Systematic functional analysis and application of a cold-active serine protease from a novel Chryseobacterium sp.

• A novel Chryseobacterium sp. was screened for cold-active protease production.
• IMDY-protease active at low temperature and even in the presence of higher concentration of NaCl.
• Tolerant to several organic solvents, surfactants and detergents.
• Myofibril fragmentation, pH, TBA values were favorable in IMDY-protease treated meat.

Psychrotolerant bacteria isolated from natural and artificially cold environments were screened for synthesis of cold-active protease. The strain IMDY showing the highest protease production at 5 °C was selected and phylogenetic analysis revealed that IMDY as novel bacterium with Chryseobacterium soliT as its nearest neighbor. Classical optimization enhanced the protease production from 18 U/mg to 26 U/mg and the enzyme was found to be active at low temperature, activity enhanced by CaCl2, inhibited by PMSF, stable against NaCl, and its activity retained in the presence of surfactants, organic solvents and detergents. On testing, the meat tenderization, myofibril fragmentation, pH, and TBA values were favorable in IMDY-protease treated meat compared to control. SDS profiling and SEM analysis also showed tenderization in meat samples. Hence, this study proposes to consider the cold-active protease from Chryseobacterium sp. IMDY as a pertinent candidate to develop potential applications in food processing industry.