ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Bioproduction of phenylacetic acid in airlift reactor by immobilized Gluconobacter oxydans

Mário Mihaľ, Ivan Červeňanský, Jozef Markoš, and Martin Rebroš

Faculty of Chemical and Food Technology, Institute of Chemical and Environmental Engineering, Slovak University of Technology, Bratislava, Slovakia

E-mail: jozef.markos@stuba.sk

Abstract: Phenylacetic acid can be produced from 2-phenylethanol by selective oxidation. This process can be performed using Gluconobacter oxydans immobilized in LentiKats^®, polyvinyl alcohol particles with lenticular shape. The biotransformation took place at non-growth conditions in an airlift bioreactor. The goal of this work was to examine the impact of the particles on the hydrodynamics and volumetric mass transfer coefficient for oxygen in the airlift reactor and to describe the activity of the immobilized biomass in such systems. For this purpose, the influence of aeration and 2-phenylethanol concentration on the activity of biomass was examined. Also, the effects of long-term storage of immobilized biomass, long duration of fermentation and repeated use of biomass on the rate of phenylacetic acid production were tested. The results were compared with the phenylacetic acid production by free cells of Gluconobacter oxydans. The results show that aeration of the airlift reactor has only a minor effect on the phenylacetic acid production for immobilized biomass but a significant one for free cells; however, the impact of 2-phenylethanol concentration on the production was notable for both forms of biocatalyst depending on the biomass concentration. Production ability of free cells was ten times higher than that of immobilized cells, but the production time was only a quarter of that of immobilized cells.

Keywords: Phenylacetic acid; Gluconobacter oxydans; Immobilization; Airlift reactor; Biotransformation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-016-0062-y

Chemical Papers 71 (1) 103–118 (2017)