ABSTRACT
Spores of the filamentous fungus Rhizopus oryzae were entrapped in macroporous poly(vinyl alcohol) cryogel (PVA-cryogel). To prepare immobilised biocatalyst capable of producing L(+)-lactic acid (LA), the fungus cells were cultivated inside the carrier beads. The growth parameters and metabolic activity of the suspended (free) and immobilised cells producing LA in a batch process were comparatively investigated. The immobilised cells possessed increased resistance to high concentrations of accumulated product and gave much higher yields of LA in the iterative working cycle than the free cells did. Detailed kinetic analysis of the changes in the intracellular adenosine triphosphate concentration, specific rate of growth, substrate consumption and LA production showed that the fungus cells entrapped in PVA-cryogel are more attractive for biotechnological applications compared to the free cells.
