Production of L-sorbose from the resting cells of Acetobacter suboxydans

Acetobacter suboxydans의 휴지 균체에 의한 L-sorbose의 생산

The production of sorbose from sorbitol in resting cell system of Acetobacter suboxydans was studied. The conversion of sorbose from sorbitol was markedly influenced by several factors such as the substrate concentration, reaction time, temperature, pH, metal ions, growth factors and aeration in the resting cells. Sorbose production rapidly increased in the range of 6 mg/ml cells with the concentration of 5% sorbitol. For production of sorbose from sorbitol, optimal temperature and pH were $30^{\circ}C$ and 6.0. The production of sorbose from sorbitol was activated by 1 mM of $Al^{+3}$ while inhibited by $Ni^{+2}$. The conversion of sorbitol to sorbose was stimulated by the adding of 1 mM p-aminobenzoic acid and nicotinic acid, respectively. During incubation of 1.5 ml of reaction mixture in 50 ml of Erlenmeyer flask, 5% sorbitol was completly converted to sorbose after 20 hours.

Acetobacter suboxydans의 휴지균체를 이용한 sorbitol로부터 sorbose 생산계에 대해 검토한 결과 5% sorbitol농도에서 균체를 약 6 mg/ml 농도까지 첨가할 때 sorbose의 생산량이 급격히 증가하였다. Sorbose 생성의 최적 반응 온도는 $30^{\circ}C$, 최적 pH는 6.0이었으며 금속 이온은 1 mM $Al^{+3}$ 이온에 의해 약 12%의 증가를 보인 반면에 $Ni^{+2}$ 이온 첨가시 현저한 sorbose 생산 저해를 보였다. p-aminobenzoic acid를 1.0 mM 첨가시 약 20%의 sorbose생성이 증가되었으며, Ca-pantothenate 첨가는 감소 효과를 나타내었으나 p-aminobenzoic acid와 혼합첨가에 의한 sorbose 생성은 약 7% 증가하였다. 총 반응액 1.5 ml를 50 ml 삼각 프라스크에서 반응시켰을 때, 기질 5% sorbitol은 20시간만에 완전히 sorbose로 전환되었다.