Chemical, physical and antimicrobial properties of essential oils of Leptospermum scoparium and Kunzea ericoides

The major components of commercial New Zealand essential oils of Leptospermum scoparium (manuka) and Kunzea ericoides (kanuka) are identified. In the manuka oil, monoterpenes are present at low levels (< or = 3%). Sesquiterpene hydrocarbons are predominant (> or = 60%) and include groups possessing cubebene/copaene, elemene, gurjunene/aromadendrene, farnesene/ caryophyllene, selinene, calamenene and cadinene skeletons. Oxygenated sesquiterpenes and triketones are present (< or = 30%). The antimicrobial activity of the manuka oil was associated with a fraction containing three major and three trace triketones, two of the latter were previously unreported. Kanuka oil was characterized by high levels of alpha-pinene (> 50%) and lower levels (< 10%) of viridiflorol and viridiflorene. GC-MS and GC-FID detector responses to the same components were noticeably different for some major components, including the triketones. Non-commercial manuka oils from different sites differed widely in composition and could be separated into four groups by the presence and levels of distinctive components. The density and refractive index of manuka and kanuka oils were closely correlated with the total sesquiterpene levels. The density of the commercial manuka oil was closely correlated with the level of the triketones. Simple density measurements enabled discrimination between the commercial oil and oils from other sites, and prediction of antimicrobial activity.     

Oils and cancer

Epidemiologic evidence on the relationship between mineral oil exposure and cancer is reviewed. The review is restricted to occupations involving substantial dermal and inhalational exposure and for which an epidemiologic literature exists: metal machining, print press operating, and cotton and jute spinning. Mineral oils are complex mixtures of aliphatic hydrocarbons, naphthenics, and aromatics, the relative distribution of which depends on the source of the oil and the method of refinement. End-use products contain a variety of additives, and contamination by other agents generally occurs during use. Suspect agents include polycyclic aromatic hydrocarbons (PAH) (particularly benz[a]pyrene), nitrosamines, chlorinated paraffins, long-chain aliphatics, sulfur, N-phenyl-2-naphthylamine, and formaldehyde. The heterogeneity of this exposure makes epidemiologic study difficult and meta-analysis inappropriate. Nonetheless, several associations emerge from the literature with varying degrees of support. There is clear evidence that early formulations of mineral oils used in cotton and jute spinning and in metal machining were carcinogenic to the skin. Associations of mineral oil exposure with laryngeal and rectal cancer have received some support in the literature, particularly with respect to straight oils. Evidence is suggestive that grinding operations (which can entail either mineral oil-based or ethanolamine-based fluids) are associated with excess risk of cancer of the esophagus, stomach, and pancreas. A number of bladder cancer case-control studies have noted an association with work as a machinist. There is limited evidence of an association with cancer of the colon, prostate, and sinonasal region. Several studies of printers have yielded positive findings for lung cancer, whereas studies in metal machinists have been generally negative. The PAH and nitrosamine content of current formulations is lower than in the past and the implications of these changes in composition to the carcinogenicity of the formulations are not yet known.     

Sequential enrichment of microbial populations exhibiting enhanced biodegradation of crude oil

The distribution of oil-degrading bacteria in the coastal water and sediments of Hokkaido, Japan, was surveyed. The potential of mixed microbial populations to degrade weathered crude oil was not confined to any ecological components (water or sediment) nor to the sampling stations. One microbial culture that was stable during repeated subculturing degraded 45% of the saturates and 20% of the aromatics present in crude oil in 10 days during the initial screening. The residual hydrocarbons in this culture were extracted by chloroform and dispersed in a fresh seawater-based medium and subsequently inoculated with microorganisms from the first culture. After full growth of the second culture, the residual hydrocarbons were again extracted and dispersed in a fresh medium in which microorganisms from the second culture had been inoculated. This sequential process was carried out six times to enrich those microorganisms that grew on the recalcitrant components of crude oil. After repeated exposure of the residual crude oil to the enriched microorganisms, about 80% of the initially added crude oil was degraded. The cultures obtained after each enrichment cycle were kept, and the degradation of fresh crude oil by the enriched microorganisms was examined. The degradative activity of the enriched cultures increased as the number of enrichment cycles increased. A microbial population that had been selected six times on the residual crude oil could degrade 70% of the saturates and 30% of the aromatics of crude oil. Thus, growth of a microbial population on residual crude oil improved its ability to biodegrade crude oil.     

Cutting fluids and their effects on the skin of mice. An experimental study with special reference to carcinogenicity

Reports of skin malignancies due to occupational exposure have decreased since the introduction of solvent-refining of mineral oil fraction in the manufacture of oil based cutting fluids. Commercial mineral oil based cutting fluids caused local and general pathological changes after repeated application to the skin of mice in the present study. Forty-eight per cent of the mice exposed to oils showed severe dysplasia or malignancy of the skin on histological examination. The corresponding figure for the control group, where various additives were used was 8 per cent. The frequency of papillomas was also increased in the mice exposed to oils. The systemic lesions included focal necrosis of the liver, associated with amyloid deposition, as well as amyloidosis of the skin, spleen and kidneys. The substances responsible for these apparent carcinogenic properties of the complex mixtures may be polycyclic hydrocarbons; the latter are still present in the commercial products despite solvent refining; on the other hand the carcinogens may be additives to the cutting oils the composition of which is generally a trade secret.     

Microencapsulation in yeast cells

A method for encapsulating high concentrations of essential oils into bakers' yeast (Saccharomyces cerevisiae) is described. The process involves mixing an aqueous suspension of yeast and an essential oil, which allows the oil to pass freely through the cell wall and membrane and remain passively within the cell. Oil droplets sequestered within the cell were clearly visible using confocal microscopy. Transmission electron microscopy demonstrated that the cell wall and membrane remain intact during the process. Cells quickly lost viability during the process and it appeared unnecessary for the cells to be viable for the process to occur. Encapsulated oil was recovered from the cells using a water/ethanol extraction procedure and analysed by gas chromatography. No significant differences were noted between encapsulated and unencapsulated oil profiles. The rate of permeation of oil into the yeast cells was found to increase significantly at higher temperatures due to the phase transition of the lipid membrane. The rates at which different essential oils permeated the cell varied considerably due to variations in terpene chemistry. The encapsulation of straight chain hydrocarbons highlighted the effects of molecular size, shape and the presence of hydroxl groups on the process. The process occurs by passive diffusion as a result of hydrophobic flavour components partitioning into the cell membrane and intracellular lipid. This paper briefly reviews the patented literature and reports some of the initial observations of the transport mechanisms involved during the accumulation of essential oils by yeast cells.     

Isolation and identification of bacteria from activated sludge purifying petroleum wastewaters

Several strains growing well in minimal media with 500 and 1000 mg/l of oil or phenol as a sole carbon source were isolated from activated sludge purifying petroleum waste waters and identified. Five of the best growing strains classified as Arthrobacter, Pseudomonas, Xanthomonas and Enterobacter were selected and their capacity to remove petroleum components and phenol (in the oil fraction of petrochemical waste waters) was studied. The enzymatic activity of the strains, including respiration intensity and dehydrogenase activity was also determined. All the examined strains were found to use oils as the sole source of carbon (percent age of the oils reduction during cultivation of the individual strains ranged from 58 to 78). Phenol was completely reduced by only one strain. The rest of the strain removed only from 7 to 24% of this compound. The activity of dehydrogenases and the respiration intensity in the presence of the studied substrates -- oil and phenol was low for all the examined strains.     

Petroleum pollution bioremediation using water-insoluble uric acid as the nitrogen source

The biodegradation of hydrocarbon pollutants in open systems is limited by the availability of a utilizable nitrogen source. This limitation can be overcome by using uric acid. Enrichment cultures grown on crude oil-uric acid media yielded mixed and pure cultures that degraded petroleum. In a simulated open system, uric acid bound to crude oil and was available for bacterial growth and petroleum biodegradation.     

Critical care management of the heart failure patient in the home

As part of a program to determine the underlying factors responsible for genotoxicity and perhaps lung cancer risk in Chinese women, we qualitatively identified the volatile components emitted during the heating of cooking oils to 265 degrees C. 1,3-Butadiene, benzene, and a series of aldehydes, olefins, and saturated hydrocarbons were elucidated in vapors from Chinese rapeseed oil. On a relative basis, the intensity of 1,3-butadiene vapors from this were 15.7-, 6.3-, and 1.4-fold greater than in the vapors from peanut, soybean, and Canola oils, respectively. Thus, the Chinese rapeseed oil yielded a higher emission rate of 1,3-butadiene than the other three oils investigated. The benzene formation rate followed a similar trend, i.e., its intensity in Chinese rapeseed oil was 14-, 6.6-, and 1.7-fold greater than in vapors from peanut, soybean, and Canola oils, respectively.     

Development of vegetable extracts by microencapsulation

The microencapsulation of essential oils offers protection against oxidation and evaporation, and allows the concurrent utilization of several vegetable extracts. Complex coacervation methods have been described for essential oils. Even though microencapsulation involves wrapping the essential oils in shells, some difficulties arise in the process of stabilizing the essential oils: oil may be lost by evaporation and partial dissolution in the water-gelatin phase and this will vary with the type of essential oil being encapsulated. In order to investigate the efficacy of the gelatin-polyphosphate methods we analysed their essential oil microcapsules peppermint and rosemary, in particular their granulometric size distribution, oil content (%) and encapsulation yield (%). In addition the essential oils were analysed by GC before and after microencapsulation so as to investigate the loss of their components during the process.     

Ready biodegradability test in seawater: a new methodological approach

To estimate the persistence of xenobiotic in the environment, a new ultimate mineralization approach for assessing ready biodegradability in seawater has been developed, based on the OECD 301 B guideline for freshwater. a few changes in the currently accepted procedure have been made to adapt the test to seawater. The assays, realized with seawater as test medium and inoculum, give high variability results of biodegradability. To lower this variability a synthetic marine medium joined to a highly concentrated inoculum from a marine aquarium filter have been used. The results reveal (i) a decrease of variability, together with an increase in degradation rate of the tested chemicals due to a better control of inoculum and test medium, and (ii) no difference in easy biodegradable compound (sodium benzoate) biodegradation rate when two marine aquarium inocula are tested. This study demonstrates that the ready biodegradability test developed on synthetic marine medium and inoculum from marine aquarium filter minimizes the effect of the sample location on the biodegradation results of compounds and allows classifying chemicals as a function of their biodegradability.     

Attenuation of Petroleum Hydrocarbons in Smear Zones: A Case Study

Soil and ground water in a shallow aquifer were contaminated by petroleum hydrocarbons, mostly comprised of toluene. The degrees of soil and ground-water contamination were closely correlated. The vertical profile of soil contamination showed an exponential or semilinear decrease both upward and downward from the mean water table, and this was closely related to water table fluctuation. Vertical and seasonal variations in the concentrations of petroleum hydrocarbon contaminants and their degradation products were analyzed in detail. Total natural attenuation rate and the contribution of biodegradation to the rate were estimated. Biodegradation was found to be an effective attenuation process at this site.     

Phage-displayed peptide libraries

The influence of various dietary marine oils and olive oil on fatty acid composition of serum and platelets and effects on platelets and serum lipids were investigated as part of an extensive study of the effects of these oils on parameters associated with cardiovascular/thrombotic diseases. Healthy volunteers (266) consumed 15 mL/d of cod liver oil (CLO); whale blubber oil (refined or unrefined); mixtures of seal blubber oil and CLO; or olive oil/CLO for 12 wk. In the CLO, seal oil/CLO, and whale oil groups, serum levels of eicosapentaenoic acid (EPA) were increased. In platelets, EPA was increased in the CLO, seal/CLO, and olive oil/CLO groups. The localization of n-3 polyunsaturated fatty acids in the triacylglycerols did not seem to influence their absorption. Intake of oleic acid is poorly reflected in serum and platelets. No significant differences in triacylglycerols (TG), total cholesterol, or high density lipoprotein cholesterol were observed, even though TG were reduced in the CLO, CLO/seal oil, and whale oil groups. Mean platelet volume increased significantly in both whale oil groups and the CLO/olive oil group. Platelet count was significantly reduced in the refined whale oil group only. Lipopolysaccharide-stimulated blood tended to generate less thromboxane B2 in CLO, CLO/seal, and CLO/olive groups. The whale oils tended to reduce in vivo release of beta-thromboglobulin. In conclusion, intake of various marine oils causes changes in platelet membranes that are favorably antithrombotic. The combination of CLO and olive oil may produce better effects than these oils given separately. The changes in platelet function are directly associated with alterations of fatty acid composition in platelet membranes.     

Low-temperature bioremediation of a waste water contaminated with anionic surfactants and fuel oil

We conducted a laboratory study at 10 degrees C on the biological decontamination of the waste water from a garage and car-wash that was contaminated with anionic surfactants (57 mg 1(-1)) and fuel oil (184 mg hydrocarbons 1(-1)). The indigenous microorganisms degraded both contaminants efficiently after biostimulation by an inorganic nutrient supply. After 7 days at 10 degrees C, the residual contaminations were 11 mg anionic surfactants 1(-1) and 26 mg hydrocarbons 1(-1). After 35 days, only the anionic surfactants had been further reduced to 3 mg 1(-1). Bioaugmentation of the unfertilized waste water with a cold-adapted inoculum, able to degrade both hydrocarbons (diesel oil) and anionic surfactants (sodium dodecyl sulphate), resulted in a significant increase of the hydrocarbon biodegradation during the first 3 days of decontamination, whereas biodegradation of anionic surfactants was inhibited during the first 21 days following inoculation. Bioaugmentation of the nutrient-amended waste water was without any effect.     

Study of the Potential for Bioremediation of Petroleum Hydrocarbons within Smear Zone Soils

A bench-scale study was completed to assess the potential for the bioremediation of smear zone soils at a leaking underground storage tank site in Fort Drum, N.Y. The study demonstrated that the vertical distribution of total petroleum hydrocarbons (TPHs) within the smear zone corresponded to differences in microbial biomass and activity. The soil core featured the lowest TPH and highest biomass levels at the top of the smear zone, and the highest TPH and median biomass levels at the bottom of the smear zone. Phospholipid fatty acid biomarkers indicate that gram-positive bacteria and fungi were associated with the in situ TPH biodegradation. The microcosm study shows that microbial respiration at the top of the smear zone was much stronger than that at the bottom of the smear zone. At the top of the smear zone, microbial mineralization was faster under the saturated condition, whereas at the bottom of the smear zone, microbial mineralization was faster under the unsaturated condition. The column study shows that the biodegradation rates of bioventing and biosparging for the specific site did not differ substantially.     

Removal of Emulsified PHCs from Brackish Water by Coagulation

Chemical coagulation is a well-known method for removing colloidal particles that cause turbidity in water. In this study coagulation was used to remove emulsified petroleum hydrocarbons (PHCs) found in fuel oils from brackish water. Comparison of the total ion chromatograms of PHCs before and after coagulation clearly showed that PHCs with carbon numbers between 11 and 35 (naphthalene to pentatriacotane) with long chain alkanes were removed completely from the brackish water by coagulation followed by settling. Smaller carbon number (C7–C9) benzene derivatives were partially removed. For the PHCs with smaller carbon numbers, the removal efficiency increased with increasing carbon number.     

Low linolenate and commercial soybean oils diminish serum HDL cholesterol in young free-living adult females

OBJECTIVE: A mutant soybean line (A16) low in linolenic acid content (2% of oil by weight) was developed to increase oil oxidative stability. It was unknown whether serum lipid and lipoprotein concentrations in humans would be affected should A16 soybean oil (A16 oil) replace commercial soybean oil in diets. This study was conducted to examine the hypothesis that in free-living normolipidemic women, the consumption of A16 oil at approximately 10% of energy intake (en%) would not affect serum lipids and lipoproteins differently than would the consumption of the same amount of a commercial soybean oil with 7% of linolenic acid content. DESIGN: Fifteen free-living female college students consumed the soybean oil daily with regular meals for 9 weeks in different orders, with each test oil being eaten for 3 weeks. During the study, 13 en% was provided by each test oil and a total of 35 en% was from dietary fat. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol) and triacylglycerides (TAG) were measured. Serum total fatty acid patterns were analyzed as well. RESULTS: Each of the three test oils decreased serum total cholesterol, LDL cholesterol and TAG concentrations from the baseline values. The feeding of A16 and commercial soybean oils decreased serum HDL cholesterol significantly compared with coconut oil (p < 0.05). Dietary inclusion of coconut oil increased serum myristic acid significantly more than did either soybean oil (p < 0.01). Serum arachidonic acid concentrations were significantly greater with A16 consumption than with commercial soybean oil consumption (p < 0.001). CONCLUSION: A16 and commercial soybean oils both diminished serum HDL cholesterol. Although the fatty acid composition differed between the two soybean oils, A16 oil and commercial oil had similar effects on serum concentrations of lipoproteins and lipids. With increased oxidative stability, A16 oil is a good alternative to commercial soybean oil.     

Effects of ions on partitioning of serum albumin and lysozyme in aqueous two-phase systems containing ethylene oxide/propylene oxide co-polymers

To examine the influence of dietary polyunsaturated fatty acids (PUFA) on the lipid composition of the pineal organ and its production of prostaglandins, Atlantic salmon were fed diets containing either fish oils rich in long-chain n-3 polyunsaturated fatty acids, or plant oils with high levels of 18:2(n-6) (sunflower oil) or 18:3(n-3) (linseed oil) for 12 weeks. Lipid content and lipid class composition of the pineal organ were not greatly influenced by the type of oil fed to the fish: choline phosphoglycerides were always the predominant lipid class and the proportion of polar lipids exceeded that of neutral lipids. The pattern of PUFA present in total lipid and individual lipid classes was, however, related to that of the dietary oil. The major PUFA in pineal total lipid from all four dietary groups was 22:6(n-3) and the proportion of n-6 PUFA present was highest in lipid from salmon fed sunflower oil. Both PGE and PGF analogues of the 2- and 3-series were detected in pineal homogenates from all dietary groups with the former prostaglandin being the most abundant. The ratio of PGE2/PGE3 was greatest in fish fed sunflower oil and lowest in those fed linseed oil. The results provide further evidence that despite its anatomical location the pineal organ resembles non-neural tissues more than brain in terms of lipid composition and prostaglandin production.     

Biodegradation of Mixtures of Phenolic Compounds in an Upward-Flow Anaerobic Sludge Blanket Reactor

The anaerobic biodegradability of mixtures of phenolic compounds was studied under continuous and batch systems. Continuous experiments were carried out in up-flow anaerobic sludge bed (UASB) reactors degrading a mixture of phenol and p-cresol as the main carbon and energy sources. The total chemical oxygen demand (COD) removal above 90% was achieved even at organic loading rates as high as 7 kg COD/m3/day. Batch experiments were conducted with mixtures of phenolic compounds (phenol, p-cresol, and o-cresol) to determine the specific biodegradation rates using unadapted and adapted anaerobic granular sludge. Phenol and p-cresol were mineralized by adapted sludge with rates several orders of magnitude higher than unadapted sludge. Additionally, an UASB reactor was operated with the mixture phenol, p-cresol, and o-cresol. After 54 days of operation, 80% of o-cresol (supplied at 132 mg/L) was eliminated. The phenol biodegradation was not affected by the presence of o-cresol. These results demonstrate that major phenolic components in petrochemical effluents can be biodegraded simultaneously during anaerobic treatment.     

Modeling of Biodegradation in an Old Unregulated European Landfill

In this note an example of modeling of biodegradation processes of an old abandoned municipal solid waste landfill for its simulation is illustrated using the landfill dynamic simulation tool MODUELO. In this program the waste biodegradation model is based on the quantification of organic matter, its chemical composition, biodegradability, accessibility to microorganisms, and the ratio nonbiodegradable leachable organic matter to gasifiable matter. Data from a characterization campaign, presented elsewhere, were used to determine these parameters. The experimental information was completed with safety factors (to compensate for sampling uncertainty) and literature values. The degradation rates were determined, after having calibrated the hydrological model, by fitting the temporal series of pollutants’ concentration measured in the leachate and the biogas composition. The achieved fit of the simulated series compared to the measured data is reported as the result of this work. Given the limited information available, the obtained simulation model is considered an acceptable tool to study the future evolution of the landfill in different circumstances.     

Physico-chemical characteristics of the Barinas nut (Caryodendron orinocense Karst. Euphorbiaceae) crude oil

A proximate analysis of the seed of the C. orinocense K. (Euphorbiaceae) has demonstrated that these are a good source of edible oil. The crude oil was analyzed to determine its physical and chemical characteristics and the lipid composition, using the AOAC methods and gas liquid chromatography. The results showed that the oil meets Venezuelan standards for edible vegetable oils, with the exception of moisture content and the acid index. It is rich in polyunsaturated fatty acids (75.13% lineoleic acid), having a polyunsaturated to saturated fatty acid ratio of 6.50, and therefore could be used for human consumption.