• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.315-318
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• 1991

- A bacterial strain No. S-76 which produced pullulanase powerfully was isolated frorn soil. The isolated bacterium was 0.4~$0.6\times 0.8$~1.4 $\mu\textrm{m}$ in size, gram negative, rods, motile and was identified as Aerornonas caviae by Bergey's manual of determinative bacteriology with various characteristics investigated. The highest yield of pullulanase of the strain was obtained by using the following medium: 1% pullulan, soluble starch or corn starch as a carbon sources and 0.5% yeast extract, peptone as nitrogen sources with an initial pH of 9.0. The optimal cutture conditions for production of pullulanase were at $32^{\circ}C$ for 2 days.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.362-367
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• 1991

The crude enzyme solution obtained by shaking culture of Aeromonas caviae No. S-76 isolated from soil as pullulanase producing bacterium was purified by 50 folds with 21% yield by salting out with ammonium sulfate and column chromatography using DEAE-Sephadex A-50 and Sephadex G-150. The purified pullulanase had a molecular weight of 118, 000 approximately by SDS-polyacrylamide slab gel electrophoresis and pI of 4.3 by isoelectric focusing. And optimum reaction temperature and pH for puHulanase were $50^{\circ}C$ and 8.0, respectively. The purified enzyme was relatively stable at pH 6.0~9.0 and below $45^{\circ}C$. This enzyme synthesized maltosyl-$\beta$-cyclodextrin from mixture of $\beta$-cyclodextrin and maltose.