Trends in biotechnology

Solar-powered factories for new vaccines and antibiotics.

Publication Date: 2010 Mar 5 PMID: 20207435
Authors: Bock, R. - Warzecha, H.
Journal: Trends Biotechnol

Chloroplasts, the green differentiation form of a group of plant cell organelles called plastids, are the sites of photosynthesis, the main energy source for life on Earth. The small circular genome of the plastid has become increasingly amenable to genetic modification, providing biotechnologists with an attractive site for the accommodation of foreign genes. In recent years, the development of optimized expression strategies has given a huge boost to the exploitation of chloroplasts in molecular farming. Exciting progress has been made with the chloroplast-based production of two particularly important classes of pharmaceuticals: vaccines and antibiotics. Extraordinarily high expression levels and the prospects of developing edible biopharmaceuticals make transgenic chloroplasts a promising platform for the production of next-generation vaccines and antimicrobials.

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Biological hydrogen production: prospectives and challenges.

Publication Date: 2010 Feb 26 PMID: 20189666
Authors: Lee, H. S. - Vermaas, W. F. - Rittmann, B. E.
Journal: Trends Biotechnol

Hydrogen gas provides exceptional value as an energy carrier and industrial feedstock, but currently is produced entirely by reforming fossil fuels. Biological hydrogen production (BioH(2)), which offers the possibility of being renewable and carbon neutral, can be achieved by photosynthesis, fermentation, and microbial electrolysis cells. This review introduces the principles, advantages and challenges of each approach to BioH(2). Photosynthetic BioH(2) is the ultimate renewable source, since it directly uses inexhaustible resources: sunlight energy and electrons from H(2)O. However, it presents major technical challenges, particularly due to oxygen sensitivity. Fermentative BioH(2) offers a high production rate, but poor conversion efficiency from the organic substrate to H(2). The microbial electrolysis cell can achieve high conversion efficiency, but is an emerging technology.

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Ultraslow microdialysis and microfiltration for in-line, on-line and off-line monitoring.

Publication Date: 2010 Mar PMID: 20079945
Authors: Korf, J. - Huinink, K. D. - Posthuma-Trumpie, G. A.
Journal: Trends Biotechnol

In medicine and biotechnology, close monitoring of molecular processes might assist to optimise therapeutic interventions and production of biochemicals, respectively. Here, we summarize the current status of two automatic and continuous sampling technologies, microdialysis and microfiltration, which facilitate both in vivo and in vitro monitoring of nearly any analyte, because they can be combined easily with many analytical techniques. Conventional microdialysis and microfiltration, which require collecting relatively large samples, are however often impractical and semi-quantitative; hence, we focus on ultraslow sampling to circumvent such limitations. Ultraslow microdialysis and microfiltration already have been used successfully for quantitative pharmacokinetics, glucose metabolism (e.g. of the brain), cytokines and proteomics (e.g. tumour secretomes), both in vivo and in vitro.

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Can tissue engineering concepts advance tumor biology research?

Publication Date: 2010 Mar PMID: 20056286
Authors: Hutmacher, D. W. - Loessner, D. - Rizzi, S. - Kaplan, D. L. - Mooney, D. J. - Clements, J. A.
Journal: Trends Biotechnol

Advances in tissue engineering have traditionally led to the design of scaffold- or matrix-based culture systems that better reflect the biological, physical and biochemical environment of the natural extracellular matrix. Although their clinical applications in regenerative medicine tend to receive most of the attention, it is obvious that other areas of biomedical research could be well served by the powerful tools that have already been developed in tissue engineering. In this article, we review the recent literature to demonstrate how tissue engineering platforms can enhance in vitro and in vivo models of tumorigenesis and thus hold great promise to contribute to future cancer research.

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Potential of siderophore-producing bacteria for improving heavy metal phytoextraction.

Publication Date: 2010 Mar PMID: 20044160
Authors: Rajkumar, M. - Ae, N. - Prasad, M. N. - Freitas, H.
Journal: Trends Biotechnol

Phytoremediation holds promise for in situ treatment of heavy metal contaminated soils. Recently, the benefits of combining siderophore-producing bacteria (SPB) with plants for metal removal from contaminated soils have been demonstrated. Metal-resistant SPB play an important role in the successful survival and growth of plants in contaminated soils by alleviating the metal toxicity and supplying the plant with nutrients, particularly iron. Furthermore, bacterial siderophores are able to bind metals other than iron and thus enhance their bioavailability in the rhizosphere of plants. Overall, an increase in plant growth and metal uptake will further enhance the effectiveness of phytoremediation processes. Here, we highlight the diversity and ecology of metal resistant SPB and discuss their potential role in phytoremediation of heavy metals.

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Engineering strategies to emulate the stem cell niche.

Publication Date: 2010 Mar PMID: 20042248
Authors: Vazin, T. - Schaffer, D. V.
Journal: Trends Biotechnol

The stem cell niche is an anatomical site that contains a reservoir of multipotent stem cells (SCs) that can maintain normal tissue, or replenish injured or aged cell populations, in response to mechanisms that regulate whether they should remain quiescent, undergo self-renewal, or differentiate. The choice among these hallmark SC behaviors is governed by intricate soluble and "solid phase" signals that are systemic or presented by the local niche cells. In this review, we discuss the progress achieved in understanding the mechanisms and principles that govern microenvironmental regulation of SC behavior, and focus on novel approaches that have been developed to synthesize this basic information to engineer creative strategies for harnessing and controlling SCs ex vivo and in vivo.

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Zinc finger nuclease technology heralds a new era in mammalian transgenesis.

Publication Date: 2010 Mar PMID: 20015561
Authors: Le Provost, F. - Lillico, S. - Passet, B. - Young, R. - Whitelaw, B. - Vilotte, J. L.
Journal: Trends Biotechnol

Non-mouse mammalian transgenesis is limited by its overall inefficiency and technical hurdles. Recent years have seen the emergence of two approaches that are applicable to most mammals. The first, based on lentivirus vectors, allows efficient generation of transgenic founders, most of them expressing the transgene. The second, recently applied to produce transgenic fish and mammals, takes advantage of the design of specific 'DNA-scissors' for efficient introduction of subtle mutations in potentially any region of the genome. This review focuses on the potential of this latter technology to modify mammalian genomes without the need to apply challenging and less-efficient protocols. We highlight the complementary aims of these new approaches and the as-yet-unexplored possibilities offered by their combination.

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Exploring microbial diversity for biotechnology: the way forward.

Publication Date: 2010 Mar PMID: 20005589
Authors: Singh, B. K.
Journal: Trends Biotechnol

Environmental microbes are immensely diverse and have numerous metabolic activities and products that could have industrial applications. However, >99% of environmental microbes cannot be cultured under current laboratory conditions, leaving their potential largely untapped. Metagenomic approaches have been used successfully in recent years to obtain novel microbial products from uncultured microorganisms. The activity, efficiency and stability of these novel enzymes can be further improved by the application of nanotechnology. Here, I highlight the approaches that can be used to obtain efficient microbial products from the uncultivable majority. I propose that a multidisciplinary approach combining different technologies including metagenomics and nanotechnology is the way forward for tapping the real potential of microbial metabolism for applications in biotechnology.

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