Publications by authors named "Mari S Chinn"

There is a significant interest in novel waste management solutions to treat wastewater from swine operations. Anaerobic digestion is a rising and prominent solution, but this technology still generates highly concentrated effluent that requires further remediation. Therefore, the aim of this study was to explore the feasibility of cultivating the cyanobacterium in swine effluent for future applications in biological waste treatment and value-added fermentation.

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Anthocyanins from purple-fleshed sweetpotatoes constitute highly valued natural colorants and functional ingredients. In the past, anthocyanin extraction conditions and efficiencies using a single acidified solvent have been assessed. However, the potential of solvent mixes that can be generated by fermentation of biomass-derived sugars have not been explored.

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A Clostridium ljungdahlii lab-isolated spontaneous-mutant strain, OTA1, has been shown to produce twice as much ethanol as the C. ljungdahlii ATCC 55383 strain when cultured in a mixotrophic medium containing fructose and syngas. Whole-genome sequencing identified four unique single nucleotide polymorphisms (SNPs) in the C.

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Clostridium ljungdahlii is an important synthesis gas-fermenting bacterium used in the biofuels industry, and a preliminary investigation showed that it has some tolerance to oxygen when cultured in rich mixotrophic medium. Batch cultures not only continue to grow and consume H2, CO, and fructose after 8% O2 exposure, but fermentation product analysis revealed an increase in ethanol concentration and decreased acetate concentration compared to non-oxygen-exposed cultures. In this study, the mechanisms for higher ethanol production and oxygen/reactive oxygen species (ROS) detoxification were identified using a combination of fermentation, transcriptome sequencing (RNA-seq) differential expression, and enzyme activity analyses.

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During the past decade, DNA sequencing output has been mostly dominated by the second generation sequencing platforms which are characterized by low cost, high throughput and shorter read lengths for example, Illumina. The emergence and development of so called third generation sequencing platforms such as PacBio has permitted exceptionally long reads (over 20 kb) to be generated. Due to read length increases, algorithm improvements and hybrid assembly approaches, the concept of one chromosome, one contig and automated finishing of microbial genomes is now a realistic and achievable task for many microbial laboratories.

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Fungal pretreatment, using lignin-degrading microorganisms to improve lignocellulosic feedstocks with minimal energy input, is a potential alternative to physiochemical pretreatment methods. Identifying the kinetics for fungal pretreatment during solid substrate cultivation is needed to help establish the processing conditions for effective scale up of this technology. In this study, a set of mathematical models were proposed for describing the interactions between holocellulose consumption, lignin degradation, cellulase, ligninolytic enzyme, and the growth of Phanerochaete chrysosporium during a 14 day fungal pretreatment process.

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Production of butanol by solventogenic clostridia is controlled through metabolic regulation of the carbon flow and limited by its toxic effects. To overcome cell sensitivity to solvents, stress-directed evolution methodology was used three decades ago on Clostridium beijerinckii NCIMB 8052 that spawned the SA-1 strain. Here, we evaluated SA-1 solventogenic capabilities when growing on a previously validated medium containing, as carbon- and energy-limiting substrates, sucrose and the products of its hydrolysis d-glucose and d-fructose and only d-fructose.

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Clostridium autoethanogenum is an anaerobic, autotrophic acetogen that is capable of converting CO and CO2 into ethanol and acetate. Here we report the draft genome sequence of C. autoethanogenum JA1-1 strain DSM 10061 (4.

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We describe a latex wet coalescence method for gas-phase immobilization of microorganisms on paper which does not require drying for adhesion. This method reduces drying stresses to the microbes. It is applicable for microorganisms that do not tolerate desiccation stress during latex drying even in the presence of carbohydrates.

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Microbial pretreatment of lignocellulosic feedstocks is an environment friendly alternative to physio-chemical pretreatment methods. A better understanding of the interactive fungal mechanisms in biological systems is essential for enhancing performance and facilitating scale-up and commercialization of this pretreatment technique. In this study, mathematical models were developed for describing cellulose and hemicellulose consumption, lignin degradation, cellulase and ligninolytic enzyme production and oxygen uptake associated with the growth of Phanerochaete chrysosporium during a 14-day shallow stationary submerged fungal pretreatment process on cotton stalks.

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World energy consumption is expected to increase 44% in the next 20 years. Today, the main sources of energy are oil, coal, and natural gas, all fossil fuels. These fuels are unsustainable and contribute to environmental pollution.

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This study used the fungus, Phanerochaete chrysosporium, to pretreat cotton stalks with two methods, shallow stationary and agitated cultivation, at three supplemental salt concentrations. Pretreatment efficiencies were compared by evaluating lignin degradation, solid recovery and carbohydrate availability over a 14-day period. Shallow stationary cultivation with no salts gave 20.

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Combined gasification and fermentation technologies can potentially produce biofuels from renewable biomass. Gasification generates synthesis gas consisting primarily of CO, CO(2), H(2), N(2), with smaller amounts of CH(4), NO(x), O(2), C(2) compounds, ash and tars. Several anaerobic bacteria species can ferment bottled mixtures of pure synthesis gas constituents.

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White rot fungi degrade lignin and have biotechnological applications in conversion of lignocellulose to valuable products. Pretreatment is an important processing step to increase the accessibility of cellulosic material in plant biomass, impacting efficiency of subsequent hydrolysis and fermentation. This study investigated microbial pretreatment of cotton stalks by solid state cultivation (SSC) using Phanerochaete chrysosporium to facilitate the conversion into ethanol.

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Avicel serves as a model microcrystalline cellulose substrate for investigations of cellulolytic microbial performance and cellulase enzyme systems in submerged liquid cultures. Clostridium thermocellum is a thermophilic, anaerobic bacterium capable of degrading lignocellulose and fermenting it to ethanol and other products, suggesting the native growth environment is similar to that supported by solid substrate cultivation. Few studies have examined the effects of process parameters on the metabolism of thermophilic anaerobes in solid substrate cultivation, however.

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Solid substrate cultivation of thermophilic, anaerobic bacteria offers an alternative production method for many bio-based chemicals; however the process must be optimized for each substrate-organism fermentation. The effects of initial substrate moisture content (SMC, 30%, 50% and 70% wet-basis), supplemental nutrient concentration (SNC, 12%, 50% and 100%) and duration of cultivation time (6, 10 and 14 days), on product formation (lactate, ethanol and acetate) by Clostridium thermocellum 27405 were examined during growth on paper pulp sludge. Water activities at moisture contents above 30% wet-basis were essentially identical ( approximately 0.

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Interest in solid substrate cultivation (SSC) techniques is gaining for biochemical production from renewable resources; however, heat and mass transfer problems may limit application of this technique. The use of anaerobic thermophiles in SSC offers a unique solution to overcoming these challenges. The production potential of nine thermophilic anaerobic bacteria was examined on corn stover, sugar cane bagasse, paper pulp sludge, and wheat bran in submerged liquid cultivation (SmC) and SSC.

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