| 摘要 |
<p>PURPOSE:A highly thermophilic bacterium in Thermus is cultured to collect a novel thermophilic fumarase, which is used to produce L-malic acid important as a perfusion component or an acidulant. CONSTITUTION:A highly thermophilic bacterium in Thermus, e.g., Thermus aquatics No.104, Thermus lactenus nov. sp. No.108, or Thermus rubens nov. sp. No.102, is cultured in a liquid medium containing carbon sources such as sucrose, starch, alcohol, nitrogen sources such as ammonium sulfate, or peptone, organic acids and metal salts at about 50-80 deg.C. A cell-free extract is obtained from the collected cell bodies, then salted out, adsorbed on DEAE and Sephadex column and eluted with saline solution to collect the active fractions. The products are subjected to additional dialysis, adsorption and elution to collect the objective enzyme. The enzyme is allowed to act on fumaric acid into L-malic acid.</p> |
