Ecotoxicology and Environmental Safety 1989-10-01

Effects of three pesticides on MSX-induced ammonia photoproduction by the cyanobacterium Nostoc linckia.

A K Mishra, A B Pandey, H D Kumar

Index: Ecotoxicol. Environ. Saf. 18(2) , 145-8, (1989)

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Abstract

Three pesticides (2,4-D, basalin, aldrin) inhibited L-methionine-DL-sulfoximine (MSX)-induced photoproduction of ammonia by the nitrogen-fixing cyanobacterium Nostoc linckia. Combinations of pesticides and MSX were inhibitory except at low concentrations (100 and 500 micrograms/ml) of 2,4-D which stimulated NH+4 production. Similar results were obtained when pesticides were added 6 hr after the addition of MSX, but the inhibition was weaker. When MSX was added to the culture 6 hr after the addition of pesticides, the pesticides stimulated NH+4 photoproduction. Similar results were obtained on nitrogenase activity of the organism.