Functional assessment of plant and microalgal lipid pathway genes in yeast to enhance microbial industrial oil production.

As promising alternatives to fossil-derived oils, microbial lipids are important as industrial feedstocks for biofuels and oleochemicals. Our broad aim is to increase lipid content in oleaginous yeast through expression of lipid accumulation genes and use Saccharomyces cerevisiae to functionally assess genes obtained from oil-producing plants and microalgae. Lipid accumulation genes DGAT (diacylglycerol acyltransferase), PDAT (phospholipid: diacylglycerol acyltransferase), and ROD1 (phosphatidylcholine: diacylglycerol choline-phosphotransferase) were separately expressed in yeast and lipid production measured by fluorescence, solvent extraction, thin layer chromatography, and gas chromatography (GC) of fatty acid methyl esters. Expression of DGAT1 from Arabidopsis thaliana effectively increased total fatty acids by 1.81-fold above control, and ROD1 led to increased unsaturated fatty acid content of yeast lipid. The functional assessment approach enabled the fast selection of candidate genes for metabolic engineering of yeast for production of lipid feedstocks.

A novel total petroleum hydrocarbon fractionation strategy for human health risk assessment for petroleum hydrocarbon-contaminated site management.

Human health risk assessments for petroleum, oil, and lubricant (POL)-contaminated sites are more complicated than for sites contaminated by single compounds due to the complex composition and various analytical methods associated with total petroleum hydrocarbons (TPH). Although several TPH fractionation methods are commonly used, including that of the TPH Criteria Working Group (TPHCWG), an efficient and economical human health risk assessment method is not yet available. To address this concern, a new modified fractionation strategy is recommended in this study, which resolves the problems of the current TPH fractionation methods while retaining reliability in the results. For the purpose of this study, the distribution characteristics of the 13 TPHCWG fractions were examined, and human health risk assessments for the POL-contaminated sites were performed. The results show that aliphatic EC8-16 and aromatic EC10-21 among the 13 TPH fractions are major contributors to human health risks along all exposure routes, making up approximately 96% of the hazard index (HI) of the TPH fractions, on average. Therefore, it is reasonable to concentrate on aliphatic EC8-16 and aromatic EC10-21 fractions, rather than to study all of the TPH fractions, in evaluating human health risk for TPH-contaminated sites.

Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil.

OBJECTIVES: Percutaneous penetration of polycyclic aromatic hydrocarbons (PAHs) is affected by various factors connected to exposure conditions. The nature of the matrix, such as that of oil, can strongly affect their percutaneous penetration. Risk assessment should consider these effects. We examined the effect of matrix on percutaneous penetration of PAHs, particularly that of lubricating oil. METHODS: The test apparatus consisted of an in vitro static diffusion cell system using full-thickness monkey (Cercopithecus aetiops) skin as the membrane and saline solution with gentamycin sulfate and 4% bovine serum albumin as receptor fluid. Chemical analysis of PAHs in the samples obtained from cells was carried out by inverse-phase HPCL, and the results were read by spectrofluorimetry. RESULTS: Comparing the penetration of 13 PAHs from a lubricating oil and from acetone solution with artificial sweat resulted in a significantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, fluoranthene, naphthalene, pyrene, fluorene (Mann-Whitney U test, P < 0.05). No significant differences in the passage were found for chrysene because, in the test with oil, its concentration was very often below the detection limit. For benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with artificial sweat. CONCLUSIONS: The results of the study suggest the necessity of dermal penetration data relevant for risk assessment, obtained under experimental conditions similar to the real exposure conditions.

China's "market economics in command": footwear workers' health in jeopardy.

This study of occupational safety and health (OSH) problems in the footwear industry in China, the world's largest shoemaker, is based on four years of research in China supplemented by research in Taiwan, Australia, and the United States. With the advent of the economic reforms of the early 1980s, the Chinese state is being driven by an economic imperative under which the profit motive overrides other concerns, causing a deterioration in OSH conditions. Footwear workers are being exposed to high levels of benzene, toluene, and other toxic solvents contained in the adhesives used in the shoe-making process. Many workers have been afflicted with aplastic anemia, leukemia, and other health problems. Most of China's current permissible exposure limits to toxins are either outdated or underenforced. As a result, the Chinese state's protection of footwear workers' health is inadequate. The article aims to draw the attention of the international OSH community to the importance of setting specific exposure standards for the footwear industry worldwide.

Exposure assessment for a field investigation of the acute respiratory effects of metalworking fluids. I. Summary of findings.

The exposure assessment summarized here is part of an epidemiologic study of the acute respiratory health effects of metalworking fluid (MF) exposures. Exposures were measured as the inhalable concentrations of the MF aerosol, a variety of metals and elements, and endotoxin as well as the level of culturable bacteria in the aerosol size fraction less than 8 microns. Bulk samples of soluble MFs were tested for pH, mineral and tramp oil fraction, endotoxin, culturable bacteria, and lipopolysaccharide levels. The MF exposed workers had higher geometric mean inhalable aerosol exposures (0.181 mg/m3) than the MF unexposed workers (0.046 mg/m3). The MF exposed workers had higher geometric mean (GM) airborne culturable microbial counts (102 colony-forming units (CFU)/m3 for bacteria < 8 microns) than the unexposed workers (GM = 14 CFU/m3). Among the unexposed, Bacillus was the predominant airborne species, while among the exposed workers, Pseudomonas predominated. Exposed workers also had higher geometric mean airborne endotoxin levels (GM = 7.1 endotoxin units (EU)/m3) than the unexposed workers (GM = 1.9 EU/m3). Elemental concentrations of iron, chlorine, and sulfur were substantially higher among the exposed workers compared to the unexposed workers. For soluble metalworking fluids, the levels of bulk constituents were examined by three categories of time since the machine sump was refilled with fresh MF (< 4 days, 4-21 days, > 21 days). Univariate analyses of percent oil, pH, culturable bacteria, tramp oil percent, endotoxin, or fatty acid levels all showed no statistically significant changes in level over time.

Assessment of the effects of atmospheric oil pollution in post war Kuwait.

A prospective study was undertaken to assess and monitor the effects of oil pollution in soldiers exposed in Kuwait in 1991 after Op Granby. One hundred and twenty five soldiers were monitored over a five month period by measurement of Forced Expiratory Volume (in one second) (FEV1) and Forced Vital Capacity (FVC). Although no demonstrable changes were observed, this study has gone some way to filling the gap in research in this environmentally sensitive field.