Metagenomic techniques

Marine natural products of the pederin class (mycalamides, onnamides, and theopederins) isolated from sponges are mixed biogenesis metabolites of polyketide synthase and nonribosomal synthase (1). In fact, biosynthesis gene clusters of this class have been cloned recently using metagenomic techniques from the marine sponge Theonella swinhoei (6). These compounds are... 

But there is still another point, not yet discussed but with considerable potential, which may also impact eventually on technical asymmetric catalysis. Even though biocatalysts are efficient, active, and selective, there still remains one big disadvantage At present, there is not yet an appropriate enzyme known or available for every given chemical reaction. It is estimated that about 25 000 enzymes exist in Nature, and 90% of these have still to be discovered [28, 29]. New biocatalysts are made available nowadays not only from screening known organism but also via screening metagenomic libraries and directed evolution techniques [30]. 

There are a number of strategies for screening the biocatalysts. These include the use and development of synthetic substrates, fermentation techniques, metagenomic methods, and genetic databases. 

The third fingerprinting technique, amplified ribosomal DNA restriction analysis (ARDRA), employs multiple restriction enzymes to cut 16S rRNA amplicons amplified directly from metagenomic DNA extracted from an... 

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