Plant Sciences & Plant Pathology

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The Department of Plant Sciences and Plant Pathology is part of the College of Agriculture at Montana State University in Bozeman. An exciting feature of this department is the diversity of programs in Plant Biology, Crop Science, Plant Pathology, Horticulture, Mycology, Plant Genetics and Entomology. The department offers BS, MS, and Ph.D. degree program

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Microbe manufacturers of semiconductors
(2004-11) Flenniken, Michelle L.; Allen, Mark; Douglas, Trevor
Synthesis of cadmium sulfide (CdS) semiconductor nanoparticles within a prokaryotic organism is reported for the first time by Sweeney et al. [1]. This paper demonstrates the utility of microorganisms to perform chemistries outside the scope of their “normal” metabolism and offers an environmentally benign synthesis of CdS nanoparticles.
Melanoma and Lymphocyte Cell Specific Targeting Incorporated into a Heat Shock Protein Cage Architecture
(2006) Flenniken, Michelle L.; Willits, Deborah A.; Harmsen, Ann L.; Liepold, Lars O.; Harmsen, Allen G.; Young, Mark J.; Douglas, Trevor
Protein cages, including viral capsids, ferritins, and heat shock proteins (Hsps), can serve as nanocontainers for biomedical applications. They are genetically and chemically malleable platforms, with potential as therapeutic and imaging agent delivery systems. Here, both genetic and chemical strategies were used to impart cell-specific targeting to the Hsp cage from Methanococcus jannaschii. A tumor vasculature targeting peptide was incorporated onto the exterior surface of the Hsp cage. This protein cage bound to αvβ3 integrin-expressing cells. Cellular tropism was also imparted by conjugating anti-CD4 antibodies to the exterior of Hsp cages. These Ab-Hsp cage conjugates specifically bound to CD4+ cells. Protein cages have the potential to simultaneously incorporate multiple functionalities, including cell-specific targeting, imaging, and therapeutic agent delivery. We demonstrate the simultaneous incorporation of two functionalities, imaging and cell-specific targeting, onto the Hsp protein cage.
Biodistribution studies of protein cage nanoparticles demonstrate broad tissue distribution and rapid clearance in vivo
(2007-12) Kaiser, Coleen R.; Flenniken, Michelle L.; Gillitzer, Eric; Harmsen, Ann L.; Harmsen, Allen G.; Jutila, Mark A.; Douglas, Trevor; Young, Mark J.
Protein cage nanoparticles have the potential to serve as multifunctional cell targeted, imaging and therapeutic platforms for broad applications in medicine. However, before they find applications in medicine, their biocompatibility in vivo needs to be demonstrated. We provide here baseline biodistribution information of two different spherical protein cage nanoplatforms, the 28 nm viral Cowpea chlorotic mottle virus (CCMV) and the 12 nm heat shock protein (Hsp) cage. In naïve and immunized mice both nanoplatforms show similar broad distribution and movement throughout most tissues and organs, rapid excretion, the absence of long term persistence within mice tissue and organs, and no overt toxicity after a single injection. These results suggest that protein cage based nanoparticles may serve as safe, biocompatible, nanoplatforms for applications in medicine.
Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus
(2009-01) Mitchell, Angela M.; Strobel, Gary A.; Moore, Emily; Robison, Richard; Sears, Joe
Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.
Inducible bronchus-associated lymphoid tissue elicited by a protein cage nanoparticle enhances protection in mice against diverse respiratory viruses
(2009-09) Wiley, James A.; Richert, Laura E.; Swain, Steve D.; Harmsen, Ann L.; Barnard, Dale L.; Randall, Troy D.; Jutila, Mark A.; Douglas, Trevor; Broomell, Chris; Young, Mark J.; Harmsen, Allen G.
Background Destruction of the architectural and subsequently the functional integrity of the lung following pulmonary viral infections is attributable to both the extent of pathogen replication and to the host-generated inflammation associated with the recruitment of immune responses. The presence of antigenically disparate pulmonary viruses and the emergence of novel viruses assures the recurrence of lung damage with infection and resolution of each primary viral infection. Thus, there is a need to develop safe broad spectrum immunoprophylactic strategies capable of enhancing protective immune responses in the lung but which limits immune-mediated lung damage. The immunoprophylactic strategy described here utilizes a protein cage nanoparticle (PCN) to significantly accelerate clearance of diverse respiratory viruses after primary infection and also results in a host immune response that causes less lung damage. Methodology/Principal Findings Mice pre-treated with PCN, independent of any specific viral antigens, were protected against both sub-lethal and lethal doses of two different influenza viruses, a mouse-adapted SARS-coronavirus, or mouse pneumovirus. Treatment with PCN significantly increased survival and was marked by enhanced viral clearance, accelerated induction of viral-specific antibody production, and significant decreases in morbidity and lung damage. The enhanced protection appears to be dependent upon the prior development of inducible bronchus-associated lymphoid tissue (iBALT) in the lung in response to the PCN treatment and to be mediated through CD4+ T cell and B cell dependent mechanisms. Conclusions/Significance The immunoprophylactic strategy described utilizes an infection-independent induction of naturally occurring iBALT prior to infection by a pulmonary viral pathogen. This strategy non-specifically enhances primary immunity to respiratory viruses and is not restricted by the antigen specificities inherent in typical vaccination strategies. PCN treatment is asymptomatic in its application and importantly, ameliorates the damaging inflammation normally associated with the recruitment of immune responses into the lung.
Something old, something new, something borrowed; how the thermoacidophilic archaeon Sulfolobus solfataricus responds to oxidative stress
(2009-09) Maaty, Walid S.; Wiedenheft, Blake A.; Tarlykov, Pavel V.; Schaff, Nathan; Heinemann, Joshua V.; Robison-Cox, James; Dougherty, Amanda; Blum, Paul; Lawrence, C. Martin; Douglas, Trevor; Young, Mark J.; Bothner, Brian
To avoid molecular damage of biomolecules due to oxidation, all cells have evolved constitutive and responsive systems to mitigate and repair chemical modifications. Archaea have adapted to some of the most extreme environments known to support life, including highly oxidizing conditions. However, in comparison to bacteria and eukaryotes, relatively little is known about the biology and biochemistry of archaea in response to changing conditions and repair of oxidative damage. In this study transcriptome, proteome, and chemical reactivity analyses of hydrogen peroxide (H2O2) induced oxidative stress in Sulfolobus solfataricus (P2) were conducted. Microarray analysis of mRNA expression showed that 102 transcripts were regulated by at least 1.5 fold, 30 minutes after exposure to 30 µM H2O2. Parallel proteomic analyses using two-dimensional differential gel electrophoresis (2D-DIGE), monitored more than 800 proteins 30 and 105 minutes after exposure and found that 18 had significant changes in abundance. A recently characterized ferritin-like antioxidant protein, DPSL, was the most highly regulated species of mRNA and protein, in addition to being post-translationally modified. As expected, a number of antioxidant related mRNAs and proteins were differentially regulated. Three of these, DPSL, superoxide dismutase, and peroxiredoxin were shown to interact and likely form a novel supramolecular complex for mitigating oxidative damage. A scheme for the ability of this complex to perform multi-step reactions is presented. Despite the central role played by DPSL, cells maintained a lower level of protection after disruption of the dpsl gene, indicating a level of redundancy in the oxidative stress pathways of S. solfataricus. This work provides the first “omics” scale assessment of the oxidative stress response for an archeal organism and together with a network analysis using data from previous studies on bacteria and eukaryotes reveals evolutionarily conserved pathways where complex and overlapping defense mechanisms protect against oxygen toxicity.
An endophytic Myrothecium inundatum producing volatile organic compounds
(2010) Banerjee, Debdulal; Strobel, Gary A.; Booth, B.; Sears, Joe; Spakowicz, Daniel; Busse, S.
Myrothecium inunduatum was isolated as an endophyte from a euphorbeacean herb, Acalypha indica in NE India. This fungus when grown in shake culture produced an abundance of foam. Contained in the foam was a mixture of volatile organic compounds (VOCs) some of which were hydrocarbons and hydrocarbon derivatives. The most prevalent compounds were 3-octanone, 3-octanol, and 7-octen-4-ol. Numerous other volatile organic compounds were also produced including many terpenes, organic acids, ketones, and alcohols. The VOCs of this fungus demonstrated growth inhibitory activity against a number of plant pathogenic fungi including Pythium ultimum and Sclerotinia sclerotiorum. However, when grown in microaerophilic conditions, the organism produced a number of hydrocarbons of interest as fuel related hydrocarbons including octane and tentatively identified- 1,4- cyclohexadiene, 1-methyl- and cyclohexane, (1-ethylpropyl) and others. An NMR method was used to measure VOC production which peaked at day 15 in a time course experiment. Numerous substrates can serve to support the production of VOCs by this fungus including potato broth and beet pulp extracts.
Geobacillus sp., a Thermophilic Soil Bacterium Producing Volatile Antibiotics
(2010-01) Ren, Yuhao; Strobel, Gary A.; Sears, Joe; Park, Melina
Geobacillus, a bacterial genus, is represented by over 25 species of Gram-positive isolates from various man-made and natural thermophilic areas around the world. An isolate of this genus (M-7) has been acquired from a thermal area near Yellowstone National Park, MT and partially characterized. The cells of this organism are globose (ca. 0.5 μ diameter), and they are covered in a matrix capsule which gives rise to elongate multicelled bacilliform structures (ranging from 3 to 12 μm) as seen by light and atomic force microscopy, respectively. The organism produces unique petal-shaped colonies (undulating margins) on nutrient agar, and it has an optimum pH of 7.0 and an optimum temperature range of 55–65°C. The partial 16S rRNA sequence of this organism has 97% similarity with Geobacillus stearothermophilus, one of its closest relatives genetically. However, uniquely among all members of this genus, Geobacillus sp. (M-7) produces volatile organic substances (VOCs) that possess potent antibiotic activities. Some of the more notable components of the VOCs are benzaldehyde, acetic acid, butanal, 3-methyl-butanoic acid, 2-methyl-butanoic acid, propanoic acid, 2-methyl-, and benzeneacetaldehyde. An exposure of test organisms such as Aspergillus fumigatus, Botrytis cinerea, Verticillium dahliae, and Geotrichum candidum produced total inhibition of growth on a 48-h exposure to Geobacillus sp.(M-7) cells (ca.107) and killing at a 72-h exposure at higher bacterial cell concentrations. A synthetic mixture of those available volatile compounds, at the ratios occurring in Geobacillus sp. (M-7), mimicked the bioactivity of this organism.
Muscodor species- Endophytes with Biological Promise
(2010-02) Strobel, Gary A.
A novel fungal genus is described that produces extremely bioactive volatile organic compounds (VOC’s). The initial fungal isolate was discovered as an endophyte in Cinnamomum zeylanicum in a botanical garden in Honduras. This endophytic fungus was named Muscodor albus because of its odor and its white color. This fungus produces a mixture of VOC’s that are lethal to a wide variety of plant and human pathogenic fungi and bacteria. It also is effective against nematodes and certain insects. The mixture of VOC’s has been analyzed using GC/MS and consists primarily of various alcohols, acids, esters, ketones, and lipids. Final verification of the identity of the VOC’s was carried out by using artificial mixtures of the putatively identified compounds and showing that the artificial mixture possessed the identical retention times and mass spectral qualities as those of the fungal derived substances. Artificial mixtures of the available VOC’s mimicked some but not all of the biological effects of the fungal VOC’s when tested against a wide range of fungal and bacterial pathogens. Other species and isolates of this genus have been found in various tropical forests in Australia, Bolivia, Ecuador, and Thailand. The most recent discovery is Muscodor crispans whose VOCs are active against many plant and human pathogens. Potential applications for “mycofumigation” by members of the Muscodor genus are currently being investigated and include uses for treating plant diseases, buildings, soils, agricultural produce and many more. This report will describe how the fungus was discovered, identified, and found potentially useful to agriculture, medicine and industry.
Metagenomes from high-temperature chemotrophic systems reveal geochemical controls on microbial community structure and function
(2010-03) Inskeep, William P.; Rusch, Douglas B.; Jay, Zackary J.; Herrgard, Markus J.; Kozubal, Mark A.; Richardson, Toby H.; Macur, Richard E.; Hamamura, Natsuko; Jennings, Ryan deM.; Fouke, Bruce W.; Reysenbach, Anna-Louise; Roberto, Frank; Young, Mark J.; Schwartz, Ariel; Boyd, Eric S.; Badger, Jonathan H.; Mathur, Eric J.; Ortmann, Alice C.; Bateson, Mary M.; Geesey, Gill G.; Frazier, Marvin
The Yellowstone caldera contains the most numerous and diverse geothermal systems on Earth, yielding an extensive array of unique high-temperature environments that host a variety of deeply-rooted and understudied Archaea, Bacteria and Eukarya. The combination of extreme temperature and chemical conditions encountered in geothermal environments often results in considerably less microbial diversity than other terrestrial habitats and offers a tremendous opportunity for studying the structure and function of indigenous microbial communities and for establishing linkages between putative metabolisms and element cycling. Metagenome sequence (14–15,000 Sanger reads per site) was obtained for five high-temperature (>65°C) chemotrophic microbial communities sampled from geothermal springs (or pools) in Yellowstone National Park (YNP) that exhibit a wide range in geochemistry including pH, dissolved sulfide, dissolved oxygen and ferrous iron. Metagenome data revealed significant differences in the predominant phyla associated with each of these geochemical environments. Novel members of the Sulfolobales are dominant in low pH environments, while other Crenarchaeota including distantly-related Thermoproteales and Desulfurococcales populations dominate in suboxic sulfidic sediments. Several novel archaeal groups are well represented in an acidic (pH 3) Fe-oxyhydroxide mat, where a higher O2 influx is accompanied with an increase in archaeal diversity. The presence or absence of genes and pathways important in S oxidation-reduction, H2-oxidation, and aerobic respiration (terminal oxidation) provide insight regarding the metabolic strategies of indigenous organisms present in geothermal systems. Multiple-pathway and protein-specific functional analysis of metagenome sequence data corroborated results from phylogenetic analyses and clearly demonstrate major differences in metabolic potential across sites. The distribution of functional genes involved in electron transport is consistent with the hypothesis that geochemical parameters (e.g., pH, sulfide, Fe, O2) control microbial community structure and function in YNP geothermal springs.
Targeted delivery of a photosensitizer to Aggregatibacter actinomycetemcomitans biofilm
(2010-04) Suci, Peter A.; Kang, Sebyung; Gmür, Rudolf; Douglas, Trevor; Young, Mark J.
The ability to selectively target specific biofilm species with antimicrobials would enable control over biofilm consortium composition, with medical applications in treatment of infections on mucosal surfaces that are colonized by a mixture of beneficial and pathogenic microorganisms. We functionalized a genetically engineered multimeric protein with both a targeting moiety (biotin) and either a fluorophore or a photosensitizer (SnCe6). Biofilm microcolonies of Aggregatibacter actinomycetemcomitans, a periodontal pathogen, were targeted with the multifunctional dodecamer. Streptavidin was used to couple biotinylated dodecamer to a biotinylated anti-A. actinomycetemcomitans antibody. This modular targeting approach enabled us to increase the loading of photosensitizer onto the cells by a cycle of amplification. Scanning laser confocal microscopy was used to characterize transport of fluorescently tagged dodecamer into the microcolonies and targeting of the cells with biotin-labeled, fluorescently tagged dodecamer. Light-induced activity of the targeted photosensitizer reduced the viability of A. actinomycetemcomitans biofilm, as indicated by membrane permeability to propidium iodide. The functionalized multimeric protein promises to be a useful tool for controlling periodontal biofilm consortia and offers a modular design whereby moieties that target different species can be readily combined with the functionalized protein construct.
A major grain protein content locus on barley (Hordeum vulgare L.) chromosome 6 influences flowering time and sequential leaf senescence
(2010-06) Lacerenza, Joseph A.; Parrott, David L.; Fischer, Andreas M.
Timing of various developmental stages including anthesis and whole-plant (‘monocarpic’) senescence influences yield and quality of annual crops. While a correlation between flowering/seed filling and whole-plant senescence has been observed in many annuals, it is unclear how the gene networks controlling these processes interact. Using near-isogenic germplasm, it has previously been demonstrated that a grain protein content (GPC) locus on barley chromosome 6 strongly influences the timing of post-anthesis flag leaf senescence, with high-GPC germplasm senescing early. Here, it is shown that the presence of high-GPC allele(s) at this locus also accelerates pre-anthesis plant development. While floral transition at the shoot apical meristem (SAM; determined by the presence of double ridges) occurred simultaneously, subsequent development was faster in the high- than in the low-GPC line, and anthesis occurred on average 5 d earlier. Similarly, sequential (pre-anthesis) leaf senescence was slightly accelerated, but only after differences in SAM development became visible. Leaf expression levels of four candidate genes (from a list of genes differentially regulated in post-anthesis flag leaves) were much higher in the high-GPC line even before faster development of the SAM became visible. One of these genes may be a functional homologue of Arabidopsis glycine-rich RNA-binding protein 7, which has previously been implicated in the promotion of flowering. Together, the data establish that the GPC locus influences pre- and post-anthesis barley development and senescence, and set the stage for a more detailed analysis of the interactions between the molecular networks controlling these important life history traits.
The diversity and antimicrobial activity of endophytic actinomycetes isolated from medicinal plants in Panxi Plateau, China
(2010-06) Zhao, Ke; Penttinen, Petri; Guan, Tongwei; Xiao, Jing; Chen, Qiang; Xu, Jun; Lindström, Kristina; Zhang, Lili; Zhang, Xiaoping; Strobel, Gary A.
Traditional Chinese medicinal plants are sources of biologically active compounds, providing raw material for pharmaceutical, cosmetic and fragrance industries. The endophytes of medicinal plants participate in biochemical pathways and produce analogous or novel bioactive compounds. Panxi plateau in South-west Sichuan in China with its unique geographical and climatological characteristics is a habitat of a great variety of medicinal plants. In this study, 560 endophytic actinomycetes were isolated from 26 medicinal plant species in Panxi plateau. 60 isolates were selected for 16S rDNA-RFLP analysis and 14 representative strains were chosen for 16S rDNA sequencing. According to the phylogenetic analysis, seven isolates were Streptomyces sp., while the remainder belonged to genera Micromonospora, Oerskovia, Nonomuraea, Promicromonospora and Rhodococcus. Antimicrobial activity analysis combined with the results of amplifying genes coding for polyketide synthetase (PKS-I, PKS-II) and nonribosomal peptide synthetase (NRPS) showed that endophytic actinomycetes isolated from medicinal plants in Panxi plateau had broad-spectrum antimicrobial activity and potential natural product diversity, which further proved that endophytic actinomycetes are valuable reservoirs of novel bioactive compounds.
Muscodor albus strain GBA, an endophytic fungus of Ginkgo biloba from United States of America, produces volatile antimicrobials
(2010-09) Banerjee, Debdulal; Strobel, Gary A.; Geary, Brad; Sears, Joe; Ezra, David; Liarzi, Orna; Coombs, James
Muscodor albus strain GBA is a newly isolated endophytic fungus from Ginko biloba (family Ginkoaceae) collected in Newport, RI, USA. The cultural characteristics (color, growth pattern) and mycelial/hyphal characteristics resemble many isolates of Muscodor albus. The ITS rDNA sequence of the strain has at least 98% similarity with other isolates of M. albus and M. crispans. This xylariaceaous species effectively inhibits and kills certain test microbes via a mixture of volatile organic compounds (VOCs) that it produces. Some of the target test microbes were totally inhibited by M. albus strain GBA and not by other M. albus isolates, making this isolate unique in its biological activity. The VOCs of this fungus were identified by gas chromatography/mass spectrometry as esters, lipids, alcohols, acids and ketones, including proportionally large quantities of 1-butanol, 3-methyl-, acetate. A terpenoid, not observed in other strains of this fungus, vitrene was tentatively identified in the VOCs of this organism. This is the first record of M. albus in Ginko biloba and is the first report of any M. albus strain from the United States. The organism is normally found in tropical latitudes (16° north/ south) but the plant host M. albus strain GBA is located at 41° north latitude. Most importantly, however, the discovery of M. albus in the USA has enormous implications vis-a.vis governmental regulation of M. albus for use as a biological control agent in agriculture and industry, as this organism naturally occurs in the USA. A discussion on the relationship of this taxon with its host is also included.
The production of myco-diesel hydrocarbons and their derivatives by the endophytic fungus Gliocladium roseum (NRRL 50072)
(2010-12) Strobel, Gary A.; Knighton, W. Berk; Kluck, Katreena; Ren, Yuhao; Livinghouse, Tom; Griffin, Meghan; Spakowicz, Daniel; Sears, Joe
An endophytic fungus, Gliocladiun roseum (NRRL 50072), produced a series of volatile hydrocarbons and hydrocarbon derivatives on an oatmeal-based agar under microaerophilic conditions as analysed by solid-phase micro-extraction (SPME)-GC/MS. As an example, this organism produced an extensive series of the acetic acid esters of straight-chained alkanes including those of pentyl, hexyl, heptyl, octyl, sec-octyl and decyl alcohols. Other hydrocarbons were also produced by this organism, including undecane, 2,6-dimethyl; decane, 3,3,5-trimethyl; cyclohexene, 4-methyl; decane, 3,3,6-trimethyl; and undecane, 4,4-dimethyl. Volatile hydrocarbons were also produced on a cellulose-based medium, including heptane, octane, benzene, and some branched hydrocarbons. An extract of the host plant, Eucryphia cordifolia (ulmo), supported the growth and hydrocarbon production of this fungus. Quantification of volatile organic compounds, as measured by proton transfer mass spectrometry (PTR-MS), indicated a level of organic substances in the order of 80 p.p.m.v. (parts per million by volume) in the air space above the oatmeal agar medium in an 18 day old culture. Scaling the PTR-MS profile the acetic acid heptyl ester was quantified (at 500 p.p.b.v.) and subsequently the amount of each compound in the GC/MS profile could be estimated; all yielded a total value of about 4.0 p.p.m.v. The hydrocarbon profile of G. roseum contains a number of compounds normally associated with diesel fuel and so the volatiles of this fungus have been dubbed ‘myco-diesel’. Extraction of liquid cultures of the fungus revealed the presence of numerous fatty acids and other lipids. All of these findings have implications in energy production and utilization.
The Prevalence of STIV c92-Like Proteins in Acidic Thermal Environments
(2011-05) Snyder, Jamie C.; Bolduc, Benjamin I.; Bateson, Mary M.; Young, Mark J.
A new type of viral-induced lysis system has recently been discovered for two unrelated archaeal viruses, STIV and SIRV2. Prior to the lysis of the infected host cell, unique pyramid-like lysis structures are formed on the cell surface by the protrusion of the underlying cell membrane through the overlying external S-layer. It is through these pyramid structures that assembled virions are released during lysis. The STIV viral protein c92 is responsible for the formation of these lysis structures. We searched for c92-like proteins in viral sequences present in multiple viral and cellular metagenomic libraries from Yellowstone National Park acidic hot spring environments. Phylogenetic analysis of these proteins demonstrates that, although c92-like proteins are detected in these environments, some are quite divergent and may represent new viral families. We hypothesize that this new viral lysis system is common within diverse archaeal viral populations found within acidic hot springs.
An endophytic/pathogenic Phoma sp. from creosote bush producing biologically active volatile compounds having fuel potential
(2011-05) Strobel, Gary A.; Singh, Sanjay K.; Ul-Hassan, Syed Riyaz; Mitchell, Angela M.; Geary, Brad; Sears, Joe
A Phoma sp. was isolated and characterized as endophytic and as a pathogen of Larrea tridentata (creosote bush) growing in the desert region of southern Utah, USA. This fungus produces a unique mixture of volatile organic compounds (VOCs), including a series of sesquiterpenoids, some alcohols and several reduced naphthalene derivatives. Trans-caryophyllene, a product in the fungal VOCs, was also noted in the VOCs of this pungent plant. The gases of Phoma sp. possess antifungal properties and is markedly similar to that of a methanolic extract of the host plant. Some of the test organisms with the greatest sensitivity to the Phoma sp. VOCs were Verticillium, Ceratocystis, Cercospora and Sclerotinia while those being the least sensitive were Trichoderma, Colletotrichum and Aspergillus. We discuss the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship with implications for utilization as an energy source.
Temporal Analysis of the Honey Bee Microbiome Reveals Four Novel Viruses and Seasonal Prevalence of Known Viruses, Nosema and Crithidia
(2011-06) Runckel, Charles; Flenniken, Michelle L.; Engel, Juan C.; Ruby, J. Graham; Ganem, Donald; Andino, Raul; DeRisi, Joseph L.
Honey bees (Apis mellifera) play a critical role in global food production as pollinators of numerous crops. Recently, honey bee populations in the United States, Canada, and Europe have suffered an unexplained increase in annual losses due to a phenomenon known as Colony Collapse Disorder (CCD). Epidemiological analysis of CCD is confounded by a relative dearth of bee pathogen field studies. To identify what constitutes an abnormal pathophysiological condition in a honey bee colony, it is critical to have characterized the spectrum of exogenous infectious agents in healthy hives over time. We conducted a prospective study of a large scale migratory bee keeping operation using high-frequency sampling paired with comprehensive molecular detection methods, including a custom microarray, qPCR, and ultra deep sequencing. We established seasonal incidence and abundance of known viruses, Nosema sp., Crithidia mellificae, and bacteria. Ultra deep sequence analysis further identified four novel RNA viruses, two of which were the most abundant observed components of the honey bee microbiome (∼1011 viruses per honey bee). Our results demonstrate episodic viral incidence and distinct pathogen patterns between summer and winter time-points. Peak infection of common honey bee viruses and Nosema occurred in the summer, whereas levels of the trypanosomatid Crithidia mellificae and Lake Sinai virus 2, a novel virus, peaked in January.
3-Carbamoylquinoxalin-1-ium chloride
(2011-12) Harper, James K.; Strobel, Gary A.; Arif, Atta M.
The title compound, C9H8N3O+·Cl-, was isolated from a liquid culture of streptomyces sp. In the cation, the ring system makes a dihedral angle of 0.2 (2)° with the amide group. The protonation creating the cation occurs at ome of the N atoms in the quinoxaline ring system. In the crystal, the ions are linked through N-H...O and N-H...Cl hydrogen bonds, forming a two-dimensional network parallel to (10\overline{3}).
An endophytic Nodulisporium sp. producing volatile organic compounds having bioactivity and fuel potential
(2012) Mends, Morgan Tess; Yu, Eizadora; Strobel, Gary A.; Hassan, S. R. U.; Booth, Eric; Geary, Brad; Sears, Joe; Taatjes, C. A.; Hadi, M.
Nodulisporium sp. has been isolated as an endophyte of Myroxylon balsamum found in the upper Napo region of the Ecuadorian Amazon. This organism produces volatile organic compounds (VOCs) that have both fuel and biological potential.Under microaerophilic growth environments, the organism produces 1, 4-cyclohexadiene, 1 methyl-,1-4 pentadiene and cyclohexene, 1-methyl-4-(1-methylethenyl)- along with some alcohols and terpenoids of interest as potential fuels. The fungus was scaled up in an aerated large fermentation flask, and the VOCs trapped by Carbotrap technology and analyzed by headspace solid –phase microextraction (SPME) fiber-GC/MS. Under these conditions, Nodulisporium sp. produces a series of alkyl alcohols starting with 1-butanol-3-methyl, 1- propanol-2-methyl, 1- pentanol, 1-hexanol, 1-heptanol, 1- octanol, 1-nonanol along with phenylethyl alcohol.The organism also produces secondary alkyl alcohols, esters, ketones, benzene derivatives, a few terpenoids, and some hydrocarbons. It appears that many of the products have fuel potential. Furthermore, the VOCs of Nodulisporium sp. were active against a number of pathogens causing death to both Aspergillus fumigatus and Rhizoctonia solani and severe growth inhibition produced in Phytophthora cinnamomi and Sclerotinia sclerotiorum within 48 hr of exposure. The Carbotrapped materials somewhat mimicked the bioactivities of the culture itself when certain test organisms were exposed to these VOCs. A brief discussion on the relationship of these fungal VOCs to those compounds found in transportation fuels is presented.

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