The Effect of -sterilization of carrier materials made with different types of soils on the shelf life of biofertilizer containing strain USDA110

Tejima, Kohei; Sato, Katsuya; Takeda, Kiyoko; Yokoyama, Tadashi*; Narumi, Issei

A biofertilizer is a substance that holds beneficial microorganisms for plant growth in a carrier material. To demonstrate the effect of -sterilization, the survival of the was monitored to assess the shelf life of biofertilizers. As biofertilizer carriers, five kinds of typical Japanese soil-based materials were used. Following the sterilization of carrier materials by -irradiation or autoclaving, was inoculated into each material. The biofertilizer was stored for 12 months at 4C or 30C. After storage, viable inoculants in the biofertilizer were enumerated. Results indicated that inoculant density after storage was greater than the initial density in biofertilizers made from sterilized carriers, whereas it decreased significantly in biofertilizers made from non-sterilized carriers. -sterilization was superior to autoclave sterilization in enhancing inoculant survival in some cases.