The present invention addresses the problem of providing novel microorganisms that impose little burden on the environment, have very little likelihood of leading to resistant pathogenic organisms, and have an exceptional ability to control a wider variety of plant diseases. In particular, present invention addresses the problem of providing novel microorganisms capable of exhibiting a control effect on not only filamentous fungal diseases but also bacterial diseases. These novel microorganisms are Pseudomonas azotoformans strain W-14-1 NITE BP-02371 or a mutant strain thereof and have a high control effect against various plant diseases including lettuce soft rot.本發明之課題在於提供一種對環境之負荷較小，產生抗藥性病原菌之可能性極低，且對更多種植物病害具有優異之防除能力之新穎微生物。本發明尤其提供一種可對絲狀菌病害及細菌病害兩者均表現出防除效果之新穎微生物。新穎微生物係產氮假單胞菌W-14-1株NITE BP-02371或其變異株，對以萵苣軟腐病為代表之多種植物病害具有高度之防除效果。
