Rapid Detection of Methanol in an Integration Microfluidic Chip

A rapid and simple technique was developed for detecting methanol with very small amount of sample by using PMMA (Polymethyl-Methacrylate) microfluidic chip, which fabricated by a commercially available CO2 laser scriber. The experimental results indicate that linearity expression R2 can approximate 0.936 using the proposed integrating microfluidic chip when the 2 unit methanol oxidase (MOX) and basic fuchsin to detect methanol. Hence, the current device provides a valuable tool for rapid methanol detection, while its micro mixer system delivers a simple yet effective solution for mixing problems in the micro-total-analysis -systems field.

Methyloversatilis universalis gen. nov., sp. nov., a novel taxon within the Betaproteobacteria represented by three methylotrophic isolates

The taxonomic positions and phylogenetic relationships of two new methylotrophic isolates from Lake Washington (USA) sediment, FAM5T and 500, and the previously described methylotrophic strain EHg5 isolated from contaminated soil in Estarreja (Portugal) were investigated. All three strains were facultative methylotrophs capable of growth on a variety of C1 and multicarbon compounds. Optimal growth occurred at pH 7.5–8 and 30–37 °C. The major fatty acids were C16 : 1 ω7c and C16 : 0. The major quinone was ubiquinone Q8. Neither methanol dehydrogenase nor methanol oxidase activities were detectable in cells grown on methanol, suggesting an alternative, as-yet unknown, mechanism for methanol oxidation. The isolates assimilated C1 units at the level of formaldehyde, via the serine cycle. The DNA G+C content of the strains ranged between 64 and 65 mol%. 16S rRNA gene sequence similarity between the three new isolates was 99.85–100 %, but was below 94 % with other members of the Betaproteobacteria, indicating that the isolates represent a novel taxon. Based on physiological, phenotypic and genomic characteristics of the three isolates, a new genus, Methyloversatilis gen. nov., is proposed within the family Rhodocyclaceae. The type strain of Methyloversatilis universalis gen. nov., sp. nov. is FAM5T (=CCUG 52030T=JCM 13912T).

Superoxide Dismutase During Glucose Repression Of Hansenula Polymorpha CBS 4732

Hansenula polymorpha CBS 4732 was studied during cultivation on methanol and different glucose concentrations. Activities of Cu/Zn and Mn superoxide dismutase, catalase and methanol oxidase were investigated. During cultivation on methanol, increased superoxide dismutase and catalase activities and an induced methanol oxidase were achieved. Transfer of a methanol grown culture to medium with a high glucose concentration caused growth inhibition, low consumption of carbon, nitrogen and phosphate substrates, methanol oxidase inactivation as well as decrease of catalase activity (21.8 ± 0.61 ΔE240 × min -1 × mg protein -1). At the same time, a high value for superoxide dismutase enzyme was found (42.9 ± 0.98 U × mg protein-1, 25% of which was represented by Mn superoxide dismutase and 75% - by the Cu/Zn type). During derepression methanol oxidase was negligible (0.005 ± 0.0001 U × mg protein -1), catalase tended to be the same as in the repressed culture, while superoxide dismutase activity increased considerably (63.67 ± 1.72 U × mg protein -1, 69% belonging to the Cu/Zn containing enzyme). Apparently, the cycle of growth inhibition and reactivation of Hansenula polymorpha CBS 4732 cells is strongly connected with the activity of the enzyme superoxide dismutase