Changes in fatty acid branching and unsaturation ofStreptomyces cinnamonensis as a response to NaCl concentration

Three differentStreptomyces cinnamonensis strains (viz. standard, regulatory, and non-differentiating) were grown in a synthetic medium containing 0–4% NaCl and the composition of total cellular fatty acids was analyzed. The increasing salt concentration resulted in an increasing proportion of even-numbered straight-chain fatty acids, mostly at the expense of branched-chain fatty acids. Unsaturated fatty acids, palmitoleic acid in particular, represent the major proportion of straight-chain fatty acids.     

Polyunsaturated fatty acids and brain white matter anisotropy in recent-onset schizophrenia: A preliminary study

Brain white matter myelin abnormalities and cell membrane fatty acid abnormalities have been implicated in schizophrenia and other psychiatric disorders. We investigated in young adults with a psychotic disorder (n=12) whether (poly)unsaturated fatty acid concentrations in erythrocyte membranes are related to an MRI measure of brain white matter, which depends on the degree of myelination. A significant correlation was found between total (poly)unsaturated fatty acid concentration and fractional anisotropy of a fronto-temporal white matter tract (r=0.503, P=0.048). Unsaturated fatty acids may be necessary for the myelinating activity of oligodendrocytes or for myelin maintenance. These results warrant further investigation.     

Identification of high affinity membrane-bound fatty acid-binding proteins using a photoreactive fatty acid

A photoaffinity labeling method was developed to identify and characterize high affinity fatty acid-binding proteins in membranes. The specific labeling of these sites requires the use of low concentrations (nanomolar) of the photoreactive fatty acid 11-m-diazirinophenoxy-[11-³H]undecanoate. It was delivered as a bovine serum albumin (BSA) complex which serves as a reservoir for fatty acid and thus allows precise control of unbound fatty acid concentrations. ThefadL protein ofE. coli, which is required for fatty acid permeation of its outer membrane, was labeled by the photoreactive fatty acid neither specifically nor saturably when the probe was added in the absence of BSA; however when a nanomolar concentration of the uncomplexed probe was maintained in the presence of BSA, the labeling of thefadL protein was highly specific and saturable. This photoaffinity labeling method was also used to characterize a 22 kDa, high affinity fatty acid-binding protein which we have recently identified in the plasma membrane of 3T3-L1 adipocytes. This protein bound the probe with a K_d of 216 nM. The approach described is easily capable of identifying membrane-bound fatty acid-binding proteins and can distinguish between those of high and low affinities for fatty acids. It represents a general method for the identification and characterization of fatty acid-binding proteins.Abbreviations BSA Bovine Serum Albumin - DAP m-Diazirinophenoxy - SDS-PAGE Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis     

Fatty Acids and Their Derivatives as Modulators of Appressorium Formation in Magnaporthe grisea

Appressorium formation in germinating conidia of Magnaporthe grisea was inhibited on inductive and on noninductive surfaces by monounsaturated fatty acids with chain lengths of 16, 18, or 20 carbon atoms. On a noninductive surface, the inhibition was only observed upon stimulation with 1,16-hexadecanediol or oleyl alcohol, but not upon stimulation with 8-(4-chlorophenylthio)-adenosine-3′,5′-monophosphate. In the C₁₈-series, fatty acids with a double bond in position 9 were the most active ones. At 1 μg/ml of oleic or elaidic acid, less than 30% of the germinated conidia formed appressoria. The mode of inhibition was competitive to the inducing agent. On an inductive surface, compared to a noninductive surface the concentrations of oleic and elaidic acid needed for inhibition of appressorium formation were one order of magnitude higher. Methyl esters of inhibitory fatty acids and acids with two double bonds were not active. Like oleyl alcohol, elaidyl alcohol and petroselinyl alcohol stimulated infection structure formation on the noninductive surface.     

Kinetics and mechanism of the cutinase-catalyzed transesterification of oils in AOT reversed micellar system

The kinetics of the enzymatic transesterification between a mixture of triglycerides (oils) and methanol for biodiesel production in a bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/isooctane reversed micellar system, using recombinant cutinase from Fusarium solani pisi as a catalyst, was investigated. In order to describe the results that were obtained, a mechanistic scheme was proposed, based on the literature and on the experimental data. This scheme includes the following reaction steps: the formation of the active enzyme–substrate complex, the addition of an alcohol molecule to the complex followed by the separation of a molecule of the fatty acid alkyl ester and a glycerol moiety, and release of the active enzyme. Enzyme inhibition and deactivation effects due to methanol and glycerol were incorporated in the model. This kinetic model was fitted to the concentration profiles of the fatty acid methyl esters (the components of biodiesel), tri-, di- and monoglycerides, obtained for a 24 h transesterification reaction performed in a stirred batch reactor under different reaction conditions of enzyme and initial substrates concentration.     

Biochemical composition of cuttlefish (Sepia esculenta) eggs during embryonic development

Changes in egg volume, water content, proteins, carbohydrates, lipids, amino acids and fatty acids in cuttlefish (Sepia esculenta) were determined during embryogenesis to understand the nutritional requirements in the early life phase. The egg volume and the water content decreased significantly (P<0.05) during early embryonic development, and then increased abruptly after the beginning of organ differentiation. During embryonic development, protein was the major content in the yolk and the per cent composition varied to a large extent (55.19–78.45%) with carbohydrates (9.86–15.56%) and lipids (1.62–2.97%). Proteins and lipids decreased 23.3% and 0.4%, respectively, in dry weight, while carbohydrates increased 0.46%. Total amino acids and essential amino acids (EAAs) were stable during the early embryonic developmental stage, but decreased significantly until the eggs hatched (P<0.05). The largest utilisation of the yolk protein possibly occurred with respect to EAAs (25.7%) because of a decrease in methionine (70.3%), valine (63.0%) and phenylalanine (58.5%). The most important fatty acids were saturated fatty acid (SFA) C16:0 and polyunsaturated fatty acids (PUFAs) C22:6 and C20:5. Unsaturated fatty acids (UFAs) and SFA decreased at a similar rate during embryonic development (5.69% and 6.15%, respectively). For UFAs, monounsaturated fatty acids were consumed at a greater rate than PUFAs (29.6% and 0.05%, respectively).     

Fatty acid alcohol ester-synthesizing activity of lipoprotein lipase

The fatty acid alcohol ester-synthesizing activity of lipoprotein lipase (LPL) was characterized using bovine milk LPL. Synthesizing activities were determined in an aqueous medium using oleic acid or trioleylglycerol as the acyl donor and equimolar amounts of long-chain alcohols as the acyl acceptor. When oleic acid and hexadecanol emulsified with gum arabic were incubated with LPL, palmityl oleate was synthesized, in a time- and dose-dependent manner. Apo-very low density lipoprotein (apoVLDL) stimulated LPL-catalyzed palmityl oleate synthesis. The apparent equilibrium ratio of fatty acid alcohol ester/oleic acid was estimated using a high concentration of LPL and a long (20 h) incubation period. The equilibrium ratio was affected by the incubation pH and the alcohol chain length. When the incubation pH was below pH 7.0 and long chain fatty acyl alcohols were used as substrates, the fatty acid alcohol ester/free fatty acid equilibrium ratio favored ester formation, with an apparent equilibrium ratio of fatty acid alcohol ester/fatty acid of about 0.9/0.1. The equilibrium ratio decreased sharply at alkaline pH (above pH 8.0). The ratio also decreased when fatty alcohols with acyl chains shorter than dodecanol were used. When a trioleoylglycerol/fatty acyl alcohol emulsion was incubated with LPL, fatty acid alcohol esters were synthesized in a dose- and time-dependent fashion. Fatty acid alcohol esters were easily synthesized from trioleoylglycerol when fatty alcohols with acyl chains longer than dodecanol were used, but synthesis was decreased with fatty alcohols with acyl chain lengths shorter than decanol, and little synthesizing activity was detected with shorter-chain fatty alcohols such as butanol or ethanol.     

Accumulation of diacylglycerol induced in platelets by exogenous fatty acids

Free fatty acids added in ethanol to human platelets prelabelled with [${}^{14}\text{C}$]arachidonate induce an accumulation of radioactive diacylglycerol. Unsaturated fatty acids are ten times more potent than palmitate. Ethanol alone does not alter the distribution of radioactivity. Increasing the concentration of arachidonate leads to increased diacylglycerol formation. The fatty acid effect is independent of thrombin, which itself causes a relatively small change in diacylglycerol levels. Neither the labelled triacylglycerol nor the labelled free fatty acid appears to be the source of the diacylglycerol formed which may arise from the activation of phosphatidylinositol phosphodiesterase.     

1-Butanol synthesis by Escherichia coli cells through butyryl-CoA formation by heterologous enzymes of clostridia and native enzymes of fatty acid β-oxidation

Anaerobic biosynthesis of 1-butanol from glucose is investigated in recombinant Escherichia coli strains which form butyryl-CoA using the heterologous enzyme complex of clostridia or as a result of a reversal in the action of native enzymes of the fatty acid β-oxidation pathway. It was revealed that when the basic pathways of acetic and lactic acid formation are inactivated due to deletions of the ackA, pta, poxB, and ldhA genes, the efficiency of butyryl-CoA biosynthesis and its reduced product, i.e., 1-butanol, by two types of recombinant stains is comparable. The limiting factor for 1-butanol production by the obtained strains is the low substrate specificity of the basic CoA-dependent alcohol/aldehyde dehydrogenase AdhE from E. coli to butyryl-CoA. It was concluded that, in order to construct an efficient 1-butanol producer based on a model strain synthesizing butyryl-CoA as a result of reversed action of fatty acid β-oxidation enzymes, it is necessary to provide intensive formation of acetyl-CoA and enhanced activity of alternative alcohol and aldehyde dehydrogenases in the cells of a strain.     

Production of thermotolerant entomopathogenic Isaria fumosorosea SFP-198 conidia in corn-corn oil mixture

Low thermotolerance of entomopathogenic fungi is a major impediment to long-term storage and effective application of these biopesticides under seasonal high temperatures. The effects of high temperatures on the viability of an entomopathogenic fungus, Isaria fumosorosea SFP-198 (KCTC 0499BP), produced on different substrates amended with various additives were explored. Ground corn was found to be superior in producing the most thermotolerant conidia compared to yellow soybean, red kidney bean, and rice in a polyethylene bag production system. Using ground corn mixed with corn oil as a substrate resulted in only 7% reduction in germination compared to ground corn alone (67% reduction) after exposure of conidia to 50°C for 2 h. Corn oil as an additive for ground corn was followed by inorganic salts (KCl and NaCl), carbohydrates (sucrose and dextrin), a sugar alcohol (sorbitol), and plant oils (soybean oil and cotton seed oil) in ability to improve conidial thermotolerance. Unsaturated fatty acids, such as linoleic acid and oleic acid, the main components of corn oil, served as effective additives for conidial thermotolerance in a dosage-dependant manner, possibly explaining the improvement by corn oil. This finding suggests that the corn-corn oil mixture can be used to produce highly thermotolerant SFP-198 conidia and provides the relation of unsaturated fatty acids as substrates with conidial thermotolerance.     

Product inhibition and its removal on josamycin fermentation by Streptomyces narbonensis var. josamyceticus

Josamycin formation was shown to be closely associated with the degree of mycelial growth. Media using glycerol or glucose were slight in josamycin accumulation. However, the mycelial growth and product formation were interrupted in the course of the fermentation. The self-resistance level of the producing organism against josamycin was shown to be not higher than 1 mg per ml. In media using fatty oil, the organism grew smoothly and gave a concentration of josamycin at least 5 times higher than the self-resistance levelMost of the josamycin was distributed in the oily phase of the broth. The josamycin concentration of the water phase of the broth was less than the self-resistance level, except in the later period of the fermentation. Unsaturated fatty acids remaining in the broth were found to be the best extractors of josamycin. It was concluded that the enhanced josamycin accumulation of this fermentation resulted from the removal of the product inhibition.     

Transient Accumulation of Fatty Alcohols by n-Paraffin-grown Microorganism

In the course of the study on glutamic acid fermentation by Arthrobacter paraffineus, in which n-paraffin was used as the sole source of carbon, it was observed that fatty alcohollike lipid was accumulated in the paraffin layer of culture medium. This was isolated and identified as the primary fatty alcohol having the corresponding carbon skeleton to that of n-paraffin used as the carbon source.

The accumulation of fatty alcohol occurred rapidly in the early-log phase. The maximum amount of the accumulation was approximately 0.5 mg/ml after 6 hr incubation. In contrast with the production of glutamic acid and trehalose, the addition of penicillin gave no effect on the accumulation of fattv alcohol.

Acetone-treated cells of the n-paraffin-grown bacterium still had the oxidative activity of n-paraffin, and the formation of fatty alcohol from n-paraffin was observed only by the reaction in alkaline pH.     

Changes in phospholipids of Microsporum species in the presence of ethanol

Ethanol supplementation to the growth medium of Microsporum gypseum and Microsporum cookie resulted in changes in phospholipid composition and degree of unsaturation of their fatty acids without affecting the growth rate of the organism. Phosphatidylethanolamine increased with a simultaneous decrease in phosphatidylserine. Unsaturated fatty acids of total phospholipids decreased significantly which was primarily due to the decreased levels of linoleic acid.Abbreviations CL Cardiolipin - LPC Lysophosphatidylcholine - PC Phosphatidylcholine - PE Phosphatidylethanolamine - PI Phosphatidylinositol - PS Phosphatidylserine - UK Unknown phospholipids     

Novel three-phase bioreactor concept for fatty acid alkyl ester production using <Emphasis Type="Italic">R. oryzae</Emphasis> as whole cell catalyst

A novel three-phase solid–gas–liquid bioreactor (SGLB) concept using gaseous alcohol and liquid rapeseed oil with immersed microorganisms overlying a nutrient agar phase (solid) is proposed for biodiesel (fatty acid alkyl esters, FAAE) production based on the high hydrophobicity and negative surface charge showed by the fungi Rhizopus oryzae. This novel bioreactor was thought to increase oil bioavailability and decrease alcohol toxicity for effective microbial growth, reaching high yields of FAAE production without any pretreatment. High growth rates were reached for R. oryzae using a SGLB simultaneously reaching a high FAAE production yield, up to 50% using methanol and up to 70% using ethanol at 144 h of incubation at 20°C. To compare the effect of gaseous alcohol, the same experiments were carried out in a three-phase solid–liquid–liquid bioreactor (SLLB), where the alcohol was added in liquid phase, showing significant R. oryzae growth but no FAAE formation. This suggests that the inhibitory effect of alcohol is more significant in lipase activity than in R. oryzae growth, and the use of alcohol in gaseous phase may decrease both of them. The experimental procedure using SGLB showed that when R. oryzae is maintained alive, it can catalyze at the same time the hydrolysis, esterification and transesterification of triglycerides from rapeseed oil, but its activity strongly depends on the used growth media. Therefore, the application of gaseous alcohol coupled with R. oryzae as immobilized whole cell catalysts may be a potential alternative to the use of commercial lipases for biodiesel production.     

<Emphasis Type="Italic">Limnocalanus macrurus</Emphasis> in the Kara Sea (Arctic Ocean): an opportunistic copepod as evident from distribution and lipid patterns

Limnocalanus macrurus is an important member of the zooplankton communities of the Siberian shelf seas. During the cruise, Boris Petrov 1999, in August/September to the southern Kara Sea and the Ob and Yenisej estuaries, its abundance and vertical distribution were investigated. In adults, salinity tolerance, egg production, feeding and lipid composition were studied. L. macrurus occurred in water with salinities ranging from 1.7 to >33 without clear preference, as revealed from salinity-tolerance experiments. The dominance of adults and their high wax-ester content, as well as the lack of egg production and feeding activity, suggest that the population was in the pre-overwintering condition. Wax esters allow L. macrurus to survive long starvation periods and to reproduce in times of little food availability, but through its potential carnivory, it should be able to replenish its diet by preying on other zooplankton. Morphology and swimming behaviour of L. macrurus resemble the omnivorous copepod Metridia longa, which, however, is mainly found in the open ocean. The overall lipid composition and the mode of lipid storage also point to an omnivorous feeding behaviour. However, the high proportion of the marker fatty acid 16:1(n-7) suggests that L. macrurus strongly exploited the existent phytoplankton bloom, consisting mainly of diatoms. A striking characteristic of its lipids is the high level of the 20:1(n-7) fatty alcohol in addition to the 18:1(n-7) fatty acid and alcohol. It is the first copepod species known to produce such high amounts of 20:1(n-7) alcohol. Since this alcohol and the corresponding fatty acid are not abundant in any prey, this long-chain monounsaturated wax-ester moiety has to be produced de novo. Owing to these particular lipid characteristics in its distribution, feeding, and life-cycle strategy, L. macrurus can be described as a very versatile and opportunistic copepod.     

Fatty Acid Hydroxamate Formation and Ester Hydrolysis by Cell-free Extracts of Micrococcus sp.

When Micrococcus sp. which was isolated from soil assimilated azelaic acid as a sole carbon source, cell-free extract of the organism catalyzed enzymic fatty acid hydroxamate formation. The enzyme was effective only for mono-carboxylic acid, but not for di-carboxylic acids such as azelaic acid. The activity was high with higher fatty acid such as oleic acid. Some of the properties of higher fatty acid hydroxamate formation were investigated.

Olelylhydroxamate was formed with the high concentration of hydroxylamine. The reaction was inhibited by PCMB, but recovered by the addition of SH-compounds (such as cysteine).

On the other hand, when methylacetate was used as a sole carbon source and cell-free extract of Micrococcus sp. hydrolyzed several fatty acid esters. The fatty acid hydroxamate degradation by esterolysis are also discussed.     

Effect of Exogenous Fatty Acids on the Cellular Fatty Acid Composition and Neomycin Formation in a Mutant Strain of Streptomyces fradiae

A mutant of Streptomyces fradiae which requires oleic acid for neomycin formation was isolated and the effects of exogenous fatty acids and other additives on the formation of neomycin were studied. Palmitic acid and high concentration of sodium ions could replace oleic acid in neomycin formation. The fatty acid spectrum of the mutant strain ST–5B was quite different from that of the parent strain 3123. The major fatty acid components of the mutant and the parent were anteiso 15:0 and iso 16: 0, respectively. However the fatty acid composition of the mutant was changed from the anteiso 15: 0-type to the parental iso 16: 0-type by the supplement of oleic acid or high concentration of sodium ions in the medium. In the case of palmitic acid, the major fatty acid component of the mutant cells was changed from anteriso 15: 0 to normal 16:0. The role of these additives in neomycin formation by the mutant is discussed.     

Effects of Fatty Acids,Lipase Activator,Phospholipids and Related Substances on the Lipase Production by Candida paralipolytica

Unsaturated long-chain fatty acids such as oleic, linoleic and ricinoleic acid except for elaidic acid were effective on the lipase production by Candida paralipolytica, but saturated fatty acids were not effective. When elaidic and myristic acids were dissolved in n-hexadecane to be dispersed in a liquid state, they became to be effective on the lipase production. These results suggest that long-chain fatty acids of a liquid state are effective on the lipase production. Lipase activator A and phosphatidylethanolamine stimulated the effect of fatty acids on the lipase production. Effects of sterols and surface-active substances on the lipase production were also reported.

A weak tributyrin-hydrolyzing activity, in the absence of fatty acids, was found in the yeast cell.     

Effect of monoterpenes on lipid oxidation in maize

The monoterpenes 1,8-cineole, thymol, geraniol, menthol and camphor strongly inhibited the root growth of Zea mays L. seedlings. They induced an oxidative stress as measured by the production of malondialdehyde, conjugated dienes and peroxides. This oxidative stress depended on the length of the exposure and on the monoterpene applied. The total fatty acid content was measured and fatty acid composition was analyzed. Unsaturated fatty acids increased in the treated samples. The alcoholic and non-alcoholic monoterpenes appeared to have different modes of action.Abbreviations MDA Malondialdehyde - TFA Total fatty acid content - FA Fatty acid - IC₈₀ Concentration causing 80% inhibition     

Complex formation of potassium salt of highly fatty acid with hemagglutinin protein in influenza virus via exothermic interaction

In our previous study, we found highly fatty acid salts, which are a skin-friendly soaps, had a high ability to inactivate the influenza virus. In order to elucidate the mechanism of inactivation of influenza virus, we investigated interactions and complex formation of potassium tetradecanoate (C14K) as a highly fatty acid salt with a virus particle (VP) derived from avian influenza virus by using isothermal titration calorimetry (ITC) and small-angle X-ray scattering (SAXS). ITC showed C14K attractively interacted with hemagglutinin protein (HA) which exists in the envelop of VP. SAXS analyses revealed C14K formed highly ordered complex with HA through the attractive interaction. Since the HA is responsible for cell entry events, inactivation of influenza viruses by highly fatty acid salts are derived owing to HA inhibition of influenza viruses through the complex formation. Time-resolved SAXS measurements elucidated the complex formation was completed within 40 s after mixing aqueous solutions of C14K and VP. This result strongly suggests that hand-washing with a highly fatty acid salts is an effective measure to prevent infection with influenza virus without causing rough hands.