Method for screening enzyme activity

Abstract

Disclosed is a process for identifying clones having a specified enzyme activity by screening for the specified enzyme activity in a library of clones prepared by (i) selectively isolating target nucleic acid from nucleic acid derived from at least one microorganism, by use of at least one polynucleotide probe comprising at least a portion of a nucleic acid sequence encoding an enzyme having the specified enzyme activity; and (ii) transforming a host with isolated target nucleic acid to produce a library of clones which are screened for the specified enzyme activity.

What is claimed is:  
     
         1 . A method for making a library containing a plurality of clones, each clone containing a cDNA or genomic DNA fragment obtained from a population of uncultivated microorganisms.  
     
     
         2 . A method for identifying a desired bioactivity or biomolecule comprising: 
 (a) producing one or more expression libraries derived from nucleic acid directly isolated from the environment;    (b) combining a cell-free extract from the expression library or libraries with crude or partially purified extracts, or pure proteins from a metabolically rich cell line to form an extract mixture free from the library and cell line cells; and    (c) screening said mixture to identify an activity or molecule produced by the extract mixture.    
     
     
         3 . A method for identifying a desired bioactivity or biomolecule comprising: 
 (a) producing one or more expression libraries containing clones having nucleic acid inserts derived from nucleic acid directly isolated from the environment;    (b) transferring said clones into a metabolically rich cell line; and    (c) screening said cell line to identify clones having a bioactivity or biomolecule of interest.