 ± 1.7
  Ethanol 1% v/v 87.4 ± 3.7* 97.8 ± 2.7
  Isopropanol 1% v/v 84.9 ± 0.7* 87.3 ± 1.2*
 Commercial detergents
  Ala 1% v/v 45.3 ± 3.2* 9.0 ± 1.1*
  Ariel 1% v/v 15.9 ± 1.4* 17.8 ± 6.6*
  Ace 1% v/v- 42.3 ± 2.1* 1.9 ± 1.5*
  Skip 1% v/v 20.1 ± 1.1* 1.2 ± 2.1*
  Drive 7 mg·l-1 9.3 ± 1.5* 5.0 ± 1.5*
  Ariel 7 mg·l-1 4.1 ± 1.2* 2.0 ± 0.7*
  Ace 7 mg·l-1 10.7 ± 1.4* 39.1 ± 1.5*
  Skip 7 mg·l-1 4.7 ± 1.3* 2.1 ± 0.6*