Immobilized cell technology applied in solubilization of insoluble inorganic (rock) phosphates and P plant acquisition

This paper reviews current knowledge of the production of organic acids by immobilized microorganisms with a simultaneous solubilization of rock phosp hate in fermentation and soil conditions. The most widely applied methods a re based on the passive immobilization in preformed porous carriers and ent rapment of the microbial cells in natural gels. In general, immobilized sys tems show higher acid producing and rock phosphate solubilizing activity th an freely suspended cells. The potential of gel-entrapped P-solubilizers an d mycorrhizal fungi as microbial soil inoculants is also pointed out. Some advantages and constraints of using immobilized cells are discussed and a s pecial emphasis on further research is given. (C) 2001 Elsevier Science Ltd . All rights reserved.