– Efficient production of liquid fertilizer by microorganism recently discovered –
Researchers) SATO Yuya, Senior Researcher, HORI Tomoyuki, Senior Researcher, HABE Hiroshi, Group Leader, Environmental Ecophysiology Research Group, Environmental Management Research Institute
Researchers in AIST developed the technology for efficient production of organic liquid fertilizer from wastewater in collaboration with IAI CORPORATION (IAI), Shizuoka University, Industrial Research Institute of Shizuoka Prefecture and the Numazu Technical Support Center. The fertilizer was produced using protein-rich food processing wastewater as starting material and can be used for hydroponics.
Production process of liquid fertilizer from food processing wastewater using Comammox bacteria
Crop cultivation using organic fertilizers draws attention rather than the use of chemical fertilizers. But few organic fertilizers for hydroponics have been developed, because of a challenge to produce plant-available nitrate nitrogen nutrients by non-chemical methods. From the viewpoint of reducing environmental impact, IAI has used food processing wastewater as a raw material to produce nitrate nitrogen organic liquid fertilizer using a microbial method. However, it is still unclear what microorganisms are actually working in the liquid fertilizer production system, and therefore a method for stable maintenance and management has not yet been established.
IAI's liquid fertilizer production system was operated for a long period (total of one year or more), and high-concentration liquid fertilizer could be continuously and stably produced (100 L or more per day, nitrate nitrogen concentration is approximately 250 mg-N/L). Analysis of the microbial community structure in the system during the first 70 days of operation revealed that different microbial communities were established in the two reaction tanks of the equipment. Furthermore, it was found that nitrate nitrogen is efficiently produced by a recently discovered unique microorganism called Comammox, and that this microorganism is stably maintained in the system. This research is an initiative to create a valuable liquid fertilizer from waste materials, which will contribute to addressing environmental issues.
Going forward, the properties of liquid fertilizer produced using the newly developed technology will be analyzed, and liquid fertilizer production system and hydroponics units will be promoted by IAI for commercialization.