Browsing by Author "Busse, S."

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Biopolymer and water dynamics in microbial biofilm extracellular polymeric substance
(2008-09) Hornemann, Jennifer A.; Lysova, Anna A.; Codd, Sarah L.; Seymour, Joseph D.; Busse, S.; Stewart, Philip S.; Brown, Jennifer R.
Nuclear magnetic resonance (NMR) is a noninvasive and nondestructive tool able to access several observable quantities in biofilms such as chemical composition, diffusion, and macroscale structure and transport. Pulsed gradient spin echo (PGSE) NMR techniques were used to measure spectrally resolved biomacromolecular diffusion in biofilm biomass, extending previous research on spectrally resolved diffusion in biofilms. The dominant free water signal was nulled using an inversion recovery modification of the traditional PGSE technique in which the signal from free water is minimized in order to view the spectra of components such as the rotationally mobile carbohydrates, DNA, and proteins. Diffusion data for the major constituents obtained from each of these spectral peaks demonstrate that the biomass of the biofilm contains both a fast and slow diffusion component. The dependence of diffusion on antimicrobial and environmental challenges suggests the polymer molecular dynamics measured by NMR are a sensitive indicator of biofilm function.
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.
Evaluation of cellulose as a substrate for hydrocarbon fuel production by Ascocoryne sarcoides (NRRL 50072)
(2014-02) Mallette, Natasha D.; Pankrantz, E. M.; Busse, S.; Strobel, Gary A.; Carlson, Ross P.; Peyton, Brent M.
The fungal endophyte, Ascocoryne sarcoides, produced aviation, gasoline and diesel-relevant hydrocarbons when grown on multiple substrates including cellulose as the sole carbon source. Substrate, growth stage, culturing pH, temperature and medium composition were statistically significant factors for the type and quantity of hydrocarbons produced. Gasoline range (C5-C12), aviation range (C8-C16) and diesel range (C9-C36) organics were detected in all cultured media. Numerous non-oxygenated hydrocarbons were produced such as isopentane, 3,3-dimethyl hexane and d-limonene during exponential growth phase. Growth on cellulose at 23˚C and pH 5.8 produced the highest overall yield of fuel range organics (105 mg * g·biomass−1). A change in metabolism was seen in late stationary phase from catabolism of cellulose to potential oxidation of hydrocarbons resulting in the production of more oxygenated compounds with longer carbon chain length and fewer fuel-related compounds. The results outline rational strategies for controlling the composition of the fuel-like compounds by changing culturing parameters.