P. F. Greenfield

Coral Reefs Under Rapid Climate Change and Ocean Acidification

Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2°C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef-associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled-up management intervention and decisive action on global emissions are required if the loss of coral-dominated ecosystems is to be avoided.

Effect of carbon dioxide on yeast growth and fermentation

Inhibition of yeast function by ethanol and by high substrate concentrations is well recognized and, to a limited extent, quantified. The role of carbon dioxide in affecting yeast metabolism (particularly growth processes) is not clear although inhibition is generally found at moderate to high concentrations of the dissolved gas. A similar situation exists with other microorganisms and with other fermentation systems. An understanding of the role of carbon dioxide, and particularly of its inhibitory effects on enzyme action and membrane function, is required if the observed global inhibition of yeasts and other fermentation systems is to be partitioned to its appropriate causes.

Synthesis of anatase TiO2 supported on porous solids by chemical vapor deposition

Coating anatase TiO2 onto three different particle supports, activated carbon (AC), gamma -alumina (Al2O3) and silica gel (SiO2), by chemical vapor deposition (CVD) was studied. The effect of the CVD synthesis conditions on the loading rate of anatase TiO2 was investigated. It was found that introducing water vapor during CVD or adsorbing water before CVD was crucial to obtain anatase TiO2 on the surface of the particle supports. The evaporation temperature of precursor, deposition temperature in the reactor, flow rate of carrier gas, and the length of coating time were also important parameters to obtain more uniform and repeatable TiO2 coating. High inflow precursor concentration, high CVD reactor temperature and long coating time tended to cause block problem. Coating TiO2 onto small particles by CVD involved both chemical vapor deposition and particle deposition. It was believed that the latter was the reason for the block problem. In addition, the mechanism of CVD process in this study included two parts, pyrolysis and hydrolysis, and one of them was dominant in the CVD process under different synthesis route. Among the three types of materials, silica gel, with higher surface hydroxyl groups and macropore surface area, was found to be the most efficient support in terms of both anatase TiO2 coating and photocatalytic reaction

Dynamic modelling of a single-stage high-rate anaerobic reactor—I. Model derivation

A structured model of the anaerobic degradation process, incorporating dynamic equations for the description of a single-stage high-rate anaerobic reactor was validated by comparing its predictions with previously reported experimental data. This data came from two different laboratory-scale reactors and a pilot-scale reactor. With the manipulation of key model parameters, significant improvements in the fit of the model to the experimental data were possible. This study was able to show that the production and consumption of lactic acid, and the moderate hydrogen inhibition and regulation of the acidic products of the acidogenic bacteria, can be successfully modelled. Insufficient experimental data were available to draw conclusions as to the importance of product inhibition in anaerobic reactors, while the need to use deterministic models to account for pH inhibition highlighted the need to develop mechanistic models able to reflect the pH inhibited behaviour of the major anaerobic groups present in the ecosystem.

Utilisation, treatment and disposal of distillery wastewater

Abstract A comprehensive review of the methods for handling distillery wastewater is presented. Wastestreams from such plants are generally high in both dissolved organic and inorganic materials, posing particular treatment difficulties; the volume to be treated per volume of ethanol produced is also high. With the increasing interest in ethanol from biomass as a liquid fuel alternative, appropriate treatment of this wastestream will become essential. Although a number of treatment schemes are being used or have been proposed, there is no widespread agreement on the most suitable methods. These discrepancies reflect in part the wide variations in the characteristics of distillery wastewater—in turn these are the result of different raw materials, agricultural practices, and distillery operating techniques. In many studies to date detailed analyses of the wastewater are not provided and this imposes limits on the relevance of the results to a particular situation. When the opportunity cost of land is low, direct irrigation often proves most cost effective. Direct utilisation or by-product recovery offers the attraction of a return on capital and in some cases, particularly for grain distilleries, is essential to the profitable operation of the plant as a whole. Anaerobic treatment followed by aerobic polishing of the supernatant is attractive from the consideration of providing energy for the distillation stage. Depending on the wastewater characteristics, however, the reliability of the system is highly variable. From a technical viewpoint, the most reliable system appears to be evaporation and incineration with the ash being returned to the soil as a fertiliser. The increased interest in ethanol production should lead to a clarification of this position over the next few years. Cost data is not reported partly because the available information is scarce and, in some cases, no longer of relevance.

Low multiplicity infection of insect cells with a recombinant baculovirus: The cell yield concept

In vitro infection of insect cells with baculoviruses is increasingly considered a viable means for the production of biopesticides, recombinant veterinary vaccines, and other recombinant products. Batch fermentation processes traditionally employ intermediate to high multiplicities of infection necessitating two parallel scale‐up processes—one for cells and one for virus. In this study, we consider the use of multiplicities of infection as low as 0.0001 plaque‐forming units per cell, a virus level low enough to enable infection of even large reactors (e.g., 10 m3) directly from a frozen stock. Using low multiplicities in the Sf9/β‐gal–AcNPV system, recombinant protein titers comparable with the maximum titer observed in high multiplicity infections were achieved. Cultures yielding the maximum titer were characterized by reaching a maximum cell density between 3 and 4 × 109 cell L−1. This optimal cell yield did not depend on the multiplicity of infection, supporting the existing view that batch cultures are limited by availability of substrate. Up to a certain cell density, product titer will increase almost linearly with availability of biocatalyst, that is, cells. Beyond this point any further cell formation comes at the expense of final product titer. Low multiplicity infections were found not to cause any significant dispersion of the protein production process. Hence, product stability is not a major issue of concern using low multiplicities of infection. The sensitivity to initial conditions and disturbances, however, remains an issue of concern for the commercial use of low multiplicity infections.

Hybridoma growth limitations: The roles of energy metabolism and ammonia production

Energy metabolism and the production of ammonia in hybridoma cell culture and its inhibitory effects on cell growth are reviewed. The interactive roles of glucose and glutamine metabolism affect the rate of production of ammonia, and these interactions are described. It is shown that growth inhibition usually occurs between 2–4 mM ammonia although some cell lines have been shown to adapt to much higher concentrations, particularly in continuous culture. In batch cultures cell growth appears to be particularly susceptible to increased ammonia concentrations during the early stages of growth; ammonia increased the rate of cell death in the late stage of batch growth. The specific productivity of monoclonal antibodies is much less sensitive to the released ammonia than is growth; lower volumetric productivities relate to the lower viable cell concentrations which are achieved at the high ammonia levels. Techniques to prevent ammonia accumulation or remove ammonia selectively have been relatively unsuccessful to date.

Towards a fourth generation R&D management model-research networks in knowledge management

Research and development (R&D) management is increasingly about managing knowledge rather than simply managing its generation. Better management of knowledge is a key success factor for industry competitiveness through continuous innovation. R&D management processes developed in the past, which can be described as the first, second, or third generation models, deal with concepts, techniques and tools for managing research as an investment portfolio of the firm. These models focus on the creation and diffusion of knowledge internal to the firm. Management of R&D is also about managing knowledge external to the firm and it involves the management of complementary skills, technological dependencies, and knowledge transfers across research links. This paper addresses the concept of research management as the generation of intellectual capital, which drives future businesses and new products. It examines, as a case study, research management practices employed by biotechnology and pharmaceutical research groups in industries and universities and outlines a fourth generation approach to managing research.

In situ respirometry in an SBR treating wastewater with high phenol concentrations

This investigation demonstrates that in situ respirometry can be an effective tool to manage the removal of an inhibitory substrate in a sequencing batch reactor (SBR). Data collected enabled the determination of an optimum operating cycle for the effective treatment of a synthetic wastewater containing up to 1300 mg/l phenol as the sole carbon source. Oxygen uptake rates were monitored in situ at various stages of a bench-scale sequencing batch reactor. Respirometry was used as an indicator of microbial activity and substrate utilisation. Although the profile of the Oxygen Uptake Rate (OUR) followed closely that of phenol substrate removal, any correlation between the OUR and soluble residual substrate COD was specific to that system. A high OUR Value corresponded to the feed period; at the end of the cycle, when the substrate was depleted, the OUR Value was low. A plot of OUR values provided a good indication of the biological activity in the reactior. It was possible to select an optimum operating cycle using the oxygen uptake rates as an indicator for the removal of phenol. The initial operating cycle was 24 h, which included phases for filling, reaction, quiescence and decanting. From oxygen uptake rates and corresponding soluble COD values of the remaining substrate, data showed that the 4 h operating cycle was able to achieve similar substrate removal efficiencies. At a SBR loading rate of 3.12 kg phenol m(-3)d(-1), removal of 97% COD was achieved at the end of the cycle. The reactor was operated at a SRT of 4-27 days with biomass concentrations ranging from 3500-3900 mg/l

A technique for determining the shear sensitivity of mammalian cells in suspension culture

A murine hybridoma was subjected to constant shear rates within a couette viscometer for periods of 15 hours. Shear effects on cells were determined by live cell counts, cell viability and by the release of the cytoplasmic enzyme lactate dehydrogenase into the culture medium. Cell damage was observed at a shear rate of 870s-1 but not at 420s-1.