Biomaterial Database

Directed molecular evolution of nitrite oxido-reductase by DNA-shuffling. 2007

Jun-Wen Li, and Jin-Lai Zheng, and Xin-Wei Wang, and Min Jin, and Fu-Huan Chao

Institute of Environment and Health, 1 Dali Road, Tianjin 300050, China. junwen9999@hotmail.com

OBJECTIVE To develop directly molecular evolution of nitrite oxido-reductase using DNA-shuffling technique because nitrobacteria grow extremely slow and are unable to nitrify effectively inorganic nitrogen in wastewater treatment. METHODS The norB gene coding the ndtrite oxido-reductase in nitrobacteria was cloned and sequenced. Then, directed molecular evolution of nitrite oxido-reductase was developed by DNA-shuffling of 15 norB genes from different nitrobacteria. RESULTS After DNA-shuffling with sexual PCR and staggered extension process PCR, the sequence was different from its parental DNA fragments and the homology ranged from 98% to 99%. The maximum nitrification rate of the modified bacterium of X16 by DNA-shuffling was up to 42.9 mg/L x d, which was almost 10 times higher than that of its parental bacteria. Furthermore, the modified bacterium had the same characteristics of its parental bacteria of E. coli and could grow rapidly in normal cultures. CONCLUSIONS DNA-shuffling was successfully used to engineer E. coli, which had norB gene and could degrade inorganic nitrogen effectively.

UI	MeSH Term	Description	Entries
D009572	Nitrite Reductases	A group of enzymes that oxidize diverse nitrogenous substances to yield nitrite. (Enzyme Nomenclature, 1992) EC 1.	Nitrite Reductase,Reductase, Nitrite,Reductases, Nitrite
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D010802	Phylogeny	The relationships of groups of organisms as reflected by their genetic makeup.	Community Phylogenetics,Molecular Phylogenetics,Phylogenetic Analyses,Phylogenetic Analysis,Phylogenetic Clustering,Phylogenetic Comparative Analysis,Phylogenetic Comparative Methods,Phylogenetic Distance,Phylogenetic Generalized Least Squares,Phylogenetic Groups,Phylogenetic Incongruence,Phylogenetic Inference,Phylogenetic Networks,Phylogenetic Reconstruction,Phylogenetic Relatedness,Phylogenetic Relationships,Phylogenetic Signal,Phylogenetic Structure,Phylogenetic Tree,Phylogenetic Trees,Phylogenomics,Analyse, Phylogenetic,Analysis, Phylogenetic,Analysis, Phylogenetic Comparative,Clustering, Phylogenetic,Community Phylogenetic,Comparative Analysis, Phylogenetic,Comparative Method, Phylogenetic,Distance, Phylogenetic,Group, Phylogenetic,Incongruence, Phylogenetic,Inference, Phylogenetic,Method, Phylogenetic Comparative,Molecular Phylogenetic,Network, Phylogenetic,Phylogenetic Analyse,Phylogenetic Clusterings,Phylogenetic Comparative Analyses,Phylogenetic Comparative Method,Phylogenetic Distances,Phylogenetic Group,Phylogenetic Incongruences,Phylogenetic Inferences,Phylogenetic Network,Phylogenetic Reconstructions,Phylogenetic Relatednesses,Phylogenetic Relationship,Phylogenetic Signals,Phylogenetic Structures,Phylogenetic, Community,Phylogenetic, Molecular,Phylogenies,Phylogenomic,Reconstruction, Phylogenetic,Relatedness, Phylogenetic,Relationship, Phylogenetic,Signal, Phylogenetic,Structure, Phylogenetic,Tree, Phylogenetic
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D017422	Sequence Analysis, DNA	A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.	DNA Sequence Analysis,Sequence Determination, DNA,Analysis, DNA Sequence,DNA Sequence Determination,DNA Sequence Determinations,DNA Sequencing,Determination, DNA Sequence,Determinations, DNA Sequence,Sequence Determinations, DNA,Analyses, DNA Sequence,DNA Sequence Analyses,Sequence Analyses, DNA,Sequencing, DNA
D019020	Directed Molecular Evolution	The techniques used to produce molecules exhibiting properties that conform to the demands of the experimenter. These techniques combine methods of generating structural changes with methods of selection. They are also used to examine proposed mechanisms of evolution under in vitro selection conditions.	Evolution, Molecular, Directed,Molecular Evolution, Directed,In Vitro Molecular Evolution,Laboratory Molecular Evolution,Directed Molecular Evolutions,Evolution, Directed Molecular,Evolution, Laboratory Molecular,Evolutions, Directed Molecular,Evolutions, Laboratory Molecular,Laboratory Molecular Evolutions,Molecular Evolution, Laboratory,Molecular Evolutions, Directed,Molecular Evolutions, Laboratory
D020563	Gammaproteobacteria	A group of the proteobacteria comprised of facultatively anaerobic and fermentative gram-negative bacteria.	gamma Proteobacteria,Proteobacteria gamma
D020564	Deltaproteobacteria	A group of PROTEOBACTERIA represented by morphologically diverse, anaerobic sulfidogens. Some members of this group are considered bacterial predators, having bacteriolytic properties.	delta Proteobacteria,Proteobacteria delta
D032621	DNA Shuffling	The use of DNA recombination (RECOMBINATION, GENETIC) to prepare a large gene library of novel, chimeric genes from a population of randomly fragmented DNA from related gene sequences.	Exon Shuffling, In Vitro,Molecular Breeding,In Vitro Exon Shuffling,Breeding, Molecular,Breedings, Molecular,DNA Shufflings,Molecular Breedings,Shuffling, DNA,Shufflings, DNA