ENHANCING STAKEHOLDER ACCEPTANCE OF BIOREMEDIATION TECHNOLOGIES

This project inquired into the judgments and beliefs of people living near DOE reservations and facilities at Oak Ridge, Tennessee; Hanford, Washington; and Los Alamos, Tennessee about bioremediation of subsurface contamination. The purpose of the investigation was to identify strategies based on these judgments and beliefs for enhancing public support of bioremediation. Several methods were used to collect and analyze data including content analysis of transcripts of face-to-face personal interviews, factor analysis of subjective perspectives using Q methodology, and statistical analysis of results from a large-sample randomized telephone survey. Content analysis of interview transcripts identified themes about public perceptions and constructions of contamination risk, risk management, and risk managers. This analysis revealed that those who have no employment relationship at the sites and are not engaged in technical professions are most concerned about contamination risks. We also found that most interviewees are unfamiliar with subsurface contamination risks and how they can be reduced, believe they have little control over exposure, are frustrated with the lack of progress in remediation, are concerned about a lack of commitment of DOE to full remediation, and distrust site managers to act in the public interest. Concern is also expressed over frequent site management turnover, excessive secrecy, ineffective and biased communication, perceived attempts to talk the public into accepting risk, and apparent lack of concern about community welfare. In the telephone survey, we asked respondents who were aware of site contamination about their perceptions of risk from exposure to subsurface contamination. Response analysis revealed that most people believe that they are at significant risk from subsurface contamination but they acknowledge that more education is needed to calibrate risk perceptions against scientific risk assessments. Most rate their personal control over exposure as low. Slightly more than half believe that risk reduction should be balanced against cost. We also found that distrust of DOE and its contractors exists, primarily due to the perception that site managers do not share public values; hence, the public is generally unwilling to defer to DOE in its decision-making. The concomitant belief of inefficacy confounds distrust by generating frustration that DOE does not care. Moreover, the public is split with respect to trust of each other, primarily because of the belief that citizens lack technical competence. With respect to bioremediation support, we found that more than 40% of the public has no opinion. However, of those who do, 3 of 4 are favorably disposed – particularly among those who believe that risk is lower and who are more trusting of site management. We presented survey respondents with four alternative participation strategies based on the results of the Q analysis and asked their judgments of each. The public prefers strategies that shifts power to them. The least empowered strategy (feedback) was supported by 46%; support grew as public power increased, reaching 66% support for independently facilitated deliberation. More DOE distrust generates more support for high power strategies. We offer the following recommendations to enhance public acceptance. First, and perhaps most importantly, site managers should pursue robust trust-building efforts to gain public confidence in DOE risk management that meets public expectations. Public trust decreases risk perception, which increases public willingness to defer to site managers’ discretion in decision-making, which in turn increases public acceptance of the decisions that result. Second, site managers should address public concerns about bioremediation such as its effectiveness in reducing risk, performance compared to other remediation alternatives, costs compared against benefits, time required to start and complete remediation, level of risk that is currently posed by contamination, and scope of application. Third, more should be done to involve the public in bioremediation decision-making. We recommend a two-stage process: independent facilitated deliberation to build trust and address concerns about the motives and competence of site managers, followed by consultation to maintain that trust. Both stages should be inclusive, transparent, and respectful. Participation objectives and roles of participants should be well specified by the participants. A record of discussion should be published that codifies the concerns raised and how they were addressed, which will facilitate progress by averting the need to reconsider the same issues repeatedly. It is most important that the processes convince the public that its participation influences decision outcomes and that participants genuinely (informed and voluntarily) consent to risk exposure

Development of a fluorescence-based method for monitoring glucose catabolism and its potential use in a biomass hydrolysis assay

<p>Abstract</p> <p>Background</p> <p>The availability and low cost of lignocellulosic biomass has caused tremendous interest in the bioconversion of this feedstock into liquid fuels. One measure of the economic viability of the bioconversion process is the ease with which a particular feedstock is hydrolyzed and fermented. Because monitoring the analytes in hydrolysis and fermentation experiments is time consuming, the objective of this study was to develop a rapid fluorescence-based method to monitor sugar production during biomass hydrolysis, and to demonstrate its application in monitoring corn stover hydrolysis.</p> <p>Results</p> <p>Hydrolytic enzymes were used in conjunction with <it>Escherichia coli </it>strain CA8404 (a hexose and pentose-consuming strain), modified to produce green fluorescent protein (GFP). The combination of hydrolytic enzymes and a sugar-consuming organism minimizes feedback inhibition of the hydrolytic enzymes. We observed that culture growth rate as measured by change in culture turbidity is proportional to GFP fluorescence and total growth and growth rate depends upon how much sugar is present at inoculation. Furthermore, it was possible to monitor the course of enzymatic hydrolysis in near real-time, though there are instrumentation challenges in doing this.</p> <p>Conclusion</p> <p>We found that instantaneous fluorescence is proportional to the bacterial growth rate. As growth rate is limited by the availability of sugar, the integral of fluorescence is proportional to the amount of sugar consumed by the microbe. We demonstrate that corn stover varieties can be differentiated based on sugar yields in enzymatic hydrolysis reactions using post-hydrolysis fluorescence measurements. Also, it may be possible to monitor fluorescence in real-time during hydrolysis to compare different hydrolysis protocols.</p

Extreme weather‐year sequences have nonadditive effects on environmental nitrogen losses

The frequency and intensity of extreme weather years, characterized by abnormal precipitation and temperature, are increasing. In isolation, these years have disproportionately large effects on environmental N losses. However, multi-year sequences of extreme weather years (e.g., wet-dry vs. dry-wet) and annual crop rotation (legume-cereal vs. cereal-legume) may interact to affect cumulative N losses across the complete crop rotation sequence. We calibrated and validated the DAYCENT model with a comprehensive set of biogeophysical measurements from a maizesoybean rotation managed at three different N fertilizer inputs with and without a winter cereal rye cover crop in Iowa, USA. Our objectives were to determine: i) how two-year sequences of extreme weather years interact with annual crop rotation sequence to affect two-year cumulative N losses, and ii) if the inclusion of a winter cover crop between corn and soybean and N fertilizer management mitigate the effect of extreme weather on N losses. Using historical weather data (1951-2013), we created nine two-year weather scenarios with all possible combinations of the hottest and driest (‘dry’), coolest and wettest (‘wet’), and average (‘normal’) weather years. We analyzed the effects of these scenarios following a period of relatively normal weather. Compared to the normal-normal two-year weather scenario, two-year extreme weather scenarios affected two-year cumulative NO3- leaching (range: -28 to +295%) more than N2O emissions (range: -54 to +21%). Moreover, the two-year weather scenarios had non-additive effects on N losses: although dry weather decreased NO3- leaching in isolation, two-year cumulative NO3- losses from the dry-wet scenario were 89% greater than the normal-normal scenario. Cover crops reduced the effect of extreme weather on NO3- leaching, but not N2O emissions. As the frequency of extreme weather events is expected to increase, understanding of interactions between crop rotation and interannual weather patterns can be used to mitigate the effect of extreme weather on environmental N losses

Understanding the DayCent model: Calibration, sensitivity, and identifiability through inverse modeling

AbstractThe ability of biogeochemical ecosystem models to represent agro-ecosystems depends on their correct integration with field observations. We report simultaneous calibration of 67 DayCent model parameters using multiple observation types through inverse modeling using the PEST parameter estimation software. Parameter estimation reduced the total sum of weighted squared residuals by 56% and improved model fit to crop productivity, soil carbon, volumetric soil water content, soil temperature, N2O, and soil NO3− compared to the default simulation. Inverse modeling substantially reduced predictive model error relative to the default model for all model predictions, except for soil NO3− and NH4+. Post-processing analyses provided insights into parameter–observation relationships based on parameter correlations, sensitivity and identifiability. Inverse modeling tools are shown to be a powerful way to systematize and accelerate the process of biogeochemical model interrogation, improving our understanding of model function and the underlying ecosystem biogeochemical processes that they represent

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available. In addition to updating the 2005 study, this report attempts to address a number of its shortcoming

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

YesHuman identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 single nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). This study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.The Technology Commercialization Innovation Program (Contracts #121668, #132043) of the Utah Governors Office of Commercial Development, the Scholarship Activitie