Evaluation of Aeromonas Hydrophila MSB16 Protease Production in Response to Low Intensity Electric Current, Surfactants, and Nanoparticles

Cost-effective production of proteases is one of the challenges facing the enzyme industry. In this regard, there are no reports concerning the influence of low-intensity electric current and nanoparticles on microbial neutral proteases production. This study aimed at investigating the effect of these treatments on the neutral protease production of Aeromonas hydrophila MSB16.

The protease production of A. hydrophila MSB16 in the presence of ionic and non-ionic surfactants (SDS, Tween 80, Triton X-100, and Span 80), glycerol as well as various nanoparticles (Ag, Fe III, Fe (0), Al, Zn, and Cu), was investigated. Furthermore, the effect of an electric current (50 µA) exposure to the bacterial cells during the logarithmic and stationary phase for 10 min and 20 min was studied.

According to the results, electric current exposure to the bacterial cells entered the stationary phase for 10 min and 20 min increased the protease production of A. hydrophila MSB16 by 48.2% and 59.1%, respectively. However, this positive effect was not observed for log phase-bacterial cells. Besides, glycerol, Tween 80, Span 80 and Ag nanoparticles enhanced the protease production of A. hydrophila MSB16 by 56.4%, 40.4%, 24.8%, and 12.5%, respectively. Discussion and

Non-ionic surfactants, glycerol, and electric current increased the protease production of A. hydrophila MSB16. Interestingly, the influence of electric current on the protease production of A. hydrophila MSB16 was dependent on the growth phase of the bacterium.