scholarly journals Chromosome Location Contributing to Ozone Tolerance in Wheat

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 261 ◽  
Author(s):  
Alsayed M. Mashaheet ◽  
Kent O. Burkey ◽  
David S. Marshall
Keyword(s):  
Grain Yield ◽  
Chinese Spring ◽  
Foliar Injury ◽  
Stirred Tank Reactors ◽  
Global Food Security ◽  
Ozone Injury ◽  
Plant Environment ◽  
Ozone Tolerance ◽  
Continuous Stirred Tank ◽  
Significant Injury

Breeding wheat for higher grain yield can contribute to global food security and sustainable production on less land. Tropospheric ozone can injure wheat plants and subsequently reduce grain yield. Identification of ozone tolerance in the wheat genome can assist plant breeders in developing new sources of tolerant germplasm. Our objective was to use the ‘Chinese Spring’ monosomic lines to screen for ozone response and identify the chromosomic locations contributing to ozone tolerance based on foliar injury. Two methodologies, Continuous Stirred Tank Reactors and Outdoor Plant Environment Chambers, were used to expose wheat monosomic lines to varying concentrations and durations of ozone. Each wheat monosomic line in ‘Chinese Spring’ has a missing chromosome in each of the wheat subgenomes (A, B, and D). In both methodologies, we found significant and repeatable data to identify chromosome 7A as a major contributor to tolerance to ozone injury in ‘Chinese Spring’. In every experiment, the absence of chromosome 7A resulted in significant injury to wheat due to ozone. This was not the case when any other chromosome was missing.

scholarly journals Effects of Nighttime Ozone Treatment at Ambient Concentrations on Sensitive and Resistant Snap Bean Genotypes

2018 ◽  
Vol 143 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau
Keyword(s):  
Stomatal Conductance ◽  
Phaseolus Vulgaris ◽  
Stirred Tank ◽  
Ozone Treatment ◽  
Foliar Injury ◽  
Snap Bean ◽  
Stirred Tank Reactors ◽  
Ambient Concentrations ◽  
Significant Yield ◽  
Continuous Stirred Tank

The effect of nighttime ozone (O3) exposure, alone and in combination with daytime O3 treatment, was tested on yield of an O3-resistant (R123) and an O3-sensitive (S156) snap bean (Phaseolus vulgaris L.) genotype. Three trials, with exposure durations ranging in length from 14 to 21 days, were conducted in continuous stirred tank reactors located within a greenhouse. The effects of day-only (0800–1900 hr = 11 hours·day−1) and day + night (0800–1900 hr + 2000–0700 hr = 22 hours·day−1) exposure timings were compared. The Fall 2014 trial also tested the effect of nighttime-only (2000–0700 hr = 11 hours·day−1) O3 exposure. Nighttime O3 exposure alone, at 62 ppb, did not cause foliar injury and had no effect on the yield of either genotype. In combination with daytime O3 exposure, nighttime O3 concentrations up to 78 ppb did not impact yields or show a consistent effect on nocturnal stomatal conductance (gsn). When data were pooled across the day and day + night exposures times, mean daytime O3 levels ≥62 ppb caused foliar injury and significant yield decreases in all three trials. Under control conditions, R123 and S156 produced similar pod masses in two of the three trials. In all three trials, R123 produced significantly greater yields by mass than S156 with elevated O3. Nighttime conductance measurements suggested that S156 and R123 have inherently different gsn rates and that cumulative O3 exposure can increase gsn in both genotypes.

Removal of lead by sulfate-reducing bacteria in anaerobic continuous stirred tank reactors

2016 ◽  
Vol 14 (3) ◽  
pp. 557-561
Author(s):  
Nguyễn Thị Yên ◽  
Kiều Thị Quỳnh Hoa
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Stirred Tank ◽  
Synthetic Wastewater ◽  
Terminal Electron Acceptor ◽  
Stirred Tank Reactors ◽  
Sulfate Reducing ◽  
Sulfide Production ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors ◽  
Reducing Bacteria

Lead contaminated wastewater negatively impacts to living organisms as well as humans. In recent years, a highly promising biological process using the anaerobic production of sulfide ions by sulfate-reducing bacteria has presented itself as an alternative option for the removal of lead. This process is based on microbial utilization of electron donors, such as organic compounds (carbon sources), and sulfate as the terminal electron acceptor for sulfide production. The biogenic hydrogen sulfide reacts with dissolved heavy metals to form insoluble metal sulfide precipitates Removal of lead by an enriched consortium of sulfate-reducing bacteria (DM10) was evaluated sulfate reduction, sulfide production and lead precipitation. Four parallel anaerobic continuous stirred tank reactors (CSTR, V = 2L) (referred as R1 - R4) were fed with synthetic wastewater containing Pb2+ in the concentrations of 0, 100, 150 and 200 mg L-1 of lead and operated with a hydraulic retention time of 5 days for 40 days. The loading rates of each metal in R1- R4 were 0, 20, 30 and 40 mg L-1 d-1, respectively. The results showed that there was no inhibition of SRB growth and that lead removal efficiencies of 99-100% for Pb2+ were achieved in R2 (100 mg L-1) and R3 (150 mg L-1) throughout the experiment. For the highest lead concentration of  200 mg L-1, a decrease in efficiency of removal (from 100 to 96%) was observed at the end of the experiment. The obtained result of this study might help for a better control operation and performance improvements of reactors.

scholarly journals Process Engineering of the Acetone-Ethanol-Butanol (ABE) Fermentation in a Linear and Feedback Loop Cascade of Continuous Stirred Tank Reactors: Experiments, Modeling and Optimization

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 108-129
Author(s):  
Katja Karstens ◽  
Sergej Trippel ◽  
Peter Götz
Keyword(s):  
Feedback Loop ◽  
Early Stage ◽  
Formation Rate ◽  
Abe Fermentation ◽  
Operating Conditions ◽  
Stirred Tank ◽  
Second Phase ◽  
Stirred Tank Reactors ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors

The production of butanol, acetone and ethanol by Clostridium acetobutylicum is a biphasic fermentation process. In the first phase the carbohydrate substrate is metabolized to acetic and butyric acid, in the following second phase the product spectrum is shifted towards the economically interesting solvents. Here we present a cascade of six continuous stirred tank reactors (CCSTR), which allows performing the time dependent metabolic phases of an acetone-butanol-ethanol (ABE) batch fermentation in a spatial domain. Experimental data of steady states under four operating conditions—with variations of the pH in the first bioreactor between 4.3 and 5.6 as well as the total dilution rate between 0.042 h−1 and 0.092 h−1—were used to optimize and validate a corresponding mathematical model. Beyond a residence time distribution representation and substrate, biomass and product kinetics this model also includes the differentiation of cells between the metabolic states. Model simulations predict a final product concentration of 8.2 g butanol L−1 and a productivity of 0.75 g butanol L−1 h−1 in the CCSTR operated at pHbr1 of 4.3 and D = 0.092 h−1, while 31% of the cells are differentiated to the solventogenic state. Aiming at an enrichment of solvent-producing cells, a feedback loop was introduced into the cascade, sending cells from a later state of the process (bioreactor 4) back to an early stage of the process (bioreactor 2). In agreement with the experimental observations, the model accurately predicted an increase in butanol formation rate in bioreactor stages 2 and 3, resulting in an overall butanol productivity of 0.76 g L−1 h−1 for the feedback loop cascade. The here presented CCSTR and the validated model will serve to investigate further ABE fermentation strategies for a controlled metabolic switch.

scholarly journals Effect of Hydraulic Retention Time on Anaerobic Digestion of Wheat Straw in the Semicontinuous Continuous Stirred-Tank Reactors

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao-Shuang Shi ◽  
Jian-Jun Dong ◽  
Jun-Hong Yu ◽  
Hua Yin ◽  
Shu-Min Hu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Wheat Straw ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Methane Content ◽  
Stirred Tank ◽  
Crystalline Cellulose ◽  
Stirred Tank Reactors ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors

Three semicontinuous continuous stirred-tank reactors (CSTR) operating at mesophilic conditions (35°C) were used to investigate the effect of hydraulic retention time (HRT) on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs.

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