Using recombinant DNA technology, the vector system containing minimal fragment of a bacterial hemoglobin gene (vgb) was constructed. When this vector was inserted into Escherichia coli, the growth of the host was significantly improved in both viable cell counts and absorbance measurement, compared to that of the wild type strain. In addition, by minimizing the size of bacterial hemoglobin in the vector, the ability of vgb in growth improvement was augmented, due to the reduction of metabolic burden from the maintenance and replication of the plasmid. By using this system, it is expected that the growth of microorganisms can be improved even in the hypoxic condition.

ABSTRACT
 I. Introduction
 II. Materials and Methods
  2.1 Bacterial Strains, Plasmids, and Media
  2.2 Chemicals and Enzymes
  2.3 Construction of Plasmid pJC1
  2.4 Spetrophotometric Analysis of VtHb Expression
  2.5 Growth Comparison in LB Medium
 III. Results
  3.1 Construction and Restriction Analysis ofPlasmid pJC1
  3.2 Spectrophotometric Analysis of VtHbexpression
  3.3 Growth Comparison and Plasmid Stabilityin LB medium
 IV. Discussion
  4.1 Construction of Minimal Plasmid Bearing vgb
  3.2 Confirmation of VtHb expression
  3.3 Growth Comparison in LB Medium
 V. Aknowledgement
 Literature cited

• Chung-Nam Chung(Dep. of Biological Science, Dong-A University)
• Suk-Ran Yoon(Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology)
• Woo-Jin Jun(Dep. of Food and Nutrition, Chonnam National Univ.)
• Sang-In Shim(Div. of Agriculture, Gyeongsang National Univ.)
• In-Ho Park(Dep. of Biological Science, Dong-A University) Corresponding author
• Jin-Woong Chung(Dep. of Biological Science, Dong-A University) Corresponding author