Plasmodium gallinaceum: development in Aedes aegypti maintained on various carbohydrate diets

Fructose, galactose, glucose, maltose, melibiose, and trehalose were evaluated for their nutritional and survival values for Aedes aegypti. The development of the exogenous stages of Plasmodium gallinaceum was evaluated by counting and averaging the number of oocysts developing on the midguts of Aedes aegypti.The nutritional and survival value for A. aegypti was greatest on glucose, sucrose, and fructose and lowest on galactose and melibiose. Mosquitoes maintained on fructose produced the greatest numbers of oocysts. Only two other sugars, galactose and melibiose produced more oocysts than their respective controls. Glucose and maltose, both of which had high nutritive and survival value for A. aegypti were less efficient than the control (sucrose) for the development of P. gallinaceum.     

Feeding responses by female Pieris brassicae butterflies to carbohydrates and amino acids

Most Lepidoptera feed during the adult stage on carbohydrate‐rich food sources, primarily floral nectar. However, little is known about the factors leading to the acceptance of a possible food source. It is reported that butterflies select for nectar rich in sucrose and amino acids. This suggests that the insects have developed a sensitivity to these nectar compounds. We tested females of the large cabbage white, Pieris brassicae L. (Lepidoptera: Pieridae) for their responses to 10 different nectar‐ or honeydew‐sugars after either tarsal or proboscis stimulation. In no‐choice experiments, food‐deprived P. brassicae showed the strongest response to sucrose, followed by fructose. Other sugars, including galactose, glucose, maltose, mannose, melezitose, melibiose, raffinose and trehalose, did not elicit a feeding response. Mixtures of essential or common non‐essential amino acids did not stimulate feeding. In a choice situation, P. brassicae preferred sucrose over fructose, whereas they accepted a sucrose and amino acid solution equally to a plain sucrose solution. The results indicate that for P. brassicae, feeding is mainly elicited by sucrose and fructose.     

The effects of various carbohydrate diets on Aedes aegypti infected with Dirofilaria immitis.

Aedes aegypti infected with Dirofilaria immitis and uninfected mosquitoes were maintained on various carbohydrate diets (glucose, galactose, fructose, sucrose, trehalose, maltose, and melibiose). The value of each of these sugars in supporting survival of adult A. aegypti, and in supporting egg production, viability of eggs, and development of third-stage larvae of D. immitis in A. aegypti was analyzed. Fructose, glucose, maltose, sucrose, and trehalose provided the strongest support for survival of adult male, and infected and uninfected adult female A. aegypti. Galactose and melibiose provided the least support for survival of all groups of mosquitoes. The mean number of eggs laid per uninfected adult female A. aegypti was greatest when mosquitoes were maintained on glucose, melibiose, maltose, fructose, sucrose, and trehalose. The same was true for female mosquitoes infected with D. immitis; except for melibiose which provided poor support for egg production. In both Dirofilaria-infected and in uninfected mosquitoes, galactose supported the production of low mean numbers of eggs per adult female A. aegypti. High percentages of eggs laid by uninfected and by infected female mosquitoes fed glucose, melibiose, maltose, sucrose, and trehalose hatched. While galactose supported a high percentage of hatching in eggs laid by uninfected A. aegypti, a much lower percentage of eggs laid by infected female mosquitoes maintained on this same carbohydrate hatched. The lowest percentages of eggs that hatched were from among those laid by infected and by uninfected females fed fructose. The highest mean number of D. immitis larvae (L₃) were recovered from adult A. aegypti fed glucose, maltose, fructose, and sucrose; the second best sugar in this regard was trehalose. The lowest mean number of D. immitis larvae were isolated from female A. aegypti fed galactose and melibiose.     

Aphid–ant mutualism: how honeydew sugars influence the behaviour of ant scouts

Honeydew is the keystone on which ant–aphid mutualism is built. The present study investigates how each sugar identified in Aphis fabae Scopoli honeydew acts upon the feeding and the laying of a recruitment trail by scouts of the aphid‐tending ant Lasius niger Linnaeus, and thus may enhance collective exploitation by the ant mutualists. The feeding preferences shown by L. niger for honeydew sugars are: melezitose = sucrose = raffinose > glucose = fructose > maltose = trehalose = melibiose = xylose. Although feeding is a prerequisite to the launching of trail recruitment, the reverse is not necessarily true: not all ingested sugar solutions elicit a trail‐laying behaviour among fed scouts. Trail mark laying is only triggered by raffinose, sucrose or melezitose, with the latter sugar being specific to honeydew. By comparing gustatory and recruitment responses of ant foragers to sugar food sources, the present study clarifies the role of honeydew composition both as a source of energy and as a mediator in ant–aphid interactions. Lasius niger feeding preferences can be related to the physiological suitability of each sugar (i.e. their detection by gustatory receptors as well as their ability to be digested and converted into energy). Regarding recruitment, the aphid‐synthesized oligosaccharide (melezitose) could be used by ant scouts as a cue indicative of a long‐lasting productive resource that is worthy of collective exploitation and defence against competitors or aphid predators.     

Sugar convertibility in the parasitoid Cotesia glomerata (Hymenoptera: Braconidae)

Lack of suitable sugar sources for adult parasitic wasps is an important cause of failure in biological control programs, but the metabolic constraints of sugar feeding are poorly understood. Here we investigated the suitability of 11 naturally occurring sugars as energy sources for the parasitoid Cotesia glomerata (L.) (Hymenoptera: Braconidae). By feeding energy-deprived individuals with given quantities of a 40% (w:w) sugar solution, we assessed recovery time and lifespan after feeding. More than 50% of the wasps recovered within 20 min, and at least 80% within 60 min after uptake of one of the monosaccharides fructose or glucose, the disaccharide sucrose, or the trisaccharide melezitose. Between 40 to 80% of the test insects recovered within an hour after intake of maltose, raffinose, galactose, or mannose. Less than 25% recovered within 1 h after uptake of melibiose, trehalose, rhamnose, or water (control). Parasitoids obtained the highest lifespan benefits after intake of glucose, fructose, sucrose, or melezitose, indicating and confirming their convertibility as an energy source for C. glomerata. In contrast, no lifespan increase was found after consumption of rhamnose and trehalose. The differences in recovery time and lifespan are discussed in terms of parasitoid enzyme activity and metabolic processes.     

Sugar best single chorda tympani nerve fiber responses to various sugar stimuli in rat and hamster

1. Sugar best single chorda tympani nerve fiber of rat and hamster were tested with six sugars. 2. Fibers were selected for this experiment, only if they responded to 1.0 M sucrose or 1.0 M maltose and they responded poorly to 0.1 M NaCl. 3. In rat, some single fibers gave larger responses to maltose than to sucrose, while in hamster nearly all nerve fibers responded best to sucrose. 4. The order of effectiveness of sugars was maltose greater than fructose greater than or equal to lactose greater than sucrose greater than glucose greater than galactose in rat and sucrose greater than fructose greater than or equal to glucose greater than or equal to galactose greater than maltose greater than lactose in hamster.     

A comparison of nectar- and honeydew sugars with respect to their utilization by the hymenopteran parasitoid Cotesia glomerata

Fourteen naturally occurring sugars were individually tested with respect to their effect on Cotesia glomerata longevity. Parasitoids kept with solutions of either sucrose, glucose and fructose lived for >30 days. This constitutes a factor 15 increase in life span in comparison to control individuals kept with water only. Stachyose, mannose, melezitose, melibiose, maltose and erlose increased parasitoid longevity by a factor of 11.2-6.9. Solutions of galactose and trehalose had a marginal, but still significant effect. Lactose and raffinose did not raise parasitoid longevity, while rhamnose actually reduced parasitoid survival. In an additional experiment, the relationship between quantity of sugar consumption and longevity was established for all 14 sugars. To study the effect of an unsuitable sugar in sugar mixtures, a range of glucose:rhamnose mixtures was tested. Even at 20% of the sugar mixture rhamnose suppressed the nutritional benefit of the 80% glucose. The nutritional suitability of the sugars shows a positive correlation with the previously reported gustatory response towards the individual sugars. Patterns of sugar utilization are discussed with respect to hydrolytic enzymes and carbohydrate biochemical characteristics. Our findings for C. glomerata are compared to patterns of sugar utilization reported for other species. The comparison between C. glomerata and its host Pieris brassicae reveals that the parasitoid is capable of utilizing a range of sugars that are unsuitable to its herbivorous host. This specificity opens up opportunities to select food supplements for biological control programs that selectively target the antagonist, without concurrently enhancing herbivore fitness.     

Influence of selected sugars and temperature on fatty acids composition in Candida lipolytica

Summary An investigation was made of the effects of temperature and of mono- and disaccharides on lipids, biomass, odd-chain and unsaturated fatty acids production of Candida lipolytica. With different sugars as carbon source at 30°C, the order for biomass production was: fructose > glucose > sucrose > lactose > galactose, while lipids production/g biomass decreased as follows: lactose, sucrose, galactose, fructose and glucose. On the other hand, the odd-chain fatty acids contents decreased in the following order: fructose, lactose, glucose, sucrose and galactose. Lowering the temperature of cultivation to 15°C, biomass, lipids and unsaturated fatty acids decreased. However, a notable decrease in the content of odd-chain fatty acids was detected.     

Studies on in vitro survival of Isoparorchis hypselobagri.

Adult parasites, Isoparorchis hypselobagri were maintained in vitro in four basic salt solutions, viz. Stephenson saline, AB saline, Tyrode's solution and Locke's solution. Survival was prolonged by adding sugars to Tyrode's solution. Of all the sugars, glucose was found most effective and parasites survived for 39 days in solution containing glucose, 6 days in galactose and sucrose, 10 days in fructose and lactose and 12 days in maltose. The parasites absorb carbohydrates through the cuticle. Ligated parasites survived for a longer period than unligated parasites. The pH 9 was considered as an optimum for maximum survival of the parasites Isoparorchis hypselobagri for 39 days.     

Effets des sucres sur le comportement alimentaire de Lambdina fiscellaria

Quatorze sucres (D-arabinose, L-arabinose, fructose, galactose, glucose, maltose, manose, mélézitose, mélibiose, raffinose, rhammose, sucrose, tréhalose, xylose) ont été étudiés en fonction de leur consommation, à différentes concentrations, par les stades IV et V de Lambdina fiscellaria fiscellaria Guén. Les indices de consommation mesurés varient avec la concentration de la solution sucrée, à l'exception du D-arabinose qui induit une consommation comparable (t_0.05) à 0.5 M, 0.1 M et 0.02 M et ce, pour les 2 stades. Une diminution de la consommation est parallèle à une diminution de la concentration des solutions de galactose et de xylose pour le stade IV, et de sucrose et xylose pour le stade V. La prise alimentaire la plus élevée pour le stade IV est mesurée avec le sucrose aux 3 molarités, tandis que celle du stade V est notée avec le sucrose et le glucose. L'écart entre les indices de comsommation des sucres diminue avec une baisse de la concentration de la solution sucrée pour les 2 stades, créant ainsi de nombreuses interrelations entre les sucres.

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Summary Fourteen sugars (D-arabionose, L-arabinose, fructose, galactose, glucose, maltose, mannose, melezitose, melibiose, raffinose, rhamnose, sucrose, trehalose, xylose) at different concentrations were studied with regard to consumption, by the fourth and fifth larval instars of Lambdina fiscellaria fiscellaria Guén. The consumption indices vary with the concentration of sugars, except for D-arabinose which induces comparable consumptions (t_0.05) at 0.5 M, 0.1 M and 0.02 M in both larval instars. A reduction in the consumption of sugars parallels decreases of galactose and xylose concentrations for the fourth larval instar, and sucrose and xylose concentrations for the fifth larval instar. According to food intake data, the fourth larval instar prefers sucrose while the fifth larval instar shows increased glucose responses, and even prefers glucose at 0.02 M. The differences among sugar consumption indices decrease when the sugar concentration is reduced.

     

金微菌的生理与金微素的生产Ⅲ.磷酸盐对于金微菌的醣的利用和金微素综合的影响

金霉菌 Streptomyces aureofaciens 菌株 A3能利用淀粉、葡萄糖、蔗糖、果糖为碳源,但不能利用麦芽糖、乳糖、甘露糖和山梨糖。培养基中磷酸盐浓度的增加,促进菌体对醣类的氧化和抑止金霉素的产量。一般而论磷酸盐促使淀粉或葡萄糖的氧化较大,同时亦以这二种醣类进行酦酵时,磷酸盐抑止金霉素的产量比较显著。磷酸盐对金霉素产量的影响,除因利用不同醣类酦酵而不同外,培养基的组合成分特别是有机碳氮源的含量和比率起着首要的作用。     

The impact of supplemental carbon sources on <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> growth,chlorophyll content and anthocyanin accumulation

This research explores the impacts of a broad range of supplemental carbon sources on growth and development of Arabidopsis thaliana. Parameters measured include dark-germinated hypocotyl length, light-germinated root growth, rosette growth, chlorophyll concentration and anthocyanin content. Treatment sugars include sucrose, maltose, d-glucose, d-fructose, l-arabinose, l-fucose, d-galactose, d-mannose, l-rhamnose and d-xylose each supplied at 4, 20 or 100 mM. This comparison of the effect of different carbon sources on multiple parameters and under identical conditions showed that every carbon source had unique qualitative and quantitative effects on Arabidopsis growth and development. Root growth was particularly sensitive to supplemental carbon source. Growth on 100 mM sucrose, maltose, glucose or xylose stimulated root growth by ~100%. Growth on arabinose, fucose, galactose, mannose or rhamnose inhibited root growth by 50% or more. Several sugars that strongly inhibited root growth had either no effect (galactose and fucose) or a positive effect (arabinose) on hypocotyl elongation and rosette growth. Rhamnose was the only carbon source that inhibited hypocotyl elongation across all concentrations. Sucrose, maltose, glucose, fructose, arabinose or xylose stimulated rosette growth by ~50%. Chlorophyll content was strongly reduced by mannose while sucrose, glucose, galactose and rhamnose caused smaller reductions. Anthocyanin accumulation was strongly induced by both galactose and mannose. Only mannose impacted all parameters across all concentrations. Based on these data it can be concluded that the effect of each carbon source on Arabidopsis growth and development is specific in terms of both magnitude and the parameters impacted.     

Variation in the fermentative pattern of some Saccharomyces species

Summary The acquisition of the ability to ferment galactose, maltose, sucrose, raffinose and melibiose by yeast strains of the genus Saccharomyces was investigated. During cultivation in selective media 11 strains belonging to 5 species gained the ability to ferment one or several of these sugars. De-adaptation was not usually observed after cultivation in glucose medium, indicating that the saltants are stable in this medium.     

Influence of 2-deoxy-D-glucose upon growth and invertase activity of carrot (Daucus carota L.) cell suspension cultures

Carrot (Daucus carota L.) cell suspension cultures grew well when provided with glucose, fructose, sucrose or raffinose. Galactose and melibiose supported less growth unless supplemented with glucose or fructose. In combination with ten different sugar mixtures, 2-deoxy-D-glucose (dGlc) inhibited culture growth. Inhibitory effects of dGlc were more marked with fructose, melibiose, raffinose or mixtures of these sugars in the culture medium. The presence of glucose or galactose reduced the inhibitory effects of dGlc on culture growth. Experiments with radioactive labelled sugars demonstrated that dGLc uptake was greater in the presence of fructose than glucose, and that growth inhibition of dGlc coincided with its uptake. Reduced protein content was also associated with the inhibitory effects of dGlc. Cultured cells contained lower levels of invertase (EC 3.2.1.26) activity during the active phase of culture growth (up to 25 days after subculture) than when growth had peaked and subsequently declined. Acid and alkaline invertase activities were not greatly reduced by exogenous hexoses. Invertase activity was greatest during periods of low protein content in all cultures and was inhibited by dGlc during the latter phases of the culture period. Free intracellular sugars throughout the culture period consisted mainly of glucose and fructose.     

Changes in concentrations of soluble carbohydrates during germination of <Emphasis Type="Italic">Amaranthus caudatus</Emphasis> L. seeds in relation to ethylene,gibberellin A<Subscript>3</Subscript> and methyl jasmonate

Unimbibed Amaranthus caudatus seeds were found to contain stachyose, raffinose, verbascose, sucrose, galactinol, myo-inositol, glucose and fructose, while no galactose, maltose and maltotriose was detected. During imbibition, seed concentrations of verbascose, stachyose, raffinose, galactinol, myo-inositol (temporary) and fructose (transient) were observed to decrease; concentrations of galactose and maltose remained fairly constant, while those of sucrose, glucose and maltotriose increased, the increase in sucrose concentration was only temporary. Effects of gibberellin A₃ (GA₃) at 3 × 10⁻⁴ M and ethephon at 3 × 10⁻⁴ M alone or in the presence of methyl jasmonate (Me-JA) at 10⁻³ M on concentrations of soluble sugars during germination of A. caudatus seeds were examined. Me-JA was found to inhibit seed germination and fresh weight of the seeds, but did not affect sucrose, myo-inositol, galactose and maltose concentrations during imbibition for up to 20 h. The exogenously applied GA₃ was observed to enhance germination, stachyose breakdown and glucose concentration after 20 h of incubation. Ethephon stimulated seed germination as well as utilisation of stachyose, galactinol (both after 14 and 20 h) and raffinose (after 14 h of incubation). Although the stimulatory effect of either GA₃ or ethephon on seed germination was blocked by Me-JA; these stimulators increased mobilisation of raffinose and stachyose, but only ethephon enhanced both glucose and fructose after 14 and/or 20 h of incubation in the presence of Me-JA. The maltose concentration was increased by both GA₃ and ethephon alone and in the presence of Me-JA. Of the growth regulators studied, ethephon alone and/or in combination with Me-JA significantly increased the concentrations of glucose, fructose, galactose, maltose and maltotriose. The differences in sugar metabolism appear to be linked to ethylene or GA₃ applied simultaneously with Me-JA.     

Influence of carbon source on α-amylase production by Aspergillus oryzae

The influence of the carbon source on alpha-amylase production by Aspergillus oryzae was quantified in carbon-limited chemostat cultures. The following carbon sources were investigated: maltose, maltodextrin (different chain lengths), glucose, fructose, galactose, sucrose, glycerol, mannitol and acetate. A. oryzae did not grow on galactose as the sole carbon source, but galactose was co-metabolized together with glucose. Relative to that on low glucose concentration (below 10 mg/l), productivity was found to be higher during growth on maltose and maltodextrins, whereas it was lower during growth on sucrose, fructose, glycerol, mannitol and acetate. During growth on acetate there was no production of alpha-amylase, whereas addition of small amounts of glucose resulted in alpha-amylase production. A possible induction by alpha-methyl-D-glucoside during growth on glucose was also investigated, but this compound was not found to be a better inducer of a-amylase production than glucose. The results strongly indicate that besides acting as a repressor via the CreA protein, glucose acts as an inducer.     

Utilization of oligosaccharides by three imperfect fungi

Summary The utilization of oligosaccharides (maltose, sucrose, lactose and raffinose) by three imperfect fungi viz.Alternaria tenuis Auct.,Colletotrichum capsici (Syd.)Butler &Bisby andColletotrichum gloeosporioides Penz. isolated from diseased leaves of tomato,Scindapsus pictus andPolyscias balfuriana respectively, was studied chromatographically. Except for lactose, all the sugars were utilizzed through a hydrolytic pathway and almost all proved to be a suitable source of carbon for the growth of fungi. Along with the utilization of sucrose, a simultaneous synthesis of an oligosaccharide was also observed in case of two species ofColletotrichum. C. gloeosporioides, however, also synthesized an oligosaccharide, maltotriose if it is grown in the medium containing maltose. During the utilization of raffinose, melibiose and fructose were detectted in the culture medium ofA. tenuis. Melibiose was further broken down into glucose and galactose by the two species ofColletotrichum.All the sugars were consumed from the media within 15 days except for lactose which persisted in the media even after 15 days.     

Sugars in the alimentary canal of Lutzomyia youngi (Diptera: Phlebotominae)

Abstract. Gas chromatography (GC) analysis of 159 specimens (144 females and 15 males) of Lutzomyia youngi collected in Shannon traps in a coffee plantation in the Andean region of western Venezuela, where leishmaniasis is endemic, revealed the presence of fructose, sucrose, glucose and maltose in the gut and crop of the wild sandflies. The identification of the sugars was confirmed by comparing retention times with those observed for standard sugars and those obtained from sandflies experimentally fed on known sugar solutions. Although the sandflies in nature may ingest each of the four sugars, the results suggest that it is more probable there is an invertase enzyme (glycosidase?) in the gut or crop of the sandfly which hydrolyses ingested disaccharides (e.g. sucrose) to the constituent monosaccharides (i.e. fructose and glucose). Ecological and altitudinal distributions of sandfly species may be related to the availability of specific sugar sources, with epidemiological implications. Identification of the preferred sugar could make breeding easier and would facilitate further research on Leishmania–wector relationships.     

Longevity of seven species of cactophilic Drosophila and D. melanogaster on carbohydrates

Adults of 6 species of Drosophila that use decaying prickly pear cactus (Opuntia sp.) as breeding and feeding sites were compared to each other and to D. nigrospiracula, whose host is saguaro cactus, and to the cosmopolitan D. melanogaster, in their utilization of 21 sugars for longevity (time to 50% mortality). In general, the utilization of sugars by these flies for longevity followed the pattern observed with the other insects. None of the species were able to live very long on solutions of pentoses, uronic acids, inositol, rhamnose, sorbose or the β-linked disaccharides, lactose and cellobiose. Althogh all could use glucose, fructose, sucrose, maltose and melezitose well, their life spans on galactose, mannose, trehalose and raffinose were more variable. Two of the Opuntia feeders were also tested on a number of other carbohydrates. Ribitol, mannitol, sorbitol and xylitol significantly prolonged the life of D. arizonensis but not that of D. wheeleri. Neither species lived long on solutions of arabitol, galactitol, starch, inulin or on arabogalactan.