Enzymatic degradation of pretreated pig bristles with crude keratinase of Bacillus cereus PCM 2849
Wojciech Łaba , Dorota Chorążyk , Anna Pudło , Joanna Trojan-Piegza , Michał Piegza , Anna Kancelista , Adam Kurzawa , Iwona Żuk , Wiesław Kopeć
AbstractPurpose The aim of the study was to apply and optimize the process of bioconversion of pig bristle waste using keratinolytic enzymes of Bacillus cereus PCM 2849, and to evaluate the amino acid composition of the resultant hydrolysate. Methods Hydrolysis with concentrated culture fluid of B. cereus was applied for bioconversion of pig bristles, after thermo-chemical pretreatment with sulfite. The effect of substrate concentration, sulfite concentration during pretreatment and reaction temperature on the release of amino acids was determined using Box-Behnken design. Amino acid composition of the obtained hydrolysate was determined by HPLC. Structural condition and substructural changes of the residual substrate were evaluated with SEM microscopy and FTIR spectroscopy. Results The applied enzymatic preparation for bristle biodegradation was verified to contain multiple proteases of a wide molecular weight range. A regression model was developed, in which influential parameters were: linear effect of substrate concentration, followed by quadratic effects of reaction temperature, substrate concentration and pretreatment. Optimum reaction conditions were also determined. The resultant hydrolysate was rich in branched-chain amino acids. Residual substrate was detriorated and sulfitolytic cleavage of disulfides and alteration of protein secondary structures was confirmed. Conclusions Application of B. cereus crude keratinase allowed for partial hydrolysis of pig bristles, preceded by sulfitolytic pretreatment. A regression model was built to describe the process of hydrolysis to release free amino acids, at constant enzyme load. Hydrolysis in given conditions allowed to obtain hydrolysate rich in branched chain amino acids. The presented process poses an alternate way of management over pig bristles, a hard-to-degrade keratinous waste.
|Journal series||Waste and Biomass Valorization, ISSN 1877-2641, (A 20 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Bacillus cereus; Biodegradation; Box-Behnken design; Hydrolysis; Keratinase; Pig bristles|
|ASJC Classification||; ;|
|Internal identifier||62531; PX-58e2064ad5de0fdf4b4d8b27|
|License||Journal (articles only); published final; ; after publication|
|Score||= 20.0, 10-09-2020, ArticleFromJournal|
|Publication indicators||= 10; = 9; : 2017 = 0.681; : 2017 = 1.874 (2) - 2017=1.787 (5)|
|Citation count*||15 (2020-09-13)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.