Cell Wall Galactofuranan of “Paenarthrobacter pyridinovorans” VKM Ac-1098D

Microbiology - The structure of the cell wall glycopolymer and the taxonomic position of the pyridine-degrading strain VKM Ac-1098D were established. By using chemical and NMR spectroscopic...     

Study of the initial stages of 2-methylpyridine catabolism by <Emphasis Type="Italic">Arthrobacter</Emphasis> sp. strain KM-2MP

Strain Arthrobacter sp. KM-2MP isolated from soil samples treated with pyridine and its derivatives is able to utilize 2-methylpyridine (2-MP) as the only source of carbon, nitrogen, and energy. According to the results of UV spectroscopy of the culture liquid, the substrate (2.5 g/l) is completely utilized within 24 h. Intermediate products of 2-MP degradation were detected and identified using gas chromatography-mass spectrometry analysis. On the basis of the obtained data, catabolic pathways of the substrate are proposed. The strain has successfully passed the tests and is recommended for 2-MP removal from industrial wastewater.     

Characterization of propionic acid bacteria using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry

It was shown that matrix-assisted laser desorption/ionization (MALDI) mass spectrometry could be used for the diagnostic characterization of propionic acid bacteria (PABs). The spectra of proteins (whole PAB cells) with a molecular mass of 3000 to 11 000 were obtained and analyzed using three matrices: sinapinic (SA), 2,5-dihydroxibenzoic (DHB), and α-cyano-4-hydroxycinnamic acid (HCCA). The MALDI spectra of PAB revealed the protein peaks characteristic of (1) the genus Propionibacterium (3496, 5386, 5605, 10 470), (2) the groups of species sharing the common composition of their cell walls and fatty acids, and (3) a species (four species were investigated). Exemplified by the P. shermanii strains (the collection and mutant ones) producing and not producing vitamin B₁₂, the possibility of using MALDI profiles for strain differentiation was confirmed. The MALDI profiles of the propionic acid cocci of the genus Luteococcus differ substantially from the profiles of PAB strains of the genus Propionibacterium, which is an additional proof of the validity of whole-cell MALDI spectra for generic differentiation of bacteria. Our investigation shows that the bacterial groups determined using the MALDI profiles correlate with the phylogenetic 16S rRNA gene groups, thus demonstrating the high resolution of this method for the differentiation of intraspecific differences (subspecies, strains).