Dunne W M, Buckmire F L
Appl Environ Microbiol. 1985 Sep;50(3):562-7. doi: 10.1128/aem.50.3.562-567.1985.
An exopolysaccharide depolymerase was isolated from a mucoid strain of Pseudomonas aeruginosa of cystic fibrosis origin. Purified preparations of the depolymerase showed maximum activity against the unacetylated polymannuronic acid exopolysaccharide from the same strain and little activity against commercially prepared alginic acid. The evidence suggests that the enzyme is either periplasmic in location or associated with the outer cell membrane and is released extracellularly, in the absence of cell lysis, after a reduction of the culture magnesium (Mg2+) concentration below 3.0 mM. The depolymerase is also released after the addition of sublethal concentrations of EDTA to cultures containing 3.0 mM Mg2+. A survey of additional mucoid P. aeruginosa isolates recovered from patients with cystic fibrosis showed that nearly 60% demonstrated similar depolymerase activity while none of the nonmucoid revertants of the parent strains produced detectable depolymerase activity.
从一株源于囊性纤维化患者的黏液型铜绿假单胞菌中分离出一种胞外多糖解聚酶。纯化后的解聚酶制剂对来自同一菌株的未乙酰化聚甘露糖醛酸胞外多糖具有最大活性，而对市售海藻酸的活性较低。有证据表明，该酶要么位于周质空间，要么与外细胞膜相关联，并且在培养物中的镁（Mg2+）浓度降至3.0 mM以下时，在无细胞裂解的情况下会被释放到细胞外。在含有3.0 mM Mg2+的培养物中添加亚致死浓度的乙二胺四乙酸（EDTA）后，解聚酶也会被释放。对从囊性纤维化患者中分离出的其他黏液型铜绿假单胞菌菌株的调查显示，近60%的菌株表现出类似的解聚酶活性，而亲本菌株的非黏液型回复突变体均未产生可检测到的解聚酶活性。
