Perspective approaches with the use of biocatalysts for improving the processes of polyaspartic acid production from oil benzene fraction after oxidative desulfurization

Abstract

Two promising approaches to greening the production of polyaspartic acid were demonstrated. The mixture of dibenzothiophene-sulfone (DBTO2) and benzothiophene-sulfone (BTO2) as potential products of oxidative desulfurization of petroleum products during benezene production was used for the first time for biocatalytic recovery to sulphide ions. The process was carrying out at the presence of biogenic H2 produced during cultivation of anaerobic cells Clostridium acetobutylicum and Desulfovibrio vulgaris. It was shown that after 240 h conversion of sulfur, contained in mixture of 0.03 mM DBTO2 and 0.03 mM BTO2 was as minimum 32.2±2.1% using ethanol as extractant. This approach can be recommended for intensification and ecologization of oxidative desulfurization of various petroleum products. For production of stereoregular polymer of polyaspartic acid the correction of native process of chemical synthesis was done by addition of biocatalytic stage during conversion of ammonium fumarate into aspartic acid. The obtained immobilized biocatalyst on a base of E. coli BL-21 cell included into poly(vinyl) alcohol cryogel make it possible to accumulate 129.1±3.4 g/L aspartic acid during biotransformation of ammonium fumarate.