Acts on short-chain (C4-C6) fatty acid esters and triglycerides, including tertiary alcohol esters. Activity on p-nitrophenyl esters is generally higher than on o-nitrophenyl esters. Lacks beta-lactamase activity; it hydrolyzes the ester bond of cephalosporin substrates but there is no opening of the beta-lactam ring observed. Strongly inhibited by eserin, NaF, HgCl2, SDS and Triton X-100. Esterase, not beta-lactamase activity of the enzyme. Optimum pH is 7.0. Optimum temperature is 43 degrees Celsius. Directed evolutionary mutagenesis has created an enzyme with 40-fold higher stability in organic solvents. It contains the following changes: Leu-8, Ser-132, Arg-134, Cys-155, Gly-251, Val-311 and Lys-316 and could have applications in antibiotic synthesis (PubMed:17137667). Belongs to the class-A beta-lactamase family.