Analysis of microbial community and nitrogen transition with enriched nitrifying soil microbes for organic hydroponics.

Nitrifying microbial consortia were enriched from bark compost in a water system by regulating the amounts of organic nitrogen compounds and by controlling the aeration conditions with addition of CaCO for maintaining suitable pH. Repeated enrichment showed reproducible mineralization of organic nitrogen via the conversion of ammonium ions ( ) and nitrite ions ( ) into nitrate ions ( ). The change in microbial composition during the enrichment was investigated by PCR-DGGE analysis with a focus on prokaryote, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, and eukaryote cell types.

The rhizosphere microbial community in a multiple parallel mineralization system suppresses the pathogenic fungus Fusarium oxysporum.

The rhizosphere microbial community in a hydroponics system with multiple parallel mineralization (MPM) can potentially suppress root-borne diseases. This study focused on revealing the biological nature of the suppression against Fusarium wilt disease, which is caused by the fungus Fusarium oxysporum, and describing the factors that may influence the fungal pathogen in the MPM system. We demonstrated that the rhizosphere microbiota that developed in the MPM system could suppress Fusarium wilt disease under in vitro and greenhouse conditions.

Non-host resistance to penetration and hyphal growth of Magnaporthe oryzae in Arabidopsis.

Rice blast caused by Magnaporthe oryzae is a devastating disease of rice. Mechanisms of rice resistance to blast have been studied extensively, and the rice-M. oryzae pathosystem has become a model for plant-microbe interaction studies.