Enhancement of Cellulose Pellicle Production by Constitutively Expressing Vitreoscilla Hemoglobin in Acetobacter xylinum

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• 作者：Liang-Jung Chien ; Hsiao-Ting Chen ; Pei-Fen Yang ; Cheng-Kang Lee
• 刊名：Biotechnology Progress
• 出版年：2006
• 出版时间：December 2006
• 年：2006
• 卷：22
• 期：6
• 页码：1598 - 1603
• 全文大小：300K
• 年卷期：v.22,no.6(December 2006)
• ISSN：1520-6033

文摘

Vitreoscilla hemoglobin (VHb) gene driven by the constitutive bla promoter was expressed inthe cellulose-producing Acetobacter xylinum. The expressed VHb was biochemically active andcould 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^-). Probablybecause of its faster growth rate, the size of tentacled cellulose beads produced by VHb⁺ wasabout 20% of that produced by VHb^- after 2 days cultivation in a shake-flask. When culturedstatically, the amount of cellulose pellicle produced by VHb⁺ could be 2-fold that produced byVHb^-. Cellulose pellicle concentration of 11 g/L was obtained for VHb⁺, whereas 6 g/L wasobtained for VHb^- after 6 days of microaerobic incubation.