Metabolomics and Metabolic Engineering
In, we described the methods for the study of genome and proteome we also discussed the progress in the field  of genomics and proteomics in animal systems and plant systems respectively. It was shown in these chapters that the systematic analysis of gene function is much more difficult that genome sequencing that precedes the study of gene function. While proteome analysis gives information of all proteins synsthesized and available in a cell in time and space, there are two other approaches used for functional genomics, one involving the study of all mRNAs (transcriptome) in a cell/tissue and described as transcriptomics, and the other involving the study of all metabolites are examined under different physiological, developmental and pathological states of the cell, tissue or organism.

For instance, in budding yeast, there are ~600 low-molecular weight intermediates (metabolites) as against ~6000 protein encoding genes. Therefore, there is no simple relationship between metabolites and genes in the way that there is for mRNAs and proteins. However, the variation among metabolites from different organisms is enormous, so that according to some estimates, as many as 200,000 metabolites may occur in the whole plant kingdom.

Metabolomics also assumed significance at the beginning of the present century, due to an emphasis on integrated genomics, which involves integration of the data resulting from analyses of genome, proteome, transcriptome and metabolome.

A candidate gene that might encode citramalate biosynthetic enzyme was also identified. Such approaches will prove to be of immense biotechnology applications in future in the field of metabolic engineering. More information on matebolomics research, and on the progress already made in this area of research is available at Metabolomics World Wide Web site (www.metabolomics.nl).