Degradation and utilization of 2,4-dioxohexahydro-1,3,5-triazine (DHT) by soil microorganisms
el-Dahtory, T.A.; Stenz, E.; Schuster, G.
Zentralblatt für Mikrobiologie 139(5): 375-382
1984
ISSN/ISBN: 0232-4393 PMID: 6388190 Document Number: 241439
The biodegradation and utilization of the antiphytoviral substance 2,4-dioxohexahydro-1,3,5-triazine (DHT) by soil microorganisms was investigated. In nutrient broth, mixed cultures of microorganisms derived from different soils decreased the content of DHT with increasing duration of culture. Microorganisms from an Egyptian garden soil degraded 10-3 mol/l DHT within 28 days in a culture without additional aeration. In deficient media, mixed cultures of microroganisms also decreased the amount of DHT present; in nitrogen-free nutrient solution a degradation rate of up to 12 mg DHT per liter per day was attained. Pure cultures of Rhizobium leguminosarum, Proteus vulgaris, Saccharomyces cerevisiae, and especially Agrobacterium radiobacter also decreased the content of DHT in nitrogen-free media. No such effect was detectable in cultures of four other species of soil bacteria. The DHT degradation was accompanied by significant cell multiplication, e.g. A. radiobacter in shaking cultures with DHT as sole nitrogen source showed a typical growth cycle with a lag-phase of 24 hours. The low persistence of DHT in soils could thus be mainly due to biodegradation by microorganisms.