title: Physiological, biochemical, and genetic characterization of an alicyclic amine-degrading Mycobacterium sp. strain THO100 isolated from a morpholine-containing culture of activated sewage sludge.
abstract: Mycobacterium sp. strain THO100 was isolated from a morpholine-containing culture of activated sewage sludge. This strain was able to utilize pyrrolidine, morpholine, piperidine, piperazine, and 1,2,3,6-tetrahydropyridine as the sole sources of carbon, nitrogen, and energy. The degradation pathway of pyrrolidine as the best substrate for cellular growth was proposed based on the assays of substrate-induced cytochrome P450 and constitutive enzyme activities toward 4-aminobutyric acid (GABA) and succinic semialdehyde (SSA). Its 16S ribosomal RNA gene sequence (16S rDNA) was identical to that of Mycobacterium tokaiense ATCC 27282(T). The morABC genes responsible for alicyclic amine degradation were nearly identical among different species of Mycobacteria. Remarkably, repetitive sequences at the intergenic spacer (IGS) region between morC and orf1' were detected by comparison of the nearly identical mor gene cluster regions. Considering the strain activity for alicyclic amine degradation, the deleted 65-bp DNA segment did not significantly alter the open reading frames, and the expression and functions of the P450(mor) system remained unaltered. In addition, we found a spontaneous deletion of P450(mor) from another strain HE5 containing the archetypal mor gene cluster, which indicated a possible occurrence of DNA recombination to rearrange the DNA.
authors.affiliation: School of Biological Sciences, Seoul National University, San 56-1 Shinrim, Kwanak, Seoul, Republic of Korea.
authors.forename: Yong-Hak
authors.initials: YH
authors.lastname: Kim
authors.forename: Ilnam
authors.initials: I
authors.lastname: Kang
authors.forename: Hélène
authors.initials: H
authors.lastname: Bergeron
authors.forename: Peter C K
authors.initials: PC
authors.lastname: Lau
authors.forename: Karl-Heinrich
authors.initials: KH
authors.lastname: Engesser
authors.forename: Sang-Jong
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000588:Amines / Q000378:metabolism*; D001673:Biodegradation, Environmental; D005798:Genes, Bacterial / Q000235:genetics; D005858:Germany; D007218:Industrial Microbiology; D009025:Morpholines / Q000378:metabolism*; D005810:Multigene Family; D009161:Mycobacterium / Q000145:classification / Q000302:isolation & purification / Q000502:physiology*; D010802:Phylogeny; D010880:Piperidines / Q000378:metabolism; D011759:Pyrrolidines / Q000378:metabolism; D017385:Sequence Homology; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013045:Species Specificity; D014865:Waste Disposal, Fluid
chemical_list: D000588:Amines; D009025:Morpholines; D010880:Piperidines; D011759:Pyrrolidines; D012722:Sewage; C032727:piperidine; C037574:morpholine; C032519:pyrrolidine