Optimization, partial purification, and characterization of a novel high molecular weight alkaline protease produced by Halobacillus sp. HAL1 using fish wastes as a substrate

Abstract

Background Hydrolytic enzymes from halophilic microorganisms have a wide range of industrial applications. Herein, we report the isolation of Halobacillus sp. HAL1, a moderately halophilic bacterium that produces a novel high molecular weight extracellular alkaline protease when grown in fish processing wastes as a substrate. Results Results showed that the isolated strain belonged to the genus Halobacillus, and it was designated as Halobacillus sp. HAL1 with the GenBank accession number OK001470. The strain secreted an extracellular alkaline protease, and the highest yield was obtained when it was grown in a medium with fish wastes substrate as the sole nutritional source (10 g/L) and incubated at 25 °C under shaking conditions. The enzyme was partially purified by Sephadex G-100 column chromatography. Zymographic analysis showed two casein degrading bands of about 190 and 250 KDa. The optimum enzyme activity was at a temperature of 50 °C at pH 8. The proteolytic activity was enhanced in the presence of metal ions (Ca2+, Mg2+, and Mn2+), surfactants (Tween 80, SDS, and Triton-X100), H2O2, and EDTA. Conclusion Our study indicates that Haobacillus sp. HAL1 is a moderately halophilic strain and secrets a novel high molecular wight alkaline protease that is suitable for detergent formulation.

Scale-Up of the Fermentation Process for the Production and Purification of Serratiopeptidase Using Silkworm Pupae as a Substrate

“…Studying the impact of different temperatures (20, 25, and 30 °C) revealed that the maximum enzyme production was obtained at 25 °C. These results align with findings reported by Pansuriya et al and Fahmy et al, both of whom observed maximum protease production at 25 °C [ 47 , 49 ]. The hydrogen ion concentration promotes microbial growth and product formation by regulating the transport of various metabolites and nutrients across the cell membrane [ 50 ].…”

“…Hence, our findings suggest that silkworm pupae offer an alternative source of carbon and nitrogen suitable for use in the fermentation process [26,43]. Several previous studies have indicated that the use of agro-industrial residues can enhance the production of proteases [31,[44][45][46][47]. Additionally, enzyme production can benefit from the presence of nutritional sources and the overall growth and metabolism of the microbial strain [4,5,14].…”

“…Moreover, the optimization of significant physicochemical variables such as pH, temperature, and fermentation time through the Taguchi methodology demonstrated a strong preference for serratiopeptidase production at pH 7, a temperature of 25 • C, an incubation time of 36 h, and a silkworm pupa concentration of 1.5% (shown in Figure 2). It is plausible that the maximum proteolytic activity observed during this fermentation period in Erlenmeyer flasks could be attributed to the availability of primary nutrients and dissolved oxygen (Figure 4a), as indicated by several studies [29,34,44,47].…”

“…Several previous studies have indicated that the use of agro-industrial residues can enhance the production of proteases [ 31 , 44 , 45 , 46 , 47 ]. Additionally, enzyme production can benefit from the presence of nutritional sources and the overall growth and metabolism of the microbial strain [ 4 , 5 , 14 ].…”

“…Temperature is also a critical parameter in this process, as it plays a significant role in microbial growth and product formation. Studying the impact of different temperatures (20, 25, and 30 • C) revealed that the maximum enzyme production was obtained at 25 [47,49]. The hydrogen ion concentration promotes microbial growth and product formation by regulating the transport of various metabolites and nutrients across the cell membrane [50].…”