Bacterial Mass Behavior in Colony Morphogenesis.

细菌通过连续的细胞繁殖和在固体介质上的聚集形成具有独特形态和内部结构的菌落。通过对这种形态发生生长过程的分析，我们发现细菌是表现出群体行为的有机体，在本研究中，通过CCD摄像机跟踪这种细菌的群体行为，并进行录像以进行精确的分析。利用转座子诱变技术收集粘质沙雷氏菌的突变株，对粘质沙雷氏菌的协同易位、相互识别等基本行为进行突变分析。1.粘质沙雷氏菌在低糖介质中的扩散生长过程中，生物表面活性物质“沙拉韦丁”的产生是至关重要的。通过各种突变分析，揭示了生物表面活性剂在细菌群体行为转移中的作用。2.奇异变形杆菌对特定氨基酸的响应表现出特定的群体行为。这种行为是奇异P.mirabilis种群对固体介质的特定反应。P.mirabilis点接种到半固体介质的中心表面，迅速传播到整个表面。这些栖息在表面的细菌随后进入特定的阶段，表现出特有的时空格局，如云纹状动态格局、集群细菌的多焦点聚集以及这些聚集体的移位和融合。由此可见，表面环境中的细菌是协同生存的。对这些特征行为的实验分析将揭示细菌在自然界中的真实生命模式。3.考察了枯草芽孢杆菌菌落生长界面的自亲和性，作为典型的随机模式生长。通过对行为数据的定量分析，得到了与微观界面生长方式相关的α(粗糙度指数)=0.5和0.78。

Bacteria form a colony with characteristic morphology and internal structure by successive cell multiplication and swarming on a solid medium. By analyzing processes of such morphogenic growth, we found that bacteria are organism exerting mass behavior.In the present study, such bacterial mass behavior was traced by CCD camera and video-recorded for precise analyzes. Mutants of Serratia marcescens were collected by transposon mutagenesis for mutational analyzes of fundamental protocols in mass behavior, such as cooperated translocation, mutual recognition.1.In a spreading growth of flagellum-less S.marcescens on a lowagar medium, production of biosurfactant "serrawettin" was shown to be critical. Roles of biosurfactants in translocating mass behavior of bacteria were indicated by various mutational analyzes.2.Proteus mirabilis exhibited specific swarming behavior in response to the presence of a specific amino acid. Such behavior was a solid medium-specific response of a P.mirabilis population.P.mirabilis point-inoculated onto the central surface of a semi-solid medium, promptly spread on the whole surface. These bacteria residing on the surface, therafter, entered into the special phase and demonstrated characteristic spatio-temporal pattern, e.g., Moire-like dynamic pattern, multifocal aggregation of swarming bacteria, and translocation and fusion of such aggregates.From findings described above, it is evident that bacteria on a surface environment are living in cooperation. Experimental analysis of these characteristic behavior will uncover bacterial real mode of life in nature.3.Growing interface of a Bacillus subtilis colony was examined for self-affinity, as a typical example of random pattern growth. By quantitative analysis of behavioral data, the values of alpha (roughness exponent) =0.5 and 0.78 depending on microscopic mode of interface growth were obtained.