Enhancement of cellulose pellicle production by constitutively expressing vitreoscilla hemoglobin in Acetobacter xylinum.
Vitreoscilla hemoglobin (VHb) gene driven by the constitutive bla promoter was expressed in the cellulose-producing Acetobacter xylinum. The expressed VHb was biochemically active and could enhance cell growth in a shaken culture containing cellulase. VHb-expressing A. xylinum (VHb+) exhibited a specific growth rate 50% higher than that of the host strain (VHb-). Probably because of its faster growth rate, the size of tentacled cellulose beads produced by VHb+ was about 20% of that produced by VHb- after 2 days cultivation in a shake-flask. When cultured statically, the amount of cellulose pellicle produced by VHb+ could be 2-fold that produced by VHb-. Cellulose pellicle concentration of 11 g/L was obtained for VHb+, whereas 6 g/L was obtained for VHb- after 6 days of microaerobic incubation.
Chien
Liang-Jung
LJ
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
Chen
Hsiao-Ting
HT
Yang
Pei-Fen
PF
Lee
Cheng-Kang
CK
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D049109:Cell Proliferation; D002482:Cellulose / Q000378:metabolism*; D024861:Genetic Enhancement / Q000379:methods*; D041822:Gluconacetobacter xylinus / Q000502:physiology*; D006454:Hemoglobins / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000378:metabolism; D054793:Truncated Hemoglobins; D020589:Vitreoscilla / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D006454:Hemoglobins; D011994:Recombinant Proteins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; D002482:Cellulose