Study confirmed that Penicillium camemberti (PC) 2221 produced an extracellular enzyme that chirally transformed dextral-fosfomycin to levo-fosfomycin. The optimal conditions of immobilized enzyme (IE) using sodium alginate as carrier were studied. The optimum conditions for immobilization and characteristic of the IE were investigated, including concentrations of sodium alginate and CaCl2, the best conditions for reaction such as pH, temperature,and the stability of repeatedly uses. The results showed that the optimal conditions of the immobilization was 3％ (w/v) sodium alginate solution, 3％ (w/v) CaCl2 solution, the volume ratio 1∶2 of sodium alginate solution (3％ w/v)and crude enzyme solution (concentrated 20 times), 6 h immobilization time. The optimal pH and temperature of the IE were pH 6.2 and 37 ℃ with the transformation rate at 14.3％. When reacted for four times continuously, the transformation rate was 57.57％ of the initial one. The enzyme produced by PC 2221 could immobilize by sodium alginate at the optimal condition, and the IE could chirally transform dextral-fosfomycin to levo-fosfomycin to improve its utilization ratio and extent its life and possessed further study on the development value.%研究确定沙门柏干酪青霉菌(Penicillium camemberti)2221能够产生手性转化右旋磷霉素的酶,以及以海藻酸钠为栽体固定化酶转化的最适条件.以海藻酸钠为载体,分别考察了海藻酸钠浓度、氯化钙浓度、海藻酸钠和酶用量的体积比、固定化时间等务件,以及固定化酶的最适反应pH、最适反应温度和反复利用的稳定性等.结果表明,最优固定化条件是3.0%(质量与体积比)海藻酸钠、3.0%(质量与体积比)氯化钙、酶液(浓缩20倍)和3.0%(质量与体积比)海藻酸钠溶液的体积比为1:2、固定化时间为6 h.固定化酶的最适温度为37℃,最适pH为6.2,转化率为14.3%,连续反应4次后转化率为最初的57.57%.利用海藻酸钠包埋固定化沙门柏干酪青霉菌产生的手性转化右旋磷霉素的酶,能够连续转化生成左旋磷霉素,提高酶的利用效率,延长使用时间,具有进一步研究开发的价值.
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