Editorial overview: Biotechnology and bioprocess engineering Eleftherios Terry Papoutsakis and Nigel J Titchener-Hooker Current Opinion in Chemical Engineering 2014, 6:iv–vi For a complete overview see the Issue Available online 4th November 2014 http://dx.doi.org/10.1016/j.coche.2014.10.002 2211-3398/# 2014 Elsevier Ltd. All right reserved. The importance of metabolic engineering in the development of new bioprocesses or improved process is now firmly established since the early, pioneering days of the 1990s. The field has experienced a huge trans- formation as a result of genome sequencing and the development of genome-scale tools. The most recent transformation of the field encom- passes not only synthetic biology, but also molecular-level computational modeling and analysis, all of which have reached levels of sophistication unimaginable even a few years ago. In this collection there are four contributions that span the whole spectrum of activities of chemical engineering as related to metabolic-engineering based strain and product development. The contribution of Wang et al., takes an integrative approach in reviewing the recent development in the industrial butanol fermentation (otherwise known as ABE (acetone–butanol–ethanol) fermentation). It examines the whole spectrum of critical aspects that affect process viability, from strain engineering to downstream process integration, and emphasizes recent developments that could lead to an integrative process based on lignocellulosic biomass, a dream many have kept alive over the last 15–20 years. Prof. Yang has been at the forefront of many of these developments, and his review will be widely read as foundational for future developments. Peabody et al. have been working over the last 8 or so years on several aspects of genome engineering with emphasis on tools for developing complex microbial traits that are not necessarily dependent on metabolic pathways. One of these traits is tolerance to toxic metabolites or substrates that most cells are exposed to in the industrial setting. Understanding chemical toxicity of microbial systems and developing tolerance are two very complex problems, both dependent on a multitude of cellular programs and a many genes, in ways that still largely elude us. As discussed in the review article, progress made in the last few years raises hope that the development of strong tolerance will be finally become a practical reality. This review paper will be a good compass for anyone interested in the developments in this field. The contribution by Senger et al. reviews recent work on an emerging specialized area of genome-scale models (GSMs), namely those of anae- robes, including those of non-pathogenic clostridia, methanogens, and Geobacter, as well as those that aim to capture the metabolism of microbial consortia. These GSMs are quite distinct from those of aerobes, and in this sense this review article draws attention to an area that Eleftherios Terry Papoutsakis 1,2 1 Department of Chemical & Biomolecular Engineering, University of Delaware, Delaware Biotechnology Institute, 15 Innovation Way, Newark, DE 19711, USA 2 Department of Biological Sciences, University of Delaware, Delaware Biotechnology Institute, 15 Innovation Way, Newark, DE 19711, USA e-mail: epaps@udel.edu Eleftherios Terry Papoutsakis received his Diploma in Chemical Engineering from the National Technical University of Athens, Greece, and his MS and PhD from Purdue University, IN (USA). Following the completion of his PhD, he started his academic career at Rice University in Houston, Texas as an Assistant Professor, and in 1987 moved to Northwestern University, Evanston, IL, USA, where he was promoted to Full Professor and eventually appointed to a Walter P. Murphy Chair Professorship. In 2007, he moved to the University of Delaware as Eugene DuPont Chair Professor. Papoutsakis’ group is active and has made important contributions in the areas of clostridia genetics and metabolic engineering; animal-cell biotechnology; & stem-cell bioengineering with emphasis in hematopoietic stem-cell engineering. He is widely recognized as a leader in metabolic engineering of the industrial anaerobes clostridia as well as in genome engineering. His lab is interested in developing strains of industrial importance in the biorenewable arena, with emphasis on complex, non- pathway dependent traits. Nigel J Titchener-Hooker Department of Biochemical Engineering and EPSRC Centre for Innovative Manufacturing of Emerging Macromolecular Therapies, University College London, Gordon Street, London WC1E 0AH, UK e-mail: nigelth@ucl.ac.uk Nigel Titchener-Hooker gained a 1st class degree in Chemical Engineering from UMIST Available online at www.sciencedirect.com ScienceDirect Current Opinion in Chemical Engineering 2014, 6:iv–vi www.sciencedirect.com