Enzymatic process using immobilized microbial cells

Abstract

Microbial cells having active enzymes associated therewith are subjected to flocculation conditions to produce a flocculated whole cell aggregate that .Iadd.is subsequently dried. The dried aggregate .Iaddend.is useful in effecting enzyme-catalyzed chemical transformations. Substrates are brought into contact with the flocculated cell aggregates where they undergo chemical transformations in the presence of active enzymes associated with the cells.

What is claimed is: 
     
       1. A process for effecting an enzyme-catalyzed transformation of a substrate in the presence of flocculated whole microbial cells having associated therewith active quantities of said enzyme which comprises contacting said substrate with an aggregate comprising said cells and a polyelectrolyte flocculating agent under conditions suitable for effecting said enzyme-catalyzed transformation, .Iadd.said aggregate having been dried prior to use in said enzyme-catalyzed transformation, .Iaddend.and recovering transformed substrate. 
     
     
       2. A process according to claim 1 in which said flocculating agent is selected from the group consisting of anionic polyelectrolytes and cationic polyelectrolytes. 
     
     
       3. A process according to claim 1 in which said aggregate comprises whole microbial cells, a flocculating agent and a filter aid. .[.4. A process according to claim 1 in which said aggregate is dried prior to use in said enzyme-catalyzed transformation..]. .[.5. A process according to claim 1 in which said aggregate is frozen prior to use in said enzyme-catalyzed 
     
     
        transformation..]. 6. In a process for converting glucose to fructose in the presence of whole microbial cells containing active quantities of a glucose-isomerizing enzyme, the improvement which comprises contacting a glucose-containing liquor with an aggregate possessing glucose-isomerizing enzyme activity and comprising said cells flocculated with a polyelectrolyte flocculating agent.Iadd., said aggregate having been dried 
     
     
        prior to use in said process.Iaddend.. 7. A process according to claim 6 in which said cells are derived from a microorganism belonging to the genus Arthrobacter. .[.8. A process according to claim 7 in which said 
     
     
        aggregate is dried prior to use in said process..]. 9. A process according to claim 6 in which said cells are derived from a microorganism belonging 
     
     
        to the genus Streptomyces. 10. A continuous process for converting glucose to fructose in the presence of polyelectrolyte-flocculated whole microbial cells containing active quantities of a glucose-isomerizing enzyme.Iadd., said polyelectrolyte-flocculated whole microbial cells having been dried prior to use in said process, .Iaddend.which comprises passing a glucose-containing liquor through a bed of said cells to convert a portion of the glucose in said liquor to fructose and recovering an effluent 
     
     
        liquor containing glucose and fructose. 11. A process according to claim 10 in which said cells are derived from a microorganism belonging to the 
     
     
        genus Arthrobacter. 12. A process according to claim 11 in which said .[.cells are dried prior to use, said.]. bed is maintained at a temperature between 50° and 90° C., said glucose-containing liquor has a pH of about 6 to 10 and the portion of glucose converted to 
     
     
        fructose is between 1 and 50 percent. 13. A process according to claim 10 in which said cells are derived from a microorganism belonging to the 
     
     
        genus Streptomyces. 14. A process for converting glucose to fructose which comprises contacting under conditions suitable for glucose isomerization an aqueous glucose-containing solution with flocculated microbial cells having active quantities of a glucose-isomerizing enzyme associated therewith to effect isomerization of a portion of said glucose, wherein said flocculated cells are used in the form of an aggregate resulting from prior treatment of unflocculated cells with a polyelectrolyte flocculating agent with said flocculating agent including a cationic polyelectrolyte 
     
     
        and said aggregate being dried prior to use. 15. A process according to claim 14 in which said aggregate is maintained at a temperature between 50° and 90° C., said glucose-containing solution has a pH of about 6 to 10 and said cells are derived from a microoganism belonging to 
     
     
        the genus Arthrobacter. 16. A process according to claim 14 in which said cells are derived from a microorganism belonging to the genus Streptomyces.