A lab-scale ethanol fermentation was investigated to determine where aflatoxin concentrated during each phase of production. Four corn samples with high levels of aflatoxin (ranging from 7750 – 17,208 parts per billi...A lab-scale ethanol fermentation was investigated to determine where aflatoxin concentrated during each phase of production. Four corn samples with high levels of aflatoxin (ranging from 7750 – 17,208 parts per billion) and their replicates were compared with a replicated negative control. Fractions were taken from the fermented mash, distilled ethanol, stillage, and dried corn solids (DCS). These fractions were analyzed using two different immunoassay methods and liquid chromatography tandem mass spectrometry (LC-MS/MS). Results indicated no aflatoxin was found in the distilled ethanol. Some aflatoxin (13%) was detected in the stillage, but most of the toxin was recovered in the DCSs ranging from 31% to 58%. A second series of experiments were conducted to investigate the effect of binders on dried distillers grains (DDGs). A brewers dried yeast anti-caking binder that contains glucomannon (MTB-100?), was mixed with contaminated DDGs. Addition of the binder showed a significant reduction in aflatoxin levels in comparison to a positive control. Aflatoxin binding at 2% binder w/w reached 72.5% and showed a minimal binding percentage increase of 80% at 6% binder w/w. Testing was also conducted to determine if environmental variables such as pH and temperature had any effect on the binding capabilities. Temperature near 0?C resulted in binding at 19.7% at a pH range of 6 to 8. Additionally, at a temperature of 40?C resulted in binding of 36%, 47%, and 45% at pHs 6, 7, and 8, respectively. These findings suggest that the addition of sorbents may be an effective way of salvaging contaminated DDGs.展开更多
Cardinal temperatures for plant processes have been used for thermotolerance screening of geNotypes, geoclimatic adaptability determination and pheNological prediction. Current simulation models for switchgrass (Panic...Cardinal temperatures for plant processes have been used for thermotolerance screening of geNotypes, geoclimatic adaptability determination and pheNological prediction. Current simulation models for switchgrass (Panicum virga-tum L.) utilize single cardinal temperatures across geNotypes for both vegetative and reproductive processes although intra-specific variation exists among geNotypes. An experiment was conducted to estimate the cardinal temperatures for seed germination of 14 diverse switchgrass geNotypes and to classify geNotypes for temperature tolerance. Strati-fied seeds of each geNotype were germinated at eight constant temperatures from 10oC to 45oC under a constant light intensity of 35 μmol m-2 s-1 for 12 h d-1. Germination was recorded at 6-h intervals in all treatments. Maximum seed germination (MSG) and germination rate (GR), estimated by fitting Sigmoidal function to germination-time series data, varied among geNotypes. Quadratic and bilinear models best described the MSG and GR responses to temperature, respectively. The mean cardinal temperatures, Tmin, Topt and Tmax, were 8.1, 26.6, and 45.1oC for MSG and 11.1, 33.1, and 46.0oC for GR, respectively. Cardinal temperatures for MSG and GR;however, varied significantly among geNotypes. GeNotypes were classified as sensitive (‘Cave-in-rock’, ‘Dacotah’, ‘Expresso’, ‘Forestburg’, ‘Kanlow’, ‘Sunburst’, ‘Trailblazer’, and ‘Warrior’), intermediate (‘Alamo’, ‘Blackwell’, ‘Carthage’, ‘Shawnee’, and ‘Shelter’) and tolerant (‘Summer’) to high temperature based on cumulative temperature response index (CTRI) estimated by summing individual response indices estimated from the MSG and GR cardinal temperatures. Similarly, geNotypes were also classified as sensitive (Alamo, Blackwell, Carthage, Dacotah, Shawnee, Shelter, and Summer), moderately sensitive (Cave-in-rock, Forestburg, Kanlow, Sunburst, and Warrior), moderately tolerant (Trailblazer), and tolerant (Expresso) to low temperatures. The cardinal temperature estimates would be useful to improve switchgrass models for field applications. Additionally, the identified cold- and heat-tolerant geNotypes can be selected for niche environments and in switchgrass breeding programs to develop new geNotypes for low and high temperature environments.展开更多
文摘A lab-scale ethanol fermentation was investigated to determine where aflatoxin concentrated during each phase of production. Four corn samples with high levels of aflatoxin (ranging from 7750 – 17,208 parts per billion) and their replicates were compared with a replicated negative control. Fractions were taken from the fermented mash, distilled ethanol, stillage, and dried corn solids (DCS). These fractions were analyzed using two different immunoassay methods and liquid chromatography tandem mass spectrometry (LC-MS/MS). Results indicated no aflatoxin was found in the distilled ethanol. Some aflatoxin (13%) was detected in the stillage, but most of the toxin was recovered in the DCSs ranging from 31% to 58%. A second series of experiments were conducted to investigate the effect of binders on dried distillers grains (DDGs). A brewers dried yeast anti-caking binder that contains glucomannon (MTB-100?), was mixed with contaminated DDGs. Addition of the binder showed a significant reduction in aflatoxin levels in comparison to a positive control. Aflatoxin binding at 2% binder w/w reached 72.5% and showed a minimal binding percentage increase of 80% at 6% binder w/w. Testing was also conducted to determine if environmental variables such as pH and temperature had any effect on the binding capabilities. Temperature near 0?C resulted in binding at 19.7% at a pH range of 6 to 8. Additionally, at a temperature of 40?C resulted in binding of 36%, 47%, and 45% at pHs 6, 7, and 8, respectively. These findings suggest that the addition of sorbents may be an effective way of salvaging contaminated DDGs.
文摘Cardinal temperatures for plant processes have been used for thermotolerance screening of geNotypes, geoclimatic adaptability determination and pheNological prediction. Current simulation models for switchgrass (Panicum virga-tum L.) utilize single cardinal temperatures across geNotypes for both vegetative and reproductive processes although intra-specific variation exists among geNotypes. An experiment was conducted to estimate the cardinal temperatures for seed germination of 14 diverse switchgrass geNotypes and to classify geNotypes for temperature tolerance. Strati-fied seeds of each geNotype were germinated at eight constant temperatures from 10oC to 45oC under a constant light intensity of 35 μmol m-2 s-1 for 12 h d-1. Germination was recorded at 6-h intervals in all treatments. Maximum seed germination (MSG) and germination rate (GR), estimated by fitting Sigmoidal function to germination-time series data, varied among geNotypes. Quadratic and bilinear models best described the MSG and GR responses to temperature, respectively. The mean cardinal temperatures, Tmin, Topt and Tmax, were 8.1, 26.6, and 45.1oC for MSG and 11.1, 33.1, and 46.0oC for GR, respectively. Cardinal temperatures for MSG and GR;however, varied significantly among geNotypes. GeNotypes were classified as sensitive (‘Cave-in-rock’, ‘Dacotah’, ‘Expresso’, ‘Forestburg’, ‘Kanlow’, ‘Sunburst’, ‘Trailblazer’, and ‘Warrior’), intermediate (‘Alamo’, ‘Blackwell’, ‘Carthage’, ‘Shawnee’, and ‘Shelter’) and tolerant (‘Summer’) to high temperature based on cumulative temperature response index (CTRI) estimated by summing individual response indices estimated from the MSG and GR cardinal temperatures. Similarly, geNotypes were also classified as sensitive (Alamo, Blackwell, Carthage, Dacotah, Shawnee, Shelter, and Summer), moderately sensitive (Cave-in-rock, Forestburg, Kanlow, Sunburst, and Warrior), moderately tolerant (Trailblazer), and tolerant (Expresso) to low temperatures. The cardinal temperature estimates would be useful to improve switchgrass models for field applications. Additionally, the identified cold- and heat-tolerant geNotypes can be selected for niche environments and in switchgrass breeding programs to develop new geNotypes for low and high temperature environments.
