Hokkaido University Research Profiles


A New Plant Growth Promotion Technology That Stimulates Growth

Masaaki Morikawa Professor
Doctor of Engineering

Next generation biomass production using wastewater and the possibility of using symbiotic bacteria for plant factories

A completely new growth-promoting bacterium, P23, was discovered in ukikusa (subfamily Lemnoideae) at the Hokkaido University Botanical Garden. The P23 bacterium accelerates the growth of plants by stimulating a surface switch. Ukikusa is a high value-added biomass that grows on wastewater as a fertilizer, and symbiosis with P23 doubles its production rate.

Content of research

The aquatic plant known as ukikusa is a soft biomass that can grow by absorbing nitrogen and phosphorus from wastewater and contains almost no lignin or cellulose. Its protein content is approximately 30%, comparable to that of soybeans, and its starch accumulation can reach 50%, depending on the growth environment. Its protein can be used directly as livestock feed, while its starch is useful as a raw material for biofuel production and the production of HMF, a precursor for chemical products. To improve the production yield of the next generation biomass, we are developing technology to promote plant growth with the symbiotic action of surface bacteria. In addition to ukikusa cultivation, it is expected to apply this technology to hydroponic cultivation of vegetables and cereals (plant factories). This is an old but new biotechnology that does not involve genetic modification and follows the natural order of things.

Potential for social implementation

  • ・It is expected to use this technology for green energy-saving in wastewater treatment processes of food factories or sewage treatment processes, and as a production technology for high-protein, high-carotenoid biomass and inedible starch biomass. It is also effective to increase yield rate and energy saving in some vegetable plant factories.

Appealing points to industry and local governments

We wish to conduct joint technological development for the effective utilization and recovery of industrial wastewater, CO2 recycling, biomass fuel production and livestock feed production. First of all, please send us approximately 10 liters of wastewater, and we will consider the best conditions for the production of ukikusa. This technology is designated as an advanced low-carbon technology development project by the Japan Science and Technology Agency (JST).

Intellectual property related to this research