The possibility of using encapsulated nitrifiers for treatment of reject water coming from anaerobic digestion.

Large wastewater treatment plants have to deal not only with the influent wastewater, but also with the highly concentrated reject water coming from anaerobic digestion. The aim of this work was to verify the suitability of using encapsulated nitrifiers in polyvinyl alcohol carrier (so called Lentikats Biocatalyst) at temperatures between 5 and 30 °C. For laboratory nitrification batch tests synthetic wastewater with ammonia nitrogen (Namon) concentration 10-800 mg L(-1) was used. The system has been proved to operate at the temperature of 10 °C, but not at 5 °C. It was found that the highest specific nitrification rates were observed at 30 °C and with ammonia nitrogen concentrations above 250 mg L(-1), which means that separate treatment of reject water by using encapsulated biomass seems to be an effective tool for wastewater treatment plant optimization.

Mild hydrolysis of nitriles by Fusarium solani strain O1.

High levels of an aromatic nitrilase (about 37 microkat/L culture) were induced in Fusarium solani O1 after transfer of the mycelium from a rich medium into a medium with 20 mmol/L picolinonitrile. The mycelium was entrapped in lense-shaped particles consisting of a polyvinyl alcohol/polyethylene glycol copolymer (LentiKats). The cell-free extract was immobilized by hydrophobic binding onto a Butyl Sepharose column. The enzyme was useful for the mild hydrolysis of nicotinonitrile, isonicotinonitrile and benzonitrile.

High efficiency ethanol fermentation by entrapment of Zymomonas mobilis into LentiKats.

AIMS: To examine the potential of Zymomonas mobilis entrapped into polyvinylalcohol (PVA) lens-shaped immobilizates in batch and continuous ethanol production. METHODS AND RESULTS: Cells, free or immobilized in PVA hydrogel-based lens-shaped immobilizates - LentiKats, were cultivated on glucose medium in a 1 l bioreactor. In comparison with free cell cultivation, volumetric productivity of immobilized batch culture was nine times higher (43.6 g l(-1) h(-1)). The continuously operated system did not improve the efficiency (volumetric productivity of the immobilized cells 30.7 g l(-1) h(-1)). CONCLUSIONS: We demonstrated Z. mobilis capability, entrapped into LentiKats, in the cost-efficient batch system of ethanol production. SIGNIFICANCE AND IMPACT OF THE STUDY: The results reported here emphasize the potential of bacteria in combination with suitable fermentation technology in industrial scale. The innovation compared with traditional systems is characterized by excellent long-term stability, high volumetric productivity and other technological advantages.