Comparative shotgun proteomic analysis of Clostridium acetobutylicum from butanol fermentation using glucose and xylose

<p>Abstract</p> <p>Background</p> <p>Butanol is a second generation biofuel produced by <it>Clostridium acetobutylicum </it>through acetone-butanol-ethanol (ABE) fermentation process. Shotgun proteomics provides a direct approach to study the whole proteome of an organism in depth. This paper focuses on shotgun proteomic profiling of <it>C. acetobutylicum </it>from ABE fermentation using glucose and xylose to understand the functional mechanisms of <it>C. acetobutylicum </it>proteins involved in butanol production.</p> <p>Results</p> <p>We identified 894 different proteins in <it>C. acetobutylicum </it>from ABE fermentation process by two dimensional - liquid chromatography - tandem mass spectrometry (2D-LC-MS/MS) method. This includes 717 proteins from glucose and 826 proteins from the xylose substrate. A total of 649 proteins were found to be common and 22 significantly differentially expressed proteins were identified between glucose and xylose substrates.</p> <p>Conclusion</p> <p>Our results demonstrate that flagellar proteins are highly up-regulated with glucose compared to xylose substrate during ABE fermentation. Chemotactic activity was also found to be lost with the xylose substrate due to the absence of CheW and CheV proteins. This is the first report on the shotgun proteomic analysis of <it>C. acetobutylicum </it>ATCC 824 in ABE fermentation between glucose and xylose substrate from a single time data point and the number of proteins identified here is more than any other study performed on this organism up to this report.</p

Biomass Production and Pigment Accumulation in Kale Grown Under Different Radiation Cycles in a Controlled Environment

Controlled plant growing systems have consistently used the standard earth day as the radiation cycle for plant growth. However, the radiation cycle can be controlled using automated systems to regulate the exact amount of time plants are exposed to irradiation (and darkness). This experiment investigated the influence of different radiation cycle periods on plant growth and carotenoid accumulation in kale (Brassica oleracea L. var. acephala DC.). Plants were grown in a controlled environment using nutrient solutions under radiation cycle treatments of 2, 12, 24 and 48 hours, with 50% irradiance and 50% darkness during each cycle. The radiation cycles significantly affected kale fresh weight, dry weight, percent dry matter, and the accumulation of lutein, ß-carotene, and chlorophyll a and b. Maximum fresh weight occurred under the 2-hour radiation cycle treatment, whereas maximum dry weight occurred under the 12-hour treatment. Maximum accumulation of lutein, ß-carotene, and chlorophyll a occurred with the 12-hour radiation cycle at values of 14.5 mg/100 g, 13.1 mg/100 g, and 263.3 mg/100 g fresh weight respectively. Maximum fresh weight production of the kale was not linked to increases in chlorophyll, lutein, or ß-carotene. Consumption of fruit and vegetable crops rich in lutein and ß-carotene carotenoids is associated with reduced risk of cancers and aging eye diseases. Increased carotenoid concentrations in vegetable crops would therefore be expected to increase the value of these crops

Nitrogen Levels Influence Biomass, Elemental Accumulations, and Pigment Concentrations in Spinach

Spinach (Spinacia oleracea L.) has one of the highest United States per capita consumption rates among leafy vegetable crops, and also ranks second for lutein and β-carotene carotenoid concentration. The objectives of this study were to determine the effects of nitrogen (N) concentration on elemental and pigment accumulation in spinach. Two spinach cultivars (\u27Melody\u27 and \u27Springer F1\u27) were greenhouse grown in nutrient solution culture under N treatments of 13, 26, 52, and 105 mg L- 1. Leaf tissue biomass increased from 45.6 to 273.2 g plant- 1 and from 127.0 to 438.6 g plant- 1 as N increased from 13 to 105 mg L- 1 for \u27Springer F1\u27 and \u27Melody\u27, respectively. Leaf tissue N, phosphorus (P), calcium (Ca), magnesium (Mg), copper (Cu), and zinc (Zn) responded to N treatments. Lutein accumulations, expressed on a fresh weight basis, responded quadratically to increasing N treatments for \u27Springer F1\u27. Maximum lutein values were 110 and 76 μ g g- 1 on a fresh weight basis, and maximum β-carotene values were 85 and 57 μ g g- 1 on a fresh weight basis for \u27Springer F1\u27 and \u27Melody\u27, respectively. Interestingly, N levels had a significant effect on carotenoid accumulation in both \u27Springer F1\u27 and \u27Melody\u27 when the pigments were expressed on a dry weight basis. Leaf tissue lutein increased from 0.59 to 1.06 mg g- 1 and from 0.59 to 0.90 mg g- 1 on a dry weight basis with increasing N treatments for \u27Springer F1\u27 and \u27Melody\u27, respectively. Reporting lutein and β-carotene on both a fresh and dry weight basis may be the most accurate way to express the carotenoid values of spinach

Irradiance from Distinct Wavelength Light-emitting Diodes Affect Secondary Metabolites in Kale

The use of light-emitting diodes (LEDs) for plant production is a new field of research that has great promise to optimize wavelength-specific lighting systems for precise management of plant physiological responses and important secondary metabolite production. In our experiment, hydroponically cultured kale plants (Brassica oleracea L. var. acephala D.C.) were grown under specific LED wavelength treatments of 730, 640, 525, 440, and 400 nm to determine changes in the accumulation of chlorophylls, carotenoids, and glucosinolates. Maximum accumulation, on a fresh mass basis, of chlorophyll a and b and lutein occurred at the wavelength of 640 nm, whereas β-carotene accumulation peaked under the 440-nm treatment. However, when lutein was measured on a dry mass basis, maximum accumulation was shifted to 440 nm. Sinigrin was the only glucosinolate to respond to wavelength treatments. Wavelength control using LED technology can affect the production of secondary metabolites such as carotenoids and glucosinolates with irradiance levels also a factor in kale. Management of irradiance and wavelength may hold promise to maximize nutritional potential of vegetable crops grown in controlled environments

Interregional Differences in Agricultural Development across Circumpolar Canada

In response to the circumpolar region’s high levels of food insecurity, many Canadian communities have identified the development of local agriculture as a means to resolve the issue. Agricultural development is varied across the circumpolar region, an area which includes Yukon, the Northwest Territories, Nunavut, Nunavik (Quebec), and Nunatsiavut (Newfoundland and Labrador). This review explores the interregional differences in circumpolar agriculture, their historical development, and their relationship to prevailing biophysical, socioeconomic, and political conditions. Drawing upon local food strategies and literature pertaining to current agricultural initiatives, we discuss the future direction of circumpolar agriculture in Canada. Yukon and the Northwest Territories are the most agriculturally developed subregions of circumpolar Canada, and their territorial governments support the development of commercial agriculture. In Nunavut, Nunavik, and Nunatsiavut, relatively few agricultural initiatives are underway although local efforts have been made to establish community gardens or greenhouses and improve access to fresh commodities through subsidization of imported goods. Because of variability in biophysical, social, institutional, and political environments, strategies for food production would be most effective if tailored to each subregion. The continued development of agriculturally favorable policies and certified processing facilities in Yukon and the Northwest Territories could improve market access, both locally and out-of-territory. The eastern subregions (Nunavut, Nunavik, and Nunatsiavut) seem more inclined towards small, community-driven projects; these initiatives could be promoted to encourage community involvement for their long-term sustainability. Most studies on circumpolar agriculture have focused on the biophysical and social challenges; the region would benefit from additional research into the institutional and political barriers to agricultural development. En réponse aux degrés d’insécurité alimentaire élevés dans la région circumpolaire, de nombreuses communautés canadiennes estiment que le développement de l’agriculture locale constitue un moyen de surmonter cet enjeu. Le développement agricole prend plusieurs formes dans la région circumpolaire, région qui comprend le Yukon, les Territoires du Nord-Ouest, le Nunavut, le Nunavik (Québec) et le Nunatsiavut (Terre-Neuve-et-Labrador). Dans cet article, nous explorons les différences interrégionales en matière d’agriculture circumpolaire, leur développement historique et leur lien avec les conditions biophysiques, socioéconomiques et politiques qui ont cours dans les diverses régions. Nous nous appuyons sur les stratégies alimentaires locales et sur la documentation concernant les initiatives agricoles actuelles pour discuter de l’orientation future de l’agriculture circumpolaire au Canada. Du point de vue agricole, le Yukon et les Territoires du Nord-Ouest sont les sous-régions les plus développées de la région circumpolaire du Canada, et les gouvernements de ces territoires soutiennent le développement de l’agriculture commerciale. Au Nunavut, au Nunavik et au Nunatsiavut, relativement peu d’initiatives agricoles sont en cours, bien que des efforts aient été déployés à l’échelle locale pour établir des jardins ou des serres communautaires et pour améliorer l’accès aux produits frais grâce à la subvention de produits importés. En raison de la variabilité des environnements biophysiques, sociaux, institutionnels et politiques, les stratégies de production alimentaire donneraient de meilleurs résultats si elles étaient adaptées à chaque sous-région. Le développement continu de politiques agricoles favorables et d’installations de transformation homologuées au Yukon et dans les Territoires du Nord-Ouest pourrait améliorer l’accès aux marchés, tant à l’échelle locale qu’à l’extérieur des territoires. Les sous-régions de l’est (Nunavut, Nunavik et Nunatsiavut) ont davantage tendance à préconiser de petits projets communautaires. Les initiatives de ce genre pourraient être facilitées pour inciter les communautés à jouer un rôle dans leur durabilité à long terme. La plupart des études sur l’agriculture circumpolaire portent sur les défis biophysiques et sociaux. La région pourrait bénéficier de recherches plus approfondies au sujet des obstacles institutionnels et politiques du développement agricole.

Biomass Production and Pigment Accumulation in Kale Grown Under Increasing Photoperiods

Consumption of fruit and vegetable crops rich in lutein and ß-carotene carotenoids is associated with reduced risk of cancers and aging eye diseases. Kale (Brassica oleracea L. var. acephala D.C.) ranks highest for lutein concentrations and is an excellent source of dietary carotenoids. Kale plants were grown under varied photoperiods to determine changes in the accumulation of fresh and dry biomass, chlorophyll a and b, and lutein and ß-carotene carotenoids. The plants were cultured in a controlled environment using nutrient solutions under photoperiod treatments of 6, 12, 16, or 24 hours (continuous). Fresh and dry mass production increased linearly as photoperiod increased, reaching a maximum under the 24-hour photoperiod. Maximum accumulation of lutein, ß-carotene, and chlorophyll b occurred under the 24-h photoperiod at 13.5, 10.4, and 58.6 mg/100 g fresh mass, respectively. However, maximum chlorophyll a (235.1 mg/100 g fresh mass) occurred under the 12-hour photoperiod. When ß-carotene and lutein were measured on a dry mass basis, the maximum accumulation was shifted to the 16-hour photoperiod. An increase in photoperiod resulted in increased pigment accumulation, but maximum concentrations of pigments were not correlated with maximum biomass production

Pigment Concentrations among Heat-tolerant Turfgrasses

Heat-tolerant bluegrass varieties were developed to resist dormancy and retain pigmentation during heat stress events. The objective of this study was to investigate the influence of grass species, nitrogen (N) fertilization, and seasonality on the accumulation patterns of lutein, β-carotene, and chlorophyll a and b in the leaf tissues of turfgrass. The heat-tolerant bluegrass cultivars Dura Blue and Thermal Blue (Poa pratensis L. x Poa arachnifera Torr.), Apollo kentucky bluegrass (Poa pratensis L.), and Kentucky 31 tall fescue (Festuca arundinacea Schreb.) were compared for the accumulation of plant pigments. Evaluations were conducted over 2 consecutive years (Years 4 and 5 after establishment) during two different seasons (spring and summer) and under varying N fertilization. Fertilizer applications of 5, 14, and 27 g N/m2/year resulted in a significant positive correlation for the accumulation of leaf blade lutein and chlorophyll a and b, but not for β-carotene. The accumulation of the four measured plant pigments among the grasses was significantly different with ‘Apollo’ having the largest concentration of pigments followed by ‘Dura Blue’, ‘Thermal Blue’, and finally ‘Kentucky 31’. Specifically, when comparing the cultivars Apollo and Kentucky 31, the pigment levels decreased 27%, 26%, 26%, and 23% for lutein, β-carotene, and chlorophyll a and b, respectively. The interesting observation of the analysis of the grass pigment concentrations was that the least reported heat-tolerant cultivar in our study (‘Apollo’) had the largest measured pigment concentrations