In this issue: Biotechnology Journal 12/2010

Human diseases in C. elegans Markaki and Tavernarakis , et al., Biotechnol. J. 2010, 5, 1261–1276 The worm Caenorhabditis elegans is one of the most versatile and powerful model organisms. Already in the early 1960's it was introduced by Sydney Brenner to study development and neurobiology. It is a free‐living, non‐parasitic nematode, 1 mm in length, with a life cycle of 3.5 days at 20°C and can be cultured at large numbers. Its completely sequenced genome shares extensive homology with that of mammals. Research in C. elegans is instrumental for the elucidation of molecular pathways implicated in many human diseases that are very well conserved. Authors from Crete, Greece review C. elegant disease models and recent relevant findings including Alzheimer's, Parkinson's and Huntington's disease, Amyotrophic lateral sclerosis (ALS), stroke and cancer that can lead to identification of new therapeutic targets. “Mix and match” gene clusters Fischbach and Voigt , et al., Biotechnol. J. 2010, 5, 1277–1296 Bacteria obtain nutrients and energy from diverse sources, synthesize complex molecules, and react to their environment. These complex phenotypes require the coordinated action of multiple genes, which are often organized as gene clusters. They sometimes contain all of the genes sufficient for a particular function. Engineering of these clusters is difficult, because of their complex regulation. Advances in synthetic biology will enable large‐scale bottom‐up engineering of gene clusters to optimize their functions, wake up cryptic clusters, or to transfer them between organisms. Authors from the University of California, San Francisco, report recent work on a number of clusters whose functions are relevant to biotechnology. Understanding and manipulating gene clusters will move towards an era of genome engineering, where multiple functions can be “mixed‐and‐matched” to create a designer organism. Biofuel bioengineering Mainguet and Liao , et al., Biotechnol. J. 2010, 5, 1297–1308 Since fossil fuel availability is decreasing, biotechnological production of fuels and chemicals is the potential alternative to fossil sources. Higher alcohols with three carbon chain and longer, i.e. propanols, butanols and pentanols (from C3 to C5), are useful substitutes for gasoline because of their high energy density and low hygroscopicity. In addition, they are important feedstocks for the synthesis of other chemicals. Some Clostridia species are known to naturally ferment sugars to isopropanol and 1‐butanol. However, other C3 to C5 alcohols are not produced in large quantities by natural microorganisms. Here, a current overview of different metabolic engineering strategies using the ubiquitous keto acid biosynthetic pathways is given by the authors from University of California, Los Angeles.