Use of Rhodotorula minuta Live Cells Hosted in Water-in-Oil Macroemulsion for Biotrasformation Reaction

A lecithin/water/isooctane water-in-oil (w/o) macroemulsion was used as a host system for biotransformation reactions. In particular, the hydrolytic activity of the yeast Rhodotorula minuta toward (+/-)-succinic acid bis-2-isopropyl-5-methylcyclohexyl ester and p-nitrophenyl butyrate is reported. Evidence that R. minuta entrapped in w/o macroemulsion is able to hydrolyze the p-nitrophenyl butyrate ester is presented. By performing the yeast-catalyzed hydrolysis of (+/-)-succinic acid bis-2-isopropyl-5-methylcyclohexyl ester, the synthesis of (-)-menthol was obtained, indicating that R. minuta retains its high stereoselectivity in the macroemulsion system. In addition, no significant differences were observed among the hydrolysis rates and yields obtained using yeast cells hosted into w/o macroemulsions containing different amounts of water. Optical microscopy studies on the distribution of diameters of the dispersed phase indicate that the macroemulsion system is stable in terms of polydispersity. The diameter of the w/o macroemulsion droplets is indeed constant irrespective of the addition of water and/or chemicals (involved in the biotransformation reaction) to the system hosting yeast cells. The reactor devised here might be applied to other interesting bioconversion processes.

Biodiesel production from heterotrophic microalgal oil

The present study introduced an integrated method for the production of biodiesel from microalgal oil. Heterotrophic growth of Chlorella protothecoides resulted in the accumulation of high lipid content (55%) in cells. Large amount of microalgal oil was efficiently extracted from these heterotrophic cells by using n-hexane. Biodiesel comparable to conventional diesel was obtained from heterotrophic microalgal oil by acidic transesterification. The best process combination was 100% catalyst quantity (based on oil weight) with 56:1 molar ratio of methanol to oil at temperature of 30 degrees C, which reduced product specific gravity from an initial value of 0.912 to a final value of 0.8637 in about 4h of reaction time. The results suggested that the new process, which combined bioengineering and transesterification, was a feasible and effective method for the production of high quality biodiesel from microalgal oil.

Effects of methylmalonyl-CoA mutase gene knockouts on erythromycin production in carbohydrate-based and oil-based fermentations of Saccharopolyspora erythraea

In carbohydrate-based fermentations of Saccharopolyspora erythraea, a polar knockout of the methylmalonyl-CoA mutase (MCM) gene, mutB, improved erythromycin production an average of 126% (within the range of 102-153% for a 0.95 confidence interval). In oil-based fermentations, where erythromycin production by the wild-type strain averages 184% higher (141-236%, 0.95 CI) than in carbohydrate-based fermentations, the same polar knockout in mutB surprisingly reduced erythromycin production by 66% (53-76%, 0.95 CI). A metabolic model is proposed where in carbohydrate-based fermentations MCM acts as a drain on the methylmalonyl-CoA metabolite pool, and in oil-based fermentations, MCM acts in the reverse direction to fill the methylmalonyl-CoA pool. Therefore, the model explains, in part, how the well-known oil-based process improvement for erythromycin production operates at the biochemical level; furthermore, it illustrates how the mutB erythromycin strain improvement mutation operates at the genetic level in carbohydrate-based fermentations.

Efficacy of lipase from Aspergillus niger as an additive in detergent formulations: a statistical approach

The efficacy of lipase from Aspergillus niger MTCC 2594 as an additive in laundry detergent formulations was assessed using response surface methodology (RSM). A five-level four-factorial central composite design was chosen to explain the washing protocol with four critical factors, viz. detergent concentration, lipase concentration, buffer pH and washing temperature. The model suggested that all the factors chosen had a significant impact on oil removal and the optimal conditions for the removal of olive oil from cotton fabric were 1.0% detergent, 75 U of lipase, buffer pH of 9.5 and washing temperature of 25 degrees C. Under optimal conditions, the removal of olive oil from cotton fabric was 33 and 17.1% at 25 and 49 degrees C, respectively, in the presence of lipase over treatment with detergent alone. Hence, lipase from A. niger could be effectively used as an additive in detergent formulation for the removal of triglyceride soil both in cold and warm wash conditions.

[The properties of hydrocarbon-oxidizing bacteria isolated from the oilfields of Tatarstan, Western Siberia, and Vietnam]

Eleven strains of hydrocarbon-oxidizing bacteria, isolated from oilfields, representing the genera Rhodococcus, Gordonia, Dietzia, and Pseudomonas, were characterized as mesophiles and neutrophiles. Rhodococci were halotolerant microorganisms growing in a media containing up to 15% NaCl. All the strains oxidized n-alkanes of crude oil. An influence of the cultivation temperatures (28 or 45 degrees C) and organic supplements on the degradation of C12-C30 n-alkanes in oxidized oil by two bacterial strains of the genus Pseudomonas was shown. The introduction of acetate, propionate, butyrate, ethanol, and sucrose led mainly to the decreased oxidation of petroleum paraffins. At certain cultivation temperatures, the addition of volatile fatty acid salts increased the content of individual n-alkanes in oxidized vs. crude oil.

Kinetic modeling of aerobic biodegradation of high oil and grease rendering wastewater

Batch scale activated sludge kinetic studies were undertaken for the treatment of pet food wastewater characterized by oil and grease concentrations of up to 21,500 mg/L, COD and BOD concentrations of 75,000 and 60,000 mg/L, respectively as well as effluent from the batch dissolved air flotation (DAF) system. The conducted kinetics studies showed that Haldane Model fit the substrates and biomass data better than Monod model in DAF-pretreated wastewater, while the modified hydrolysis Monod model better fit the raw wastewater kinetic data. For the DAF pretreated batches, Haldane Model kinetic coefficients k, K(S), Y and Ki values of 1.28-5.35 g COD/g VSS-d, 17,833-23,477 mg/L, 0.13-0.41 mg VSS/mg COD and 48,168 mg/L, respectively were obtained reflecting the slow biodegradation rate. Modified hydrolysis Monod model kinetic constants for the raw wastewater i.e., k, K(S), Y, and K(H) varied from 1-1.3 g COD/g VSS-d, 5580-5600 mg COD/l, 0.08-0.85 mg VSS/mg COD, and 0.21-0.66 d(-1), respectively.

Identifying cytoplasmic input to the cell wall of growing Chara corallina

Plants enlarge mostly because the walls of certain cells enlarge, with accompanying input of wall constituents and other factors from the cytoplasm. However, the enlargement can occur without input, suggesting an uncertain relationship between cytoplasmic input and plant growth. Therefore, the role of the input was investigated by quantitatively comparing growth in isolated walls (no input) with that in living cells (input occurring). Cell walls were isolated from growing internodes of Chara corallina and filled with pressurized oil to control turgor pressure while elongation was monitored. Turgor pressure in living cells was similarly controlled and monitored by adding/removing cell solution. Temperature was varied in some experiments. At all pressures and temperatures, isolated walls displayed turgor-driven growth indistinguishable in every respect from that in living cells, except the rate decelerated in the isolated walls while the living cells grew rapidly. The growth in the isolated walls was highly responsive to temperature, in contrast to the elastic extension that has been shown to be insensitive to similar temperatures. Consequently, strong intermolecular bonds were responsible for growth and weak bonds for elastic extension. Boiling the walls gave the same results, indicating that enzyme activities were not controlling these bonds. However, pectin added to isolated walls reversed their growth deceleration and returned the rate to that in the living cells. The pectin was similar to that normally produced by the cytoplasm and deposited in the wall, suggesting that continued cytoplasmic input of pectin may play a role in sustaining turgor-driven growth in Chara.

Effect of lipid-containing, positively charged nanoemulsions on skin hydration, elasticity and erythema--an in vivo study

Dry skin and other skin disorders such as atopic dermatitis are characterized by impaired stratum corneum (SC) barrier function and by an increase in transepidermal water loss (TEWL) leading to a decrease in skin hydration. The possibility that dermatological and cosmetic products containing SC lipids could play a part in the restoration of disturbed skin barrier function is of great interest in the field of dermatology and cosmetics. The aim of the present study was to evaluate the effect of positively charged oil/water nanoemulsions (PN) containing ceramide 3B and naturally found SC lipids (PNSC) such as ceramide 3, cholesterol, and palmitic acid on skin hydration, elasticity, and erythema. Creams of PNSC were compared to PN creams, to creams with negatively charged o/w nanoemulsion and SC lipids (NNSC) and to Physiogel cream, a SC lipid containing formulation, which is already on the market. The formulations (PN, PNSC, and NNSC) were prepared by high-pressure homogenization. After adding Carbopol 940 as thickener, particle size and stability of the creams were not significantly changed compared to the nanoemulsions. The studies were carried out on three groups, each with 14 healthy female test subjects between 25 and 50 years of age, using Corneometer 825, Cutometer SEM 575 and Mexameter 18 for measurements of skin hydration, elasticity, and erythema of the skin, respectively. The creams were applied regularly and well tolerated throughout the study. All formulations increased skin hydration and elasticity. There was no significant difference between PNSC and Physiogel. However, PNSC was significantly more effective in increasing skin hydration and elasticity than PN and NNSC indicating that phytosphingosine inducing the positive charge, SC lipids and ceramide 3B are crucial for the enhanced effect on skin hydration and viscoelasticity.

[Development of an oil-degrading biopreparation by activation of aboriginal hydrocarbon-oxidizing microflora]

A method of activation of aboriginal hydrocarbon-oxidizing microorganisms for remediation of soil and water basins polluted with oil products was developed. The optimum composition of activating additives was found (g/l): mineral components, 10.0; oil, 5.0; and a synthetic detergent, 0.2. The resulting biopreparations increased the degree of purification by factors of 4-8 in soil and 18-24 in water when applied at a concentration of 10(7) cells/g(ml).

The Use of Phase Inversion Temperature (PIT) Microemulsion Technology to Enhance Oil Utilisation during Streptomyces rimosus Fed-batch Fermentations to Produce Oxytetracycline

The use of a rapeseed oil emulsion feed, produced by a phase inversion temperature (PIT) process, produced more biomass, gave a 3-fold increase in oil utilisation and a higher oxytetracycline titre but a higher residual oil concentration when compared to a conventional fed-batch Streptomyces rimosus process fed with crude rapeseed oil. Importantly, microbial utilisation of the surfactant was confirmed for the first time.

Activity, diversity and population size of ammonia-oxidising bacteria in oil-contaminated landfarming soil

Chemolithotrophic ammonia-oxidising bacteria (AOB) present in oil-contaminated landfarming soil were studied over two growing seasons in 1999 and 2000. The number of AOB (4-9 x 10(5) cellsg(-1) of dry soil) determined with the quantitative polymerase chain reaction (real-time PCR) and the rate of potential ammonium oxidation (0.05-0.28 microg NO2(-)-N g(-1) of dry soil h(-1)) indicated the presence of stable AOB populations. Denaturing gradient gel electrophoresis (DGGE) profiling and sequence analysis of PCR-amplified AOB 16S rRNA genes showed dominance of Nitrosospira-like sequences in clusters 2 and 3. The present results from the chronically oil-contaminated landfarming soil support the suggested importance of Nitrosospira-like AOB in terrestrial environments.

Composition and functional properties of Lupinus campestris protein isolates

Protein isolates from L. campestris and soybean seeds were prepared using isoelectric precipitation (PI) and micellization (MI) procedures. The amount of protein recovered was considerably higher with the isoelectric precipitation than with the micellization procedure (60% and 30%, respectively). Protein contents were higher than 90% in protein isolates. Antinutritional factors content (alkaloids, lectins, and tannins) were reduced to innocuous levels after protein isolate preparation. Minimum protein solubility for the precipitated lupin protein isolate (LPI) was at pH 4.0, and between pH 4 and 6 for the micellized lupin protein isolate (LMI), increasing at both extremes of the pH scale. Water absorption for the LMI was 1.3 ml/g of protein and its oil absorption 2.2 ml/g of protein. The LPI had 1.7 ml/g of protein in both water and oil absorption. Foaming capacity and stability was pH-dependent. Foaming capacity was higher at pH 2 and lower near the protein isoelectric points. Minimum protein concentration for gelation in LMI was 8% w/v at pH 4, while for LPI was 6% at pH 4 and 6. Amino acid composition in L. campestris flour and protein isolates was high in lysine and low in methionine. Most of the essential amino acids in lupin protein isolates were at acceptable levels compared to a reference pattern for infants and adults. The electrophoretic pattern of both protein isolates showed three bands with different mobilities, suggesting that the protein fractions belong to alpha-conglutin (11S-like protein), beta-conglutin (7S-like protein) and gamma-conglutin. It is proven that some of the functional properties of L. campestris protein isolates are similar to those soybean protein isolates recovered under equal conditions.

Spatial and temporal patterns of growth and differentiation of cone oil droplets in the chick retina

Avian cone photoreceptors have an oil droplet in the outer portion of their inner segment that acts as a long-pass cut-off filter between incident light and visual pigment. Chick cone droplets are mainly red, orange, yellow, green, and colorless, and the colors are due to three carotenoid pigments with characteristic absorption spectra. Little is known of the differentiation of this organelle, the natural marker of cones, and the little that is known is largely controversial. We used flat whole-mounts of fresh retinas to study the time and place of the appearance of droplets, their growth rates, the sequence of droplet color differentiation, and the spatial distribution of these colors. We show that droplet differentiation starts on embryonic Day 10 (E10) in a relatively small area above the optic nerve head. The differentiation spreads to the rest of the retina in a manner similar to that of photoreceptor neurogenesis, with three decreasing gradients of droplet size and color between E13-E20: from central to peripheral, dorsal to ventral, and temporal to nasal. The rate of growth of the droplets was not constant, but showed a maximum between E17 and postnatal Day 1 (P1) in most of the retinal zones. Color differentiation started at E16-E17, 5-6 days after their appearance, when the droplets were already of considerable size. Initially, all droplets were colorless, and then turned pale green or yellow to acquire progressively the mature colors. Differentiation ended in the whole retina by P15, with ventral droplets of larger diameter than dorsal ones, the peripheral ones generally larger than the central ones, and with the color distribution varying with the retinal area. Our results show that growth and color differentiation of the droplets is regulated temporally and spatially, and the cones complete differentiation at P15 rather than at prenatal stages, as is thought generally.

Restaurant emissions removal by a biofilter with immobilized bacteria

Pseudomonas sp. ZD8 isolated from contaminated soil was immobilized with platane wood chips to produce packing materials for a novel biofilter system utilized to control restaurant emissions. The effects of operational parameters including retention time, temperature, and inlet gas concentration on the removal efficiency and elimination capacity were evaluated. Criteria necessary for a scale-up design of the biofilter was established. High and satisfactory level of rapeseed oil smoke removal efficiency was maintained during operation and the optimal retention time was found to be 18 s corresponding to smoke removal efficiency greater than 97%. The optimal inlet rapeseed oil smoke loading was 120 mg/(m(3) x h) at the upper end of the linear correlation between inlet loading and elimination capacity.

Hydrophobic substrate utilisation by the yeast , and its potential applications

The alkane-assimilating yeast Yarrowia lipolytica degrades very efficiently hydrophobic substrates such as n-alkanes, fatty acids, fats and oils for which it has specific metabolic pathways. An overview of the oxidative degradation pathways for alkanes and triglycerides in Y. lipolytica is given, with new insights arising from the recent genome sequencing of this yeast. This includes the interaction of hydrophobic substrates with yeast cells, their uptake and transport, the primary alkane oxidation to the corresponding fatty alcohols and then by different enzymes to fatty acids, and the subsequent degradation in peroxisomal beta-oxidation or storage into lipid bodies. Several enzymes involved in hydrophobic substrate utilisation belong to multigene families, such as lipases/esterases (LIP genes), cytochromes P450 (ALK genes) and peroxisomal acyl-CoA oxidases (POX genes). Examples are presented demonstrating that wild-type and genetically engineered strains of Y. lipolytica can be used for alkane and fatty-acid bioconversion, such as aroma production, for production of SCP and SCO, for citric acid production, in bioremediation, in fine chemistry, for steroid biotransformation, and in food industry. These examples demonstrate distinct advantages of Y. lipolytica for their use in bioconversion reactions of biotechnologically interesting hydrophobic substrates.

Isolation of lipid- and polysaccharide-degrading micro-organisms from subtropical forest soil, and analysis of lipolytic strain Bacillus sp. CR-179

AIMS

To isolate the micro-organisms from three soil samples obtained from a subtropical forest of Puerto Iguazu (Argentina), to analyse them for detection of the biotechnologically interesting enzymatic activities lipase, esterase, cellulase, xylanase and pectinase, and to identify the most active strain.

METHODS AND RESULTS

A total of 724 strains were isolated using different culture media and temperatures, and 449 of them showed at least one of the hydrolytic activities pursued. Lipolytic activity of the lipid-degrading strains was further determined using MUF-butyrate and MUF-oleate as substrates. The alkalophilic strain CR-179, one of the most active for all the enzymatic activities assayed, was characterized and preliminarily identified by morphological, physiological and 16S rDNA tests, as a Bacillus sp. closely related to Bacillus subtilis.

CONCLUSIONS

Highly hydrolytic strains were isolated from all soil samples, suggesting the existence of a microbial community well-adapted to nutrient recycling. Strain CR-179, one of the most active, has been preliminarily identified as a Bacillus sp.

SIGNIFICANCE AND IMPACT OF THE STUDY

A collection of hydrolytic strains with high biotechnological potential was obtained. Presence of sequences codifying for a lipolytic system related to the B. subtilis group lipases was revealed by PCR for the best lipolytic strain.

Degradation of anthracene and pyrene supplied by microcrystals and non-aqueous-phase liquids

Polycyclic aromatic hydrocarbons (PAHs) are worldwide environmental pollutants. Their bioavailability is limited by a low aqueous solubility, which causes specific adaptations in degrading bacteria. To compare bacterial degrading behavior, a study was conducted on the mineralization, metabolization and formation of biomass from (14)C-anthracene by Sphingomonas sp. BA2 compared with those from (14)C-pyrene by Gordonia-like strain BP9 and Mycobacterium gilvum VF1. Different conditions of PAH supply were used in the medium: crystals <0.5 mm, microcrystals <<0.1 mm formed by sonication, or PAH solubilized in 2,2,4,4,6,8,8-heptamethylnonane (HMN) or silicone oil. Anthracene supply by crystals and silicone oil led to similar maximum mineralization rates 33 ng ml(-1) h(-1) and the same amount of mineralization (24%) after 168 h. Microcrystals increased the rates and amounts only slightly. HMN decreased the values to less than one-third. In comparison with crystals, microcrystals increased overall pyrene mineralization by strain BP9 from 53% to 58%, with maximum mineralization rates of 160 ng ml(-1) h(-1) and 166 ng ml(-1) h(-1). Silicone oil heavily increased the rate to 292 ng ml(-1) h(-1) and the amount mineralized to 71%, whereas HMN inhibited the degradation by one order of magnitude. A similar degradation behavior showing lower mineralization rates and extent was observed with strain VF1. However, inhibition by HMN was less pronounced. Sonication, leading to decreased PAH crystal size, increased the mass transfer and mineralization rates. PAH supply by silicone oil led to a much higher mass transfer, which may be due to emulsification of the oil, whereas such effects were not observed with HMN.

High yield bio-oil production from fast pyrolysis by metabolic controlling of Chlorella protothecoides

The use of renewable energy sources is becoming increasingly necessary to mitigate global warming. Recently much research has been focused on identifying suitable biomass species, which can provide high-energy outputs, to replace conventional fossil fuels. This paper reports an approach for increasing the yield of bio-oil production from fast pyrolysis after manipulating the metabolic pathway in microalgae through heterotrophic growth. The yield of bio-oil (57.9%) produced from heterotrophic Chlorella protothecoides cells was 3.4 times higher than from autotrophic cells by fast pyrolysis. The bio-oil was characterized by a much lower oxygen content, with a higher heating value (41 MJ kg(-1)), a lower density (0.92 kg l(-1)), and lower viscosity (0.02 Pas) compared to those of bio-oil from autotrophic cells and wood. These properties are comparable to fossil oil. The research could contribute to the creation of a system to produce energy from microalgae, and also could have great commercial potential for liquid fuel production.

Enzymatic synthesis of structured lipids

Structured lipids (SLs) are defined as lipids that are modified chemically or enzymatically in order to change their structure. This review deals with structured triacylglycerols (STGs) and structured phospholipids (SPLs). The most typical STGs are MLM-type STGs, having medium chain fatty acids (FAs) at the 1- and 3-positions and a long chain fatty acid at the 2- position. MLM-type STGs are synthesized by: 1) 1,3-position-specific lipase-catalyzed acyl exchange of TG with FA or with FA ethylester (FAEt); 2) 1,3-position-specific lipase-catalyzed acylation of glycerol with FA, giving symmetric 1,3-diacyl-sn-glycerol, followed by chemical acylation at the sn-2 position, and; 3) 1,3-position-specific lipase-catalyzed deacylation of TG, giving 2-monoacylglycerol, followed by reacylation at the 1- and 3-positions with FA or with (FAEt). Enzymatic preparation of SPLs requires: 1) acyl group modification, and 2) head group modification of phospholipids. Acyl group modification is performed using lipases or phospholipase A2-mediated transesterification or ester synthesis to introduce arbitrary fatty acid to phospholipids. Head group modification is carried out by phospholipase D-catalyzed transphosphatidylation. A wide range of compounds can be introduced into the polar head of phospholipids, making it possible to prepare various SPLs.

Winery solid residue revalorization into oil and antioxidant with nutraceutical properties by an enzyme assisted process

Revalorization of the winery industry residue, grape seed is studied for the production of an oil and defatted meal with nutraceutical properties. Conventional grape seed oil extraction process is carried out by pressing at high temperature affecting the product quality. Oil extraction by cold pressing improves product quality, but it gives a low oil yield. Oil extracted is increased at the pressing stage, when an enzymatic pre-treatment is incorporated in to the conventional process. The yield is determined by determining the residual oil in the pressed cake. Using an enzymatic treatment during 9 hours at 45 degrees C and 50% of moisture, with a mixture of two commercial enzymes grape seed oil extraction yield by cold pressing is raised up to 72%, being a 59.4% increment in comparison to the yield obtained by the control, without enzymes. The defatted meal by enzimatic assisted process improves its phenolic compounds between 2 and 4 times, depending on the conditions of phenolics extraction in comparison to the control samples.

Preliminary identification and classification of five new yeast strains isolated from oil-polluted environment

Bioremediation is a very interesting alternative for restoring the oil-polluted ecosystems. Many studies concerning the possibility of using microorganisms (bacteria and yeasts) in the degradation of oil compounds have as starting point the isolation and taxonomical identification of new species and strains with degradative abilities. Our study focusses on the preliminary classification of five yeast strains (D1, D2, D3, D4 and D6) isolated from oil-polluted environments. The strains were characterized by conventional taxonomical techniques: microscopical and macroscopical appearance, fermentation abilities, assimilation of various carbon or nitrogen compounds, growth under stress conditions (non-permissive temperatures, high glucose concentration) and urea degradation. According to these tests, D1, D2 and D4 showed great similarity to Rhodotorula glutinis, D3 to Candida parapsilosis and D6 to Candida tropicalis. Further supplementary tests were performed in order to establish their ability to degrade hydrocarbons, by observing growth in media with n-alkanes (n-decane, n-dodecane, n-tetradecane, n-hexadecane). Thus, D1, D2 and D4 were the best alkane-consuming strains, presenting possible similar degrading abilities and pathways, which correlates well to our identification as Rhodotorula strains. For D3 and D6 the growth was not so spectacular as for D1, D2 and D4, but continuous along the entire experiment. The resemblance between the curves profiles confirms the idea that both belong to the same genus, Candida.

Stabilization of oil-water emulsions by hydrophobic bacteria

Formation of oil-water emulsions during bacterial growth on hydrocarbons is often attributed to biosurfactants. Here we report the ability of certain intact bacterial cells to stabilize oil-in-water and water-in-oil emulsions without changing the interfacial tension, by inhibition of droplet coalescence as observed in emulsion stabilization by solid particles like silica.

Effect of Oil-in-Water Emulsions on 5-Aminolevulinic Acid Uptake and Metabolism to PpIX in Cultured MCF-7 Cells

PURPOSE

To identify the optimal vehicle for fast and efficient cellular production of the photosensitizer, protoporphyrin IX (PpIX), upon administration of 5-aminolevulinic acid (ALA).

METHODS

ALA in various oil/water o/w emulsions was applied to the human mammary epithelial cell line (MCF-7) cultured in microplates. Upon incubation for 14 h, the accumulated amount of PpIX was determined by fluorescence spectroscopy. Variables such as the pH and concentration of the emulsions, the temperature and duration of incubation were examined along with the importance of ALA concentration and the presence of endocytosis inhibitors.

RESULTS

An increase in the amount of produced PpIX was observed with an increase in extracellular pH, incubation temperature, and ALA concentration. A saturable mechanism of PpIX accumulation was evident, mainly as a result of the uptake mechanism for ALA. Some of the o/w emulsions increased the amount of intracellular PpIX, and the results indicated that this was not due to an increased k(m) of the extracellular ALA to intracellular PpIX conversion, but to the increased endocytotic uptake in the presence of the emulsions. In general, the increase in PpIX in the presence of emulsions relative to the control was more pronounced after 1 h as compared to after 2-4 h.

CONCLUSIONS

The formation of PpIX in MCF-7 cells exposed to ALA is improved by the presence of certain o/w emulsions, which could be explained by endocytosis.

Effects of two P/S ratios with same peroxidizability index value and antioxidants supplementation on serum lipid concentration and hepatic enzyme activities of rats

BACKGROUND

High polyunsaturated/saturated fatty acid (P/S) ratio of diet decreases the risk of cardiovascular disease (CVD) with improvement of serum lipid profiles and inhibition of lipid peroxidation. This study was to investigate the effects of P/S ratio and antioxidants supplementation on lipid and peroxidation when dietary peroxidizability index (PI) value was the same.

METHODS

Female Sprague-Dawley rats weighing 100-120 g were fed four different experimental diets for 4 weeks. The P/S ratios were 0.38 (LP) and 4.81 (HP) when the PI value of diet was 81.22. These diets were supplemented with vitamin E 1000 mg/kg diet and selenium 2.5 mg/kg diet (LPS and HPS).

RESULTS

The total-cholesterol (T-C) and HDL-cholesterol concentrations of serum were higher in HP and HPS (p<0.001). The cardiac index and atherogenic index were lower in HP and HPS (p<0.001). Hepatic thiobarbituric acid reactive substance concentrations were higher in LP and LPS (p<0.001). However, P/S ratio and antioxidants had no effect on antioxidant enzyme activities in the liver.

CONCLUSION

A high P/S ratio diet has a beneficial effect on CVD risk even without antioxidant when the PI value is the same. We suggest that P/S ratio as well as PI value should be considered for reducing the risk of CVD.

Biodegradabilities of some chain oils in groundwater as determined by the respirometric BOD OxiTop method

The respirometric BOD OxiTop method was used to monitor the biodegradation of different chain oils (mineral, rapeseed and tall oils) over 28 days in groundwater, as well as in standard conditions described by OECD 301 F. The aim of the study was to gather more information about the biodegradability of forestry oils in groundwater, as well as about the suitability of the automatic OxiTop method for biodegradation measurements. The BOD OxiTop method proved to be a precise and reliable technique for determining the biodegradations of different oils. Some comparative studies were also made using a traditional IR method in order to clarify the total oil concentrations. The results show that if biodegradation only is to be monitored, the OxiTop method is preferable. This is due to the influence of other reactions aside from biodegradation on total hydrocarbon concentrations when using the IR method.

Cloning and sequencing of the ura3 and ura5 genes, and isolation and characterization of uracil auxotrophs of the fungus Mortierella alpina 1S-4

The oil-producing fungus Mortierella alpina 1S-4 is an industrial strain. In order to prepare host strains for a transformation system for this fungus, six uracil auxotrophs were obtained by means of random mutation with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). When the activities of orotate phosphoribosyl transferase (OPRTase, EC 2.4.2.10) and orotidine-5'-phosphate decarboxylase (OMPdecase, EC 4.1.1.23) were examined in the mutants and wild strain, OPRTase activity was found to be completely absent in all mutants, on the other hand, OMPdecase activity was intact. The genomic DNA and cDNA of the ura5 gene encoding OPRTase and the ura3 gene encoding OMPdecase were cloned and sequenced. The Ura5p deduced amino acid sequence of this fungus showed highest similarity to that of Vibrio cholerae classed among prokaryote. Furthermore, the mutational points in the ura5 genes of two selected mutants were identified; a base-replacement and a base-insertion.

Isolation, identification, and characterization of a novel, oil-degrading bacterium, Pseudomonas aeruginosa T1

A novel, oil-degrading bacterium (strain T1) was isolated from a hot spring in Hokkaido, Japan. It efficiently degrades different types of fats and oils, including edible oil waste. When grown in a mineral salt medium containing 1% triacylglycerol (as salad oil), hydrolysis products were 1,3- and 1,2-diacylglycerols, monoacylglycerol, and free fatty acid. However, these products were almost completely consumed during cultivation at 30 degrees C for 5 days, indicating that extracellular lipase acts randomly at different sn-positions of acylglycerols and that strain T1 has a high capacity to utilize free fatty acids. Secreted lipase activity was induced by salad oil and oleic acid. This strain was a Gram-negative straight rod shaped, aerobic, with a polar flagellum, capable of growing in temperature ranges between 15 degrees C and 55 degrees C. The 16S rRNA gene sequence analysis and DNA-DNA hybridization revealed it as a new strain of Pseudomonas aeruginosa. The type strain was T1.

Establishment of an overall transformation system for an oil-producing filamentous fungus, Mortierella alpina 1S-4

Oil-producing fungus Mortierella alpina 1S-4 is an industrial strain. To determine its physiological properties and to clarify the biosynthetic pathways for polyunsaturated fatty acids, a transformation system for this fungus was established using a derivative of it, i.e., a ura5- mutant lacking orotate phosphoribosyl transferase (OPRTase, EC.2.4.2.10) activity. Transformation with a vector containing the homologous ura5 gene as a marker was successfully performed using microprojectile bombardment, other methods frequently used for transformation, such as the protoplasting, lithium acetate, or electroporation methods, not giving satisfactory results. As a result, two types of transformants were obtained: a few stable transformants overexpressing the ura5 gene, and many unstable transformants showing OPRTase activity comparable to that of the wild-type strain. The results of quantitative PCR indicated that the stable transformants could retain the ura5 genes originating from the transformation vector regardless of the culture conditions. On the other hand, unstable transformants easily lost the marker gene under uracil-containing conditions, as expected. In this paper, we report that an overall transformation system for this fungus was successfully established, and propose how to select useful transformants as experimental and industrial strains.

A glycerol-inducible thermostable lipase fromBacillussp.: medium optimization by a Plackett–Burman design and by response surface methodology

The production of a neutral lipase from a Bacillus sp. was improved tremendously (193-fold) following media optimization involving both the "one-at-a-time" and the statistical designing approaches. The present lipase was poorly induced by oils, instead its production was induced in the presence of sugars and sugar alcohols, mainly galactose, lactose, glycerol, and mannitol. A high inoculum density of 15% v/v (A550= 0.8) led to maximum lipase production. Interestingly, the enzyme induction was growth independent, a property very different from most of the lipases investigated to date. The optimal composition of the growth medium to achieve maximum lipase production was determined to be as follows: NH4Cl, 35 g·L–1; glycerol, 10 mL·L–1; K2HPO4, 3 g·L–1; KH2PO4, 1 g·L–1; MgSO4·7H2O, 0.1 g·L–1; glucose, 2 g·L–1; MgCl2, 0.6 mmol·L–1, with 15% inoculum density and an incubation period of 24 h. About 62 U·mL–1of enzyme production was achieved in the optimized medium.Key words: lipase, glycerol inducible, statistical designing.

Surfactant activity of a naphthalene degrading Bacillus pumilus strain isolated from oil sludge

We studied the growth, biosurfactant activities and petroleum hydrocarbon compounds utilisation of strain 28-11 isolated from a solid waste oil. The isolate was identified as Bacillus pumilus. It grew well in the presence of 0.1% (w/v) of crude oil and naphthalene under aerobic conditions and utilised these substances as carbon and energy source. The capacity of strain 28-11 to emulsify crude oil and its ability to remove hydrocarbons looks promising for its application in environmental technologies.

A strain isolated from gas oil-contaminated soil displays chemotaxis towards gas oil and hexadecane

In this report we describe the isolation of a strain from soil contaminated with gas oil by taking bacteria from a chemotactic ring on gas oil-containing soft agar plates. Partial 16 S rDNA sequencing of the isolated strain showed 99.1% identity with Flavimonas oryzihabitans. It was not only able to degrade different aliphatic hydrocarbons but it was also chemotactic towards gas oil and hexadecane, as demonstrated by the use of three different chemotaxis methods, such as agarose plug and capillary assays and swarm plate analysis. In addition, the strain was chemotactic to a variety of carbon sources that serve as growth substrates, including glucose, arabinose, mannitol, glycerol, gluconate, acetate, succinate, citrate, malate, lactate and casaminoacids. This is the first report on chemotaxis of a hydrocarbon-degrading bacterium towards a pure alkane, such as hexadecane. The fact that environmental isolates show chemotaxis towards contaminant/s present in the site of isolation suggests that chemotaxis might enhance biodegradation by favouring contact between the degrading microorganism and its substrate.

Hydrolysis of the oil phase of a W/O/W emulsion by pancreatic lipase

W/O/W emulsions are expected to protect bioactive substances from degradation by pancreatic enzymes. We investigated the enzymatic hydrolysis of the oil phase and release of a marker substance from the inner-aqueous phase to the outer-aqueous phase using an artificial digestive fluid. Octanoic acid triacylglycerol (C8TG) was used as the oil phase. W/O/W emulsions were prepared by two-step homogenization and succeeding membrane filtration. When the artificial digestive fluid containing lipase and gall was added to the emulsion, release of the marker substance from the inner-phase solution, oil-phase hydrolysis, and emulsion coalescence occurred in that order. When a coarse emulsion and 0.2- and 0.8-microm membrane-filtered fine emulsions were treated with the fluid for 1 h, the degrees of C8TG hydrolysis were 3.8%, 55% and 57%, the fractions of the marker substance released from the inner-water phase were 2.7%, 89% and 72%, and the median diameters of the oil droplets were changed from 32 to 23 microm, 0.71 to 27 microm, and from 2.2 to 26 microm, respectively. These results suggested that the diameter of the oil droplets in the W/O/W emulsion significantly affected the release profile of the marker loaded in the inner-water phase of the emulsion.

Regiospecific analysis by ethanolysis of oil with immobilized Candida antarctica lipase

A mixture of oil/ethanol (1:3, w/w) was shaken at 30 degrees C with 4% immobilized Candida antarctica lipase by weight of the reaction mixture. The reaction regiospecifically converted FA at the 1- and 3-positions to FA ethyl esters, and the lipase acted on C14-C24 FA to a similar degree. The content of 2-MAG reached a maximum after 4 h; the content was 28-29 mol% based on the total amount of FA in the reaction mixture at 59-69% ethanolysis. Only 2-MAG were present in the reaction mixture during the first 4 h, and 1(3)-MAG were detected after 7 h. After removal of ethanol from the 4-h reaction mixture by evaporation, 2-MAG were fractionated by silica gel column chromatography. The contents of FA in the 2-MAG obtained by ethanolysis of several oils coincided well with FA compositions at the 2-position, which was analyzed by Grignard degradation. It was shown that ethanolysis of oil with C. antarctica lipase can be applied to analysis of FA composition at the 2-position in TAG.

Improvement of monacolin K, ?-aminobutyric acid and citrinin production ratio as a function of environmental conditions of Monascus purpureus NTU 601

Monascus, a traditional Chinese fermentation fungus, is used as a natural dietary supplement. Its metabolic products monacolin K and gamma-aminobutyric acid (GABA) have each been proven to be a cholesterol-lowering drug and a hypotensive agent. Citrinin, another secondary metabolite, is toxic to humans, thus lowering the acceptability of red mold rice to the general public. In this study, the influence of different carbon and nitrogen sources, and fatty acid or oils, on the production of monacolin K, citrinin and GABA by Monascus purpureus NTU 601 was studied. When 0.5% ethanol was added to the culture medium, the production of citrinin decreased from 813 ppb to 561 ppb while monacolin K increased from 136 mg/kg to 383 mg/kg and GABA increased from 1,060 mg/kg to 7,453 mg/kg. In addition, response surface methodology was used to optimize culture conditions for monacolin K, citrinin and GABA production, and data were collected according to a three-factor (temperature, ethanol concentration and amount of water supplemented), three-level central composite design. When 500 g rice was used as a solid substrate with 120 ml water and 0.3% ethanol, the production of monacolin K at 30 degrees C increased from 136 mg/kg to 530 mg/kg, GABA production increased from 1,060 mg/kg to 5,004 mg/kg and citrinin decreased from 813 ppb to 460 ppb.

Anaerobic treatability of high oil and grease rendering wastewater

This study evaluated the use of a new biosurfactant, BOD-Balance, derived from cactus for the treatment of oil-and-grease-laden rendering wastewater anaerobically. Batch laboratory experimental results and preliminary full-scale data are presented. The biosurfactant affected a significant increase in the COD degradation rate for the raw wastewater. However, after reduction of the oil and grease (O&G) by dissolved air flotation, the biosurfactant did not exhibit any advantages. Modeling of the data indicated that various COD fractions, i.e. both soluble and particulate as well as total COD at various testing conditions conformed well to both zero-order and first-order models. The biosurfactant affected a 164-238 and 164-247% increase in COD and particulate COD biodegradation rate for the raw wastewater. The reduction of O&G concentration to <800 mg/l increased total and soluble COD degradation rates by 106%. Results from the full-scale mesophilic anaerobic digestion system indicated that the addition of the biosurfactant at doses of 130-200 mg/l decreased O&G concentrations from 66,300 to 10,200 mg/l over a 2-month-period.

Chemical ecology of oribatid mites III. Chemical composition of oil gland exudates from two oribatid mites, Trhypochthoniellus sp. and Trhypochthonius japonicus (Acari: Trhypochthoniidae)

The composition of oil gland exudates from two oribatid mites, Trhypochthoniellus sp. and Trhypochthonius japonicus, was studied with reference to the related species Trhypochthoniellus crassus. Trhypochthoniellus sp. contained a mixture of seven compounds; (Z,Z)-6,9-heptadecadiene, geranial, 3-hydroxybenzene-1,2-dicarbaldehyde (gamma-acaridial), neryl formate, neral, (Z)-8-heptadecene and geranyl formate in decreasing order of abundance. The profile of the components from T. japonicus consisted of two types depending on the locality of sampling with unknown reason; one possessing a mixture of eight compounds [(Z,E)-farnesal, gamma-acaridial, (Z,Z)-6,9-heptadecadiene, (E,E)-farnesal, (Z)-8-heptadecene and geranial in decreasing order] together with two unknown compounds, and the other composed of the same set of compounds together with 2-hydroxy-6-methylbenzaldehyde as the most abundant component. Relative abundance among common components was consistent between the two types of T. japonicus. Profiles of components differed among three species including T. crasus. The phylogenetic relationship between Oribatida and Astigmata was discussed based on secretory compounds commonly distributed between these two suborders.

[Biochemical processing of fats and oils into new lipid products with improved biological and physico-chemical properties]

Recent advances in the improvement of biological and physicochemical characteristics of lipids are reviewed, with emphasis on products of biochemical processing of natural (animal or plant) fats and oils. Possible utilities of these new lipid products include their use in food and forage industries, as well as in the production of new medicines and in biotechnology. Specific features of biochemical transformations of lipids (hydrolysis, esterification, and re-esterification) in the presence of water-soluble and immobilized lipases of animal, plant, and microbial origin are scrutinized.

Industrial enzyme applications

The effective catalytic properties of enzymes have already promoted their introduction into several industrial products and processes. Recent developments in biotechnology, particularly in areas such as protein engineering and directed evolution, have provided important tools for the efficient development of new enzymes. This has resulted in the development of enzymes with improved properties for established technical applications and in the production of new enzymes tailor-made for entirely new areas of application where enzymes have not previously been used.

Blocking the tunnel: engineering of Candida rugosa lipase mutants with short chain length specificity

The molecular basis of chain length specificity of Candida rugosa lipase 1 was investigated by molecular modeling and site-directed mutagenesis. The synthetic lip1 gene and the lipase mutants were expressed in Pichia pastoris and assayed for their chain length specificity in single substrate assays using triglycerides as well as in a competitive substrate assay using a randomized oil. Mutation of amino acids at different locations inside the tunnel (P246F, L413F, L410W, L410F/S300E, L410F/S365L) resulted in mutants with a different chain length specificity. Mutants P246F and L413F have a strong preference for short chain lengths whereas substrates longer than C10 are hardly hydrolyzed. Increasing the bulkiness of the amino acid at position 410 led to mutants that show a strong discrimination of chain lengths longer than C14. The results obtained can be explained by a simple mechanical model: the activity for a fatty acid sharply decreases as it becomes long enough to reach the mutated site. In contrast, a mutation at the entrance of the tunnel (L304F) has a strong impact on C4 and C6 substrates. This mutant is nevertheless capable of hydrolyzing chain lengths longer than C8.

Visual pigments and oil droplets in diurnal lizards

We report microspectrophotometric (MSP) data for the visual pigments and oil droplets of 17 species of Caribbean anoline lizard known to live in differing photic habitats and having distinctly different dewlap colors. The outgroup Polychrus marmoratus was also examined to gain insight into the ancestral condition. Except for Anolis carolinensis, which is known to use vitamin A2 as its visual pigment chromophore, all anoline species examined possessed at least four vitamin-A1-based visual pigments with maximum absorbance (λmax) at 564, 495,455 and 365 nm. To the previously reported visual pigments for A. carolinensis we add an ultraviolet-sensitive one withλ max at 365 nm. Five common classes of oil droplet were measured, named according to apparent color and associated with specific cone classes — yellow and green in long-wavelength-sensitive (LWS) cones,green only in medium-wavelength-sensitive (MWS) cones and colorless in short-wavelength-sensitive (SWS) and ultraviolet-sensitive (UVS) cones. MSP data showed that the colorless droplet in the SWS cone had significant absorption between 350 and 400 nm, while the colorless droplet in the UVS cone did not. The pattern for Polychrus marmoratus was identical to that for the anoles except for the presence of a previously undescribed visual cell with a rod-like outer segment, a visual pigment with a λmaxof 497 nm and a colorless oil droplet like that in the UVS cones. These findings suggest that anoline visual pigments, as far as they determine visual system spectral sensitivity, are not necessarily adapted to the photic environment or to the color of significant visual targets (e.g. dewlaps).

An update on the use of unconventional substrates for biosurfactant production and their new applications

Biosurfactants are valuable microbial amphiphilic molecules with effective surface-active and biological properties applicable to several industries and processes. Microbes synthesize them, especially during growth on water-immiscible substrates, providing an alternative to chemically prepared conventional surfactants. Because of their structural diversity (i.e., glycolipids, lipopeptides, fatty acids, etc.), low toxicity, and biodegradability, these molecules could be widely used in cosmetic, pharmaceutical, and food processes as emulsifiers, humectants, preservatives, and detergents. Moreover, they are ecologically safe and can be applied in bioremediation and waste treatments. They can be produced from various substrates, mainly renewable resources such as vegetable oils, distillery and dairy wastes, which are economical but have not been reported in detail. In this review, we report advances made in using renewable substrates for biosurfactant production and their newer applications.

Single cell oil production by Yarrowia lipolytica growing on an industrial derivative of animal fat in batch cultures

The growth of an oleaginous strain of Yarrowia lipolytica on an industrial fat composed of saturated free fatty acids (stearin) was studied. Lipid accumulation during primary anabolic growth was critically influenced by the medium pH and the incubation temperature. This process was independent of the nitrogen concentration in the culture medium, but was favored at a high carbon substrate level and at a low aeration rate. At pH 6 and a temperature of 28-33 degrees C, 9-12 g/l of dry biomass was produced, whereas significant quantities of lipids were accumulated inside the yeast cells (0.44-0.54 g of lipid per gram of biomass). The strain showed the tendency to degrade its storage lipids, although significant amounts of substrate fat, rich in stearic acid, remained unconsumed in the culture medium. Y. lipolytica presented a strong fatty acid specificity. The fatty acids C12:0, C14:0, and C16:0 were rapidly incorporated and mainly used for growth needs, while C18:0 was incorporated with reduced rates and was mainly accumulated as storage material. Reserve lipids, principally composed of triacylglycerols (55% w/w of total lipids) and free fatty acids (35% w/w), were rich in stearic acid (80% w/w), while negligible amounts of unsaturated fatty acids were detected. When industrial glycerol was used as co-substrate, together with stearin, unsaturated fatty acid concentration in the reserve lipid increased.

Mobile intracranial oily substances from a ruptured teratoma

A patient with a ruptured intracranial teratoma is presented. The distinctive imaging and neuroendoscopic findings of mobile fatty or oily globules in the subarachnoid or ventricular space are described. Fat suppression magnetic resonance imaging (MRI) and MRI performed with the patient prone was helpful in distinguishing tumour tissue from floating oil.

Variations in cone photoreceptor abundance and the visual ecology of birds

The relative abundance and topographical distribution of retinal cone photoreceptors was measured in 19 bird species to identify possible correlations between photoreceptor complement and visual ecology. In contrast to previous studies, all five types of cone photoreceptor were distinguished, using bright field and epifluorescent light microscopy, in four retinal quadrants. Land birds tended to show either posterior dorsal to anterior ventral or anterior dorsal to posterior ventral gradients in cone photoreceptor distribution, fundus coloration and oil droplet pigmentation across the retina. Marine birds tended to show dorsal to ventral gradients instead. Statistical analyses showed that the proportions of the different cone types varied significantly across the retinae of all species investigated. Cluster analysis was performed on the data to identify groups or clusters of species on the basis of their oil droplet complement. Using the absolute percentages of each oil droplet type in each quadrant for the analysis produced clusters that tended to reflect phylogenetic relatedness between species rather than similarities in their visual ecology. Repeating the analysis after subtracting the mean percentage of a given oil droplet type across the whole retina (the 'eye mean') from the percentage of that oil droplet type in each quadrant, i.e. to give a measure of the variation about the mean, resulted in clusters that reflected diet, feeding behaviour and habitat to a greater extent than phylogeny.

Viscosity properties of mineral paraffinic base oils as a key factor in their primary biodegradability

The primary biodegradability of two types of paraffinic base oils (solvent and catalytically dewaxed oils) and their blends was evaluated using the CEC L-33-A-93 test. The biodegradability values varied between 10% and 75%. Base oil mixtures displayed varying contents in aromatic and polar compounds and a wide range of kinematic viscosity (KV) values, from roughly 10 to 600 cSt (at 40 degrees C), while their viscosity indices were almost constant (90-100). The biodegradability of oils was closely related to their content in polycyclic aromatic hydrocarbons and was also decreasing with kinematic viscosity. For the two types of base oils, a linear relationship could be set between the biodegradation percentages and the logarithms of KV values. These results show that, beside overall chemical features such as the contents in aromatic compounds, KV may be a prominent parameter for assessing the primary biodegradability of mineral base oils.

Biodegradation and conversion of alkanes and crude oil by a marine Rhodococcus sp

A hydrocarbon degrader isolated from a chronically oil-polluted marine site was identified as Rhodococcus sp. on the basis of morphology, fatty acid methyl ester pattern, cell wall analysis, biochemical tests and G + C content of DNA. It degraded up to 50% of the aliphatic fraction of Assam crude oil, in seawater supplemented with 35 mM nitrogen as urea and 0.1 mM phosphorus as dipotassium hydrogen orthophosphate, after 72 h at 30 degrees C and 150 revolutions per minute. The relative percentage of intracellular fatty acid was higher in hydrocarbon-grown cells compared to fructose-grown cells. The fatty acids C16, C16:1, C18 and C18:1 were constitutively present regardless of the growth substrate. In addition to these constitutive acids, other intracellular fatty acids varied in correlation to the hydrocarbon chain length supplied as a substrate. When grown on odd carbon number alkanes, the isolate released only monocarboxylic acids into the growth medium. On even carbon number alkanes only dicarboxylic acids were produced.

Organic reactions without organic solvents and oils and fats as renewable raw materials for the chemical industry

The use of organic solvents should be minimized as far as possible to reduce atmospheric volatile organic compounds (VOCs). Examples of solvent-free organic syntheses are described. The increasing usage of renewable feedstocks taking advantage of the synthetic potential of nature is another way to avoid organic solvents. Most important is the development of chemical products, i.e., coatings that can be processed without organic solvents.

Vitamin requirements of hydrocarbon-utilizing soil bacteria

The numbers of oil-utilizing bacteria in several samples of clean and oil-polluted soils counted on vitamin-containing media were severalfold higher than the numbers counted on vitamin-free media. Colonies that grew on a medium containing a vitamin mixture were tested for growth on the same medium lacking any vitamins. More than 90% of the total colonies failed to grow. The remaining 10% grew, yet their growth was enhanced, when vitamins were added. The predominant oil-utilizing bacteria in one of the test desert soil samples were various strains of Cellulomonas flavigena and Rhodococcus erythropolis. Minor organisms belonged to the genera Pseudomonas, Bacillus and Arthrobacter. Two vitamin-requiring biovars of C. flavigena and R. erythropolis were selected for further study. Their growth on n-octadecane and phenanthrene as sole sources of carbon and energy as well as their potential for hydrocarbon consumption were enhanced by added vitamins, e.g. folic acid, pyridoxine, vitamin B12, biotin and others. In a field experiment, it was confirmed that vitamin fertilization of an oil-polluted sand sample enhanced the biodegradation of constituent hydrocarbons of that sample.