Energy, heat, flavours and aromas of Microbial Biotechnology

The second issue of Molecular Biotechnology offers us a variety of interesting topics ranging from basic science to industrial applications. The current strength of the field and this new journal come into conjunction when we verify how close new genomic tools and commonly used products really are. Indeed, it would not be outrageous to say that we can taste the flavours and sense the aroma of microbial biotechnology while cheering for systems biology. This new issue opens with a wonderfully tasting review entitled ‘Wine genomics’ (Siezen, 2008) who takes us from grape diversity to wine bacteria and yeast genomics. The article is a real overview on winemaking in which ancient traditions and modern systems biology walk hand in hand. It might be far too daring to say that all the richness of wine resides in its microbes; we hope that wooden hand-made tonels, the temperature of the caves and other factors will still have a say in maintaining wine diversity, as well as its final flavour, texture and scent, and that wine metagenomics will not reveal all the secrets behind a good glass wine. We propose a toast to Roland Siezen’s opening genomic update! Tino Krell introduces us to the field of microcalorimetry, an increasingly demanded technique in biotechnology. Have you ever considered that measuring ‘heat’ could be at the core of quality control in a pharmaceutical company? This interesting issue and other matters are elegantly tackled by Dr Krell (2008) in the second issue of Microbial Biotechnology. The article digs into the potential of monitoring heat changes using a variety of calorimetric techniques. Isothermal titration calorimetry (ITC) is at the heart of precise determinations of interactions of certain proteins with a range of substrates, other proteins or target DNAs (Holdgate, 2001; Lacal et al., 2006; Busch et al., 2007). Krell discusses how protein stability can hamper the development of a new product and how microcalorimetry can help to identify best excipients or improved proteins upon genetic engineering. Another extremely relevant issue is the use of ‘heat’ techniques in strategies designed to overcome drug resistance problem or to develop adaptive inhibitors versus HlV protease variants (Ohtaka et al., 2002). Differential scanning calorimetry can become a key technique in the establishment of free-drying conditions for chemicals and maybe live cells. There is an ever-growing interest on the biosynthesis of poly-hydroxyalkanoates (PHAs) because of their potential applications as ‘bioplastics’. However, some aspects of their biosynthesis still remain obscure. Systems biology has been used by Arias and colleagues (2008) in their study about the substrate specificity of poly-3hydroxyalkanoate synthases in Pseudomonas putida U. The article has the added-value of being an impeccable study based on mutant phenotypic assays that have allowed the authors to demonstrate that two high-identity PHA polymerases (PhaC1 and PhaC2) work with different substrates in this microbe. The authors present an exhaustive in silico analysis of these proteins and postulate that the different catalytic activities could be based on subtle structural/functional differences that may seem of no significance at first glance. Biosensors are one of the classical tools that have seen the light with the advancement of gene fusion technology. The full potential of biological systems to detect ‘signals’ is still pending of refinement and further developments. In this issue of Microbial Biotechnology there are two fascinating articles dealing with biosensors. The review by Elad and colleagues (2008) presents a futuristic approach to revolutionary whole-cell array technology. The article offers a state-of-the-art vision of the field, including genetic engineering of biological components, technologies for live depositions, cell viability, etc., as well as some of the current transduction methodologies to decipher the mathematical output. And yet, this review goes beyond all of that and identifies the needs of this technique to achieve longer-lasting life for whole cells and chips. No doubt that with the expected scientific *For correspondence. E-mail [email protected]; Tel. (+34) 958 750980; Fax (+34) 958 750980. Microbial Biotechnology (2008) 1(3), 199–201 doi:10.1111/j.1751-7915.2008.00036.x