Impact of a novel caseinolytic protease single mutation on Lactiplantibacillus pentosus growth performance

Abstract

The caseinolytic protease (ClpP)-producing strain CHFM, isolated from Algerian goat milk, was identified as Lactiplantibacillus pentosus through 16 S rRNA sequence analysis. The optimal conditions for ClpP expression by Lpb. pentosus CHFM were determined in a modified MRS medium, where peptone was replaced with casein. The most favourable conditions were a pH of 8.0, a temperature between 25°C and 55°C, and an incubation period of 48 h. PCR screening and subsequent cloning and sequencing of the ClpP-encoding gene from the Lpb. pentosus CHFM genome revealed two conservative substitutions: threonine to serine at position 161, and aspartic acid to glutamic acid at position 182. Bioinformatic analysis indicated an instability index value of 40.51 for ClpP CHFM, suggesting stability, with an alpha-helix being the predominant secondary structure element, followed by a random coil. The aliphatic index was 97.60, indicating thermal stability. The GRAVY index was −0.23, suggesting enhanced interaction with water. The molecular weight was found to be 25.5 kDa with an isoelectric point (pI) of 4.78. The structural and docking analysis demonstrated that ClpP CHFM possesses the ability to hydrolyze αS1-casein.