High morpholine degradation rates and formation of cytochrome P450 during growth on different cyclic amines by newly isolated Mycobacterium sp. strain HE5 The EMBL accession number of the 16S rRNA gene of Mycobacterium sp. strain HE5 is AJ012738.

Abstract

Using morpholine as sole source of carbon, nitrogen and energy, strain HE5 (DSM 44238) was isolated from forest soil. The isolated strain was identified as a member of the subgroup of fast-growing Mycobacterium species as revealed by 16S rDNA analysis. An identity of 994 % was obtained to Mycobacterium gilvum ; however, the type strain was unable to utilize morpholine. A maximal growth rate of 017 h N1 was observed at a morpholine concentration of 30 mM, 30 SC and pH 72. The substrate was tolerated at concentrations up to 100 mM. Besides morpholine, the strain utilized pyrrolidine, piperidine and proposed intermediates in morpholine metabolism such as glycolate, glyoxylate and ethanolamine. Degradation of morpholine, piperidine and pyrrolidine by resting or permeabilized cells was strictly dependent on the presence of oxygen. Addition of the cytochrome-P450-specific inhibitor metyrapone to the growth medium resulted in a significantly decreased growth rate if these cyclic amines were used as a substrate. Carbon monoxide difference spectra of crude extracts from cells grown on these substrates compared to spectra obtained for extracts of succinate-grown cells indicated that cytochrome P450 is specifically expressed during growth on the cyclic amines. These data indicated that a cytochrome-P450-dependent monooxygenase is involved in the degradation of the three cyclic amines.

Biodegradation of bisphenol A by cells and cell lysate from Sphingomonas sp. strain AO1

“…Metyrapone has been shown to inhibit many bacterial cytochrome P450 systems, including the pyrrolidine and morpholine catabolic enzymes from Mycobacterium sp. (Poupin et al 1998;Schrader et al 2000), the biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to 4-nitro-2,4-diazabutanol by Rhodococcus sp. (Bhushan et al 2003;Coleman et al 2002;Seth-Smith et al 2002), and the dechlorination of pentachlorophenol (PCP) by Rhodococcus chlorophenolicus PCP-I (Uotila et al 1991).…”

Occurrence and community composition of fast-growing Mycobacterium in soils contaminated with polycyclic aromatic hydrocarbons

“…In spite of the limited bioavailability and poor biodegradability of PAHs, different bacteria, often mycobacteria, have been isolated that are able to use PAHs as sole sources of carbon and energy [2][3][4][5][6][7]. So far, all PAH-biodegrading Mycobacterium isolates [2][3][4][5][6][7][8][9][10][11] have been placed in the phylogenetic branch of the Ôfast-growing mycobacteriaÕ. In the Mycobacterium phylogenetic tree, the Ôfast-growing mycobacteriaÕ form a coherent line of descent, distinct from the more recently evolved slow-growers, within which the wellknown mycobacterial pathogens are clustered [12][13][14][15].…”

Degradation of 2,5-dimethylpyrazine by Rhodococcus erythropolis strain DP-45 isolated from a waste gas treatment plant of a fishmeal processing company

“…strain RP1 and Mycobacterium sp. strain HE5, the formation of 2-hydroxymorpholine by a cytochrome P450-dependent monooxygenase was suggested as the initial step (Poupin et al 1998;Schrä der et al 2000;Sielaff et al 2001). The transformation of 2,5-DMP to HDMP was inhibited by the presence of DPI, an irreversibly inactivator of flavoproteins (Shiemke et al 2004), methimazole, a competitive inhibitor of flavin-containing monooxygenases (Tomasi et al 1995).…”