【摘要】 从土壤中分离得到一株(R)-扁桃酸选择性降解菌,经鉴定为恶臭假单胞菌,保存于中国普通微生物保藏中心,编号为CGMCC1388。考察了扁桃酸及其降解产物对扁桃酸脱氢酶活力的影响。研究表明,在培养基中添加少量扁桃酸、苯甲酰甲酸或苯甲酸均可显著提高其产量,以扁桃酸的诱导效果最佳。3种诱导物的最适添加质量浓度分别为4、4和2 g/L。当以消旋扁桃酸为反应底物时,该菌可高选择性降解(R)-扁桃酸,回收得到的(S)-扁桃酸对映体过量值(e.e.)高于99%,反应的对映选择率(E)达130。用静息细胞催化扁桃酸降解的最适温度和pH分别为30℃和6.0,最适底物浓度为60 mmol/L,以双倒数法求得Km为47 mmol/L。考察了该菌对扁桃酸苯环取代衍生物的生物转化,并以高产率制备获得高对映纯度的(S)-对羟基扁桃酸和(S)-对氯扁桃酸。更多还原

【Abstract】 A mandelate-degrading bacterium,Pseudomonas putida CGMCC1388,was newly isolated from soil using benzoylformic acid as sole carbon source.It could degrade（R）-mandelic acid with high enantioselectivity（E=130）.Supplement of mandelic acid,benzoylformic acid or benzoic acid to the culture medium as the enzyme inducer significantly enhanced the degradation activity of the bacterial cells.The optimal concentrates of these inducers were 4 g/L,4 g/L and 2 g/L respectively.The optimal temperature and pH for the mandelate degradation were 30 ℃ and 6.0 respectively,and the optimal substrate concentration was 60 mmol/L.The apparent kinetic constants K_m determined was 47 mmol/L.Using the resting cells as biocatalyst,（S）-mandelic acid,（S）-p-hydroxymandelic acid and（S）-p-chloromandelic acid were readily prepared,with moderate to high yields and excellent enantiopurity （>99%e.e.）.更多还原