Microbiology Commons^™

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. Khan, Madeline Lopez-Munoz, Charles Kaspar, Kai Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. A. Khan, Madeline M. Lopez-Munoz, Charles W. Kaspar, Kai F. Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

Phenotypic And Genotypic Characterization Of Escherichia Coli Isolated From Untreated Surface Waters, Kai Hung, Steven Daniel, Kristopher Janezic, Blake Ferry, Eric Hendricks, Brian Janiga, Tiffany Johnson, Samantha Murphy, Morgan Roberts, Sarah Scott, Alexandra Theisen

Faculty Research & Creative Activity

A common member of the intestinal microbiota in humans and animals is Escherichia coli. Based on the presence of virulence factors, E. coli can be potentially pathogenic. The focus of this study was to isolate E. coli from untreated surface waters (37 sites) in Illinois and Missouri and determine phenotypic and genotypic diversity among isolates. Water samples positive for fecal coliforms based on the Colisure® test were streaked directly onto Eosin Methylene Blue (EMB) agar (37°C) or transferred to EC broth (44.5°C). EC broth cultures producing gas were then streaked onto EMB agar. Forty-five isolates were identified as E. coli …

Phenotypic And Genotypic Characterization Of Escherichia Coli Isolated From Untreated Surface Waters, Kai F. Hung, Steven L. Daniel, Kristopher J. Janezic, Blake Ferry, Eric W. Hendricks, Brian A. Janiga, Tiffany Johnson, Samantha Murphy, Morgan E. Roberts, Sarah M. Scott, Alexandra N. Theisen

Faculty Research & Creative Activity

A common member of the intestinal microbiota in humans and animals is Escherichia coli. Based on the presence of virulence factors, E. coli can be potentially pathogenic. The focus of this study was to isolate E. coli from untreated surface waters (37 sites) in Illinois and Missouri and determine phenotypic and genotypic diversity among isolates. Water samples positive for fecal coliforms based on the Colisure® test were streaked directly onto Eosin Methylene Blue (EMB) agar (37°C) or transferred to EC broth (44.5°C). EC broth cultures producing gas were then streaked onto EMB agar. Forty-five isolates were identified as E. coli …

Using Comparative Genomics For Inquiry-Based Learning To Dissect Virulence Of Escherichia Coli O157:H7 And Yersinia Pestis, David J. Baumler, Lois M. Banta, Kai F. Hung, Jodi A. Schwarz, Eric L. Cabot, Jeremy D. Glasner, Nicole T. Perna

Faculty Research & Creative Activity

Genomics and bioinformatics are topics of increasing interest in undergraduate biological science curricula. Many existing exercises focus on gene annotation and analysis of a single genome. In this paper, we present two educational modules designed to enable students to learn and apply fundamental concepts in comparative genomics using examples related to bacterial pathogenesis. Students first examine alignments of genomes of Escherichia coli O157:H7 strains isolated from three food-poisoning outbreaks using the multiple-genome alignment tool Mauve. Students investigate conservation of virulence factors using the Mauve viewer and by browsing annotations available at the A Systematic Annotation Package for Community Analysis of …

Using Comparative Genomics For Inquiry-Based Learning To Dissect Virulence Of Escherichia Coli O157:H7 And Yersinia Pestis, David Baumler, Lois Banta, Kai Hung, Jodi Schwarz, Eric Cabot, Jeremy Glasner, Nicole Perna

Faculty Research & Creative Activity

Genomics and bioinformatics are topics of increasing interest in undergraduate biological science curricula. Many existing exercises focus on gene annotation and analysis of a single genome. In this paper, we present two educational modules designed to enable students to learn and apply fundamental concepts in comparative genomics using examples related to bacterial pathogenesis. Students first examine alignments of genomes of Escherichia coli O157:H7 strains isolated from three food-poisoning outbreaks using the multiple-genome alignment tool Mauve. Students investigate conservation of virulence factors using the Mauve viewer and by browsing annotations available at the A Systematic Annotation Package for Community Analysis of …

Evaluation Of Glyphosate-Tolerant Soybean Cultivars For Resistance To Bacterial Pustule, Lopa Goradia, Glen Hartman, Steven Daniel

Faculty Research & Creative Activity

Xanthomonas axonopodis pv. glycines causes bacterial pustule of soybean, which is a common disease in many soybean-growing areas of the world and is controlled by a single recessive gene (rxp gene) commonly found in many conventional glyphosate-sensitive soybean cultivars. Since glyphosate-tolerant cultivars are commonly planted today, there has been no information about whether these new cultivars have bacterial pustule resistance. The goal of this study was to screen glyphosate-tolerant soybean cultivars for resistance to X. axonopodis pv. glycines. Three experiments were completed to evaluate resistance. In experiment 1, 525 commercial glyphosate-tolerant cultivars from 2001 were inoculated with X. axonopodis pv. …

Evaluation Of Glyphosate-Tolerant Soybean Cultivars For Resistance To Bacterial Pustule, Lopa Goradia, Glen Hartman, Steven L. Daniel

Faculty Research & Creative Activity

Xanthomonas axonopodis pv. glycines causes bacterial pustule of soybean, which is a common disease in many soybean-growing areas of the world and is controlled by a single recessive gene (rxp gene) commonly found in many conventional glyphosate-sensitive soybean cultivars. Since glyphosate-tolerant cultivars are commonly planted today, there has been no information about whether these new cultivars have bacterial pustule resistance. The goal of this study was to screen glyphosate-tolerant soybean cultivars for resistance to X. axonopodis pv. glycines. Three experiments were completed to evaluate resistance. In experiment 1, 525 commercial glyphosate-tolerant cultivars from 2001 were inoculated with X. axonopodis pv. …

Molybdate Treatment And Sulfate Starvation Decrease Atp And Dna Levels In Ferroplasma Acidarmanus, Kai Hung

Faculty Research & Creative Activity

Sulfate is a primary source of sulfur for most microbes and in some prokaryotes it is used an electron acceptor. The acidophile Ferroplasma acidarmanus (strain fer1) requires a minimum of 150 mM of a sulfate-containing salt for growth. Sulfate is assimilated by F. acidarmanus into proteins and reduced to form the volatile organic sulfur compounds methanethiol and dimethyldisulfide. In the absence of sulfate, cell death occurs by an unknown mechanism. In this study, cell viability and genomic DNA and ATP contents of F. acidarmanus were monitored in response to the absence of sulfate or the presence of sulfate and the …

Annotation Of The Bacteriophage 933w Genome: An In-Class Interactive Web-Based Exercise, Kai F. Hung

Faculty Research & Creative Activity

No abstract provided.

Old Acetogens, New Light, Steven L. Daniel, Harold L. Drake, Anita S. Gößner

Faculty Research & Creative Activity

Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO2-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO2-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and …

Molybdate Treatment And Sulfate Starvation Decrease Atp And Dna Levels In Ferroplasma Acidarmanus, Kai F. Hung

Faculty Research & Creative Activity

Sulfate is a primary source of sulfur for most microbes and in some prokaryotes it is used an electron acceptor. The acidophile Ferroplasma acidarmanus (strain fer1) requires a minimum of 150 mM of a sulfate-containing salt for growth. Sulfate is assimilated by F. acidarmanus into proteins and reduced to form the volatile organic sulfur compounds methanethiol and dimethyldisulfide. In the absence of sulfate, cell death occurs by an unknown mechanism. In this study, cell viability and genomic DNA and ATP contents of F. acidarmanus were monitored in response to the absence of sulfate or the presence of sulfate and the …

Old Acetogens, New Light, Steven Daniel, Harold Drake, Anita Gößner

Faculty Research & Creative Activity

Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO2-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO2-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and …

Impact Of Carbon Sources On Growth And Oxalate Synthesis By The Phytopathogenic Fungus Sclerotinia Sclerotiorum, Bryan J. Culbertson, Jaymie Krone, Erastus Gatebe, Norbert C. Furumo, Steven L. Daniel

Faculty Research & Creative Activity

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic …

Impact Of Carbon Sources On Growth And Oxalate Synthesis By The Phytopathogenic Fungus Sclerotinia Sclerotiorum, Steven L. Daniel, Bryan J. Culbertson, Jaymie Krone, Norbert Furumo

Faculty Research & Creative Activity

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic …

Impact Of Carbon Sources On Growth And Oxalate Synthesis By The Phytopathogenic Fungus Sclerotinia Sclerotiorum, Bryan Culbertson, Jaymie Krone, Erastus Gatebe, Norbert Furumo, Steven Daniel

Faculty Research & Creative Activity

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic …

Mammalian Cell Cytotoxicity Analysis Of Soybean Rust Fungicides, Steven L. Daniel, G. L. Hartman, E. D. Wagner, M. J. Plewa

Faculty Research & Creative Activity

The identification of soybean rust, caused by Phakopsora

pachyrhizi H. Sydow & Sydow, in the southern United

States in November 2004 (Schneider et al. 2005 ), in the

Midwest in 2006 (Hartman et al. 2007 ), and elsewhere has

increased the concerns of the impact of the pathogen on US

soybean production (Miles et al. 2007 ). The rapid spread of

P. pachyrhizi and its potential to cause severe yield losses

makes this among the most destructive foliar diseases of

soybean. Yield losses of 20%–60% were reported in Asia,

with losses of 80% reported from experimental plots in

Taiwan (Hartman …

Mammalian Cell Cytotoxicity Analysis Of Soybean Rust Fungicides, Steven Daniel, G. Hartman, E. Wagner, M. Plewa

Faculty Research & Creative Activity

No abstract provided.

Mammalian Cell Cytotoxicity Analysis Of Soybean Rust Fungicides, Steven L. Daniel, G. L. Hartman, E. D. Wagner, M. J. Plewa

Faculty Research & Creative Activity

No abstract provided.

Impact Of Nutritional Supplements And Monosaccharides On Growth, Oxalate Accumulation, And Culture Ph By Sclerotinia Sclerotiorum, Steven Daniel, Bryan Culbertson, Norbert Furumo

Faculty Research & Creative Activity

Sclerotinia sclerotiorum D-E7 was studied to determine the impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH in broth media (initial pH c. 5). Cultures with 0.1% nutritional supplement (tryptone, yeast extract, or soytone) yielded minimal growth, 2–3 mM oxalate, and a final culture pH of 4.2–4.8. In contrast, cultures with 0.1% nutritional supplement and 25 mM glucose yielded significant growth, minimal oxalate (<1 mM), and a final culture pH of 2.8–3.7. Similar trends were observed when glucose in 0.1% soytone cultures was replaced with 25 mM d-mannose, l-arabinose, or d-xylose. With 1% soytone-25 mM glucose cultures, growth and oxalate accumulation (∼21 mM) occurred with little change in initial pH. This was not the case with 1% soytone-250 mM glucose cultures; increased glucose levels resulted in a decrease in oxalate accumulation (∼7 mM) and in final culture pH (3.4). Time-course studies with these cultures revealed that oxalate accumulation was suppressed during growth when the culture pH dropped to <4. Overall, these results indicate that (1) the decrease in external pH (i.e. acidification) was independent of oxalate accumulation and (2) acidification coupled to glucose-dependent growth regulated oxalate accumulation by Sclerotinia sclerotiorum.

Impact Of Nutritional Supplements And Monosaccharides On Growth, Oxalate Accumulation, And Culture Ph By Sclerotinia Sclerotiorum, Steven L. Daniel, Bryan J. Culbertson, Norbert C. Furumo

Faculty Research & Creative Activity

Sclerotinia sclerotiorum D-E7 was studied to determine the impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH in broth media (initial pH c. 5). Cultures with 0.1% nutritional supplement (tryptone, yeast extract, or soytone) yielded minimal growth, 2–3 mM oxalate, and a final culture pH of 4.2–4.8. In contrast, cultures with 0.1% nutritional supplement and 25 mM glucose yielded significant growth, minimal oxalate (<1 mM), and a final culture pH of 2.8–3.7. Similar trends were observed when glucose in 0.1% soytone cultures was replaced with 25 mM d-mannose, l-arabinose, or d-xylose. With 1% soytone-25 mM glucose cultures, growth and oxalate accumulation (∼21 mM) occurred with little change in initial pH. This was not the case with 1% soytone-250 mM glucose cultures; increased glucose levels resulted in a decrease in oxalate accumulation (∼7 mM) and in final culture pH (3.4). Time-course studies with these cultures revealed that oxalate accumulation was suppressed during growth when the culture pH dropped to <4. Overall, these results indicate that (1) the decrease in external pH (i.e. acidification) was independent of oxalate accumulation and (2) acidification coupled to glucose-dependent growth regulated oxalate accumulation by Sclerotinia sclerotiorum.

Anaerobic Oxalate Consumption By Microorganisms In Forest Soils, Steven Daniel, Christine Pilsl, Harold Drake

Faculty Research & Creative Activity

The microbial consumption of oxalate was examined under anaerobic conditions in soil suspensions at 15-20 degree C. With soil (horizon Ah, pH 6.4) from a beech forest, microbial consumption of added oxalate (15 mM) began after 10 days, and oxalate was totally consumed by day 20. The presence of supplemental electron donors (acetate, glucose, vanillate, or hydrogen) or electron acceptors (nitrate or sulfate) did not significantly influence anaerobic oxalate consumption, whereas supplementation of soil suspensions with CO2/bicarbonate totally repressed oxalate consumption. Thus, CO2-, nitrate- or sulfate-respiring bacteria were apparently not active in the anaerobic consumption of oxalate in these soil …

Anaerobic Oxalate Consumption By Microorganisms In Forest Soils, Steven L. Daniel, Christine Pilsl, Harold L. Drake

Faculty Research & Creative Activity

The microbial consumption of oxalate was examined under anaerobic conditions in soil suspensions at 15-20 degree C. With soil (horizon Ah, pH 6.4) from a beech forest, microbial consumption of added oxalate (15 mM) began after 10 days, and oxalate was totally consumed by day 20. The presence of supplemental electron donors (acetate, glucose, vanillate, or hydrogen) or electron acceptors (nitrate or sulfate) did not significantly influence anaerobic oxalate consumption, whereas supplementation of soil suspensions with CO2/bicarbonate totally repressed oxalate consumption. Thus, CO2-, nitrate- or sulfate-respiring bacteria were apparently not active in the anaerobic consumption of oxalate in these soil …

Physiology Of The Thermophilic Acetogen Moorella Thermoacetica, Harold Drake, Steven Daniel

Faculty Research & Creative Activity

Moorella thermoacetica (originally isolated as Clostridium thermoaceticum) has served as the primary acetogenic bacterium for the resolution of the acetyl coenzyme A (acetyl-CoA) orWood–Ljungdahl pathway, a metabolic pathway that (i) autotrophically assimilates CO2 and (ii) is centrally important to the turnover of carbon in many habitats. The purpose of this article is to highlight the diverse physiological features of this model acetogen and to examine some of the consequences of its metabolic capabilities.

Physiology Of The Thermophilic Acetogen Moorella Thermoacetica, Harold L. Drake, Steven L. Daniel

Faculty Research & Creative Activity

Moorella thermoacetica (originally isolated as Clostridium thermoaceticum) has served as the primary acetogenic bacterium for the resolution of the acetyl coenzyme A (acetyl-CoA) orWood–Ljungdahl pathway, a metabolic pathway that (i) autotrophically assimilates CO2 and (ii) is centrally important to the turnover of carbon in many habitats. The purpose of this article is to highlight the diverse physiological features of this model acetogen and to examine some of the consequences of its metabolic capabilities.

Oxalate Metabolism By The Acetogenic Bacterium Moorella Thermoacetica, Steven Daniel, Christine Pilsl, Harold Drake

Faculty Research & Creative Activity

Whole-cell and cell-extract experiments were performed to study the mechanism of oxalate metabolism in the acetogenic bacterium Moorella thermoacetica. In short-term, whole-cell assays, oxalate consumption was low unless cell suspensions were supplemented with CO2, KNO3, or Na2S2O3. Cell extracts catalyzed the oxalate-dependent reduction of benzyl viologen. Oxalate consumption occurred concomitant to benzyl viologen reduction; when benzyl viologen was omitted, oxalate was not appreciably consumed. Based on benzyl viologen reduction, specific activities of extracts averaged 0.6 μmol oxalate oxidized min−1 mg protein−1. Extracts also catalyzed the formate-dependent reduction of NADP+; however, oxalate-dependent reduction of NADP+ was negligible. Oxalate- or formate-dependent reduction …

Oxalate Metabolism By The Acetogenic Bacterium Moorella Thermoacetica, Steven L. Daniel, Christine Pilsl, Harold L. Drake

Faculty Research & Creative Activity

Whole-cell and cell-extract experiments were performed to study the mechanism of oxalate metabolism in the acetogenic bacterium Moorella thermoacetica. In short-term, whole-cell assays, oxalate consumption was low unless cell suspensions were supplemented with CO2, KNO3, or Na2S2O3. Cell extracts catalyzed the oxalate-dependent reduction of benzyl viologen. Oxalate consumption occurred concomitant to benzyl viologen reduction; when benzyl viologen was omitted, oxalate was not appreciably consumed. Based on benzyl viologen reduction, specific activities of extracts averaged 0.6 μmol oxalate oxidized min−1 mg protein−1. Extracts also catalyzed the formate-dependent reduction of NADP+; however, oxalate-dependent reduction of NADP+ was negligible. Oxalate- or formate-dependent reduction …

Review Of Searching For Hawa's Secret, John Stephen Brantley

Faculty Research & Creative Activity

No abstract provided.

Review Of Searching For Hawa's Secret, John Brantley

Faculty Research & Creative Activity

No abstract provided.

Carbon Monoxide-Dependent Chemolithotrophic Growth Of Clostridium Thermoautotrophicum, M. Dean Savage, Zhongren Wu, Steven L. Daniel, Leon L. Lundie Jr, Harold L. Drake

Faculty Research & Creative Activity

The acetogen Clostridium thermoautotrophicum was cultivated under CO-dependent chemolithotrophic conditions. CO-dependent growth profiles and energetics indicated that supplemental CO2 was fundamental to efficient growth at the expense of CO. Overall product stoichiometry approximated 6.5CO --> CH3CO2H + 3.5CO2 + 0.6 cell C + 0.5 unrecovered C. Initial CO/CO2 ratios of 2 to 4 yielded optimal doubling times and cell yields. Maximal YCO values approximated 2.5 g of cell dry weight per mol of CO consumed; Y H2 , was considerably lower than Y CO Cross-transfer growth experiments and protein profiles indicated differential expression of genes between CO and methanol cultures.