Processing of extracellular lipase of Lactobacillus plantarum: involvement of a metalloprotease.

The hypothesis of a proteolytic involvement in the extracellular lipase processing of a strain of Lactobacillus plantarum was considered and tested, in vitro assays with acid proteases, cathepsin D and renin revealed that both did affect lipolytic activity positively. In vivo assays with growth in the presence of the protease inhibitors pepstatin, phenylmethylsulfonyl fluoride, transepoxysuccinyl-L-leucylamido-(4-guanidino)butane and ethylenediaminetetraacetic acid showed that ethylenediaminetetraacetic acid did affect the pattern of the proteins that possess lipolytic activity. Therefore, it is suggested that a metalloprotease is involved in the processing of the extracellular lipases of L. plantarum, although other proteases can also be important.