Effects of zinc deficiency on the fatty acid composition and metabolism in rats fed a fat-free diet

The effects of dietary zinc deficiency (ZD) on the composition and metabolism of the fatty acyl chains of phospholipids in rat liver were investigated with a fat-free diet. The levels of (n−9) fatty acids such as 18∶1 and 20∶3(n−9) in liver phospholipids (PL) were significantly lower in ZD-rats (19.4% and 5.4%, respectively) than in PF-rats (25.2 and 8.3%). On the other hand, the level of (n−6) acids such as 18∶2 and 20∶4 were higher in ZD-rats (3.3 and 19.1%, respectively) than in PF-rats (2.1 and 14.9%). In order to study the metabolism of fatty acids in vivo,¹⁴C-18∶0 or¹⁴C-18∶2 was intravenously injected, and then the conversion to the respective metabolite was examined. After the injection of¹⁴C-18∶0, the radioactivity was found in 18∶0 (49.3% of the total), 18∶1 (33.2%), and 20∶3 (n−9) (9.1%) in liver PL in PF-rats at 24h. In ZD-rats, the radioactivity was dramatically lower in 18∶1 (23.5%) and 20∶ (n−9) (3.6%), suggesting that the conversion of 18∶0 to 18∶1 and 20∶3 (n−9) was strongly inhibited in ZD-rats. When¹⁴C-18∶2 was injected, the radioactivity was mainly found in 18∶2, 20∶3(n−6), and 20∶4. The radioactivity in 20∶4 in ZD-rats was slightly higher than that in control rats. These results indicate that zinc deficiency affects the fatty acid metabolism in liver, in particular, it causes a reduction in δ9 desaturase activity, when rats are fed a fat-free diet.     

Eight newArizona serotypes isolated from reptiles

Summary Eight hitherto unrecognizedArizona serotypes (5∶13, 15; 5∶27∶28; 13∶1, 6, 7; 19∶29∶25; 22∶1, 2, 5; 22∶23∶31; 26∶24∶25; and 30∶22∶21) are described. All of the cultures were isolated from reptiles. Action of the organisms on lactose as well as departures from the normal pattern of biochemical behavior of theArizona group are noted.     

Detection of anti-Candida antibodies by the indirect immunofluorescence assay in patients with cancer in the orofacial region

An indirect immunofluorescence assay was performed to detect antibodies toCandida albicans blastospores and germ tubes. Serum specimens were obtained from 82 patients with neoplastic diseases in the orofacial region and thrush of the oral mucosa.C. albicans was identified in the oral cavity of 63 patients investigated but serum anti-Candida antibodies were detected in only 23 of them. Serological examination showed that titers of antibodies toC. albicans blastospores ranged from 1∶20 to 1∶1280. High titers from 1∶640 to 1∶1280 were detected in patients without antibiotic, cytostatic, or radiotherapeutic treatment. The titers of antibodies toC. albicans germ tubes ranged from 1∶20 to 1∶640. Our results indicate that titers of antibodies to theC. albicans germ tubes were lower and were detected in a smaller number of patients.     

Eleven undescribedArizona serotypes isolated from man

Summary Eleven newArizona serotypes (1,3∶17, 20; 9∶1, 2, 10; 9∶1, 2, 36; 10∶1, 2, 36; 12∶23∶28; 14∶1, 2, 6; 18∶1, 3, 11; 19∶16, 17, 18; 20∶23∶21; 22∶13, 14; and 24∶24∶31) are described. With the exception of two strains (18∶1, 3, 11 and 24∶24∶31) isolated from the feces of asymptomatic persons, the organisms were derived from definite episodes of enteric, focal, or generalized infections. Types 1,3∶17, 20 and 10∶1, 2, 36 were isolated from blood cultures and type 22∶13, 14 from the blood, spinal fluid, and cerebral abscesses in a fatal case of meningoencephalitis.     

Diapause induction in the thrips predatorAmblyseius cucumeris [Acarina: phytoseiidae] under greenhouse conditions

The predatory miteAmblyseius cucumeris (Oudemans) is an important biological control agent for thrips in commercial greenhouses, but its effectiveness in fall and winter is limited by reproductive diapause induced under short day conditions. Influence of photoperiod and temperature on diapause induction was investigated to provide information for successful management of the predator. Under 8∶16 (L∶D) photoperiods and 22°C photophase temperatures, diapause incidence was inversely related to scotophase temperature, decreasing from 100% diapause at 15°C to no diapause at 21°C. In continuous darkness, diapause was induced by thermoperiods of 20∶10 and 22∶17 and 22∶17 but not 25∶15°C (T∶C) (8h thermophase). Critical daylength for inducing diapause under 22∶17°C (T∶C) was 12.45 h, which was consistent with the trend in diapause incidence in mites collected from an established greenhouse population September to November. MostA. cucumeris diapaused only when exposed to diapause inducing conditions throughout their juvenile development and none stopped laying eggs when transferred from nondiapause to diapause inducing conditions as adults. After 14 generations of genetic selection for a nondiapause strain, diapause incidence was 33.3%.      

Influence of cultural conditions on growth and lipolytic activity inNocardia asteroides

The growth and the production of extracellular and intracellular lipases were measured fromNocardia asteroides grown under different cultural conditions. Maximal growth and intracellular and extracellular activities were observed at 3 d after inoculation. Among the tested media, synthetic medium induced maximal growth and extracellular activity, whereas tryptic soy broth induced the maximal intracellular lipase activity. The best carbon and nitrogen sources for growth and lipolytic activity were glucose, fructose, glutamate and nitrate, respectively. The optimal C∶N ratio for growth was in the range of 1∶4 to 2∶3 and for lipase activity the range was 2∶3 to 3∶2. Anything above or below this range was detrimental to the organism and its enzyme activity. Under the conditions of this study,N. asteroides grew best and had the highest lipase activity when compared toN. brasiliensis andN. caviae.     

Beneficial effects of combination of P and Zn for green gram (Phaseolus aureus L.)

Summary Dicalcium phosphate dihydrate and potassium dihydrogen phosphate were applied to calcareous soil in combination with zinc sulphate in the molar ratio of 100∶0, 100∶1, 100∶2 and 100∶4. Increasing addition of zinc sulphate into P sources gradually increased KCl (0.01M) soluble P and Zn, NaHCO₃ (0.5M, pH 8.5) extractable P and DTPA extractable Zn from soil and grain and straw yields of green gram.     

Pathogen specific carbohydrate antigen microarrays: a chip for detection of Salmonella O-antigen specific antibodies

A Salmonella O-antigen microarray was developed by covalent coupling of oligosaccharide antigens specific for serogroups Salmonella enterica sv. Paratyphi (group A), Typhimurium (group B) and Enteritidis (group D). Antibodies were correctly detected in sera from patients with culture verified salmonellosis. High serogroup-specificity was seen with the disaccharide antigens. With the larger antigens, containing the backbone sequence Manα1–2Rhaα1–2Gal (MRG), common backbone-specific antibodies (O-antigen 12) were also detected. This is “proof of principle” that pathogen-specific carbohydrate antigen microarrays constitute a novel technology for rapid and specific serological diagnosis in either individual patients or larger sero-epidemiological and vaccine studies.     

Characterization of Edwardsiella tarda waaL: roles in lipopolysaccharide biosynthesis, stress adaptation, and virulence toward fish

Edwardsiella tarda is the causative agent of edwardsiellosis in fish. The genome sequence of a virulent strain EIB202 has been determined. According to the genome sequence, the lipopolysaccharide (LPS) synthesis cluster containing a putative O-antigen ligase gene waaL was identified. Here, the in-frame deletion mutant ΔwaaL was constructed to analyze the function of WaaL in E. tarda EIB202. The ΔwaaL mutant displayed absence in O-antigen side chains in the LPS production. The ΔwaaL mutant exhibited an increased sensitivity to hydrogen peroxide indicating that the LPS was involved in the endurance to the oxidative stress in hosts during infection. In addition, the resistance of ΔwaaL to serum and polymyxin B decreased remarkably. The ΔwaaL mutant was also attenuated in virulence, showed an impaired ability in internalization of epithelioma papulosum cyprinid (EPC) cells and a comparatively poor ability of proliferation in vivo, which was in line with the increased LD₅₀ value. These results indicated that waaL gene was a functional member of the gene cluster involved in LPS synthesis and highlighted the importance of the O-antigen side chains to stress adaption and virulence in E. tarda, signifying the gene as a potential target for live attenuated vaccine against this bacterium.     

Structure elucidation of the O-antigen of <Emphasis Type="Italic">Salmonella enterica</Emphasis> O51 and its structural and genetic relation to the O-antigen of <Emphasis Type="Italic">Escherichia coli</Emphasis> O23

The O-polysaccharide (O-antigen) of Salmonella enterica O51 was isolated by mild acid degradation of the lipopolysaccharide and its structure was established using sugar analysis and NMR spectroscopy. The O-antigen of Escherichia coli O23, whose structure was elucidated earlier, possesses a similar structure and differs only in the presence of an additional lateral α-D-Glcp residue at position 6 of the GlcNAc residue in the main chain. Sequencing of the O-antigen gene clusters of S. enterica O51 and E. coli O23 revealed the same genes with a high-level similarity. By comparison with opened gene databases, all genes expected for the synthesis of the common structure of the two O-antigens were assigned functions. It is suggested that the gene clusters of both bacteria originated from a common ancestor, whereas the O-antigen modification in E. coli O23, which, most probably, is induced by prophage genes outside the gene cluster, could be introduced after the species divergence.     

Enhancement of growth and antibiotic titre inCephalosporium acremonium induced by sesame oil

The role of sesame oil as part of the carbon source on growth and cephalosporin C production byCephalosporium acremonium was studied in shake-flask fermentation. The growth and antibiotic production were maximum on the fifth and sixth day, respectively, irrespective of the presence of sesame oil. Sesame oil enhanced cephalosporin C production by 54%. Analysis of fatty acid profile indicated that C_18∶1, C_18∶2 and C_18∶3 are the major fatty acids inC. acremonium. The percentage of C_18∶2 was higher in the culture grown with sesame oil.     

Laboratory-scale production of lignin-degrading enzymes by free and entrapped cells ofPhanerochœte chrysosporium in a tubular air-lift bioreactor

The production of lignin-degrading enzymes by free and entrapped cells ofPhanerochœte chrysosporium in a tubular air-lift bioreactor was studied. Under optimized cultural conditions the production of lignin peroxidase by free cells, calcium-alginate-entrapped cells and scouring-mesh-entrapped cells was in a ratio of 520∶720∶950 mU/mL, while the production of manganese peroxidase was in a ratio of 350∶480∶620 mU/mL. The stability of the entrapped cells by fed-batch systems was highest after 3 feeding experiments which is similarly demonstrated in the repeated use of the preparations in batch system.     

Predation on eggs and larvae ofHeliothis virescens [Lep.: Noctuidae] by an adult predator complex in cage studies on cotton

Predation by a predator complex consisting of adults of the lygaeidGeocoris punctipes (Say), the nabidsNabis roseipennis Reuter and/orTropiconabis capsiformis Germar and the coccinelids,Hippodamia convergens Guerin-Meneville andColeomegilla maculata (DeGeer) onHeliothis virescens (F.) eggs, 1st-instar larvae or both on late pinhead square and early bloom stage cotton was evaluated in field cages in Mississippi. Prey densities of 4 (11, 512/ha) or 8 per cage and predator: prey (P:p) ratios of 1∶1, 2∶1, 3∶1, 4∶1 and 5∶1 were used. Prey were labeled with phosphorus-32 or carbon-14 to determine predator ingestion and effectiveness. Average percent egg predation as a function of P:p ratio ranged from 2.1 to 12.1 for a 48 h period. The average percent predation on larvae as a function of P:p ratio ranged from 5.3 to 22.0. The hemiptera fed more than the coleoptera on larvae, andG. punctipes was the best egg predator. For the range of predator densities used, the average area of discovery for the predator complex was 6.98 × 10⁻³ m/day and 2.34 × 10⁻² m/day when exposed to eggs and larvae, respectively. Publication N^o 5936-Mississippi Agricultural and Forestry Experiment Station, Mississippi State, MS 39762.     

The significance of blends of two sex pheromone components on the behavior of maleSpodoptera litura F. (Lepidoptera: Noctuidae)

Behavioral responses of maleSpodoptera litura to the female sex pheromone components, (Z, E)-9, 11-tetradecadienyl acetate (compound A) and (Z, E)-9, 12-tetradecadienyl acetate (compound B), and mixtures of compounds A and B were analyzed in the laboratory. Male orientation flight in a wind tunnel was induced by a lure dispenser onto which 1.1×10⁻³ ng of a mixture (A∶B=10∶1) was absorbed, while 1 ng of compound A was required to induced the same level of behavior. The blend ratio was important for trap catch and orientation flight of males and a 10∶1 mixture of compounds A and B was most effective. A mixture (10∶1) was more effective than compound A alone in induction of movement, walking, and flying in resting males in a glass tube. These results indicated that 2 sex pheromone components act as a set from the initial to final steps of male attraction to female.     

Effect of metabolites ofAspergillus niger andTrichoderma viride on development and structure of radicle of cocoa (Theobroma cacao) seedlings

Both the volume and concentration of filtrate ofAspergillus niger andTrichoderma viride influenced the development of the radicles of cocoa seedlings. Radicles placed in Petri dishes containing filter paper moistened with 20 and 30 ml of undiluted filtrate and filtrate dilutions of 1∶1 and 1∶2 failed to develop lateral roots and eventually died. The culture filtrate ofA. niger was more repressive. Radicles in the same volume of filtrate (20 and 30 ml) of higher dilutions (1∶5 and 1∶10) developed lateral roots and survived. Radicles placed in less volume (≤10 ml) survived and produced lateral roots irrespective of concentration of filtrates. Development of the radicles and roots in the control was consistently better (P=0.05) than in filtrate solutions of eitherA. niger orT. viride. The hypocotyls of seedlings under the influence of metabolites ofA niger showed greater cambial activity and formed xylem vessels and tracheids with larger lumina.     

Viability and formation of conjugated dienes in plasma membrane lipids of Saccharomyces cerevisiae,Schizosaccharomyces pombe,Rhodotorula glutinis and Candida albicans exposed to hydrophilic,amphiphilic and hydrophobic pro-oxidants

Effects of four lipid peroxidation-inducing pro-oxidants-amphiphilictert-butyl hydroperoxide (TBHP), hydrophobic 1,1′-azobis(4-cyclohexanecarbonitrile) (ACHN), hydrophilic Fe¹¹ and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-on cell growth and on generation of peroxidation products in isolated plasma membrane lipids were determined in four yeast species (S. cerevisiae, S. pombe, R. glutinis andC. albicans) differing in their plasma membrane lipid composition. TBHP and ACHN inhibited cell growth most strongly, Fe¹¹ and AAPH exerted inhibitory action for about 2 h, with subsequent cell growth resumption.S. cerevisiae strain SP4 was doped during growth with unsaturated linoleic (18∶2) and linolenic (18∶3) acids to change its resistance to lipid peroxidation. Its plasma membranes then contained some 30% of these acids as compared with some 1.3% of 18∶2 acid found in undopedS. cerevisiae, while the content of (16∶1) and (18∶1) acids was lower than in undopedS. cerevisiae. The presence of linoleic and linolenic acids inS. cerevisiae cells lowered cell survival and increased the sensitivity to pro-oxidants. Peroxidationgenerated conjugated dienes (CD) were measured in pure TBHP- and ACHN-exposed fatty acids used as standards. The CD level depended on the extent of unsaturation and the pro-oxidant used. The TBHP-induced CD production in a mixture of oleic acid and its ester was somewhat lower than in free acid and ester alone. In lipids isolated from the yeast plasma membranes, the CD production was time-dependent and decreased after a 5–15-min pro-oxidant exposure. ACHN was less active than TBHP. The most oxidizable were lipids fromS. cerevisiae plasma membranes doped with linoleic and linolenic acids and fromC. albicans with indigenous linolenic acid.     

Interspecific competition and coexistence of the two chrysomelids,Gastrophysa atrocyanea motschulsky andGalerucella vittaticollis baly (Coleoptera: Chrysomelidae), under limited food resource conditions

Field experiments were conducted in order to investigate the mode of exploitation of food resources and the mechanism of coexistence of mixed larval populations of the two chrysomelids,Gastrophysa atrocyanea andGalerucella vittaticollis, under limited food resource conditions. The larval survival rates seemed high enough to assure coexistence when hatchlings of the two species were released in 1∶1 and 1∶3 ratios on a host plant. However, the survival rate became almost nil for both species when a 3∶1 ratio was employed, suggesting asymmetrical interspecific competition. Wasted food consumption was much higher inG. atrocyanea larvae. The population ofG. atrocyanea seemed to be regulated more by intraspecific competition, while on the other hand, the population ofG. vittaticollis was considered to be more likely affected by the interspecific competition withG. atrocyanea, depending on the initial ratio and density of the two species.     

Characterization of a novel lipopolysaccharide biosurfactant fromKlebsiella oxitoca

The chemical, physical, and emulsifying properties of BSF-1, which is an extracellular lipopolysaccharide biosurfactant produced byKlebsiella oxytoca strain BSF-1, were studied. BSF-1 was found to be composed mainly of carbohydrate and fatty acids. The average molecular weight was 1,700–2,000 kDa. The polysaccharide fraction containedl-rhamnose,d-galactose,d-glucose, andd-glucuronic acid at a molar ratio of 3∶1∶1∶1. The fatty acid content was 1.1% (w/w) and consisted mainly of palmitic acid (C16∶0), 3-hydroxylauric acid (3-OH-C12∶0), and lauric acid (C12∶0). In terms of thermal properties, BSF-1 was revealed to have inter- and intra-molecular hydrogen bonds. The hydrodynamic volume (intrinsic viscosity) of BSF-1 was 22.8 dL/g. BSF-1 could be maintained as a stable emulsion for 48 h through a low-level reduction in surface tension. The optimal emulsification temperature was 30°C. Emulsification by BSF-1 was efficient at both acidic and neutral pH values.     

Sex ratios of adultScymnodes lividigaster andLeptothea galbula [Col.: Coccinellidae], sampled in the field

A 3 year field study ofScymnodes lividigaster (Mulsant) adults near Sydney indicated sex ratios close to 50∶50, ♀∶♂. Ratios deviated between samples collected in various periods of year and in individual years. Deviation was related to collecting methods, environmental conditions and behaviour of sexes in different developmental phases. SamplingLeptothea galbula (Mulsant) in 2 different habitats indicated all sex ratios biased towards ♀; ratios apparently not related to collecting methods and with little seasonality. In laboratory sex ratios ofL. galbula were close to 50∶50.

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Résumé Trois années d'étude deScymnodes lividigaster (Mulsant) dans les conditions naturelles près de Sydney ont montré que la proportion des sexes était 50∶50. Les proportions varient selon les échantillons prélevés à différentes périodes de l'année et suivant les années. Les variations dépendent des méthodes de prélèvement, des conditions de milieu et du comportement des sexes aux différentes étapes de leur développement. L'échantillonnage deLeptothea galbula (Mulsant) dans 2 habitats différents a mis en évidence des proportions des sexes favorables aux femelles, sans relation apparente avec les méthodes de collecte et avec peu de dépendance avec la saison. Au laboratoire la proportion de sexes deL. galbula était voisine de 50∶50.

     

Fatty acids compositions of polar and non-polar lipid fractions of wheat leaves inoculated with three brown rust races during progressive pathogenesis

The fatty acids composition of the polar and non-polar lipid fractions of wheat leaves was affected due to progressive brown rust infection during early stages of pathogenesis,i.e. 0, 12, 24, 36, 48 and 72 h after inoculation. The three races ofPuccinia recondita differentially affected the composition of saturated and unsaturated fatty acids and their relative occurrence in wheat leaves. The infection of wheat by race 77 resulted in a relative decrease in fatty acid chain length as measured through C₁₆∶C₁₈ fatty acid ratio. An increase in the relative degree of unsaturation (18∶2/18∶3 acids ratio) was recorded in both lipid fractions. Such changes may be taken as one of the earliest characteristics of disease development.