Fermentative processes for environmental remediation

The growing interest in environmental protection has led to the development of emerging biotechnologies for environmental remediation also introducing the biorefinery concept. This work mainly aimed to evaluate the applicability of innovative biotechnologies for environmental remediation and bioenergy production, throught fermentative processes. The investigated biotechnologies for waste and wastewater treatment and for the valorisation of specific feedstocks and energy recovery, were mainly focused on four research lines. 1. Biotechnology for textile wastewater treatment and water reuse that involving anaerobic and aerobic processes in combination with membrane technologies. Combinations of different treatments were also implemented for water reuse in a textile company. 2. Biotechnology for the treatment of solid waste and leachate in landfill and for biogas production. Landfill operated as Bioreactor with recirculation of the generated leachate was proposed for organic matter biostabilisation and for ammonia removal from leachate by favouring the Anammox process. 3. An innovative two-stage anaerobic process for effective codigestion of waste from the dairy industry, as cheese whey and dairy manure, was studied by combining conventional fermentative processes with a simplified system design for enhancing biomethanisation. 4) The valorisation of the glycerol waste as surplus by-product of the biodiesel industry was investigated via microbial conversion to value-added chemicals, as 1,3-propanediol. The investigated fermentative processes have been successfully implemented and reached high yields of the produced bio-chemical. The studied biotechnological systems proved to be feasible for environmental remediation and bioenergy and chemicals production.

Vanillin production from ferulic acid with Pseudomonas fluorescens BF13-1p4

Bioconversion of ferulic acid to vanillin represents an attractive opportunity for replacing synthetic vanillin with a bio-based product, that can be label “natural”, according to current food regulations. Ferulic acid is an abundant phenolic compound in cereals processing by-products, such as wheat bran, where it is linked to the cell wall constituents. In this work, the possibility of producing vanillin from ferulic acid released enzymatically from wheat bran was investigated by using resting cells of Pseudomonas fluorescens strain BF13-1p4 carrying an insertional inactivation of vdh gene and ech and fcs BF13 genes on a low copy number plasmid. Process parameters were optimized both for the biomass production phase and the bioconversion phase using food-grade ferulic acid as substrate and the approach of changing one variable while fixing the others at a certain level followed by the response surface methodology (RSM). Under optimized conditions, vanillin up to 8.46 mM (1.4 g/L) was achieved, whereas highest productivity was 0.53 mmoles vanillin L-1 h-1). Cocktails of a number of commercial enzyme (amylases, xylanases, proteases, feruloyl esterases) combined with bran pre-treatment with steam explosion and instant controlled pressure drop technology were then tested for the release of ferulic acid from wheat bran. The highest ferulic acid release was limited to 15-20 % of the ferulic acid occurring in bran, depending on the treatment conditions. Ferulic acid 1 mM in enzymatic hydrolyzates could be bioconverted into vanillin with molar yield (55.1%) and selectivity (68%) comparable to those obtained with food-grade ferulic acid after purification from reducing sugars with a non polar adsorption resin. Further improvement of ferulic acid recovery from wheat bran is however required to make more attractive the production of natural vanillin from this by-product.

Recycling of end of life concrete fines (0 - 4 mm) into silica and cement

The purpose of this work is to find a methodology in order to make possible the recycling of fines (0 - 4 mm) in the Construction and Demolition Waste (CDW) process. At the moment this fraction is a not desired by-product: it has high contaminant content, it has to be separated from the coarse fraction, because of its high water absorption which can affect the properties of the concrete. In fact, in some countries the use of fines recycled aggregates is highly restricted or even banned. This work is placed inside the European project C2CA (from Concrete to Cement and Clean Aggregates) and it has been held in the Faculty of Civil Engineering and Geosciences of the Technical University of Delft, in particular, in the laboratory of Resources And Recycling. This research proposes some procedures in order to close the loop of the entire recycling process. After the classification done by ADR (Advanced Dry Recovery) the two fractions "airknife" and "rotor" (that together constitute the fraction 0 - 4 mm) are inserted in a new machine that works at high temperatures. The temperatures analysed in this research are 600 °C and 750 °C, cause at that temperature it is supposed that the cement bounds become very weak. The final goal is "to clean" the coarse fraction (0,250 - 4 mm) from the cement still attached to the sand and try to concentrate the cement paste in the fraction 0 - 0,250 mm. This new set-up is able to dry the material in very few seconds, divide it into two fractions (the coarse one and the fine one) thanks to the air and increase the amount of fines (0 - 0,250 mm) promoting the attrition between the particles through a vibration device. The coarse fraction is then processed in a ball mill in order to improve the result and reach the final goal. Thanks to the high temperature it is possible to markedly reduce the milling time. The sand 0 - 2 mm, after being heated and milled is used to replace 100% of norm sand in mortar production. The results are very promising: the mortar made with recycled sand reaches an early strength, in fact the increment with respect to the mortar made with norm sand is 20% after three days and 7% after seven days. With this research it has been demonstrated that once the temperature is increased it is possible to obtain a clean coarse fraction (0,250 - 4 mm), free from cement paste that is concentrated in the fine fraction 0 - 0,250 mm. The milling time and the drying time can be largely reduced. The recycled sand shows better performance in terms of mechanical properties with respect to the natural one.

Effects of different types of solid feeds on health status and performance of Swiss veal calves. I. Basic feeding with milk by-products

The objective of this study was to identify a suitable alternative to the current practice of complementing the feeding of milk by-products with straw. The influence of 5 different types of solid feeds on health and performance of Swiss veal calves was investigated in 2 production cycles of 200 veal calves each with a mean initial age of 40 days (d). The calves were housed in groups of 40 in stalls with outside pen. Liquid feeding consisted of a milk by-product combined with an additional skim milk powder ad libitum. Groups were assigned to 1 of the 5 following experimental solid feeds provided ad libitum: mix (composition: soy flakes, corn, barley, wheat, oat, barley middling, plant oil, molasses), whole plant corn pellets, corn silage, hay, and wheat straw as control. Daily dry matter intake per calf averaged 2.25 kg of the liquid food, 0.16 kg of straw, 0.33 kg of mix, 0.47 kg of corn silage, 0.38 kg of corn pellets, and 0.39 kg of hay. No significant differences (P > 0.05) among groups were found in calf losses that amounted to 4.8 % (68 % because of gastrointestinal disorders). Four percent of the calves were slaughtered prematurely. Daily doses of antibiotics were higher in the mix (36.9 d, P < 0.01) and in the corn silage groups (35 d, P < 0.01) compared to control. Compared to the 4 other groups, calves of the straw group showed the highest prevalence of abnormal ruminal content (73 %, P < 0.05), of abnormal ruminal papillae (42 %, P < 0.05), of abomasal fundic lesions (13.5 %, P < 0.1), and the lowest number of chewing movements per bolus (45, P < 0.05). The hemoglobin concentration averaged 85 g/l at the beginning and 99 g/l at the end of the fattening period with no significant differences among groups (P > 0.1). The duration of the fattening period averaged 114 d, slaughter age 157 d, and carcass weight 122 kg. The average daily weight gain (ADG) was highest in the control group straw (1.35 kg), and lowest in the hay group (1.22 kg, P < 0.01). The number of carcasses classified as C, H, and T (very high to medium quality) was lower in the hay group compared to straw (P < 0.01). No significant differences between groups were found in meat color (P > 0.1): 73 % of the carcasses were assessed as pale (267/364), 18 % as pink (66/364), and 9 % (31/364) as red. The results reveal that whole-plant corn pellets are most consistent with an optimal result combining the calves' health and fattening performance. Therefore, it can be recommended as an additional solid feed for veal calves under Swiss conditions.

Production of Ethanol from Hardwood

Diminishing crude oil and natural gas supplies, along with concern about greenhouse gas are major driving forces in the search for efficient renewable energy sources. The conversion of lignocellulosic biomass to energy and useful chemicals is a component of the solution. Ethanol is most commonly produced by enzymatic hydrolysis of complex carbohydrates to simple sugars followed by fermentation using yeast. C6Hl0O5 + H2O −Enxymes→ C6H12O6 −Yeast→ 2CH3CH2OH + 2C02 In the U.S. corn is the primary starting raw material for commercial ethanol production. However, there is insufficient corn available to meet the future demand for ethanol as a gasoline additive. Consequently a variety of processes are being developed for producing ethanol from biomass; among which is the NREL process for the production of ethanol from white hardwood. The objective of the thesis reported here was to perform a technical economic analysis of the hardwood to ethanol process. In this analysis a Greenfield plant was compared to co-locating the ethanol plant adjacent to a Kraft pulp mill. The advantage of the latter case is that facilities can be shared jointly for ethanol production and for the production of pulp. Preliminary process designs were performed for three cases; a base case size of 2205 dry tons/day of hardwood (52 million gallons of ethanol per year) as well as the two cases of half and double this size. The thermal efficiency of the NREL process was estimated to be approximately 36%; that is about 36% of the thermal energy in the wood is retained in the product ethanol and by-product electrical energy. The discounted cash flow rate of return on investment and the net present value methods of evaluating process alternatives were used to evaluate the economic feasibility of the NREL process. The minimum acceptable discounted cash flow rate of return after taxes was assumed to be 10%. In all of the process alternatives investigated, the dominant cost factors are the capital recovery charges and the cost of wood. The Greenfield NREL process is not economically viable with the cost of producing ethanol varying from $2.58 to $2.08/gallon for the half capacity and double capacity cases respectively. The co-location cases appear more promising due to reductions in capital costs. The most profitable co-location case resulted in a discounted cash flow rate of return improving from 8.5% for the half capacity case to 20.3% for the double capacity case. Due to economy of scale, the investments become more and more profitable as the size of the plant increases. This concept is limited by the amount of wood that can be delivered to the plant on a sustainable basis as well as the demand for ethanol within a reasonable distance of the plant.

Identifying the roles of the Escherichia coli FtsZ-associated proteins by minimizing the requirements for division

Formation of the FtsZ ring (Z ring) in Escherichia coli is the first step in assembly of the divisome, a molecular machine composed of 14 known proteins which are all required for cell division. Although the biochemical functions of most divisome proteins are unknown, several of these have overlapping roles in ensuring that the Z ring assembles at the cytoplasmic membrane and is active. ^ We identified a single amino acid change in FtsA, R286W, renamed FtsA*, that completely bypasses the requirement for ZipA in cell division. This and other data suggest that FtsA* is a hyperactive form of FtsA that can replace the multiple functions normally assumed by ZipA, which include stabilization of Z rings, recruitment of downstream cell division proteins, and anchoring the Z ring to the membrane. This is the first example of complete functional replacement of an essential prokaryotic cell division protein by another. ^ Cells expressing ftsA* with a complete deletion of ftsK are viable and divide, although many of these ftsK null cells formed multiseptate chains, suggesting a role in cell separation for FtsK. In addition, strains expressing extra ftsAZ, ftsQ, ftsB, zipA or ftsN, were also able to survive and divide in the absence of ftsK. The cytoplasmic and transmembrane domains of FtsQ were sufficient to allow viability and septum formation to ftsK deleted strains. These findings suggest that FtsK is normally involved in stabilizing the divisome and shares functional overlap with other cell division proteins. ^ As well as permitting the removal of other divisome components, the presence of FtsA* in otherwise wild-type cells accelerated Z-ring assembly, which resulted in a significant decrease in the average length of cells. In support of its role in Z-ring stability, FtsA* suppressed the cell division inhibition caused by overexpressing FtsZ. FtsA* did not affect FtsZ turnover within the Z ring as measured by fluorescence recovery after photobleaching. Turnover of FtsA* in the ring was somewhat faster than wild-type FtsA. Yeast two-hybrid data suggest that FtsA* has an increased affinity for FtsZ relative to wild-type FtsA. These results indicate that FtsA* interacts with FtsZ more strongly, and its enhancement of Z ring assembly may explain why FtsA* can permit survival of cells lacking ZipA or FtsK.^

Proceedings of the Eighteenth Annual Biochemical Engineering Symposium

The eighteenth annual biochemical engineering symposium was held during April 22–23, 1988 at the YMCA of the Rockies conference center in Estes Park, Colorado, under the sponsorship of the University of Colorado. Previous symposia in this series have been hosted by Kansas State University (1st, 3rd, 5th, 9th, 12th, 16th), University of Nebraska-Lincoln (2nd, 4th), Iowa State University (6th, 7th, l0th, 13th, 17th), University of Missouri–Columbia (8th, 14th), and Colorado State University (11th, 15th). Next year's symposium is scheduled to be held at the University of Missouri-Columbia. The symposia are devoted to talks by students about their ongoing research. Because final publication usually takes place elsewhere, the papers included in the proceedings are brief, and often cover work in progress. ContentsApplications of mass spectrometers in biochemical engineeringJohn P. McDonald, Ayush Gupta, and Lourdes Taladriz, Kansas State University Enzymatic hydrolysis of corn gluten proteinsJulie Hardwick; Iowa State University Improved Acetone-Butanol Fermentation AnalysisZ. Buday; Colorado State University On-Line State Identification for Batch FermentationD. A. Gee and W. F. Ramirez; University of Colorado Role of Spargers in Air-Lift ReactorsPeter U. Sohn and Rakesh K. Bajpai; University of Missouri–Columbia The Interaction of Microcarriers and Turbulence within an Airlift FermenterG. Travis Jones; Kansas State University Oxygen Diffusion in the Inter-Fiber Gel/Cell Matrix of NMR-Compatible Hollow Fiber Bio-ReactorsS. L. Hanson, B. E. Dale, and R. J. Gillies; Colorado State University Characterization of Ca-alginate Gel Beads FormationHorngtwu Su, Rakesh K. Bajpai, and George W. Preckshot; University of Missouri–Columbia Metabolic Effects of Chloramphenicol Resistance in the Recombinant Host/Vector System: E. coli RRl [pBR329]William E. Bentley, Dana C. Andersen, Dhinakar S. Kompala, and Robert H. Davis; University of Colorado Genetic Engineering of Beta-Galactosidase to Aid in Fermentation Product Recovery by Polyelectrolyte PrecipitationD. E. Parker, C. E. Glatz, J. Zhao, C. F. Ford, S. M. Gendel, and M. A. Rougvie; Iowa State University Biodegradation of Organic Compounds in SoilLourdes Taladriz, L. E. Erickson, and L. T. Fan; Kansas State University Effect of Dilution, pH and Nutrient Composition on the Biodegradation of Metalworking FluidsAyush Gupta, L. E. Erickson, and L. T. Fan; Kansas State University Dissolved Hydrogen Correlation with Redox Potential in Acetone-Butanol FermentationXiangdong Zhou; Colorado State University Modeling of Ensiling Fermentation of Sweet SorghumA. K. Hilaly; Colorado State University

Proceedings of the 22nd Annual Biochemical Engineering Symposium

This is the twenty-second of a series of symposia devoted to talks and posters by students about their biochemical engineering research. The first, third, fifth, ninth, twelfth, sixteenth, and twenti~th were hosted by Kansas State University, the second and fourth by the University of Nebraska- Lincoln, the sixth, seventh, tenth, thirteenth, seventeenth, and twenty-second by Iowa State University, the eighth, fourteenth, and nineteenth by the University of Missouri-Columbia, the eleventh, fifteenth, and twenty-first by Colorado State University, and the eighteenth by the University of Colorado. Next year's symposium will be at the University of Oklahoma. Symposium proceedings are edited and issued by faculty of the host institution. Because final publication usually takes place in refereed journals, articles included here are brief and often cover work in progress. ContentsC. A. Baldwin, J.P. McDonald, and L. E. Erickson, Kansas State University. Effect of Hydrocarbon Phase on Kinetic and Transport Limitations for Bioremediation of Microporous Soil J. C. Wang, S. K. Banerji, and Rakesh Bajpai, University of Missouri-Columbia. Migration of PCP in Soil-Columns in Presence of a Second Organic Phase Cheng-Hsien Hsu and Roger G. Harrison, University of Oklahoma. Bacterial Leaching of Zinc and Copper from Mining Wastes James A. Searles, Paul Todd, and Dhinakar S. Kompala, University of Colorado. Suspension Culture of Chinese Hamster Ovary Cells Utilizing Inclined Sedimentation Ron Beyerinck and Eric H. Dunlop, Colorado State University. The Effect of Feed Zone Turbulence as Measured by Laser Doppler Velocimetry on Baker's Yeast Metabolism in a Chemostat Paul Li-Hong Yeh, GraceY. Sun, Gary A. Weisman, and Rakesh Bajpai, University of Missouri-Columbia. Effect of Medium Constituents upon Membrane Composition of Insect Cells R. Shane Gold, M. M. Meagher, R. Hutkins, and T. Conway, University of Nebraska-Lincoin. Ethanol Tolerance and Carbohydrate Metabolism in Lactobacilli John Sargantanis and M. N. Karim, Colorado State University. Application of Kalman Filter and Adaptive Control in Solid Substrate Fermentation D. Vrana, M. Meagher, and R. Hutkins, University of Nebraska-Lincoln. Product Recovery Optimization in the ABE Fermentation Kalyan R. Tadikonda and Robert H. Davis, University of Colorado. Cell Separations Using Targeted Monoclonal Antibodies Against Surface Proteins Meng H. Heng and Charles E. Glatz, Iowa State University. Charged Fusion for Selective Recovery of B-Galactosidase from Cell Extract Using Hollow Fiber Ion-Exchange Membrane Adsorption Hsiu-Mei Chen, Peter J. Reilly, and Clark Ford, Iowa State University. Site-Directed Mutagenesis to Enhance Thermostability of Glucoamylase from Aspergillus: A Rational Approach P. Tuitemwong, L. E. Erickson, and D. Y. C. Fung, Kansas State University. Applications of Enzymatic Hydrolysis and Fermentation on the Reduction of Flatulent Sugars in the Rapid Hydration Hydrothermal Cooked Soy Milk Sanjeev Redkar and Robert H. Davis, University of Colorado. Crossflow Microfiltration of Yeast Suspensions Linda Henk and James C. Linden, Colorado State University, and Irving C. Anderson, Iowa State University. Evaluation of Sorghum Ensilage as an Ethanol Feedstock Marc Lipovitch and James C. Linden, Colorado State University. Stability and Biomass Feedstock Pretreatability for Simultaneous Saccharification and Fermentation Ali Demirci, Anthony L. Pometto Ill, and Kenneth E. Johnson, Iowa State University. Application of Biofilm Reactors in Lactic Acid Fermentation Michael K. Dowd, Peter I. Reilly, and WalterS. Trahanovsky, Iowa State University. Low Molecular-Weight Organic Composition of Ethanol Stillage from Corn Craig E. Forney, Meng H. Heng, John R. Luther, Mark Q. Niederauer, and Charles E. Glatz, Iowa State University. Enhancement of Protein Separation Using Genetic Engineering J. F. Shimp, J. C. Tracy, E. Lee, L. C. Davis, and L. E. Erickson, Kansas State University. Modeling Contaminant Transport, Biodegradation and Uptake by Plants in the Rhizosphere Xiaoqing Yang, L. E. Erickson, and L. T. Fan, Kansas State University. Modeling of Dispersive-Convective Characteristics in Bioremediation of Contaminated Soil Jan Johansson and Rakesh Bajpai, University of Missouri-Columbia. Fouling of Membranes J. M. Wang, S. K. Banerji, and R. K. Bajpai, University of Missouri-Columbia. Migration of Sodium-Pentachorophenol (Na-PCP) in Unsaturated and Saturated Soil-Columns J. Sweeney and M. Meagher, University of Nebraska-Lincoln. The Purification of Alpha-D-Glucuronidase from Trichoderma reesei

Implications of the mesophyll conductance to CO2 for photosynthesis and water-use efficiency during long-term water stress and recovery in two contrasting Eucalyptu species

Water stress (WS) slows growth and photosynthesis (An), but most knowledge comes from short-time studies that do not account for longer term acclimation processes that are especially relevant in tree species. Using two Eucalyptus species that contrast in drought tolerance, we induced moderate and severe water deficits by withholding water until stomatal conductance (gsw) decreased to two pre-defined values for 24 d, WS was maintained at the target gsw for 29 d and then plants were re-watered. Additionally, we developed new equations to simulate the effect on mesophyll conductance (gm) of accounting for the resistance to refixation of CO2. The diffusive limitations to CO2, dominated by the stomata, were the most important constraints to An. Full recovery of An was reached after re-watering, characterized by quick recovery of gm and even higher biochemical capacity, in contrast to the slower recovery of gsw. The acclimation to long-term WS led to decreased mesophyll and biochemical limitations, in contrast to studies in which stress was imposed more rapidly. Finally, we provide evidence that higher gm under WS contributes to higher intrinsic water-use efficiency (iWUE) and reduces the leaf oxidative stress, highlighting the importance of gm as a target for breeding/genetic engineering.

Spontaneous corticospinal axonal plasticity and functional recovery after adult central nervous system injury

Although it is believed that little recovery occurs after adult mammalian spinal cord injury, in fact significant spontaneous functional improvement commonly occurs after spinal cord injury in humans. To investigate potential mechanisms underlying spontaneous recovery, lesions of defined components of the corticospinal motor pathway were made in adult rats in the rostral cervical spinal cord or caudal medulla. Following complete lesions of the dorsal corticospinal motor pathway, which contains more than 95% of all corticospinal axons, spontaneous sprouting from the ventral corticospinal tract occurred onto medial motoneuron pools in the cervical spinal cord; this sprouting was paralleled by functional recovery. Combined lesions of both dorsal and ventral corticospinal tract components eliminated sprouting and functional recovery. In addition, functional recovery was also abolished if dorsal corticospinal tract lesions were followed 5 weeks later by ventral corticospinal tract lesions. We found extensive spontaneous structural plasticity as a mechanism correlating with functional recovery in motor systems in the adult central nervous system. Experimental enhancement of spontaneous plasticity may be useful to promote further recovery after adult central nervous system injury.

Potent Inhibition of Ribulose-Bisphosphate Carboxylase by an Oxidized Impurity in Ribulose-1,5-Bisphosphate1

Oxidation of d-ribulose-1,5-bisphosphate (ribulose-P2) during synthesis and/or storage produces d-glycero-2,3-pentodiulose-1,5-bisphosphate (pentodiulose-P2), a potent slow, tight-binding inhibitor of spinach (Spinacia oleracea L.) ribulose-P2 carboxylase/oxygenase (Rubisco). Differing degrees of contamination with pentodiulose-P2 caused the decline in Rubisco activity seen during Rubisco assay time courses to vary between different preparations of ribulose-P2. With some ribulose-P2 preparations, this compound can be the dominant cause of the decline, far exceeding the significance of the catalytic by-product, d-xylulose-1,5-bisphosphate. Unlike xylulose-1,5-bisphosphate, pentodiulose-P2 did not appear to be a significant by-product of catalysis by wild-type Rubisco at saturating CO2 concentration. It was produced slowly during frozen storage of ribulose-P2, even at low pH, more rapidly in Rubisco assay buffers at room temperature, and particularly rapidly on deliberate oxidation of ribulose-P2 with Cu2+. Its formation was prevented by the exclusion of transition metals and O2. Pentodiulose-P2 was unstable and decayed to a variety of other less-inhibitory compounds, particularly in the presence of some buffers. However, it formed a tight, stable complex with carbamylated spinach Rubisco, which could be isolated by gel filtration, presumably because its structure mimics that of the enediol intermediate of Rubisco catalysis. Rubisco catalyzes the cleavage of pentodiulose-P2 by H2O2, producing P-glycolate.

Nitric oxide inhibits creatine kinase and regulates rat heart contractile reserve.

Cardiac myocytes express both constitutive and cytokine-inducible nitric oxide syntheses (NOS). NO and its congeners have been implicated in the regulation of cardiac contractile function. To determine whether NO could affect myocardial energetics, 31P NMR spectroscopy was used to evaluate high-energy phosphate metabolism in isolated rat hearts perfused with the NO donor S-nitrosoacetylcysteine (SNAC). All hearts were exposed to an initial high Ca2+ (3.5 mM) challenge followed by a recovery period, and then, either in the presence or absence of SNAC, to a second high Ca2+ challenge. This protocol allowed us to monitor simultaneously the effect of SNAC infusion on both contractile reserve (i.e., baseline versus high workload contractile function) and high-energy phosphate metabolism. The initial high Ca2+ challenge caused the rate-pressure product to increase by 74 +/- 5% in all hearts. As expected, ATP was maintained as phosphocreatine (PCr) content briefly dropped and then returned to baseline during the subsequent recovery period. Control hearts responded similarLy to the second high Ca2+ challenge, but SNAC-treated hearts did not demonstrate the expected increase in rate-pressure product. In these hearts, ATP declined significantly during the second high Ca2+ challenge, whereas phosphocreatine did not differ from controls, suggesting that phosphoryl transfer by creatine kinase (CK) was inhibited. CK activity, measured biochemically, was decreased by 61 +/- 13% in SNAC-treated hearts compared to controls. Purified CK in solution was also inhibited by SNAC, and reversal could be accomplished with DTT, a sulfhydryl reducing agent. Thus, NO can regulate contractile reserve, possibly by reversible nitrosothiol modification of CK.

Characterization of soluble and bound EPS obtained from 2 submerged membrane bioreactors by 3D-EEM and HPSEC

This research study deals with the quantification and characterization of the EPS obtained from two 25 L bench scale membrane bioreactors (MBRs) with micro-(MF-MBR) and ultrafiltration (UF-MBR) submerged membranes. Both reactors were fed with synthetic water and operated for 168 days without sludge extraction, increasing their mixed liquor suspended solid (MLSS) concentration during the experimentation time. The characterization of soluble EPS (EPSs) was achieved by the centrifugation of mixed liquor and bound EPS (EPSb) by extraction using a cationic resin exchange (CER). EPS characterization was carried out by applying the 3-dimensional excitation–emission matrix fluorescence spectroscopy (3D-EEM) and high-performance size exclusion chromatography (HPSEC) with the aim of obtaining structural and functional information thereof. With regard to the 3D-EEM analysis, fluorescence spectra of EPSb and EPSs showed 2 peaks in both MBRs at all the MLSS concentrations studied. The peaks obtained for EPSb were associated to soluble microbial by-product-like (predominantly protein-derived compounds) and to aromatic protein. For EPSs, the peaks were associated with humic and fulvic acids. In both MBRs, the fluorescence intensity (FI) of the peaks increased as MLSS and protein concentrations increased. The FI of the EPSs peaks was much lower than for EPSb. It was verified that the evolution of the FI clearly depends on the concentration of protein and humic acids for EPSb and EPSs, respectively. Chromatographic analysis showed that the intensity of the EPSb peak increased while the concentrations of MLSS did. Additionally, the mean MW calculated was always higher the higher the MLSS concentrations in the reactors. MW was higher for the MF-MBR than for the UF-MBR for the same MLSS concentrations demonstrating that the filtration carried out with a UF membrane lead to retentions of lower MW particles.

The effect of provocation in the form of mild erotica on attitude to the ad and corporate image: Differences between cause-related and product-based advertising

Provocative advertising is characterized by a deliberate attempt to gain attention through shock. This research investigates the reactions of individuals to a provocative appeal for a cause as opposed to a provocative advertisement for a standard consumer product, using mild erotica as the element of provocative imagery. An experiment using 391 adult subjects was conducted, and two analyses were performed. The first examined the effect of stimulus type (mildly erotic/nonerotic) by product category (cause appeal/consumer product) on attitude to the ad. The second examined the effect of stimulus type (mildly erotic/nonerotic) by cause (AIDS [acquired immunodeficiency syndrome]/SIDS [sudden infant death syndrome]) on corporate image. Both analyses also included gender as a third independent variable. The results suggest that people prefer mildly erotic ads generally, that an organization using mild erotica in appeals for a cause will be viewed more favorably where the erotica is congruent with the cause, and that women may be more responsive to mild erotica in cause appeals than are men.

Fast pyrolysis of biomass in a circulating fluidised bed reactor

The objective of this work was to design, construct, test and operate a novel circulating fluid bed fast pyrolysis reactor system for production of liquids from biomass. The novelty lies in incorporating an integral char combustor to provide autothermal operation. A reactor design methodology was devised which correlated input parameters to process variables, namely temperature, heat transfer and gas/vapour residence time, for both the char combustor and biomass pyrolyser. From this methodology a CFB reactor was designed with integral char combustion for 10 kg/h biomass throughput. A full-scale cold model of the CFB unit was constructed and tested to derive suitable hydrodynamic relationships and performance constraints. Early difficulties encountered with poor solids circulation and inefficient product recovery were overcome by a series of modifications. A total of 11 runs in a pyrolysis mode were carried out with a maximum total liquids yield of 61.50% wt on a maf biomass basis, obtained at 500°C and with 0.46 s gas/vapour residence time. This could be improved by improved vapour recovery by direct quenching up to an anticipated 75 % wt on a moisture-and-ash-free biomass basis. The reactor provides a very high specific throughput of 1.12 - 1.48 kg/hm2 and the lowest gas-to-feed ratio of 1.3 - 1.9 kg gas/kg feed compared to other fast pyrolysis processes based on pneumatic reactors and has a good scale-up potential. These features should provide significant capital cost reduction. Results to date suggest that the process is limited by the extent of char combustion. Future work will address resizing of the char combustor to increase overall system capacity, improvement in solid separation and substantially better liquid recovery. Extended testing will provide better evaluation of steady state operation and provide data for process simulation and reactor modeling.