Fourth International Conference on High-Pressure Biosciences and Biotechnology

This biannual international conference on High-Pressure Biosciences and Biotechnology (HPBB) draws great attention from scientists interested in high pressure (HP)-related, basic biological sciences and applied industrial fields. The last meeting was attended by approximately 100 scientists.

In the area of basic biosciences, the effects of HP on water molecules, and the volume properties and compressibilities of proteins were the topics of several presentations. Karel Heremans from the Katholieke University (Leuvan, Belgium) presented new findings of cavities in proteins using positron annihilation lifetime spectroscopy. Kazuyuki Akasaka from the Kinki University (Higashi-Osaka City, Japan) has produced the first high-resolution structures of rare, high-energy conformers within the native state ensemble and has proposed specific outlines of their role in protein function using high-pressure nuclear magnetic resonance (NMR) techniques. Dmitri Davydov of The University of Texas Medical Branch (TX, USA). described his studies of P450 allosteric mechanisms using HP visible spectrometry. Roland Winter from the University of Dortmund (Germany) presented studies of lipid–protein interfaces using model systems to demonstrate how membrane proteins and lipid bilayers behave in response to HP.

Another very active area in HP bioscience research relates to deep-sea microorganisms. In the past few years, much effort has been placed on the sequencing of representative deep-sea organisms and the determination of their transcriptional profiles. Douglas Bartlett from the University of California, San Diego (CA, USA) and Scripps Institute of Oceanography (CA, USA) presented recent progress in the characterization and functional genomic studies of selected piezophile microbes based on information of the whole-genome sequences. Chiaki Kato talked about genomic findings from microbes obtained from the ocean’s deepest point, the Mariana Trench. Paul Yancey from the Whitman University (WA, USA) presented studies describing the roles of organic osmolytes for HP resistance of deep-sea organisms.

Food processing to inactive pathogens and extension in food shelf life remains the largest HP application in biotechnology. Volker Heinz from the Technical University (Berlin, Germany) and Carole Tonello from NC Hyperbaric, (Madrid, Spain) provided overviews on HP food processing in the world. There were 91 HP systems installed around the world in food processing plants in 2006. There are more than 150 different HP-processed food products sold in the market. Also presented were new capabilities in computer simulations of HP in adiabatic heating. New techniques were reported for inactivation, such as the use of excessive O₂ as a toxin in yeast inactivation. A call for an international standard for bacterial inactivation for food safety was discussed in a special session, including the identification of biomarkers that can be used to demonstrate bacterial death to replace the conventional viability assay and an establishment of a web-accessible inactivation database with HP parameters. Experimental HP microbe inactivation p and T profiles were developed by Heinz and his colleagues at the Technical University Berlin for a web-accessible database [1]. In HP pathogen inactivation, it was reported that a number of microbes are very difficult to kill, such as the Bacillus spp. For these pathogens, a combination of high p and T is now recommended, and is being studied in a number of laboratories. Bernhard Tauscher from Federal Research Centre for Nutrition and Food (Germany) discussed chemical reactions under HP that may influence food flavor.

One of the highlights of this conference was the many potential applications of HP in medical and biotechnological disciplines. For example, Jerson Silva from the Universidade Federal do Rio de Janeiro (Brazil) presented their results from HP studies in conformational features of amyloid proteins responsible for protein folding disorders ([PFDs]; associated with approximately 50 known common diseases). Their efforts are of great importance in pathological interpretation of these diseases and the development of new therapeutics. Toshi Fujisato presented their research on regenerative tissue for transplantation using cold HP processing. The porcine cartilage tissues, free of viable cells, were completely converted for transplantation after treatment with 980 MPa pressure at 4°C for 10 min, followed by washing for 2 weeks. Physiological response of muscle to HP was presented by Oliver Friedrich from the University of Heidelberg (Germany).

A new trend in HP biotechnology is in the application of cyclic pressure as opposed to static pressure. For example, Yamamoto’s group reported that 300 MPa pressurization repeated four times for a total of 40 min, inactivated more Escherichia coli O157:H7 in tomato juice than one cycle for 40 min Horst Ludwig from the University of Heidelberg demonstrated that high temperature used in combination with pressure cycling was more effective than static pressure for food pathogen inactivation, including prion and Bacillus. Phil Heindl from the Federal Research Centre for Nutrition and Food also reported that HP process at 800 MPa used in three 5 min cycles at 80°C can convert infectious prions to their noninfectious form, in opposition to the 120 min single pressure cycle suggested in the literature. He also reported that pressure has no effect on ‘matured’ amyloidal fibrils. Feng Tao from Pressure BioSciences (MA, USA) presented his company’s platform technology, namely Pressure Cycling Technology (PCT), for the extraction of biomolecules from challenging biological samples. Several PCT applications were described as critical to the success of genomic, proteomic and forensic analyses of several technologically challenging samples, such as adipose tissues, microbes, nematodes and bone fragments.

The HPBB conference has traditionally been a meeting for scientists who use HP as a tool in basic biosciences, food processing and biotechnology. HP is now being applied in broader areas, as evidenced by the growing numbers of diverse presentations at HPBB over recent years. Fueled with new and more powerful HP equipment, applications of HP continue to develop in genomic, proteomic, forensic and other new frontiers in biology and biotechnology. This rapid growth of the HP field is driven by the necessity of solving complicated biological and biotechnological equations by employing pressure as an additional parameter in addition to electrical field, temperature and chemicals that are commonly applied in laboratories and the biotechnology industry. Advances in HPBB will undoubtedly attract more attendees for the Fifth HPBB Conference to be held in San Diego (CA, USA) in 2008.