Tudor J J, McCann M P, Acrich I A
Biology Department, Saint Joseph's University, Philadelphia, Pennsylvania 19131.
J Bacteriol. 1990 May;172(5):2421-6. doi: 10.1128/jb.172.5.2421-2426.1990.
Bdellovibrio bacteriovorus 109J and most other bdellovibrios cause prey cells to round following penetration. Bdellovibrio sp. strain W does not cause rounding of the prey. Analysis of enzyme activities during the early stages of bdellovibrio attack indicated that strain W differs from most other bdellovibrios in that there is no glycanase activity produced during penetration. Likewise, heat-killed prey were penetrated normally by strain 109J, but the resulting bdelloplast did not become round and no glycanase was detected, indicating that glycanase is not essential for penetration. Peptidoglycan from prey cells penetrated by strain W was sensitive to lysozyme, but these cells were not susceptible to attack and penetration by strain 109J, indicating that peptidoglycan deacetylation is not the primary exclusion mechanism. We propose a model in which it is the peptidase activity of the bdellovibrios which allows them to breach the peptidoglycan of their prey and in which the glycanase activity exhibited by strain 109J and other bdellovibrios is responsible for the rounding of the bdelloplast.
食菌蛭弧菌109J及大多数其他蛭弧菌在穿透猎物细胞后会使其变圆。蛭弧菌W菌株不会导致猎物变圆。对蛭弧菌攻击早期阶段的酶活性分析表明，W菌株与大多数其他蛭弧菌不同，在穿透过程中不会产生聚糖酶活性。同样，热灭活的猎物能被109J菌株正常穿透，但产生的蛭质体不会变圆，也未检测到聚糖酶，这表明聚糖酶对于穿透并非必不可少。被W菌株穿透的猎物细胞的肽聚糖对溶菌酶敏感，但这些细胞不易受到109J菌株的攻击和穿透，这表明肽聚糖脱乙酰化不是主要的排斥机制。我们提出了一个模型，其中蛭弧菌的肽酶活性使其能够突破猎物的肽聚糖，而109J菌株和其他蛭弧菌所表现出的聚糖酶活性则导致蛭质体变圆。
