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Biomass Composition (biomass + composition)
Selected AbstractsDetermination of Biomass Composition of Catharanthusroseus Hairy Roots for Metabolic Flux AnalysisBIOTECHNOLOGY PROGRESS, Issue 6 2006Ganesh Sriram Metabolic flux analysis is a powerful diagnostic tool in metabolic engineering, and determination of biomass composition is indispensable to accurate flux evaluation. We report the elemental and biomolecular composition of Catharanthus roseus hairy roots, a pharmaceutically significant plant system and an important metabolic engineering target. The molecular formula of the organic material in the hairy roots was C12.0H22.7N0.4O7.6 during mid-exponential growth. The abundances of lipids, lignin, cellulose, hemicellulose, starch, protein, proteinogenic amino acids, mineral ash, and moisture in the biomass were quantified. Analysis of water-soluble components of the biomass with 1-D 13C and 2-D [1H,1H] correlation (COSY) NMR spectroscopy revealed that the water-soluble components were composed almost entirely of ,-glucans. Agropine, a frequently reported hairy root biomass component, was not detected. Our measurements of the biomass components quantified 83.6 ± 9.3% (w/w) of the biomass. Together with previously reported abundances of indole alkaloids, we accounted for at least 85.9 ± 11.6% (w/w) of the carbon in the biomass, which enabled the precise determination of 12 biomass synthesis fluxes. [source] Low algal carbon content and its effect on the C : P stoichiometry of periphytonFRESHWATER BIOLOGY, Issue 11 2005PAUL C. FROST Summary 1. We examined the contribution of algal cells to periphytic organic carbon and assessed the effects of variable biomass composition on the carbon : phosphorus (C : P) ratio of periphyton. We compiled more than 5000 published and unpublished observations of periphytic carbon : chlorophyll a (C : Chl) ratios, an index of algal prevalence, from a variety of substrata collected from lake and low-salinity coastal habitats. In addition, we converted estimates of algal biovolume into algal C to obtain an independent measure of cellular algal carbon in periphyton. This information was used in a model relating periphyton C : P ratio to algal cellular carbon, the algal C : P ratio, and the C : P ratio of non-algal organic matter in periphyton. 2. The mean C : Chl ratio of periphyton (405) was relatively high with values in >25% of the samples exceeding 500. On average, 8.4% of total periphyton C was accounted for by C in algal cells. Only 15% of samples were found to have more than 15% periphyton C in cellular algal carbon. Our model showed a nonlinear relationship between periphytic C : P ratios and the C : P ratio of algal cells in the periphyton when non-algal organic matter was present. However, even at relatively low cellular algal C (<10% of total C), algal C : P ratios can strongly affect the C : P ratio of periphyton as a whole (i.e. algal cells plus other organic matter). 3. The high C : Chl ratios and the low biovolume-derived algal C of periphyton samples in our data set indicate that algal cells are typically a minor component of organic carbon in periphyton, However, this minor contribution would not preclude algal cellular stoichiometry from notably influencing periphyton C : P ratios. [source] Species richness and susceptibility to heat and drought extremes in synthesized grassland ecosystems: compositional vs physiological effectsFUNCTIONAL ECOLOGY, Issue 6 2004L. VAN PEER Summary 1We investigated effects of declining plant species richness (S) on resistance to extremes in grassland communities. 2Synthesized model ecosystems of different S, grown outdoors in containers, were exposed to a stress peak combining heat and drought. The heat wave was induced experimentally by infrared irradiation in free air conditions. 3Before the heat wave, the more species-rich communities produced more biomass as a result of a large and positive complementarity effect that outweighed a small negative selection effect. 4Water use during the heat wave was likewise enhanced by S, which could not be attributed to dominance of ,water-wasting' species. Instead, water consumption at high S exceeded that expected from changes in community biomass and biomass composition. The observed enhancement of resource (water) acquisition under stress with increasing S therefore probably originated from complementarity. 5Despite enhanced water use in the more diverse communities, plant survival was significantly less, affecting all species alike. Physiological stress, recorded as photochemical efficiency of photosystem II electron transport, was significantly greater. Before the heat wave, the changes in biomass composition that coincided with increasing S did not favour species that would later prove intrinsically sensitive or insensitive. 6Complementarity in resource use for biomass production had a cost in terms of reduced survival under stress, despite the likelihood of complementarity in water acquisition during exposure. The greater loss of individuals from the more diverse grasslands suggests enhanced risk of local extinction. [source] Biomass removal by dolphins and fisheries in a Mediterranean Sea coastal area: do dolphins have an ecological impact on fisheries?AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2010Giovanni Bearzi Abstract 1.Dolphins are often claimed to compete with fisheries, including through removal of substantial biomass. To calculate the biomass removed by fisheries and the degree of resource overlap with dolphins in a coastal area of Greece, estimates of dolphin abundance based on photographic capture,recapture were combined with an assessment of fishing effort and catch. 2.The estimated total biomass consumed annually by local dolphin populations , 15 short-beaked common dolphins and 42 common bottlenose dolphins , was 15.5 and 89.8 tonnes, respectively. The total biomass removed by the local fishing fleet (307 fishing boats) was 3469.2 tonnes, i.e. about 33 times greater than that removed by dolphins. 3.Dolphins removed 2.9% of the total biomass, fisheries 97.1%. Nine purse seiners (representing only 3% of the active fishing fleet) were responsible for 31.9% of biomass removal. Similarity of biomass composition between dolphins and fisheries was expressed by a Pianka index of 0.46 for common dolphins and 0.66 for bottlenose dolphins. 4.Overlap differed according to fishing gear. Common dolphin overlap was higher with purse seiners (0.82), and lower with beach seiners (0.31), bottom trawlers (0.11) and trammel boats (0.06). There was virtually no overlap with longliners (0.02). Bottlenose dolphin overlap was higher with trammel boats (0.89) and bottom trawlers (0.75), and lower with longliners (0.38), purse seiners (0.24) and beach seiners (0.18). There was minimal overlap (0.12) between the two dolphin species. 5.This study suggests that ecological interactions between dolphins and fisheries in this coastal area have minor effects on fisheries. Conversely, prey depletion resulting from overfishing can negatively affect dolphins. Fisheries management measures consistent with national and EU legislation are proposed to ensure sustainability and to protect marine biodiversity. Copyright © 2010 John Wiley & Sons, Ltd. [source] Genome-derived minimal metabolic models for Escherichia coli MG1655 with estimated in vivo respiratory ATP stoichiometryBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010Hilal Taymaz-Nikerel Abstract Metabolic network models describing growth of Escherichia coli on glucose, glycerol and acetate were derived from a genome scale model of E. coli. One of the uncertainties in the metabolic networks is the exact stoichiometry of energy generating and consuming processes. Accurate estimation of biomass and product yields requires correct information on the ATP stoichiometry. The unknown ATP stoichiometry parameters of the constructed E. coli network were estimated from experimental data of eight different aerobic chemostat experiments carried out with E. coli MG1655, grown at different dilution rates (0.025, 0.05, 0.1, and 0.3,h,1) and on different carbon substrates (glucose, glycerol, and acetate). Proper estimation of the ATP stoichiometry requires proper information on the biomass composition of the organism as well as accurate assessment of net conversion rates under well-defined conditions. For this purpose a growth rate dependent biomass composition was derived, based on measurements and literature data. After incorporation of the growth rate dependent biomass composition in a metabolic network model, an effective P/O ratio of 1.49,±,0.26,mol of ATP/mol of O, KX (growth dependent maintenance) of 0.46,±,0.27,mol of ATP/C-mol of biomass and mATP (growth independent maintenance) of 0.075,±,0.015,mol of ATP/C-mol of biomass/h were estimated using a newly developed Comprehensive Data Reconciliation (CDR) method, assuming that the three energetic parameters were independent of the growth rate and the used substrate. The resulting metabolic network model only requires the specific rate of growth, µ, as an input in order to accurately predict all other fluxes and yields. Biotechnol. Bioeng. 2010;107: 369,381. © 2010 Wiley Periodicals, Inc. [source] Monitoring of biomass composition from microbiological sources by means of FT-IR spectroscopyBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2009Arthur M.A. Pistorius Abstract An FT-IR spectroscopic method was developed for the simultaneous quantitative analysis of biomacromolecular components in biomass, originating from various microbiological sources. For the determination of protein, lipid and carbohydrate content, creatine phosphokinase, egg phosphatidyl choline and starch hydrolysate were chosen as external standards. This selection was based on spectral similarity and ease of availability. Protein content was based on the area under the amide II band profile around 1,545 cm,1. Because of the heterogeneous lipid composition in the different species, lipid content was determined using integration over the CH stretching vibrational population between 2,984 and 2,780 cm,1. Carbohydrate content was determined using integration over a CO and COC stretching band area between 1,180 and 1,133 cm,1. Linear regression analysis provided three calibration lines, according to which biomasses from ten species were analyzed. This approach showed good intra-batch reproducibility. With this method we could demonstrate good reproducibility between batches of the same species with similar growth conditions while large differences in biomass composition were observed between the various species. Protein content as determined by FT-IR spectroscopy compared well with the results obtained from elemental analysis. Biotechnol. Bioeng. 2009;103: 123,129. © 2008 Wiley Periodicals, Inc. [source] Determination of Biomass Composition of Catharanthusroseus Hairy Roots for Metabolic Flux AnalysisBIOTECHNOLOGY PROGRESS, Issue 6 2006Ganesh Sriram Metabolic flux analysis is a powerful diagnostic tool in metabolic engineering, and determination of biomass composition is indispensable to accurate flux evaluation. We report the elemental and biomolecular composition of Catharanthus roseus hairy roots, a pharmaceutically significant plant system and an important metabolic engineering target. The molecular formula of the organic material in the hairy roots was C12.0H22.7N0.4O7.6 during mid-exponential growth. The abundances of lipids, lignin, cellulose, hemicellulose, starch, protein, proteinogenic amino acids, mineral ash, and moisture in the biomass were quantified. Analysis of water-soluble components of the biomass with 1-D 13C and 2-D [1H,1H] correlation (COSY) NMR spectroscopy revealed that the water-soluble components were composed almost entirely of ,-glucans. Agropine, a frequently reported hairy root biomass component, was not detected. Our measurements of the biomass components quantified 83.6 ± 9.3% (w/w) of the biomass. Together with previously reported abundances of indole alkaloids, we accounted for at least 85.9 ± 11.6% (w/w) of the carbon in the biomass, which enabled the precise determination of 12 biomass synthesis fluxes. [source] Kinetic Modeling of the Autotrophic Growth of Pavlova lutheri: Study of the Combined Influence of Light and TemperatureBIOTECHNOLOGY PROGRESS, Issue 4 2003Ana P. Carvalho The optimization and control of biochemical processes require the previous establishment of mathematical models that can describe the effect of process variables on their actual kinetics. Environmental temperature is a modulating factor to which the algal cells respond continuously by adjusting their rates of cellular reactions, their nutritional requirements, and, consequently, their biomass composition. Light intensity is an exhaustible resource, indispensable to autotrophic organisms. The effects of light intensity and temperature on growth of the microalga Pavlova lutheri, which have hardly been considered to date in a simultaneous fashion, were experimentally assessed using a factorial experimental design; in this way, the effects of each variable independently and their interactions could be quantified, using maximum biomass (Xmax) or maximum specific growth rate (,max) as objective functions. The preliminary results produced indicated that light intensity plays a more important role on ,max than temperature; in the case of Xmax, both temperature and, to a lesser extent, light intensity do apparently play a role. The highest values of Xmax were associated with low temperatures and high light intensities; a similar behavior could be observed for ,max concerning light intensity, although the dependency on temperature did not seem to be as important. A more complex mechanistic model was then postulated, incorporating light and temperature as input variables, which was successfully fitted to the experimental data generated during batch cultivation of P. lutheri. [source] | ||||||||||||||||||||||