Autolytic Enzymes in Growth of Bacteria
Autolytic Enzymes in Growth of Bacteria
复制标题
细菌生长中的自溶酶
作者：
C. Forsberg;H. Rogers
许多细菌在培养物停止生长时裂解，不管生长停止是因为生长培养基耗尽还是因为向培养物中添加了有毒物质如青霉素。裂解是由微生物中存在的自溶酶（自溶素）引起的，所述自溶酶特异性地水解细菌细胞壁中的粘肽聚合物。至少在某些物种中，这种攻击发生在细菌分裂点周围的一个非常有限的区域。这导致了自溶素参与细菌生长的建议。人们提出了三种假设。首先，酶是必不可少的，使开放的粘肽在壁的假定连续网络3，4，使新的积木可以在生长过程中添加3，5;第二，酶是必不可少的重塑壁，使隔膜分为两个子细胞一个细菌6，7;第三，它们是将两个新形成的细菌彼此分开所必需的。
MANY bacteria lyse when growth of the cultures ceases, irrespective of whether growth has stopped because of the exhaustion of the growth medium or the addition of toxic substances such as the penicillins to the cultures. Lysis is caused by the presence in the microorganisms of autolytic enzymes (autolysins) which specifically hydrolyse mucopeptide polymers in the bacterial cell wall. The attack occurs, at least in some species, in a very restricted area around the point at which the bacteria will divide1,2. This has led to suggestions that the autolysins are involved in bacterial growth. Three sorts of hypotheses have been suggested. First, that the enzymes are essential to make openings in the supposedly continuous network of mucopeptides in the wall3,4 so that the new building blocks can be added during growth3,5; second, that the enzymes are essential for the remodelling of the wall in making the septum that divides one bacterium into two daughter cells6,7; and third, that they are necessary to break the two newly formed bacteria apart from each other8.