Complex sentence: Performing casein hydrolysis allows for "S. marcescens" to produce extracellular metalloprteases which are believed to function in cell-to-extracellular matrix interactions.
Split into simpler sentences: Performing casein hydrolysis allows for "S. marcescens" to produce extracellular "S. marcescens" metalloproteases. These metalloprteases are believed to function in cell to extracellular matrix interactions.