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Indol-3yl-acetic acid (IAA) was identified in Phaseolus vulgaris L. Shoot tissue of seedlings, exposed to light for 5 days, had a higher level of IAA than etiolated seedlings of the same age. The content of IAA increased in green seedlings during light treatment for 5-12 days. No increase could be measured in dark-grown seedlings. Inhibitory substances appeared at different Rf-values. The main part was identical to the inhibitor-β complex and occurred in a higher amount in light-grown seedlings than in etiolated taller ones. One part of the inhibitor-complex appeared to be abscisic acid (ABA). It is suggested that both IAA and acid inhibitors may play an important role in the control of stem growth and differentiation, although light effects on other hormones and regulatory systems cannot be ignored. [ABSTRACT FROM AUTHOR]

The incorporation of 14C-labelled phenylalanine into proteins of mitochondria prepared from 48-h germinating seeds of Vigna sinensis (L.) Savi can be stimulated by gibberellic acid (GA3), kinetin and polyuridylic acid [poly(U)]. The incorporation is sensitive to various metabolic inhibitors which include rifampicin, actinomycin D, ethidium bromide, kanamycin, 5-azauracil, 8-azaadenine, and rotenone. They were used to study the effect of GA3 and kinetin, on the sequential steps in protein synthesis (DNA → RNA → protein), which are variously affected by the inhibitors. The inhibitory effect of actinomycin D on the incorporation can be reversed by GA3 and kinetin, which implies that these two plant hormones act at the transcription level. With ethidium bromide the effect of hormones is not so convincing, though the trend is towards some release of inhibition. The plant hormones have apparently no effect on the incorporation sensitive to other inhibitors studied. GA3 and kinetin can also stimulate the normal and polyadenylic acid [poly(lA)]-directed incorporation of 14-labelled lysine into proteins by a mitochondrial preparation. Indole-3-acetic acid and 2,4-dichlorophenoxyacetic acid can only stimulate the normal synthesis, which is not further stepped up by poly (A). The polynucleotide even seems to depress the action of IAA. This anomaly has been discussed. [ABSTRACT FROM AUTHOR]

Over a hundred compounds and natural materials were examined for their ability to induce arthritis in rats when mixed with heat-killed delipidated Mycobacteria tuberculosis. Many of these materials were also assessed for (CMI) adjuvant activity by their ability to induce allergic encephalomyelitis (EAE) in rats when mixed with guinea-pig spinal cord, both with and without added M. tuberculosis. Cyclization and/or the presence of oxygen atoms, or double boiids reduced (or abolished) the arthritogenic potential and adjuvanticity of alkanes>C10. Esters/ triglycerides of fatty acids > C12, retinol acetate (not palmitate) and vitamins E and K showed co-arthritogenic and adjuvant activity. Other active lipids included squalene and cholesterol oleate, which are both present in human sebum. Sebaccous lipids may therefore perhaps function as natural adjuvants if resorbed during abrasion and infection. Squalane (perhydrosqualene), pristane and hexadecane were excellent substitutes for mineral oil in preparing arthritogenic adjuvants from various mycobacteria, C. rubrum and N. asteroides. These oily compounds were also very effective adjuvants per se, in the absence of bacterial material or emulsifier, for inducing EAE in Lewis rats. [ABSTRACT FROM AUTHOR]

Following infection by Puccinia poarum, there is an accumulation of lipid in leaf tissue of Tussilago farfara. Most of this increase is in the fungus, which accounts for nearly half of the dry weight of mature aecial pustules. While the lipid content of infected tissue rises to more than three times that of healthy leaves, that of the uninfected parts of diseased leaves is reduced by one-third. Aecial pustules accumulate a high proportion of neutral lipid, particularly triglycerides and fatty acids. As infection progresses, a loss of chloroplast glycolipids and phosphatidyl glycerol is accompanied by increases in phosphatidyl ethanolamine and phosphatidyl choline and the formation of phosphatidyl serine, which is not readily detectable in healthy leaf tissue. The lipid changes following rust infection have been compared with those of senescing Tussilago leaves. Both neutral lipids and phospholipids incorporated more photosynthetically assimilated 14C in rust-infected tissue than in healthy leaves. Greatest differences were in free fatty acids, triglycerides, phosphatidyl ethanolamine and phosphatidyl choline with significant increases also in sterols, phosphatidyl inositol and phosphatidyl serine. Whereas three-quarters of the activity incorporated from 14CO2 into lipid appears in the neutral lipids of diseased tissue, in healthy tissue these contain only one-quarter. [ABSTRACT FROM AUTHOR]

An examination was made of the effects of low-temperature acclimatization on the fatty-acid composition of the polar lipids of two chill-sensitive species Gossypium hirsutum and Phaseolus vulgaris which harden readily against chilling injury. As controls, the effect of hardening temperatures on a chill-resistant species, Hordeum vulgare, and a chill-sensitive species, Episcia reptans, which did not harden were also investigated. The degree of unsaturation of the fatty acids associated with the phospholipid fraction increased during hardening of Gossypium hirsutum and Phaseolus vulgaris. Furthermore, the degree of unsaturation and weight of phospholipids decreased in the leaves of these species with increase in physiological age at 25° C and was related to the increased susceptibility of older leaves to chilling injury. The acclimatization treatment produced no effects on the fatty-acid composition of the glycolipids of these plants and this agreed with earlier observations which showed no increase in unsaturation of the total leaf fatty acid on hardening (Wilson and Crawford, 1974). Therefore, in leaves, it was the phospholipid fraction alone and representing only 22% of the total leaf fatty acids that had its degree of unsaturation positively related to the chilling tolerance of the species investigated. These findings are discussed in relation to similar ones made on the acclimatization of animals to low temperatures. [ABSTRACT FROM AUTHOR]

The results presented in this paper establish relationships between structural morphological and functional properties of cytoplasmic membrane vesicles isolated from an Escherichia coli unsaturated fatty acid auxotroph. The membranes were isolated from cells grown in the presence of either oleic, linoleic, linolenic or elaidic acids. High-angle X-ray diffraction studies show that the order-disorder transitions induced by temperature variations and associated with the paraffin chains of the lipids are a function of the fatty acid composition of the membranes. In some cases "cocrystallization" of various lipid species takes place within a single type of ordered domains. In other cases there is segregation of various lipid species into more than one distinct type of ordered domain. The various order-disorder transitions observed induce morphological changes in the hydrophobic core of the membranes which can be detected by freeze-etch electron microscopy. A random distribution of particles on the fracture faces is observed when the paraffin chains of the lipids are disordered. Upon ordering of the paraffin chains, particles are excluded from the ordered domains and as a consequence, smooth areas and areas with densely packed particles are observed. The ratio of the smooth surface to particulated surface is proportional to the amount of ordered paraffin chains present. Moreover, the size of the smooth domains is a function of the fatty acid composition of the membranes. Discontinuities in the rate of D-lactate-dependent proline uptake as a function of temperature correlate with the order-disorder transitions observed. The high energies of activation at low temperatures are attributed to decreased mobility of the carrier proteins upon aggregation. In contrast, phosphoenolpyruvate-dependent vectorial phosphorylation does not respond to the ordering of the paraffin chains. [ABSTRACT FROM AUTHOR]

Epididymal adipose tissue of rats fed a high-fat diet and submitted or not to a 24-h fast before the experiment, was incubated with 10 mM glucose labelled with 14C at C-6. C-l or universally. in the presence of insulin (1000 µU/ml). The results were used to estimate the glucose carbon flow through the various metabolic pathways and to establish a balance of production and utilization of reducing equivalents in the cytoplasmic compartment. Although previously altered by the fat diet. glucose metabolism is shown to be still highly sensitive to the effect of fasting which mostly results in a further reduction of fatty acid synthesis and in a further increase of glucose conversion into lactate. This effect is rather parallel to the known effect of fasting on glucose metabolism in adipose tissue of rats fed a normal fat-poor diet. In adipose tissue of rats fed a fat diet, the lactate/pyruvate ratio reaches an abnormally high value which is consistent with a calculated excess of production over utilization of reducing equivalents. A 24-h fast induces a drop of the lactate/pyruvate ratio together with a significant improvement of the balance between production and utilization. Thus, this effect is quite in opposition with the slight increase in the NADH : NAD' ratio currently observed in adipose tissue of fasted rats after a normal fat-poor diet. It can be concluded from the results of this work that the cytoplasmic redox potential is not a major factor in the control of glucose metabolism in adipose tissue. [ABSTRACT FROM AUTHOR]

In rat liver some highly unsaturated fatty acids are partially degraded. In contrast to ‘normal’ β-oxidation some intermediates accumulate in this catabolic pathway. When a docosapolyenoic acid with the first double bond in position 4 is metabolized, two degradation products are to be found. The sequence of reactions has been elucidated. As a first step the docosapolyenoic acid loses its double bond in position 4 while the carbon chain remains unchanged. The enzyme involved has tentatively been called 4-enoyl-CoA reductase. Subsequently chain shortening occurs. Using polyenoic acids with different chain lengths and different double bond positions, it has been possible to demonstrate that the double bond positions rather than the chain length determine whether or not an unsaturated fatty acid is partially degraded. The four double bonds in the positions 4, 7, 10 and 13 seem to be the minimal structural requirement for docosapolyenoic acids in order to function as substrates for the 4-enoyl-CoA reductase. 4, 7,10-docosatrienoic, 4, 7-docosadienoic, and 4-docosenoic acid, which have not been detected in nature so far, are not metabolized when incubated with rat liver mitochondria. [ABSTRACT FROM AUTHOR]

1. Brown-adipose-tissue mitochondria prepared from the cold-adapted rat and guinea-pig require malate for significant palmitoyl-L-carnitine oxidation. In contrast the mitochondria prepared from the cold-adapted hamster (a hibernator) rapidly oxidize palmitoyl-L-carnitine in the absence of added malate. 2. The major end product of malate-independent fatty acid oxidation in the hamster is identified as acetate. In the presence of malate or L-carnitine, citric acid cycle intermediates or acetyl-L-carnitine are also produced. 3. Factors controlling the formation of these products are investigated. Acetate production is highly dependent on the rate of fatty acid oxidation, and on the acetyl-carnitine/carnitine ratio. 4. The rate of acetate production in the presence of malate is independent of the incubation temperature over the range from 37 °C to 10 °C, while the entry into the citric acid cycle is decreased 10-fold. 5. Acetate production is most pronounced under conditions where a high acetyl-CoA/CoA ratio would be predicted to occur. 6. It is suggested that the acetate pathway is of particular significance in brown adipose tissue from hibernators as a means of allowing fatty acid oxidation, and hence heat production, to occur at temperatures where the citric acid cycle is apparently unable to function. [ABSTRACT FROM AUTHOR]

Investigations have been conducted into the relationship between fatty acid and phenol synthesis in submerged cultures of Aspergillus fumigatus. Both groups of metabolites are derived from acetate but phenol synthesis only occurs at a late stage in the incubation period and is dependent on a change in the internal environment of the mycelium. Secretion of acetate-derived phenols commenced many hours after exhaustion of ammonium ions from the culture medium, or transfer of mycelium to glucose solution. Lipid synthesis, however, was maintained at this stage and continued into the phenol-secreting phase when sufficient glucose was present to provide the necessary substrates. The additional lipid formed was identified as triglyceride. The composition of fatty acids in the total lipids was very similar to that found in other Aspergillus sp. and related Ascomycetes and consisted principally of C18:2 with C16:0, C16:1, C18:0 and C18:1. Addition of 4-fluorophenylalanine, but not cycloheximide, caused a rapid reduction in fatty acid synthetase activity and lipid synthesis, and abolished formation of orsellinic acid and trihydroxytoluene, the normal secreted products. Certain enzymes examined, including the dehydrogenases of the pentose phosphate pathway, maintained their specific activity during the "stationary" phase whereas fatty acid synthetase was present at greatly reduced activity. The activity of ATP citrate lyase was severely reduced to an undetectable level after approximately 40 h incubation; acetyl-CoA would therefore not be made available for fatty acid, phenol or ergosterol synthesis after this time. Initiation of phenol synthesis cannot be ascribed simply to diversion of substrates from fatty acid synthesis or to reduction in fatty acid synthetase activity. [ABSTRACT FROM AUTHOR]

1. The purification of the microsomal fatty acid chain elongating system from beef adrenal cortex is described. 2. The elongation system requires for optimal activity malonyl-CoA, ATP, Mg2+, NADPH or NADH. Long-chain fatty acyl-CoA derivatives inhibit the incorporation of [1,3-14C]malonyl-CoA into fatty acids. Supplementation of the system with enzymes of the C-3 oxidation sequence allows also an acetyl-CoA-dependent chain elongation. 3. Microsomes from beef adrenal cortex contain 2,3-trans-hexenoyl-CoA reductase with similar properties as described for rat liver. 4. The ratio of the specific activities of the hexenoyl-CoA reductase and chain elongation remains constant in the course of purification from rat liver and beef adernal cortex. From this finding it is concluded that hexenoyl-CoA reductase is an integrated part of the microsomal malonyl-CoA-dependent chain elongation system. 5. The physiological substrates of hexenoyl-CoA reductase are 2,3-unsaturated acyl-CoA derivatives of polyenoic long-chain fatty acids with a preference for structures present in γ-linolenic acid. 6. Competitive inhibition of the microsomal enoyl-CoA reductase by malonyl-CoA with respect to enoyl-CoA suggests that a multienzyme complex is involved in the microsomal chain elongation process. 7. Octenoyl-CoA, octenoyl-pantethein and octenyl-acyl-carrier protein are substrates of the microsomal hexenoyl-CoA reductase from rat liver with decreasing maximal velocities and affinities. Octenoyl-acyl-carrier protein and malonyl-CoA are competitive, suggesting identical mechanisms of reduction for octenoyl-acyl-carrier protein and octenoyl-CoA by the multienzyme complex.

1. The 700 × g fat-poor internatant from epididymal adipose tissue homogenate of fasted refed rats was incubated at pH 6.5 with 0.5 mM [1-14C]acetate in the peesence of cofactors. After incubation, six lipid classes were separated by thin-layer chromatography and their fatty acids analyzed by radio gas-liquid chromatography. The incorporation of [-14C]acetate into glycerides was limited by the activity of acetyl-CoA carboxylase, and was stimulated two to three-fold by the addition of 0.1 mM unlabelled malonyl-CoA. 2. The chain-length of fatty acids labelled in vitro was controlled by the relative concentrations of malonyl-CoA and acetyl-CoA. Addition of unlabelled malonyl-CoA influenced the operation of fatty acid synthetase in such a way that the ratio of radioactive palmitate to radioactive myristate increased markedly. 3. sn-Glycerol 3-phosphate stimulated the esterification of fatty acids into triglycerides. Under these conditions whereas the specific activity of free fatty acids was much higher than that observed in triglycerides, the specific activity of diglycerides was low, when compared to the same triglycerides. Newly synthesized monounsaturated fatty acids were preferentially esterified into triglycerides. 4. 0.5 mM [1-14C]palmitate was efficiently incorporated into triglycerides but not into diglycerides. [ABSTRACT FROM AUTHOR]

Homogenates of newborn mouse skin were centrifuged at 900 × g, 15,000 × g, and 100,000 × g. Sediment from the last two centrifugations, as well as the 100,000 × g supernatant fraction incorporated [1-14C]-acetyl CoA and [1, 3-14C]-malonyl CoA into fatty acids which were analyzed by chromatographic procedures and scintillation counting. All three fractions, especially the supernatant fraction, utilized malonyl CoA in labeling saturated acids. The particulate fractions used both malonyl CoA and acetyl CoA in labeling unsaturated acids. Several cofactor requirements were established. Coenzyme A was markedly inhibitory. When oxygen was replaced by nitrogen, incorporation of both precursors was increased by 50%. Comparison of the incorporation of [1-14C]-acetyl CoA into fatty acids of the 15,000 × g and 100,000 × g pellet fractions was studied with and without oxygen. Results showed that chain elongation predominated as the mode of labeling of unsaturated acids. This was confirmed by estimating the extent of carboxyl carbon labeling. The principal chain extensions were: 16: 1→ 18: 1 → 20: 1, 18: 2 → 20:2, and 20:4 → 22:4. Desaturase activity was not observed, even in the 100,000 × g (microsomal) pellet fraction. The distribution of radioactivity among polyunsaturated acids of whole skin in after exposure to [14C]-acetate was compared to the pattern observed with a 15,000 × g pellet fraction after incubation with [14C]-acetyl CoA. Results indicated that 18:2ω6 (linoleic acid), 20:3ω6, and other were probably labeled in whole skin by a retroconversion mechanism which was inoperative under the conditions used with the subcellular fractions. [ABSTRACT FROM AUTHOR]

The proportion of sterols in esterified form increase during stratification and cornification of the fetal and newborn rat whole skin and epidermis. This change cannot e ascribed either to development of alternative biosynthetic pathways favoring formation of sterol esters or to a commensurate increase in cholesterol-fatty acyl transferase. The activity of the latter enzyme, in fact, decreases from day 17 of gestation to 7 days postpartum. The decline in enzymatic activity is not due to the presence of inhibitors or exhaustion of endogenous substrate but may reflect changing proportions of epidermal cells in progressive stages of maturation. It is concluded that the increase in sterol esters is due to the increased availability of free fatty acids and sterols provided by the degradation of intracellular membranes during cornification. [ABSTRACT FROM AUTHOR]

According In our current state of knowledge, free fatty acids are formed in sebaceous follicles primarily through hydrolysis of sebum triglycerides by microbial lipases. Because of their comedogenic and irritant qualities, these free fatty acids are probably responsible for many of the alterations in the follicle that result in acne lesions. [ABSTRACT FROM AUTHOR]

This article provides information on dermatological aspects of prostaglandins in normal and pathological skin. Prostaglandins are fatty acids containing 20 carbon atoms with C8 to C12 closed to form a five membered ring. Many effects attributed to prostaglandins are manifest through changes in the intracellular concentration of the nucleotide cyclic adenosine. The detection of prostaglandins in normal skin started since 1970. Eccrine glands produces aqueous sweat responsible for heat regulation. In pathological skin conditions prostaglandins of the E-series seem to play a role as mediators of sustained cutaneous inflammation which may lead to entirely new therapeutical approaches in this field.

Eighty patients with aorto-iliac / femoro-popliteal atherosclerosis were collected to examine in detail their plasma cholesteryl ester fatty acid compositions and to compare them with the incidence of ischaemic heart disease through a 4-year follow-up. Various other biochemical and rheological parameters were also measured to see if these might explain any association between the abnormal fatty acid pattern and ischaemic heart disease. The abnormal fatty acid pattern was specifically and generally similar to that found in essential fatty acid (EFA) deficient animals and children as shown by the increase of the specific trienoic acid (C.20: 3ω9) by reduced linoleic acid concentrations, and by an increase of C.18 and C.16 monoenoic acids (oleic and palmitoleic), but not of their corresponding saturated forms, stearic and palmitic. The results suggest that the abnormal fatty acid composition resulted from an increased synthesis of monoenoic acids and monounsaturase activity, coupled with a relative inadequacy of linoleic acid. The patients with a reduced concentration of linoleic acid (<35%) subsequently had a higher incidence of myocardial infarction. No significant correlations were found between the fatty acid concentration and various other biochemical or rheological parameters except marginally between linoleic acid and platelet adhesiveness. Only the linoleic acid concentration distinguished between the patients with and without myocardial infarction. A marked inverse correlation was found, however, between the monoenoic and linoleic acid concentration, without parallel changes in other fatty acids. It seems that as in animals, a balance exists between EFA and monoenoic pathways which are known to compete for the same desaturase systems and acyl sites. It appears that human EFA requirements and effects need to be considered not only by their intake and metabolism, but also through individual factors which vary the monoenoic concentrations and monounsaturase activity. Since these factors include several currently associated with human atherosclerosis the question arises of whether the EFA-monoenoic balance is one link between them and the pathology of the arterial occlusions and myocardial infarction. [ABSTRACT FROM PUBLISHER]

Although erythrocytes from vitamin E-depleted rats are highly susceptible to dialuric acid peroxidative hemolysis, those from rabbits were not, nor did the rabbits become dystrophic when they were maintained on stripped lard diets. Rabbit RBC became susceptible (and dystrophy appeared) following supplementation with arachidonate, the latter being preferentially destroyed in the RBC membranes during the peroxidizing process. Similar but less severe physiological findings were made following cod liver oil or safflower oil feeding. Fragiligrams of RBC from the arachidonate-fed rabbits were biphasic, suggesting two populations of RBC, one old and one young. Reticulocytes were present, although hematocrit levels were normal. Therefore, the feeding of PUFA to clinically normal, vitamin E-depleted rabbits acutely initiated the onset of RBC hemolysis and muscular dystrophy. [ABSTRACT FROM AUTHOR]

According to the vitamin D hypothesis, demyelination in multiple sclerosis results from a breakdown of myelin due to abnormal lipid composition and structure, produced during the period of brain development. The observed abnormalities (altered lipid concentrations and fatty acid profiles are viewed as a consequence of deficiencies in enzymes that govern myelin lipid synthesis and membrane assembly. The enzyme deficiencies, genetic in origin, are proposed to occur because of inadequate supplies of vitamin D and calcium at times of rapid myelination and growth, mainly in adolescence. If the theory proves to be correct, it may be possible to suppress the disease by dietary supplementation with vitamin D and calcium during puberty. [ABSTRACT FROM AUTHOR]

Apparently new information about a metabolic abnormality has been obtained by measuring biochemical and respiratory responses to controlled exercise in a patient with abnormal mitochondria in muscle fibres. A male patient (49 years old) presented with bilateral ptosis of 15 to 20 years' duration and weakness for one to two years. Biopsies from the deltoid and triceps muscles were subjected to histological, histochemical, and electron microscopical examination. Routine histology showed only minor changes; 2-5% of muscle fibres had pale borders in which there were aggregates of mitochondria and 1-5% of fibres showed atrophy. Histochemical examination showed increased activity of succinic dehydrogenase in mitochondria and lactate dehydrogenase in cytoplasm. Electron microscopy showed crystalline inclusions in many subsarcolemmal mitochondria. Metabolites were studied during and after exercise on an ergometer and revealed remarkable differences from normal. Blood lactate rose to 12·5 μmol/ml and pyruvate to 0·39 μmol/ml compared with up to 4·0 and 0·16 μmol/ml respectively in controls exercising to a comparable percentage of capacity. Concentrations of ketone-bodies and free fatty acids fell during and after exercise, while they rose in the controls. These observations imply a major mitochondrial defect which causes dramatic biochemical changes in fuel supply in blood during exercise. The changes suggest that fat metabolism was accelerated (in this patient) and was related to a block of carbohydrate utilization as fuel. [ABSTRACT FROM AUTHOR]

At a concentration of 1-2 nM, acetic acid caused pronounced or complete inhibition of growth of several mycorrhizal species of the genus Boletus. In species of the litter-decomposing genus Marasmius, the same effect was obtained only at concentrations of 8 mM or higher. B. variegatus was especially sensitive to propionic and butyric acids. With M. foetidus the inhibiting effect increased with increasing chain length of the acids. [ABSTRACT FROM AUTHOR]

A complex, consisting of protein (38%), pheophytin plus protochlorophyll (20%), fatty acids (13%), sugars (15.5%) and other minor components, excreted by mutant strains of Rhodopseudomonas capsulata during exponential growth, was found to be synthesized at a low pO. The correlations between the protein, sugar and fatty acid components of the pigment complex with those of the intracytoplasmic membranes and cell walls were investigated and discussed. [ABSTRACT FROM AUTHOR]

A temperature-sensitive mutant of a thermophilic bacillus was isolated which was unable to maintain membrane integrity at high temperature. The mutant appeared to lose cytoplasmic contents, as indicated by a decrease in turbidity and cell refractivity, when shifted from a permissive (52° C) to a restrictive (65° C) temperature. Cell number remained fairly constant, however. At the approximate onset of the decline in turbidity, viability decreased and net synthesis of ribonucleic acid, deoxyribonucleic acid, and protein ceased. Both chloramphenicol and sucrose were effective in retarding the decline in turbidity at 65° C. An abnormal fatty acid composition at high temperature suggested that the lesion in the mutant involved lipid synthesis. The proportion of fatty acids with a high melting point (> 55° C) increased in the parent from 42% at 42° C to 69% at 65° C. Similar changes were not made by the mutant. An abnormal phospholipid composition was also observed in the mutant at 42° C and 52° C. However, at 58° C, the maximum growth temperature of the mutant, the proportion of major phospholipids (phosphatidylglycerol, phosphatidylethanolamine, and cardiolipin) was similar to the parent strain. The mutant's apparent loss of membrane stability at high temperature and its inability to regulate fatty acid and phospholipid composition in a normal manner suggested that (i) the temperature-sensitivity of the mutant may be a result of a defect in normal lipid metabolism at high temperature and (ii) the normal changes in fatty acid composition observed at increased growth temperatures may be an essential feature of thermophily. [ABSTRACT FROM AUTHOR]

A method for the isolation of anaerobic bacteria from endodontic specimens under Continuous anaerobiosis is described. A mobile anaerobe unit supplies a gentle stream of oxygen-free gas over the tooth when the bacteriologic sample is taken. The paper-points are then, under oxygen-free gas, immediately transferred to prereduced, anaerobically sterilized roll tubes. The different isolated anaerobic bacteria are typed with biochemical tests, antibiotic susceptibility testing and gas chromatographic analysis of volatile fatty acids and alcohols. [ABSTRACT FROM AUTHOR]

The level of indoI-3yl-acetic acid (IAA) in the cotyledons of cucumber seedlings increases in the period 4 to 11 days after germination. In hypocotyls and roots the IAA level decreases. IAA-oxidase activity of homogenates of cotyledons, hypocotyls and roots decreases with age. The soluble fraction of all three organs contains an IAA-oxidase, which may be allosteric. It is suggested that this IAA oxidase limits the upper level of IAA in the cell. The cell wall fraction of the three organs contains IAA-oxidases with conventional kinetics. The function of this IAA oxidase is probably to degrade exogenous IAA. [ABSTRACT FROM AUTHOR]

The present investigation shows the ability of peptides to induce capture organ formation in Arthrobotrys oligospora, when applied in a synthetic low nutrient medium. Under certain conditions casitone was shown to induce capture organ formation. The active principle in casitone was concentrated and purified by alternating procedures of ion exchange chromatography and gel chromatography in pyridine-acetic acid buffers. Crude casitone solutions were applied to columns of Dowex 50 W-X2 and eluted stepwise with 0.1-1.0 M pyridine-acetic acid pH 3.2-5.1. Active portions, free from most acid and neutral amino acids, were further purified on columns of Sephadex G-10 in 0.1 M pyridine-acetic acid pH 4.6, Aromatic amino acids and large molecules in the void volume could be separated from an active peptide mixture which was subjected to renewed ion exchange chromatography on Bio-Rad AG 5.0 W-X2. By stepwise and/or gradient elution in 0.1-0.5 M pyridine-acetic acid pH 3.2 fairly purified peptides were obtained. The composition of the test medium is an important factor in spontaneous capture organ formation. The peptides isolated from casitone induced capture organ formation, when given to the fungus in a synthetic mineral salt medium supplied with thiamin and biotin. Similar effects were obtained with small synthetic peptides in the same concentration (0.1 mg/mI). A large variety of peptides seem to be active when applied in a suitable medium. This was especially true for peptides with Rf > Rfleu on thin layers of cellulose developed with butanol-acetic acid-water (4: 1: 1). Of the peptides investigated valyl-peptides exerted the most drastic effect. [ABSTRACT FROM AUTHOR]

The ribosomes and their qualitative (monosomes-polysomes) and quantitative variations over a whole vegetative period of the tuber of Helianthus tuberosus L. (cv. OB 1) were examined. Tubers in different phases of growth, dormancy and sprouting or slices of dormant tubers activated with 2 × 10-6 M indol-3-acetic acid were used. The ribosomes were analyzed by a linear sucrose gradient. During flowering, polysomes of tuber disappeared almost completely and rRNA decreased in comparison with the level present at the beginning of tuber formation. After flowering, there was a new synthesis of monosomes and polysomes until the onset of dormancy; this last period was characterized by a marked increase in polysomes and a proportional increase in monosomes. The level remained almost constant till the break of dormancy. When the tubers sprouted, ribosomes, present almost exclusively as monosomes, decreased considerably; on the contrary the non-photosynthetic sprouts contained many monosomes and polysomes. The first phases of activation (3 h) of tuber slices were characterized by a RNA synthesis, which occurred during one hour, in the subunit region of the gradient. Successively (10 h of activation) the 32P incorporation was seen also in the polysome region and increased with time. Some possible interpretations of these last results are discussed. [ABSTRACT FROM AUTHOR]

Parenchyma tissue from potato (Solanum tuberosum L. cv. Russet) tubers was treated with inhibitors to the release of metabolic energy in order to determine the importance of an active transport system for (2,4-dichlorophenoxy)acetic acid (2,4-D) and (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) accumulation. Results from treatments with carbonylcyanide m-chlorophenylhydrazone, an inhibitor of oxidative phosphorylation, and N,N'-dicyclohexylcarbodiimide, an inhibitor of membrane-bound adenosine triphosphatase, indicated 2,4-D and 2,4,5-T accumulation to be independent of available energy as influenced by these metabolic inhibitors. Lecithin treated parenchyma tissue accumulated more 2,4-D and 2,4,5-T than untreated tissue indicating possible binding of the herbicide to the lecithin moiety. [ABSTRACT FROM AUTHOR]

Protocorms of Cymbidium (Orchidaceae) were grown on solid or liquid medium with macro-nutrients according to Wimber (van Raalte 1967) and iron, micro-nutrients and vitamins according to Nitsch (1968) the medium also contained 2 % sucrose. The effects of 1) the auxins; indol-3yl-acetic acid (IA A), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D); 2) the cytokinins; 6-furfurylaminopurine (kinetin) and benzyladenine (BA) and 3) the gibberellin; gibberellic acid (GA) were examined alone or in combinations. IAA had no effect alone. NAA resulted in optimal fresh weight at 10 μMand the protocorms were vigorous, but lighter green than usual. 2,4-D caused a high weight increase at 1 μM, but the protocorms were abnormal. Higher concentrations of NAA and 2,4-D inhibited chlorophyll synthesis. On solid medium kinetin (100 μM) induced a growth of many small shoots, but had no effect on the fresh weight. In liquid medium, kinetin promoted a callus formation and fresh weight increase. BA had effects similar to kinetin, but at lower concentrations. GA alone promoted shoot and leaf growth. Combinations of kinetin and NAA resulted in a maximal fresh weight increase at kinetin concentrations one tenth of the NAA concentrations. The optimal growth and the best development occurred at 10 μM NAA and 1 μM kinetin. NAA and kinetin together could limit the shoot and leaf growth induced by GA. [ABSTRACT FROM AUTHOR]

Changes in lipid and fatty acid composition of pine needle chloroplasts were determined upon transfer of the trees from outside (-5°C) to 32°C. Within 7 ½ hours after transfer, conversion of a portion of digalactosyldiglyceride into monogalactosyl diglyceride was observed. This portion consisted of a conjugate with extra long chain fatty acids (cerotic acid, 26: 0, and C20-cyclopropane fatty acid). Only minor further changes in lipid and fatty acid composition were observed. Dehardening of the needles occurred within the same period. The data support the hypothesis that the degalactosidation reaction specifically depends on the fatty acid composition. The extra long chain fatty acids may link different sub-units of the chloroplasts and may contribute to an additional layer of H-bonded water on the membrane surface because of the increased exposure of the galactose groups. [ABSTRACT FROM AUTHOR]

The ability of fatty acids to sensitize gram-negative and ram-positive bacterial cells to the action of bacteriolytic enzymes was studied. By synergetic effects between bacteriolytic enzymes and fatty acids. isolated from Myxococcus such bacterial, which were otherwise resistant to the enzymes, could be lysed. Isobranched and unbranched acids with 11-15 carbon atoms were active and could sensitize Bacillus megaterium and Aerobacter aerogenes to the action of bacteriolytic enzymes from myxobacteria and to lysozyme. The sensitizing activity of tetradecanoic acid was enhanced with increasing concentration even after the solution was saturated. Neither ethylene diaminetetraacetate (0.1 and 1 mM) nor Triton X-100 (1 ‰) could sensitize resistant bacteria to the action of bacteriolytic enzymes. However, they were active in combination and they could also increase the effect of tetradecanoic acid. [ABSTRACT FROM AUTHOR]

Field grown leaves of sugar beet contained 0.89 % of their fresh weight as chloroform:methanol 1:2 extractable material, whereas climate chamber grown material contained 0.34, 0.15, and 0.16 % in leaves, stalks, and roots respectively. A striking feature was high proportion of sulfolipid: 7 % of the total extractable of the field grown leaves, 19.5, 28.0, and 37.0 % of the total extractable of respectively leaves, stalks, and roots from the climate chamber grown material. Among the fatty acids, all chain lengths from C12 to C28 were found, except only C17 and C19. -- Exceptionally high contents of fatty acids with a chain length of C26 or C28 were noted in some cases. The 2500-20,000 g fraction of root homogenates contained 19 % of the total root lipids. Almost all of the phosphatidyl choline and about half of the phosphatidyl ethanolamine, but only 5 % of the sulfolipid followed the fraction. A fractionation of conjugates lipid types was evident, with a loss of 18/2 and 18/3 conjugates, and with an increase in the proportions of 16/0 and, possibly, of the long-chain (around C260 conjugates. The unspecific ATPase activity of the 2500-20,000 g fraction was rendered specific for (Na+ + K+) stimulation by treatment with 0.1 % deoxycholate for 1 hour. This induced a more than 2-fold swelling of the preparation. About half of its total lipids were lost. Again, this loss was a fractions one, so that the phosphatidyl choline lost its long-chain (about C26) fatty acid conjugate while the short to medium length chain conjugates remained; whereas the reverse was the case with the sulfolipid. The ATPase activity of the 2500-20,000 g fraction was destroyed by a 24 hour treatment with deoxycholate. As compared with the 1 hour treatment, the preparation lost about 20 % both of its volume and of its chloroform:methanol extractable material. The quantitatively dominating loss was found in the (pigment + neutral fat) fraction. The monogalactosyl diglyceride, the phosphatidyl inositol, and a strongly acidic unknown fraction survived the deoxycholate treatments comparatively well. In the sulfolipid the fractionating effect of the prolonged deoxycholate treatment expressed itself as a loss mainly from the long-chain (about C26) fatty acid conjugate. The (Na+ + K+) stimulation of the ATPase function of the particulate preparation is thus correlated with the balance between the long-chain (about C26) fatty acid conjugates of zwitterionic phosphatidyl choline and anionic sulfolipid. This is of theoretical interest, since it indicates that the specific lipid composition under appropriate conditions may influence the charge and conformation of a lipoprotein complex, thereby determining its functional capacities. [ABSTRACT FROM AUTHOR]

Two breeding lines of “zero‐erucic‐acid” rapeseed (Brassica napus) were grown in climate chambers at a constant night temperature (12°C) and constant photoperiod (16 hours) but with different day temperatures (15, 20 and 25°C). Samples of leaves, siliques and immature seeds were analysed for total fatty acid pattern. The content of different acyl lipids and the fatty acid pattern of these lipids were also determined in some of the samples by use of preparative TLC followed by GLC of the fatty acids. The mature seeds produced by ten plants of each selection in each climate were analysed separately for total fatty acid composition. Mono‐ and digalactosyl diglycerides (MGDG, DGDG) were the predominant acyl lipids in leaves and siliques. In developing seeds they also were more abundant than the phospholipids, but in this case the neutral lipids, mainly triacylglycerols, contained about 95% of the total fatty acids. Large variations were found in the fatty acid composition of monogalactosyl diglyceride and digalactosyl diglyceride, isolated from leaves, siliques and immature seeds. The palmitic acid content of leaf MGDG was about 15 %, atypically high for MGDG from photosynthetic tissue. The linolenic acid content of the MGDG was about 45 %, 30 % and 10 % in the leaf, silique and seed tissues respectively. A hexadecatrienoic acid (16: 3) was found almost exclusively in the MGDG samples of leaves, siliques and immature seeds (about 25 %, 10 % and 3 % 16:3 respectively). The lipids of siliques — mainly photosynthetising tissue — were different from those of leaves and had especially high contents of stearic acid (6–12 % in the different lipids). For all lipid classes studied, leaves grown at the lowest day temperature had a slightly lower oleic and higher linolenic acid content than those grown at the highest temperature. On the other hand, increasing the day temperature caused a decreased level of oleic, an increased level of linoleic and an essentially unchanged level of linolenic acids in the mature seeds from both selections. [ABSTRACT FROM AUTHOR]

Shoots grown out from aspen root sections in light or in darkness were extracted and the content of growth-regulating substances in various fractions was determined with the Avena coleoptile straight-growth assay. The most obvious difference was obtained for the inhibitor β-fraction This was about ten times more active in the light-grown than in the dark-grown shoots. Some indications of more growth inhibitory material in ether-insoluble fractions of light-grown plants were also obtained. The stimulation obtained at the Rf of indol-3-yl-acetic acid was somewhat lower in the etiolated shoots than in the light-grown ones.

The applicability of synchronous cultures of Chlorella fusca as a reproducible experimental system for the study of growth regulators has been investigated using indole-3-acetic acid (IAA) and gibberellin. 1. None of these compounds stimulated growth or sporulation. 2. IAA inhibited growth and sporulation at concentrations higher than 6 × 10-5 M, the effect increasing with increasing acidity. Gibberellin had no effect.

Tryptophan (Try) metabolism of Arthrobacter sp. was examined. The inducibility of the Try oxidizing enzyme system seems to be correlated with that of the indole-3-acetic acid (IAA) oxidizing enzyme system. Try is metabolized to IAA via indole-3-pyruvic acid (Ip) and indole-3-acetaldehyde (IAAld). Indole-3-acetamide (IAm) is formed as a product of Try oxidation. Exogenous IAm, indole-3-acetonitrile (IAN) and tryptamine are not oxidized by Try-induced cells. [ABSTRACT FROM AUTHOR]

The endogenous respiration of resting, submerged grown Boletus variegatus mycelium has been determined. In young cultures the intensity of the endogenous oxygen uptake was subject to great variations during the first few hours of starvation. However, by using six to eight days old mycelium the Qo2 values could be kept at a relatively low and constant level for at least nine hours. Inhibition of the endogenous respiration was found after addition of n-saturated C-2 to C-12 fatty acids (2 · 10-3M, pH 4.85). The inhibitory effect of the compound was dependent on the length of the carbon chain. Maximum effects were obtained for acids with eight to twelve carbon atoms per molecule. The inhibition was also dependent on the amount of undissociated acid present. By raising the pH so that the fatty acid dissociated the established inhibition was partly reversed. The effect of the neutral compound methyl octanoate was in essence identical to that obtained with octanoic acid. After fatty acid addition a close correspondence was found between the degree of inhibition of the oxygen uptake and the amount of UV absorbing substances leaking out from the cells. This extracellular material had an absorption maximum at 260 nm and a minimum around 240 nm. The leaking was ascribed to interaction between fatty acids or methyl octanoate and lipophilic substances of the cytoplasmic membrane. It is suggested that the inhibitory action on the endogenous respiration is due to similar effects on intracellular membrane systems. [ABSTRACT FROM AUTHOR]

Several indolic compounds are formed when tryptophan or tryptamine is metabolized by Rhizobium. Among these are indole-3-acetaldehyde (IAAld), tryptophol (Tr-ol), and indole-3-acetic acid (IAA). The metabolic relationship among the three compounds was investigated. The experiments were carried out either in the culture medium of growing Rhizobium cultures or in suspensions of washed bacterial cells. In neither case Tr-ol would function as a precursor of IAA, but tryptophan-2-14C gave rise to the formation of both IAA and Tr-ol. The ratio of IAA to Tr-ol depended on the experimental conditions, shaking favoring the formation of IAA. Also IAAld gave rise to the formation of IAA and Tr-ol when incubated with suspensions of washed cells. The ratio of the two compounds depended on experimental conditions such as pH value and shaking, the latter reducing the formation of Tr-ol. These results cannot be explained by the assumption of a dismutation mechanism catalyzed by a single enzymatic unit. The operation of two enzyme mechanism responsible for the reduction and the oxidation, respectively, of IAAld is suggested and discussed. [ABSTRACT FROM AUTHOR]