The optimal pH and temperature, maximum specific degradation rate, half rate constant and flocculation rate for the hybrid cell Foaz were measured in the reaction for the degradation of soybean processing wastewater (SPW) in this study. The optimal pH and temperature for Foaz in SPW were the same as those of its parental strains S accharomyces cerevisiae Y9407 and Rhodobacter sphaeroi des P9479, but the flocculation rate, the maximum specific degradation rate and the half rate constant for Foaz were higher than those of its parental strains. The results suggest that the characteristics of the inter2kingdom fusant Foaz constructed from the protoplast fusion between the eukaryote cell yeast S. cerevisiae and the prokaryote cell photosynthetic bacteria R. sphaeroi des may favor degrading organic pollutant in SPW and removing biomass from the effluent.

The fundamental differentiation of toxicity is between reactive and nonreactive toxicity. Reactive toxicity is associated with a specific mechanism for the reaction with an enzyme or inhibition of a metabolic pathway, and nonreactive toxicity is related directly to the quantity of toxicant acting upon the cell. The quantitative structure-activity relationships (QSARs) have been successfully used in the nonreactive toxicity, such as prediction of the toxicity of nonreactive compounds based on their solubility in the lipids of organisms (Mackay 1988; Yoshioka et al. 1986). The elements of molecular structure that are most closely related to nonreactive toxicity are those that describe the partitioning of the toxicant into the organism (Blume and Speece 1990), while QSARs for the reactive toxicity are less common in the environmental toxicology literature. With the recent increase in the use of synthetic substituted benzenes as industrial chemicals, the accurate analysis of the effect of reactive toxic chemicals has become recognized with QSAR (Nendza et al. 1988). For this purpose, we selected the fish (Carassias auratus) as the test organism, measured the acute toxicity of 50% lethal concentration (LC50) of the chemicals and the adenosine triphosphate (ATP) content of the liver cells for the organism. These determined the relationships of the acute toxicity of some substituted benzenes with their physicochemical structural parameters. The effects on the ATP content was also compared to predict biological reactivities of the chemicals, so as to find some clues to explain the mode of mechanism of the toxicity.

There were 6 target DNA fragments of the three parental strains existing in the cell of genetically engineered microorganism strain (GEMs) Fhhh measured in this research by polymerase chain reaction (PCR). And Fhhh was a fusant GEMs of the three parental strains Phanerochaete chrysosporium; Saccharomyces cerevisiae and the native bacterium YZ1, and they have the 6 target DNA fragments of mnp1, mnp2、lip1、lip2,FLO1 and 16SrDNA respectively. The results showed that Fhhh contained the total 6 target DNA fragments with the molecular genetic stability. Meanwhile the PCR productions of the three parental strains only had their target DNA fragments individually and were different from each other. It may illustrate that the technique of the inter-kingdom protoplast fusion through the process of intercellular gene recombination can be used as a reliable bioengineering technique to construct the specific stain for the pollution control.