Optimization of Keratinase Production for Feather Degradation by Bacillus subtilis

Abstract

Background: The feather is an environmental pollutant that can be degraded by bacterial and fungal microorganisms. The keratin sheets constitute 90% of the feather mass. Due to the extremely rigid structure, keratin is insoluble and hard to degrade. Some microorganisms such as Bacillus spp. were reported to be able to degrade keratin by secretion of keratinase.Objectives: The aim of this study was the isolation of feather degrading Bacillus spp.from a poultry waste and the optimization of conditions for the highest enzyme activity and feather degradation.Materials and Methods: The microorganisms were isolated from the waste of a poultry in Miyaneh, Iran, and the Bacillus spp. were identified using morphological, physiological and biochemical tests. The Bacillus spp. cultured in a medium consisted of feather at pH 7.4 and 27 ºC for seven days to identify the feather-degrading Bacillus spp. The biochemical tests were performed to determine the strain of the bacterium. The study was repeated under different pH and temperatures to find the optimum conditions for best enzyme activity.Results: The PCR approved the Bacillus genus of the isolates. The strain of Bacillus subtilis was identified using biochemical tests. 40 ºC and pH 11 are the optimum condition for maximum keratinase enzyme activity.Conclusions: B. subtilis was found to be able to degrade the feather

A Statistical-Mathematical Model to Optimize Chicken Feather Waste Bioconversion via Bacillus licheniformis SHG10: A Low Cost Effective and Ecologically Safe Approach

“…Bioconversion of the accumulated non-efficiently utilized chicken feather waste derived from poultry industry worldwide into valuable end products is an issue of a prime importance in the agenda of efficient feathers waste valorization. The up to date literature of review has a main concern for utilizing chicken feather waste in keratinase/ protease production by the aid of feather-degrading microorganisms [7,16,22,27,28,48,49]. Therefore, employment of feather waste for soluble proteins and amino acids industrialization is the main interest of the present work.…”

Response Surface Methodology for the Optimization of Keratinase Production in Culture Medium Containing Feathers by Bacillus sp. UPM-AAG1

“…In keratinase research, the main objective is to maximize keratinase production through manipulating external and internal parameters [46]. Most of the optimization studied involving keratinase involved conventional optimization through one factor-at-a-time (OFAT) [22,41,47] or both conventional and statistical approach [17,48] but with non-keratin carbon and nitrogen sources (Table 7). By carrying out optimization relying on no additional supplements, as well as optimizing process at ambient temperature suiting Malaysia (from 24 to 32 • C), will increase the chances of a successful keratinase production by local small and medium enterprise (SME) companies.…”

Optimization of Production and Partial Characterization of Keratinase Produced by Bacillus thuringiensis strain Bt407 Isolated from Poultry Soil

“…In our studies enrichment and isolation of keratinase producer was carried out by using medium containing Whole feather as a sole carbon and nitrogen source which had induced higher keratinase activity (Lin et al, 1992;Szabo et al, 2000;Gushterva et al, 2005). Feather meal was used for isolation of keratinase producer by many scientists (Tapia and Simoes,2008;Ramya et al, 2014;Mousavi et al, 2013;Govarthanan et al, 2011;Shah, 2015;Fakhfakh-Zouari et al, 2010). The abilities of bacterial isolates to produce keratinase were also confirmed in earlier reports by cultivation on agar plates containing skimmed milk (Tork et al, 2010;Allpress et al, 2002;Preethi et al, 2015;Ramya et al, 2014;Kazi et al, 2015).…”