Biotechnology, in terms of exploitation of catalytic activities for industrial applications, is increasingly recognized as one of the pillars of the knowledge-based economy that we are heading for. Comprehensive knowledge of enzymology should be of practical importance for effective intervention on whole cell processes and enzymatic networks. Over the last decade metagenome-based technologies have been developed to take us farther and deeper into the enzyme universe from uncultivable microbes. This sophisticated platform, which identifies new enzymes from vast genetic pools available, and assesses their potential for novel chemical applications, should be increasingly important in the discovery of advanced biotechnological resources. (c) 2007 Society of Chemical Industry.