DEGRADATION OF PHOSPHONATE HERBICIDE GLYPHOSATE BY ACINETOBACTER-LWOFFII HN401

An Acinetobacter Iwoffii HN401 isolated from heavily polluted urban st reams metabolized glyphosate as well as aminomethylphosphonate (AMPn) as source of phosphorus. The strain also exhibited similar growth yiel ds in media containing glyphosate, AMPn, or orthophosphate. The HN401 grown in the 1 mM glyphosate followed by phosphate-free minimal medium treatment without glyphosate showed a growth curve virtually indistin guishable from that of cells grown in 0.1 mM glyphosate. The HN401 com pletely depleted the orthophosphate from the medium before it started to take up glyphosate. But we could not detect the phosphate from prod uct(s) of glyphosate degradaton. The HN401 transported nearly 85% of t he glyphosate in the medium into the cells within 10 min and could not transport glyphosate even in the presence of 0.1 mM [C-14]glyphosate, while glyphosate uptake rate of the cells starved for 6 h increased n oticeably. Thus, phosphorus deprivation in the medium may induce the s ystem by which glyphosate is taken up.