“…The first was the use of 1-methyl-3-nitro-1-nitrosoguanidine for the treatment of Bacillus subtilis KD1, that produced a mutant with a keratinolytic activity double that of the wild type (Cai et al 2008). The second one was the use of EMS to mutate Candida parapsilosis, which produced three mutants presenting 1.4-, 1.5-and 1.7fold activity of the wild type (Duarte et al 2011). Looking at the proportion of increase of protein expression, the results of this work are similar to those obtained in the two works mentioned above.…”
Section: Discussionsupporting
confidence: 77%
“…Thus, keratinous materials can remain inert in the environment for a long time, as keratinase producing microorganisms are not widespread (Lange et al 2016). However, despite their rigid structure, keratins are recycled in nature and can be efficiently degraded by a few microorganisms such as bacteria from the genus Bacillus (Fellahi et al 2016), Streptomyces (Ramakrishnan et al 2011) from several species of fungi (El-Gendy 2010; Duarte et al 2011;Bohacz 2017) and from Archaea (Kublanov et al 2009;Brandelli et al 2010) that are capable of producing keratinolytic peptidases known as keratinases.…”
Discarded feathers represent an important residue from the poultry industry and are a rich source of keratin. Bacillus subtilis LFB-FIOCRUZ 1266, previously isolated from industrial poultry wastes, was used in this work and, through random mutation using ethyl methanesulfonate, ten strains were selected based on the size of their degradation halos. The feather degradation was increased to 115% and all selected mutants showed 1.4-to 2.4-fold increase in keratinolytic activity compared to their wild-type counterparts. The protein concentrations in the culture supernatants increased approximately 2.5 times, as a result of feather degradation. The mutants produced more sulfide than the wild-type bacteria that produced 0.45 µg/ml, while mutant D8 produced 1.45 µg/ml. The best pH for enzyme production and feather degradation was pH 8. Zymography showed differences in the intensity and molecular mass of some bands. The peptidase activity of the enzyme blend was predominantly inhibited by PMSF and EDTA, suggesting the presence of serine peptidases. HPTLC analysis evidenced few differences in band intensities of the amino acid profiles produced by the mutant peptidase activities. The mutants showed an increase in keratinolytic and peptidase activities, demonstrating their biotechnological potential to recycle feather and help to reduce the environmental impact.
“…The first was the use of 1-methyl-3-nitro-1-nitrosoguanidine for the treatment of Bacillus subtilis KD1, that produced a mutant with a keratinolytic activity double that of the wild type (Cai et al 2008). The second one was the use of EMS to mutate Candida parapsilosis, which produced three mutants presenting 1.4-, 1.5-and 1.7fold activity of the wild type (Duarte et al 2011). Looking at the proportion of increase of protein expression, the results of this work are similar to those obtained in the two works mentioned above.…”
Section: Discussionsupporting
confidence: 77%
“…Thus, keratinous materials can remain inert in the environment for a long time, as keratinase producing microorganisms are not widespread (Lange et al 2016). However, despite their rigid structure, keratins are recycled in nature and can be efficiently degraded by a few microorganisms such as bacteria from the genus Bacillus (Fellahi et al 2016), Streptomyces (Ramakrishnan et al 2011) from several species of fungi (El-Gendy 2010; Duarte et al 2011;Bohacz 2017) and from Archaea (Kublanov et al 2009;Brandelli et al 2010) that are capable of producing keratinolytic peptidases known as keratinases.…”
Discarded feathers represent an important residue from the poultry industry and are a rich source of keratin. Bacillus subtilis LFB-FIOCRUZ 1266, previously isolated from industrial poultry wastes, was used in this work and, through random mutation using ethyl methanesulfonate, ten strains were selected based on the size of their degradation halos. The feather degradation was increased to 115% and all selected mutants showed 1.4-to 2.4-fold increase in keratinolytic activity compared to their wild-type counterparts. The protein concentrations in the culture supernatants increased approximately 2.5 times, as a result of feather degradation. The mutants produced more sulfide than the wild-type bacteria that produced 0.45 µg/ml, while mutant D8 produced 1.45 µg/ml. The best pH for enzyme production and feather degradation was pH 8. Zymography showed differences in the intensity and molecular mass of some bands. The peptidase activity of the enzyme blend was predominantly inhibited by PMSF and EDTA, suggesting the presence of serine peptidases. HPTLC analysis evidenced few differences in band intensities of the amino acid profiles produced by the mutant peptidase activities. The mutants showed an increase in keratinolytic and peptidase activities, demonstrating their biotechnological potential to recycle feather and help to reduce the environmental impact.
“…Temperature (A), and pH (B). The enzymatic extract was obtained after growth in medium F with 1% feather at pH 8.0 been observed for other microorganisms such as Candida parapsilosis and other bacillus strains isolated from industrial waste (Williams et al 1990;Kim et al 2001;Rozs et al 2001;Duarte et al 2011).…”
The aim of this study is to investigate the culture conditions of chicken feather degradation and keratinolytic enzyme production by the recently isolated Bacillus subtilis SLC and to evaluate the potential of the SLC strain to recycle feather waste discarded by the poultry industry. The SLC strain was isolated from the agroindustrial waste of a poultry farm in Brazil and was confirmed to belong to Bacillus subtilis by rDNA gene analysis. There was high keratinase production when the medium was at pH 8 (280 U ml(-1)). Activity was higher using the inoculum propagated for 72 h on 1% whole feathers supplemented with 0.1% yeast extract. In the enzymatic extract, the keratinases were active in the pH range from 2.0 to 12.0 with a maximum activity at pH 10.0 and temperature 60°C. For gelatinase the best pH was 5.0 and the best temperature was 37°C. All keratinases are serine peptidases. The crude enzymatic extract degraded keratin, gelatin, casein, and hemoglobin. Scanning electron microscopy showed Bacillus cells adhered onto feather surfaces after 98 h of culture and degraded feather filaments were observed. MALDI-TOF mass spectrometric analysis showed multiple peaks from 522 to 892 m/z indicating feather degradation. The presence of sulfide was detected on extracellular medium probably participating in the breakdown of sulfide bridges of the feather keratin. External addition of sulfide increased feather degradation.
“…9 Despite known differences in virulence, it is unclear what virulence factors (biofilm development, lipases, or aspartyl proteinases) may play a role in the final outcome. [10][11][12][13][14][15] Murine models are the gold standard for virulence studies; however, ethical considerations associated with mammalian models have made invertebrate models (Caenorhabditis elegans, Drosophila melanogaster, Galleria mellonella, Dictyostelium discoideum, etc.) an attractive alternative.…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.