Bio-conversion of methane into high profit margin compounds: an innovative, environmentally friendly and cost-effective platform for methane abatement.

Despite the environmental relevance of CH4 and forthcoming stricter regulations, the development of cost-efficient and environmentally friendly technologies for CH4 abatement is still limited. To date, one of the most promising solutions for the mitigation of this important GHG consists of the bioconversion of CH4 into bioproducts with a high profit margin. In this context, methanotrophs have been already proven as cell-factories of some of the most expensive products synthesized by microorganisms. In the case of ectoine (1000 $ kg-1), already described methanotrophic genera such as Methylomicrobium can accumulate up to 20% (ectoine wt-1) using methane as the only carbon source. Moreover, α-methanotrophs, such as Methylosynus and Methylocystis, are able to store bioplastic concentrations up to 50-60% of their total cell content. More than that, methanotrophs are one of the greatest potential producers of methanol and exopolysaccharides. Although this methanotrophic factory could be enhanced throughout metabolic engineering, the valorization of CH4 into valuable metabolites has been already consistently demonstrated under continuous and discontinuous mode, producing more than one compound in the same bioprocess, and using both, single strains and specific consortia. This review states the state-of-the-art of this innovative biotechnological platform by assessing its potential and current limitations.

Validation of a New Low-Cost, Methanol-Based Fixative for Cervical Cytology and Human Papillomavirus Detection.

OBJECTIVE: To test the performance of a new fixative for pap smear collection for liquid-based cervical cytology, CellPreserv® and compare it with the commercially available, PreservCyt® used in the diagnosis and detection of human papillomavirus (HPV). METHODS: Seven hundred twenty five women participated in this study after signing an informed consent. The specimens were collected using a traditional device, agitated in PBS, and equally divided in both fixatives. The slides were prepared routinely, stained by Papanicolaou, examined blindly by 2 cytologists, and reviewed by one cytopathologist. To search for HPV, 1,000 µL from each fixative was taken and processed by polymerase chain reaction. RESULTS: Considering the adequacy of samples, both fixatives had similar results - 0.33 and 0.32% of the cases unsatisfactory for PreservCyt® and CellPreserv®, respectively. Considering the 701 satisfactory cases and comparing the new fixative to the traditional fixative, there was 99.3% concordance between both. The results regarding the HPV detection was 100% concordant between the 2 fixatives. CONCLUSION: The new methanol-based fixative, CellPreserv®, is cheaper and equally efficient for treating cervical cancer screening and for HPV detection, and can be safely used by the health system prevailing in low-income countries.

Surrogate alcohol containing methanol, social deprivation and public health in Novosibirsk, Russia.

Surrogate alcohol, i.e. alcohol not intended or not officially intended for human consumption, continues to play an important role in alcohol consumption in Russia, especially for people with alcohol dependence. Among the different types of surrogate alcohol, there are windshield washer antifreeze liquids; these products are the cheapest kinds of non-beverage alcohol available and thus likely to be used by the most deprived and marginalised groups such as homeless people with alcohol dependence. Although it is well known, that non-beverage alcohol is used for consumption by various groups in Russia, and although there are laws to prohibit the use of methanol as part of windshield washer antifreeze liquids for the very reason that such products could be used as surrogate alcohol, we detected products in retail sale which were a mix of water and methanol only. Methanol poses serious health threats including blindness and death, and there had been repeated methanol deaths from surrogate alcohol in Russia over the last years. If law-enforcement does not change for surrogate products, we can expect more methanol-resulting deaths in the most deprived and marginalized groups of people with alcohol dependence in Russia. In addition, ingredients with questionable safety profiles such as formic acid should also be prohibited in non-beverage alcohol products that are likely to be consumed as surrogate alcohol.

Impact of the nature and composition of the mobile phase on the mass transfer mechanism in chiral reversed phase liquid chromatography. Application to the minimization of the solvent cost in chiral separations.

The mechanism of mass transfer was studied on a cellulose-based chiral stationary phase (CSP, Lux Cellulose-1) using aqueous mixtures of acetonitrile (50/50-90/10, v/v) or methanol (90/10 and 100/0, v/v) as the mobile phase. An experimental protocol validated in RPLC and HILIC chromatography and recently extended to chiral RPLC was applied. The five mass-transfer contributions (longitudinal diffusion, short-range and long-range eddy dispersion, solid-liquid mass transfer resistances due to finite intra-particle diffusivity and slow adsorption-desorption) to the reduced height equivalent to a theoretical plate (HETP) were measured. The experimental results show that the adsorption rate constants kads of trans-stilbene enantiomers onto the CSP are three times larger with acetonitrile than with methanol as the organic modifier. This is correlated to the decrease of enantioselectivity from 1.4 (in methanol) to only 1.1 (in acetonitrile). The amount of solvent needed to achieve a separation factor of exactly 2.0 was determined. This showed that analysis cost could be reduced seven times by selecting pure methanol as the eluent for a 5cm long column rather than an acetonitrile-water mixture for a longer (20-45cm) column.

Surrogate alcohol drinking in Estonia.

BACKGROUND: Surrogate, nonbeverage alcohols, provide a cheap and concentrated source of ethanol for drinking that has been associated with premature mortality. The aim of this study was to provide the first estimate of the prevalence of surrogate alcohol consumption in a national population sample of Estonia. METHODS: The Estonian Health Interview Survey conducted in 2006 to 2007 was a nationally representative sample of the population aged 15 to 84 years (N = 6,370). The age-standardized percentage prevalences of ever having drunk surrogates were estimated. The association of age, ethnicity, and education with the prevalence of surrogate drinking was estimated using logistic regression. RESULTS: Of all respondents who reported drinking at least once in their lifetime (N = 5,423), 65% had consumed alcohol during the previous 4 weeks. In this group (N = 3,525), the age-standardized prevalence rate of surrogate drinking was 1.4% (2.3% men, 0.3% women). Among men, surrogate drinking was rare under the age of 35 years (0.3%). Ethnicity and education were both related to surrogate drinking: relative to Estonian men, non-Estonians (mainly Russians) had an odds ratio (OR) for surrogate drinking (adjusted for age and education) of 2.58 (95% CI 1.41, 4.72), while relative to those with higher education those with secondary education had an OR (adjusted for age and ethnicity) of 2.28 (0.78, 6.67) and those with basic education an OR of 3.91 (1.29, 11.84). CONCLUSION: Surrogate alcohols are drunk in Estonia, particularly among men. This behavior shows pronounced variation in prevalence by ethnicity and education. Reducing consumption of these substances needs to be part of any strategy to reduce the burden of alcohol-related problems in Estonia today.

Reduced alcohol use in the staining of Pap smears: a satisfactory low-cost protocol for cervical cancer screening.

OBJECTIVE: To describe a low-cost Papanicolaou staining procedure that can be applied to conventional and monolayer gynecologic preparations. STUDY DESIGN: The amount of alcohol consumed in the procedure, which normally accounts for > 80% of the cost of processing, was reduced drastically by (1) using only 1 modified cytoplasmic counterstain (EA type), thereby (2) reducing the number of alcohol rinses by over half Orange-G dye is omitted. RESULTS: The resultant effect of the modified staining protocol is quite satisfactory and attractive to screening eyes: nuclear details are sharp and crisp, while the cytoplasm contains transparent differential staining with blue-green and pink. CONCLUSION: A reduction in the cost of staining should encourage cervical cancer screening, especially in developing countries, where cost is a limiting factor, thus making it possible for more women to be screened without increasing the cost of the program.