Global ETD Search

71	Production of a cloned xylanase gene in Bacillus cereus and its performance in kraft pulp prebleaching Tremblay, Louis January 1993 (has links) Xylanase production from a Bacillus subtilis gene cloned into a strain of Escherichia coli was measured. Although this gene was expressed in E. coli at several temperatures, efficient normal xylanase secretion did not occur, the observed protein release apparently depending on cell leakage or lysis. Screening for a better microbial protein secretor free of cellulase selected B. cereus #259. The strain had wild plasmids that were hard to eliminate using acridine orange and elevated temperature curing techniques. While still bearing 5 wild plasmids, attempts to transform B. cereus #259 were unsuccessful using conventional methods and electroporation. Another strain, B. cereus #518, found to be free of wild plasmids, was then used. A bidirectional vector shuttle plasmid (pMK3) was employed to carry the cloned gene into this B. cereus strain. Transformation was carried out by high voltage electroporation. Xylanase production by the new B. cereus clone was similar to that from E. coli, but was shown to be continuously and normally secreted. The xylanase gene products from the E. coli and B. cereus hosts were shown to function identically. Both xylanases improved the delignification of unbleached softwood and hardwood kraft pulps, thus reducing the Cl$ sb2$ required to achieve a given degree of bleaching, without altering the physical properties of the fibers. Using a target kappa number lignin content) of 5, xylanase pretreatment of aspen kraft pulp led to a 22% saving of chlorine. Adsorbable organic halogens in the bleachery effluent were also lowered by more than 50%. Sulfate pulping process. Bacillus cereus. Escherichia coli. Xylanases.
72	Material flow in a wood-chip refiner Fan, Xiaolin January 1987 (has links) No description available. Mechanical pulping process Pulp mills
73	Dynamic simulation of the first two stages of a kraft softwood bleach process Mackinnon, John, 1963- January 1987 (has links) No description available. Sulfate pulping process.
74	Oxidation of sodium thiosulfate in weak kraft black liquor Sen Gupta, Supriya Kumar January 1987 (has links) No description available. Sulfate waste liquor. Sulfate pulping process. Sodium thiosulphate.
75	Characterization of black liquor sprays for application to entrained-flow processes / Mackrory, Andrew John, January 2006 (has links) (PDF) Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2006. / Includes bibliographical references (p. 137-140).
76	Application of near infrared spectroscopy to pulp yield and kappa number estimation Lightle, Roy William, Krishnagopalan, Gopal A. January 2006 (has links) (PDF) Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.93-94).
77	Kinetics and mass transfer in the chlorination of draft pulp fibers Pugliese, Sebastian C. January 1988 (has links) Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 1988. / Includes bibliography.
78	Relating mechanical properties of paper to papermaking variables Ingalsbe, Dana I. January 2001 (has links) Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2001. / Includes bibliography.
79	Chemo-enzymatic modification of high-kappa kraft pulps with laccase Chandra, Richard P. January 2003 (has links) Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2005. / Includes bibliography.
80	Oxidation of sodium thiosulfate in weak kraft black liquor Sen Gupta, Supriya Kumar January 1987 (has links) No description available. Sulfate waste liquor. Sulfate pulping process. Sodium thiosulphate.

Search results