Purification and characterization of a Bacillus cereus collagenolytic/proteolytic enzyme and its effect on Meloidogyne javanica cuticular proteins

Abstract

A novel collagenolytic/proteolytic enzyme isolated from the bacterium Bacillus cereus was purified and characterized. The extracellular enzyme was secreted into the growth medium only after induction by collagen. It was purified by two-step chromatography, consisting of gel filtration through a Sephadex G-100 column and then through an anion-exchange column. Molecular mass, as determined by SDS-PAGE was 42.8. The 42.8-kDa collagenase band was eluted from the gel to obtain the purified enzyme. The enzyme was found to have a very wide range of optimal pHs for activity (5.4 – 8.2), and was stable at temperatures between 4 and 40 °C. In addition to its collagenolytic property, the enzyme revealed very strong proteolytic activity, demonstrated by its ability to digest bovine serum albumin. The enzyme's ability to damage nematode cuticles was demonstrated by the digestion of collagens extracted from intact cuticles of second-stage juveniles of the root-knot nematode Meloidogyne javanica.