EFFECT OF ENCAPSULATED CELLS OF ENTEROBACTER SP ON PLANT-GROWTH AND PHOSPHATE-UPTAKE

Cells of Enterobacter sp., a phosphate-solubilizing bacterium, were en capsulated in calcium-alginate beads supplemented with skim milk. Free -cell and encapsulated-cell formulations were introduced into a soil, amended with rock phosphate, to compare their effect on non-mycorrhiza l and mycorrhizal Lactuca sativa plants. Bacterial inoculation affecte d plant growth and P uptake but encapsulated-cell formulation caused t he better plant response. Combined inoculation of encapsulated cells a nd Glomus deserticola provided the best microbial inoculum and enhance d plant growth by 96% as compared to the uninoculated control. The hig her number of bacterial cells (log 4.4 CFU/g soil) detected in soil in oculated with encapsulated cells stimulated the plant mycorrhization. The continuous flow of bacterial cells from the skim-milk-enriched car rier beads appeared to be the main reason for the enhanced plant growt h and P uptake. (C) 1998 Elsevier Science Ltd. All rights reserved.