Keratinolytic activity of Bacillus subtilis AMR using human hair.
OBJECTIVE
To determine the ability of a novel Bacillus subtilis AMR isolated from poultry waste to hydrolyse human hair producing peptidases including keratinases and hair keratin peptides.


RESULTS
The Bacillus subtilis AMR was identified using biochemical tests and by analysis of 16S rDNA sequence. The isolate was grown in medium containing human hair as the sole source of carbon and nitrogen. The supplementation of hair medium (HM) with 0.01% yeast extract increased the keratinolytic activity 4.2-fold. B. subtilis AMR presented high keratinase production on the 8th day of fermentation in hair medium (HM) supplemented with 0.01% yeast extract (HMY) at pH 8.0. Keratinase yield was not correlated with increase in biomass. Zymography showed keratin-degrading peptidases migrating at c. 54, 80 and 100 kDa and gelatin-degrading bands at c. 80, 70 63, 54 32 and 15 kDa. Keratinases were optimally active at 50 degrees C and pH 9.0 and was fully inhibited by the serine proteinase inhibitor (PMSF). Scanning electron microscopy showed complete degradation of the hair cuticle after exposure to B. subtilis AMR grown in HMY. MALDI-TOF analysis of culture supernatant containing peptides produced during enzymatic hydrolysis of hair by B. subtilis AMR revealed fragments in a range of 800-2600 Da.


CONCLUSIONS
This study showed that B. subtilis AMR was able to hydrolyse human hair producing serine peptidases with keratinase and gelatinase activity as well as hair keratin peptides.


CONCLUSIONS
This is the first report describing the production and partial characterization of keratinases by a B. subtilis strain grown in a medium containing human hair. These data suggest that peptides obtained from enzymatic hair hydrolysis may be useful for future applications on pharmaceutical and cosmetic formulations.
Mazotto
A M
AM
Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes (IMPPG), Centro de Ciências da Saúde (CCS), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
Cedrola
S M Lage
SM
Lins
U
U
Rosado
A S
AS
Silva
K T
KT
Chaves
J Q
JQ
Rabinovitch
L
L
Zingali
R B
RB
Vermelho
A B
AB
D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D057075:Enzyme Assays; D005285:Fermentation; D018093:Gelatinases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D006197:Hair / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste; D053564:Keratins, Hair-Specific / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011200:Poultry; D011480:Protease Inhibitors / Q000494:pharmacology; D013379:Substrate Specificity; D013696:Temperature
D001426:Bacterial Proteins; D003470:Culture Media; D007220:Industrial Waste; D053564:Keratins, Hair-Specific; D011480:Protease Inhibitors; D002244:Carbon; D010447:Peptide Hydrolases; C035855:keratinase; D018093:Gelatinases; D009584:Nitrogen