RESUMEN
The ecological importance of heterotrophic nitrification has been difficult to assess because of low levels of nitrification associated with this phenomenon. Nitrification by a soil isolate, an Alcaligenes sp., which oxidizes pyruvic oxime to produce up to 1867 mg nitrite-nitrogen/L, is described. Sequential nitrification with the chemoautotroph Nitrobacter agilis, ATCC 14123, resulted in nitrate accumulation and a concomitant decrease of the nitrite produced by the Alcaligenes sp. when the bacteria were jointly cultured. The ecological significance of such a sequential system is discussed.
Asunto(s)
Alcaligenes/metabolismo , Nitratos/metabolismo , Nitritos/metabolismo , Nitrobacter/metabolismo , Ecología , Oximas/metabolismo , Propionatos/metabolismoRESUMEN
Chitinolytic microorganisms isolated from forest soil and from healthy gypsy moth larvae (Porthetria dispar (L.) were screened for their ability to lyse Trichophyton rubrum mycelia. A few of these isolates were mycolytic on both autoclaved and on actively growing, intact, T. rubrum mycelia. Supernatants from these isolates, utilizing live T. rubrum as the sole carbon source, showed the same mycolytic ability. Assays of the supernatants for enzymatic activity revealed exocellular, stable enzymes that releases reducing substances including N-acetylglucosamine from the mycelia.
Asunto(s)
Arthrobacter/enzimología , Bacillus/enzimología , Enzimas/metabolismo , Lepidópteros/microbiología , Mariposas Nocturnas/microbiología , Microbiología del Suelo , Streptomyces/enzimología , Trichophyton/metabolismo , Animales , Arthrobacter/metabolismo , Bacillus/metabolismo , Pared Celular/ultraestructura , Quitina/metabolismo , Citoplasma/ultraestructura , Concentración de Iones de Hidrógeno , Larva/microbiología , Streptomyces/metabolismo , Trichophyton/ultraestructuraRESUMEN
A new method is described for measuring environmental stress through the use of the duckweed (Lemna minor) rhizosphere.
