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Bacteria

Biological Engineering

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Full-Text Articles in Engineering

Characterization Of Xylan Utilization And Discovery Of A New Endoxylanase In Thermoanaerobacterium Saccharolyticum Through Targeted Gene Deletions, Kara K. Podkaminer, Adam M. Guss, Heather L. Trajano, David A. Hogsett, Lee R. Lynd Sep 2012

Characterization Of Xylan Utilization And Discovery Of A New Endoxylanase In Thermoanaerobacterium Saccharolyticum Through Targeted Gene Deletions, Kara K. Podkaminer, Adam M. Guss, Heather L. Trajano, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

The economical production of fuels and commodity chemicals from lignocellulose requires the utilization of both the cellulose and hemicellulose fractions. Xylanase enzymes allow greater utilization of hemicellulose while also increasing cellulose hydrolysis. Recent metabolic engineering efforts have resulted in a strain of Thermoanaerobacterium saccharolyticum that can convert C5 and C6 sugars, as well as insoluble xylan, into ethanol at high yield. To better understand the process of xylan solubilization in this organism, a series of targeted deletions were constructed in the homoethanologenic T. saccharolyticum strain M0355 to characterize xylan hydrolysis and xylose utilization in this organism. While the deletion of …


Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza Aug 2010

Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

We report development of a genetic system for making targeted gene knockouts in Clostridium thermocellum, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the pyrF gene. The ΔpyrF strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of pyrF from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed pyrF, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely pta, which encodes …


Scanning Electron Microscopy Study Of Biofilms On Silicone Voice Prosthesis, T. R. Neu, F. Dijk, G. J. Verkerke, H. C. Van Der Mei, H. J. Busscher Jan 1992

Scanning Electron Microscopy Study Of Biofilms On Silicone Voice Prosthesis, T. R. Neu, F. Dijk, G. J. Verkerke, H. C. Van Der Mei, H. J. Busscher

Cells and Materials

Patients after laryngectomy often receive silicone made voice prostheses fot speech rehabilitation. The prosthesis is inserted in a shunt between the trachea and the digestive tract. As the prosthesis is placed in a nonsterile environment it becomes rapidly colonized by microorganisms eventually leading to failure and frequent exchange of the implant. In this study, explanted "Groningen Button" silicone voice prostheses were used to investigate by scanning electron microscopy the biofilm developing on the implant. Two main types of microbial colonization forms could be distinguished. Firstly, macroscopically visible, single colonies dominating on the esophagus side of the prosthesis were found, which …


Interactions Of Bacteria And Amoebae With Ocular Biomaterials, Thomas John Jan 1991

Interactions Of Bacteria And Amoebae With Ocular Biomaterials, Thomas John

Cells and Materials

The use of biomaterials in periocular and intraocular sites has resulted in some ocular inflammations and infections which can result in vision-threatening ocular disease. This review addresses bacterial interactions with, and adherence to ocular biomaterials such as soft contact lenses, surgical suture materials, and intraocular lenses. In addition, adherence of Acanthamoeba to soft contact lenses is described, and the role of these lenses in the development of Acanthamoeba keratitis is discussed.