1. 域: 细菌域：微生物包 木耳 灵芝)所以微生物不一定是看不见的. 细菌包括球菌 杆菌 螺旋菌 弧菌,细菌是单细胞的原核生物,域: 细菌域(Bacteria) 门: 变形菌门(Proteobacteria) 纲:γ-变形菌纲(Gammaproteobacteria

2. 细菌类：培养细菌类(Bacteria)武器的原理,大致上跟酿酒大同小异:将冷冻保存的「细菌种子」放入发酵锅(Fermenter)内繁殖,细菌便会以几何级数的速度生长,在很短时间就可以繁殖出大量细菌.

3. 真细菌：按照现行的生物系统发育(Phylogeny)关系(与1987年之前的分类系统不同;2层下段),可将这些物种分为3个域,即真细菌(Bacteria)、古细菌(Archaea)和真核生物(Eucarya).

1. 细菌
    Bacteria are very small organisms. Some bacteria can cause disease.

    e.g. Chlorine is added to kill bacteria.
           加氯是为了杀死细菌。

1. (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission
    important as pathogens and for biochemical properties
    taxonomy is difficult
    often considered to be plants

    Synonym: bacterium