Poly(3-hydroxybutyrate) production by <Emphasis Type="Italic">Halomonas boliviensis</Emphasis> in fed-batch culture

High poly(3-hydroxybutyrate) (PHB) content and volumetric productivity were achieved by fed-batch culture of Halomonas boliviensis using a defined medium. Initial shake flask cultivations in a minimal medium revealed that the growth of H. boliviensis was supported only when the medium was supplemented with aspartic acid, glycine, or glutamine. Addition of 0.1% (w/v) glutamine in the medium resulted in the highest cell dry weight (CDW; 3.9 g l⁻¹). Glutamine was replaced by the less expensive monosodium glutamate (MSG) in the medium without any notable change in the final cell density. Effect of initial concentrations of NH₄Cl and K₂HPO₄ on cell growth and PHB accumulation by H. boliviensis was then analyzed using a fed-batch fermentation system. The best conditions for PHB production by H. boliviensis were attained using 0.4% (w/v) NH₄Cl and 0.22% (w/v) K₂HPO₄ and adding MSG intermittently to the fermentor. Poly(3-hydroxybutyrate) content and CDW reached 90 wt.% and 23 g l⁻¹, respectively, after 18 h of cultivation. In order to increase CDW and PHB content, MSG, NH₄Cl, and K₂HPO₄ were initially fed to the fermentor to maintain their concentrations at 2%, 0.4%, and 0.22% (w/v), respectively, and subsequently their feed was suppressed. This resulted in a CDW of 44 g l⁻¹, PHB content of 81 wt.%, and PHB volumetric productivity of 1.1 g l⁻¹ h⁻¹.     

Calcium carbonate budgets for two coral reefs affected by different terrestrial runoff regimes, Rio Bueno, Jamaica

A process-based carbonate budget was used to compare carbonate framework production at two reef sites subject to varying degrees of fluvial influence in Rio Bueno, Jamaica. The turbid, central embayment was subjected to high rates of fluvial sediment input, framework accretion was restricted to ≤30 m, and net carbonate production was 1,887 g CaCO₃ m⁻² year⁻¹. Gross carbonate production (GCP) was dominated by scleractinians (97%), particularly by sediment-resistant species, e.g. Diploria strigosa on the reef flat (<2 m). Calcareous encrusters contributed very little carbonate. Total bioerosion removed 265 g CaCO₃ m⁻² year⁻¹ and was dominated by microborers. At the clear-water site, net carbonate production was 1,236 g CaCO₃ m⁻² year⁻¹; the most productive zone was on the fore-reef (10 m). Corals accounted for 82% of GCP, and encrusting organisms 16%. Bioerosion removed 126 g CaCO₃ m⁻² year⁻¹ and was dominated by macroborers. Total fish and urchin grazing was limited throughout (≤20 g CaCO₃ m⁻² year⁻¹). The study demonstrates that: (1) carbonate production and net reef accretion can occur where environmental conditions approach or exceed perceived threshold levels for coral survival; and (2) although live coral cover (and carbonate production rates) were reduced on reef-front sites along the North Jamaican coast, low population densities of grazing fish and echinoids to some extent offset this, thus maintaining positive carbonate budgets.     

Genotyping of somatic hybrids between <Emphasis Type="Italic">Festuca arundinacea</Emphasis> Schreb. and <Emphasis Type="Italic">Triticum aestivum</Emphasis> L.

In order to genotype hybrid genomes of distant asymmetric somatic hybrids, we synthesized hybrid calli and plants via PEG-mediated protoplast fusion between recipient tall fescue (Festuca. arundinacea Schreb.) and donor wheat (Triticum aestivum L.). Seventeen and 25 putative hybrid clones were produced from the fusion combinations I and II, each with the donor wheat protoplast treated by UV light for 30 s and 1 min, respectively. Isozyme and RAPD profiles confirmed that ten hybrid clones were obtained from combination I and 19 from combination II. Out of the 29 hybrids, 12 regenerated hybrid plants with tall fescue phenotype. Composition and methylation-variation of the nuclear and cytoplasmic genomes of some hybrids, either with or without regenerative ability, were compared by genomic in situ hybridization, restriction fragment length polymorphism, and DNA methylation-sensitive amplification polymorphism. Our results indicated that these selected hybrids all contained introgressed nuclear and cytoplasmic DNA as well as obvious methylation variations compared to both parents. However, there were no differences either in nuclear/cytoplasmic DNA or methylation degree between the regenerable and non-regenerable hybrid clones. We conclude that both regeneration complementation and genetic material balance are crucial for hybrid plant regeneration.     

Spatial Analysis of Production by Macrophytes,Phytoplankton and Epiphyton in a Large River System under Different Water-Level Conditions

Relative contributions by macrophytes, epiphyton and phytoplankton to total primary production was estimated in a large (∼300 km²) widening of the St. Lawrence River (Canada), over a 2-year period with contrasting flows and water levels. Spatially-explicit estimates of whole-system production were obtained by combining field measurements with remotely sensed data and empirical models using GIS. Primary production and relative contributions of each producer type differed markedly between open-water and wetland habitats. Spatial differences within each habitat arose from interactions between physical factors including light, water depth, water transit times and wind stress. At the whole-system level, annual primary production represented 105 gC m⁻² y⁻¹, divided roughly equally among phytoplankton (34%), submerged macrophytes (27%), emergent macrophytes (23%) and epiphyton (16%). A 10% decrease in annual flows and 1-m decline in water levels between 2000 and 2001 resulted in a 50% loss of marsh habitat, a 60% increase in phytoplankton production in the open-water zone, and in the appearance of conspicuous filamentous algal mats. Low water levels induced substantial shifts in the spatial configuration and relative importance of primary producers although total river primary production remained stable between years.     

Influence of agitation and aeration on growth and antibiotic production by <Emphasis Type="Italic">Xenorhabdus nematophila</Emphasis>

The effect of agitation and aeration on the growth and antibiotic production by Xenorhabdus nematophila YL001 grown in batch cultures were investigated. Efficiency of aeration and agitation was evaluated through the oxygen mass transfer coefficient (K _L a). With increase in K _L a, the biomass and antibiotic activity increased. Activity units of antibiotic and dry cell weight were increased to 232 U ml⁻¹ and 19.58 g l⁻¹, respectively, productivity in cell and antibiotic was up more than 30% when K _L a increased from 115.9 h⁻¹ to 185.7 h⁻¹. During the exponential growth phase, DO concentration was zero, the oxygen supply was not sufficient. So, based on process analysis, a three-stage oxygen supply control strategy was used to improved the DO concentration above 30% by controlling the agitation speed and aeration rate. The dry cell weight and activity units of antibiotic were further increased to 24.22 g l⁻¹ and 249 U ml⁻¹, and were improved by 24.0% and 7.0%, compared with fermentation at a constant agitation speed and a constant aeration rate (300 rev min⁻¹, 2.5 l min⁻¹).     

Attraction of Fruit-Eating Bats with Essential Oils of Fruits: A Potential Tool for Forest Restoration

Previous tests with essential oils from ripe chiropterochoric fruits suggested they can be used to attract and capture fruit-eating bats inside forest remnants. Here we evaluated the efficiency of these oils to attract frugivorous bats to open areas. We performed field tests with artificial fruits impregnated with essential oils of the genera Piper or Ficus that were attached to two groups of mist-nets set 50 m outside the border of a forest remnant. One group of artificial fruits received the corresponding oil isolated through hydrodistillation and the other received water only. Fruits with oils attracted significantly more fruit-eating bats, especially Artibeus lituratus that regularly crosses open habitats to reach other forest remnants. The highly significant attraction of A. lituratus by the oil of Piper was unexpected, since this bat is a specialist on Ficus fruits. We hypothesize that in habitats with no fruit available it is possible to attract frugivorous bats with the odor of several ripe fruit species. Furthermore, we verified that almost half of the individuals captured defecated seeds, indicating that the oils also attract recently fed bats, even when their preferred food is available nearby. This technique potentially may increase seed rain at specific locations, being particularly promising to restoration projects.     

Isolation and Characterization of Mustard (Sinapis alba L.) Seed Storage Proteins

A total storage protein fraction was prepared from mustard (Sinapis alba L.) seeds via isolated protein bodies and characterized by sedimentation, immunological, and electrophoretic techniques. Mustard seed storage protein consists of three fractions (1) a “legumin-like” 13-S complex composed of two pairs of disulfide-linked polypeptides (16.5 + 28.5 kDa and 19.5 + 34 kDa, respectively) and two single polypeptides (18 kDa and 26 kDa), (2) a “vicilin-like” 9-S complex composed of two glycoproteins (64 kDa and 77 kDa), and (3) two small polypeptides (10 kDa and 11 kDa) which probably represent the 1.7-S complex found in other Cruciferae. In contrast to related species, no glycosylated polypeptide was found in the 13-S complex. Immunological relationships were found between the paired polypeptides of the 13-S complex but not between polypeptides of the 13-S complex and polypeptides of the 9-S complex. Pulse-chase labeling and in vitro translation of polysomal RNA from young embryos demonstrated that the polypeptides of the 13-S complex originate from high molecular mass precursors, except for the 18 kDa polypeptide which appears to be synthesized in its final size. The amino-acid composition of the major polypeptides of the mustard storage protein is given.     

Cell Growth and Flavonoids Production in Suspension Culture of Saussurea medusa

Cell suspension cultures were established from Saussurea medusa Maxim. callus cultures. The effects of different rotation speeds of the gyratory shaker, different inoeulum sizes and different pH values of the medium on cell growth and flavonoid formation were studied. The result showed that the optimum rotation speed, inoeulum size and initial pH value of the medium were 90–120 r/min,50– 80 g FW/L and 5.5–6.0 respectively for cell growth and flavonoids formation in the suspension cultures. Sucrose was better than glucose and fructose for the suspension cultures. The optimum concentration of sucrose for cell growth and flavonoid production was 40 g/L, and the concentration of flavonoids could be as high as 1 423.25 mg/L. High performance liquid chromatographic analysis of cell suspension culture extracts showed that the concentrations of jaceosidin and hispidulin in the flavonoids were 22.11% and 0. 15% respectively.     

Considering land–sea interactions and trade‐offs for food and biodiversity

With the human population expected to near 10 billion by 2050, and diets shifting towards greater per‐capita consumption of animal protein, meeting future food demands will place ever‐growing burdens on natural resources and those dependent on them. Solutions proposed to increase the sustainability of agriculture, aquaculture, and capture fisheries have typically approached development from single sector perspectives. Recent work highlights the importance of recognising links among food sectors, and the challenge cross‐sector dependencies create for sustainable food production. Yet without understanding the full suite of interactions between food systems on land and sea, development in one sector may result in unanticipated trade‐offs in another. We review the interactions between terrestrial and aquatic food systems. We show that most of the studied land–sea interactions fall into at least one of four categories: ecosystem connectivity, feed interdependencies, livelihood interactions, and climate feedback. Critically, these interactions modify nutrient flows, and the partitioning of natural resource use between land and sea, amid a backdrop of climate variability and change that reaches across all sectors. Addressing counter‐productive trade‐offs resulting from land‐sea links will require simultaneous improvements in food production and consumption efficiency, while creating more sustainable feed products for fish and livestock. Food security research and policy also needs to better integrate aquatic and terrestrial production to anticipate how cross‐sector interactions could transmit change across ecosystem and governance boundaries into the future.