Metagenome approach

In the metagenomic approach, DNA was directly extracted from uncultured samples followed by cloning and expression [3]. For example, by combination of directed evolution with the metagenome approach, an a-amylase mutant with optimal activity at pH 4.5 and optimal thermostability at 105 °C was discovered for starch liquefaction and EtOH production [4]. 

Although, the true metagenomic approach has yet to prove its usefulness in discovering novel secondary metabolites,67 there is still the opportunity to... 

DNA samples is possible with these massively parallel sequencing systems. It is clear that the metagenomic approach is becoming a major tool for understanding the genetic diversity of our environment, which will identity a vast array of new genes and their role in the environment. 

Unlocking Environmental DNA Derived Gene Clusters Using a Metagenomics Approach... 

Metagenomic approaches have been used to study metabolites produced by bacterial symbionts of marine animals, insects, and nematodes. The literature now provides several examples where DNA-based strategies targeting specific genetic loci have enabled the isolation and cloning of biosynthetic gene clusters encoding for the biosynthesis of important symbiont-associated molecules such as pederin, onn amide A, bryostatins, trunkamide, theopalauamide, and the patellamides. These studies are the focus of another chapter in this series and therefore will not be discussed here. 

Wolcott, R. D., Gontcharova, V., Sun, Y., and Down, S. E. (2009). Evaluation of the bacterial diversity among and within individual venous leg ulcers using bacterial tag-encoded FLX and titanium amplicon pyrosequencing and metagenomic approaches. BMC Microbiol. 9, 226. 

Recent advances in recombinant DNA technology, high-throughput technologies, genomics and proteomics, have fuelled the development of new biocatalysts and biocatalytic processes. In particular, site directed mutagenesis, directed evolution or metagenome approach are very valuable tools to enhance lipase properties. 

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