Exploring substrate specificities of a recombinant Rhizopus oryzae lipase in biodiesel synthesis

The alcoholysis of triolein was used to explore the specific features of a recombinant Rhizopus oryzae lipase (rROL) for biodiesel synthesis. For this purpose, different acylglycerols were compared as substrates in lipase-catalysed transesterification. rROL was shown to exhibit a higher specificity towards 1-monoolein than triolein compared to other R. oryzae lipases, being more than 4-fold more specific; in contrast, rROL did not accept 2-monoolein as substrate, concluding that it is highly 1,3-positional specific. Comparing ethanol and methanol as acyl-acceptors, it was observed that the latter caused more lipase inactivation. Regarding alcohols, it was also demonstrated that acyl migration occurred in moderate alcohol concentrations.