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In earlier days, production of industrially important enzymes was carried out by conventional methods of optimizing cultural conditions in flasks and fermentors. With passage of time new techniques are being developed like cloning. In cloning specific genes are amplified and ligated in specific plasmid that is in turn transformed into the host cells. In this book cloning and expression of xylanase gene of Bacillus licheniformis is discussed. pTZ57R/T and pET22b plasmids are used to clone xylanase gene. Reasonable amount of xylanase is obtained. By using this technique large amount of enzyme is produced with less effort as compared to conventional fermentation methods. This book could be helpful for students and teachers in the subjects of biology, biochemistry, biotechnology, genetics and molecular biology.

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Dr. Muhammad Nauman Aftab has completed two Ph.D. degrees, one from Chinese Academy of Sciences, Beijing, China and other from GC University, Lahore, Pakistan. He is now serving as Assistant Professor at IIB , GC University, Lahore, Pakistan. His area of research is Molecular Biology, Fermentation, Bioinformatics and Genomics.

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