Lipid productivity and cell wall ultrastructure of six strains of Nannochloropsis: Implications for biofuel production and downstream processing

Microalgae are generating considerable interest for third generation biodiesel production. However, appropriate strain selection is proving challenging due to the significant variation in cellular physiology, metabolic potential and genetics observed even amongst strains deemed morphologically similar. Six strains of Nannochloropsis from the CCAP culture collection were assessed for their lipid productivity and cellular structure, as proxies for oil production and harvesting ease, to assess their suitability as biodiesel production platforms. Differences in growth rate and lipid accumulation across the strains were observed. Nannochloropsis oculata strain 849/7 showed significantly reduced doubling time compared to Nannochloropsis salina strain 849/3, whilst Nannochloropsis oceanica 849/10 produced the highest lipid content. In addition the six strains could be differentiated into 3 distinct classes based on their cell wall thickness, which varied across the strains from 63 to 119 nm and which is independent of both species and geographical isolation location. The importance of these variations in ultrastructure and physiology for biodiesel production is discussed.

On the Potential of Surfers to Monitor Environmental Indicators in the Coastal Zone

The social and economic benefits of the coastal zone make it one of the most treasured environments on our planet. Yet it is vulnerable to increasing anthropogenic pressure and climate change. Coastal management aims to mitigate these pressures while augmenting the socio-economic benefits the coastal region has to offer. However, coastal management is challenged by inadequate sampling of key environmental indicators, partly due to issues relating to cost of data collection. Here, we investigate the use of recreational surfers as platforms to improve sampling coverage of environmental indicators in the coastal zone. We equipped a recreational surfer, based in the south west United Kingdom (UK), with a temperature sensor and Global Positioning System (GPS) device that they used when surfing for a period of one year (85 surfing sessions). The temperature sensor was used to derive estimates of sea-surface temperature (SST), an important environmental indicator, and the GPS device used to provide sample location and to extract information on surfer performance. SST data acquired by the surfer were compared with data from an oceanographic station in the south west UK and with satellite observations. Our results demonstrate: (i) high-quality SST data can be acquired by surfers using low cost sensors; and (ii) GPS data can provide information on surfing performance that may help motivate data collection by surfers. Using recent estimates of the UK surfing population, and frequency of surfer participation, we speculate around 40 million measurements on environmental indicators per year could be acquired at the UK coastline by surfers. This quantity of data is likely to enhance coastal monitoring and aid UK coastal management. Considering surfing is a world-wide sport, our results have global implications and the approach could be expanded to other popular marine recreational activities for coastal monitoring of environmental indicators.

Towards the Industrial Production of Omega-3 Long Chain Polyunsaturated Fatty Acids from a Genetically Modified Diatom Phaeodactylum tricornutum.

The marine diatom Phaeodactylum tricornutum can accumulate up to 30% of the omega-3 long chain polyunsaturated fatty acid (LC-PUFA) eicosapentaenoic acid (EPA) and, as such, is considered a good source for the industrial production of EPA. However, P. tricornutum does not naturally accumulate significant levels of the more valuable omega-3 LC-PUFA docosahexaenoic acid (DHA). Previously, we have engineered P. tricornutum to accumulate elevated levels of DHA and docosapentaenoic acid (DPA) by overexpressing heterologous genes encoding enzyme activities of the LC-PUFA biosynthetic pathway. Here, the transgenic strain Pt_Elo5 has been investigated for the scalable production of EPA and DHA. Studies have been performed at the laboratory scale on the cultures growing in up to 1 L flasks a 3.5 L bubble column, a 550 L closed photobioreactor and a 1250 L raceway pond with artificial illumination. Detailed studies were carried out on the effect of different media, carbon sources and illumination on omega-3 LC-PUFAs production by transgenic strain Pt_Elo5 and wild type P. tricornutum grown in 3.5 L bubble columns. The highest content of DHA (7.5% of total fatty acids, TFA) in transgenic strain was achieved in cultures grown in seawater salts, Instant Ocean (IO), supplemented with F/2 nutrients (F2N) under continuous light. After identifying the optimal conditions for omega-3 LC-PUFA accumulation in the small-scale experiments we compared EPA and DHA levels of the transgenic strain grown in a larger fence-style tubular photobioreactor and a raceway pond. We observed a significant production of DHA over EPA, generating an EPA/DPA/DHA profile of 8.7%/4.5%/12.3% of TFA in cells grown in a photobioreactor, equivalent to 6.4 μg/mg dry weight DHA in a mid-exponentially growing algal culture. Omega-3 LC-PUFAs production in a raceway pond at ambient temperature but supplemented with artificial illumination (110 μmol photons m-2s-1) on a 16:8h light:dark cycle, in natural seawater and F/2 nutrients was 24.8% EPA and 10.3% DHA. Transgenic strain grown in RP produced the highest levels of EPA (12.8%) incorporated in neutral lipids. However, the highest partitioning of DHA in neutral lipids was observed in cultures grown in PBR (7.1%). Our results clearly demonstrate the potential for the development of the transgenic Pt_Elo5 as a platform for the commercial production of EPA and DHA.

Polycyclic aromatic hydrocarbons (PAHS) (I): Measures of prevention and control

Measures of prevention and control against polycyclic aromatic hydrocarbons (PAHs) focus on an official food control, a code of best practice to reduce PAHs levels by controlling industry and in the development of a chemopreventive strategy. Regulation (EU) 835/2011 establishes maximum levels of PAHs for each food group. In addition, Regulations (EU) 333/2007 and 836/2011 set up the methods of sampling and analysis for its official control. Scientific studies prove that the chemopreventive strategy is effective against these genotoxic compounds effects. Most chemopreventive compounds studied with proven protective effects against PAHs are found in fruit and vegetables.

Fitness reduction and potential extinction of wild populations of Atlantic salmon, Salmo salar, as a result of interactions with escaped farm salmon.

The high level of escapes from Atlantic salmon farms, up to two million fishes per year in the North Atlantic, has raised concern about the potential impact on wild populations. We report on a twogeneration experiment examining the estimated lifetime successes, relative to wild natives, of farm, F1 and F2 hybrids and BC1 backcrosses to wild and farm salmon. Offspring of farm and hybrids (i.e. all F1 , F2 and BC1 groups) showed reduced survival compared with wild salmon but grew faster as juveniles and displaced wild parr, which as a group were significantly smaller. Where suitable habitat for these emigrant parr is absent, this competition would result in reduced wild smolt production. In the experimental conditions, where emigrants survived downstream, the relative estimated lifetime success ranged from 2% (farm) to 89% (BC1 wild) of that of wild salmon, indicating additive genetic variation for survival . Wild salmon primarily returned to fresh water after one sea winter (1SW) but farm and hybrids produced proportionately more 2SW salmon. However, lower overall survival means that this would result in reduced recruitment despite increased 2SW fecundity. We thus demonstrate that interaction of farm with wild salmon results in lowered fitness, with repeated escapes causing cumulative fitness depression and potentially an extinction vortex in vulnerable populations.

GIP(Lys16PAL) and GIP(Lys37PAL): novel long-acting acylated analogues of glucose-dependent insulinotropic polypeptide with improved antidiabetic potential.

Glucose-dependent insulinotropic polypeptide (GIP) is a physiological insulin releasing peptide. We have developed two novel fatty acid derivatized GIP analogues, which bind to serum albumin and demonstrate enhanced duration of action in vivo. GIP(Lys(16)PAL) and GIP(Lys(37)PAL) were resistant to dipeptidyl peptidase IV (DPP IV) degradation. In vitro studies demonstrated that GIP analogues retained their ability to activate the GIP receptor through production of cAMP and to stimulate insulin secretion. Intraperitoneal administration of GIP analogues to obese diabetic (ob/ob) mice significantly decreased the glycemic excursion and elicited increased and prolonged insulin responses compared to native GIP. A protracted glucose-lowering effect was observed 24 h following GIP(LyS(37)PAL) administration. Once a day injection for 14 days decreased nonfasting glucose, improved glucose tolerance, and enhanced the insulin response to glucose. These data demonstrate that fatty acid derivatized GIP peptides represent a novel class of long-acting stable GIP analogues for therapy of type 2 diabetes.

Comparative effects of GLP-1 and GIP on cAMP production, insulin secretion, and in vivo antidiabetic actions following substitution of Ala8/Ala2 with 2-aminobutyric acid

The two major incretin hormones, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP), are currently being considered as prospective drug candidates for treatment of type 2 diabetes. Interest in these gut hormones was initially spurred by their potent insulinotropic activities, but a number of other antihyperglycaemic actions are now established. One of the foremost barriers in progressing GLP-1 and GIP to the clinic concerns their rapid degradation and inactivation by the ubiquitous enzyme, dipeptidyl peptidase IV (DPP IV). Here, we compare the DPP IV resistance and biological properties of Abu(8)/ Abu(2) (2-aminobutyric acid) substituted analogues of GLP-1 and GIP engineered to impart DPP IV resistance. Whereas (Abu(8))GLP-1 was completely stable to human plasma (half-life > 12h), GLP-1, GIP, and (Abu(2))GIP were rapidly degraded (half-lives: 6.2, 6.0, and 7.1 h, respectively). Native GIP, GLP-1, and particularly (Abu(8))GLP-1 elicited significant adenylate cyclase and insulinotropic activity, while (Abu(2))GIP was less effective. Similarly, in obese diabetic (ob/ob) mice, GIP, GLP-1, and (Abu(8))GLP-1 displayed substantial glucose-lowering and insulin -releasing activities, whereas (Abu(2))GIP was only weakly active. These studies illustrate divergent effects of penultimate amino acid Ala(8)/Ala(2) substitution with Abu on the biological properties of GLP-1 and GIP, suggesting that (Abu(8))GLP-1 represents a potential candidate for future therapeutic development. (C) 2004 Elsevier Inc. All rights reserved.

Degradation, cyclic adenosine monophosphate production, insulin secretion, and glycemic effects of two novel N-terminal Ala(2)-substituted analogs of glucose-dependent insulinotropic polypeptide with preserved biological activity in vivo

Glucose-dependent insulinotropic polypeptide (GIP) has significant potential in diabetes therapy due to its ability to serve as a glucose-dependent activator of insulin secretion. However, its biological activity is severely compromised by the ubiquitous enzyme dipeptidylpeptidase IV (DPP IV), which removes the N-terminal Tyr(1)-Ala(2) dipeptide from GIP. Therefore, 2 novel N-terminal Ala(2)-substituted analogs of GIP, with Ala substituted by 2-aminobutyric acid (Abu) or sarcosine (Sar), were synthesized and tested for metabolic stability and biological activity both in vitro and in vivo. Incubation with DPP IV gave half-lives for degradation of native GIP, (Abu(2))GIP, and (Sar(2))GIP to be 2.3, 1.9, and 1.6 hours, respectively, while in human plasma, the half-lives were 6.2, 7.6, and 5.4 hours, respectively. In Chinese hamster lung (CHL) cells expressing the cloned human GIP receptor, native GIP, (Abu(2))GIP, and (Sar(2))GIP dose-dependently stimulated cyclic adenosine monophosphate (camp) production with EC50 values of 18.2, 38.5, and 54.6 nmol/L, respectively. In BRIN-BD11 cells, both (Abu(2))GIP and (Sar(2))GIP (10(-13) to 10(-8) mol/L) dose-dependently stimulated insulin secretion with significantly enhanced effects at 16.7 mmol/L compared with 5.6 mmol/L glucose. In obese diabetic (ob/ob) mice, GIP and (Sar(2))GIP significantly increased (1.4-fold to 1.5-fold; P <.05) plasma insulin concentrations, whereas (Abu(2))GIP exerted only minor effects. Changes in plasma glucose were small reflecting the severe insulin resistance of this mutant. The present data show that substitution of the penultimate N-terminal Ala(2) in GIP by Abu or Sar results in analogs with moderately reduced metabolic stability and biological activity in vitro, but with preserved biological activity in vivo. (C) 2003 Elsevier Inc. All rights reserved.

Improved stability, insulin-releasing activity and antidiabetic potential of two novel N-terminal analogues of gastric inhibitory polypeptide: N-acetyl-GIP and pGlu-GIP

Aims/hypothesis: This study examined the plasma stability, biological activity and antidiabetic potential of two novel N-terminally modified analogues of gastric inhibitory polypeptide (GIP).

Methods: Degradation studies were carried out on GIP, N-acetyl-GIP (Ac-GIP) and N-pyroglutamyl-GIP (pGlu-GIP) in vitro following incubation with either dipeptidylpeptidase IV or human plasma. Cyclic adenosine 3'5' monophosphate (cAMP) production was assessed in Chinese hamster lung fibroblast cells transfected with the human GIP receptor. Insulin-releasing ability was assessed in vitro in BRIN-BD11 cells and in obese diabetic (ob/ob) mice.

Results: GIP was rapidly degraded by dipeptidylpeptidase IV and plasma (t1/2 2.3 and 6.2 h, respectively) whereas Ac-GIP and pGlu-GIP remained intact even after 24 h. Both Ac-GIP and pGlu-GIP were extremely potent (p<0.001) at stimulating cAMP production (EC50 values 1.9 and 2.7 nmol/l, respectively), almost a tenfold increase compared to native GIP (18.2 nmol/l). Both Ac-GIP and pGlu-GIP (10–13–10–8 mmol/l) were more potent at stimulating insulin release compared to the native GIP (p<0.001), with 1.3-fold and 1.2-fold increases observed at 10–8 mol/l, respectively. Administration of GIP analogues (25 nmol/kg body weight, i.p.) together with glucose (18 mmol/kg) in (ob/ob) mice lowered (p<0.001) individual glucose values at 60 min together with the areas under the curve for glucose compared to native GIP. This antihyperglycaemic effect was coupled to a raised (p<0.001) and more prolonged insulin response after administration of Ac-GIP and pGlu-GIP (AUC, 644±54 and 576±51 ng·ml–1·min, respectively) compared with native GIP (AUC, 257±29 ng·ml–1·min).

Conclusion/interpretation: Ac-GIP and pGlu-GIP, show resistance to plasma dipeptidylpeptidase IV degradation, resulting in enhanced biological activity and improved antidiabetic potential in vivo, raising the possibility of their use in therapy of Type II (non-insulin-dependent) diabetes mellitus.

High-solid-content hydroxyapatite slurry for the production of bone substitute scaffolds

Key to various bone substitute scaffold production techniques is the development of free-flowing ceramic slurry with optimum theological properties. The aim is to achieve a colloidal suspension with as high a solid content as possible while maintaining a low viscosity which easily penetrates the pores of relevant sacrificial templates. The following investigation describes the optimization of a hydroxyapatite slip and demonstrates its potential application in scaffold production. Using predominantly spherical particles of hydroxyapatite of between 0.82 mu m and 16.2 mu m, coupled with a 2 wt % addition of the anionic polyelectrolyte, ammonium polyacrylate, an 80 wt % (55.9 vol %) hydroxyapatite solid loaded slip with a viscosity of approximately 126 mPa s has been developed. Its ability to infiltrate and replicate porous preforms has been shown using polyurethane foam. The enhanced particle packing achieved has allowed for the production of scaffolds with highly dense and uniform grain structures. The results represent a significant improvement in current slurry production techniques and can be utilized to develop high-density ceramic bone substitute scaffolds.

Collaborative artistic laboratories. Transfrontier spaces of cultural production

The appearance of the open code paradigm and the demands of social movements have permeated the ways in which today’s cultural institutions are organized. This article analyzes the birth of a new critical and cooperative spatiality and how it is transforming current modes of cultural research and production. It centers on the potential for establishing the new means of cooperation that are being tested in what are defined as collaborative artistic laboratories. These are hybrid spaces of research and creation based on networked and cooperative structures producing a new societal-technical body that forces us to reconsider the traditional organic conditions of the productive scenarios of knowledge and artistic practice.

Influence of environmental enrichment on the behaviour, performance and meat quality of domestic pigs

Three hundred and twenty pigs were reared from birth to slaughter at 21 weeks in either barren or enriched environments. The barren environments were defined as intensive housing (slatted floors and minimum recommended space allowances) and the enriched environments incorporated extra space, an area which contained peat and straw in a rack. Behavioural observations showed that environmental enrichment reduced time spent inactive and time spent involved in harmful social and aggressive behaviour while increasing the time spent in exploratory behaviour. During the finishing period (15-21 weeks) mean daily food intakes were higher and food conversion ratios were lower for pigs in enriched environments compared with their counterparts in barren environments (P

Potential output in a rapidly developing economy: the case of China and a comparison with the United States and the European Union

The authors use a growth accounting framework to examine growth of the rapidly developing Chinese economy. Their findings support the view that, although feasible in the intermediate term, China's recent pattern of extensive growth is not sustainable in the long run. The authors believe that China will be able to sustain a growth rate of 8 to 9 percent for an extended period if it moves from extensive to intensive growth. They next compare potential growth in China with historical developments in the United States and the European Union. They discuss the differences in production structure and level of development across the three economies that may explain the countries' varied intermediate-term growth prospects. Finally, the authors provide an analysis of "green" gross domestic product and the role of natural resources in China's growth. © 2009, The Federal Reserve Bank of St. Louis.

The effect of feedstock cost on biofuel cost as exemplified by biomethane production from grass silage.

Abstract: The potential variance in feedstock costs can have signifi cant implications for the cost of a biofuel and the fi nancial viability of a biofuel facility. This paper employs the Grange Feed Costing Model to assess the cost of on-farm biomethane production using grass silages produced under a range of management scenarios. These costs were compared with the cost of wheat grain and sugarbeet roots for ethanol production at an industrial scale. Of the three feedstocks examined, grass silage represents the cheapest feedstock per GJ of biofuel produced. At a production cost of €27/tonne (t) feedstock (or €150/t volatile solids (VS)), the feedstock production cost of grass silage per gigajoule (GJ) of biofuel (€12.27) is lower than that of sugarbeet (€16.82) and wheat grain (€18.61). Grass biomethane is also the cheapest biofuel when grass silage is costed at the bottom quartile purchase price of silage of €19/t (€93/t VS). However, when considering the production costs (full-costing) of the three feedstocks, the total cost of grass biomethane (€32.37/GJ of biofuel; intensive 2-cut system) from a small on-farm facility ranks between that of sugarbeet (€29.62) and wheat grain ethanol (€34.31) produced in large industrial facilities. The feedstock costs for the above three biofuels represent 0.38, 0.57, and 0.54 of the total biofuel cost. The importance of feedstock cost on biofuel cost is further highlighted by the 0.43 increase in the cost of biomethane when grass silage is priced at the top quartile (€46/t or €232/t VS) compared to the bottom quartile purchase price.

The potential for human exposure, direct and indirect, to the suspected carcinogenic triphenylmethane dye Brilliant Green from green paper towels

Triphenylmethanes - Malachite Green (MG), Crystal Violet (CV) and Brilliant Green (BC) are dyes with known genotoxic and carcinogenic properties. Apart from being illegally used in aquaculture for treatment of fish diseases they are also applied in industry such as paper production to colour paper towels widely used in hospitals, factories and other locations for hand drying after washing. The present study provides evidence that the triphenylmethane dye (BC) present in green paper towels can migrate through the skin even when the exposure time is short (30-300 s). The transfer of the dye from the towel to food (fish) was also studied and a high amount of colour was found to migrate during overnight exposure. The risk to humans associated with these two dye transfer studies was assessed using a 'margin of exposure approach' on the basis of the toxicological data available for the closely related dye MG and its metabolite Leucomalachite Green. The data indicated that the risk associated with the use of triphenylmethane containing paper towels is of a similar proportion to the risk associated with consumption of fish contaminated with these dyes due to the illegal application in aquaculture. (C) 2011 Elsevier Ltd. All rights reserved.