 Because of the abundance of genes in the human microbiome (200 times the amount in the human genome) many enzymes and/or their mechanisms have not been characterized.Two of Balskus' aims is therefore to elucidate the mechanisms by which these microbial enzymes perform chemistry and to identify the specific microbes, genes, and enzymes responsible for key metabolic activities.A third aim is to develop biocompatible methods to control, manipulate, and study microbial chemistry in situ.