一株产多种β-内酰胺类抗生素酰化酶菌株的筛选

为了从大量的候选菌株中快速筛选头孢菌素酰化酶产生菌，设计并合成了一系列头孢菌素酰化酶的底物类似物。这些酰胺类的底物类似物由二部分组成，一部分为与头孢菌素相同或相似的侧链，另外一部分为发色基团或便于检测的基团。它们被酰化酶水解酰胺键以后可以方便快速的检测，因此用于对大量菌株进行快速筛选。采用这些化合物筛选到6株酰化酶阳性菌株。其中菌株ZH0650能够同时水解GL-7ACA和多个底物类似物。进一步研究表明，该菌至少产生3种酰化酶，AD-NABA酰化酶，青霉素G酰化酶和头孢菌素C酰化酶。我们初步纯化了AD-NABA酰化酶和青霉素G酰化酶，并对头孢菌素C酰化酶的活力进行了鉴定。这是首次报道的可以产生青霉素G酰化酶和头孢菌素酰化酶等多种酰化酶的菌株，具有良好的应用前景。

Selection of A Strain Producing β-Lactam Antibiotics Acylases

A series of substrates analogues containing the same or similar side chain of its substrate have been synthesized and applied to screen cephalosporin acylase producers from a mass of microorganisms. The deacylation products of these analogues can be detected conveniently and used as screening indicators for the cephalosporin-acylase-producing-microorganism. Six strains possessing deacylation activity have been screened out with these substrate analogs. Among them, strain ZH0650 can simultaneously hydrolyze GL-7ACA, NIPAB and other analogues including AD-NABA. Further investigation on this strain confirmed that it could produce at least three acylases, AD-NABA acylase, penicillin G acylase and cephalosporin acylase, which were characterized by bioassay with multiple substrate analogues. This is the first report that three different acylases were produced by one strain. =