Chemical Nature of Phagostimulants in Pollen Attractive to Honeybees

Honey bees display a powerful ability to recognize pollen from most plants as food and non-pollen materials as not being food. We sequentially extracted a mixed species blend of pollen with a range of non polar to polar solvents and tested the extracts for attractiveness and feeding enhancement by young bees. Both non polar and polar materials were independently attractive when added in trace quantities to a plain artificial diet. The attractants have little inherent nutritional value, as addition of phagostimulants to artificial diets did not increase the life spans of bees compared to phagostimulant-free diets. These data indicate that pollen phagostimulants consist not of a single or a few specific compounds, but rather are a suite of diverse components that additively or synergistically serve to exceed a threshold level of stimulation necessary for feeding.     

Contribution of symbiotic mycangial fungi to larval nutrition of a leaf-rolling weevil

Some phytophagous insects have been known to inoculate certain fungi on plant substrates. In many cases of such insect–fungi relationships it has been considered that fungi contribute to insects by decomposing lignin or polysaccharides, and that the insects feed on the decomposition products or fungi themselves. Females of the leaf-rolling weevil in the genus Euops (Attelabidae) store spores of symbiotic fungi in the mycangia and inoculate them on leaf rolls. To determine the effect of mycangial fungi on larval nutrition in E. lespedezae, the nutritional value was compared between leaves with and without mycangial fungi. Two Penicillium species were isolated from the mycangia. These mycangial fungi showed little effect on the decomposition of lignin and polysaccharides, and showed little effect on enhancement of soluble sugars within leaves. Thus, the mutualism between Euops and its mycangial fungi contrasts with the mainly nutritional mutualisms between wood-infesting insects (termites, bark/ambrosia beetles, and wood wasps) and lignin/polysaccharide-decomposing fungi.     

Genetic Variation in Hippophae rhamnoides ssp. sinensis (Elaeagnaceae) Revealed by RAPD Markers

Hippophae rhamnoides ssp. sinensis is endemic to China, and it is a dioecious, outcrossing plant. Although many studies have been undertaken mainly on its agricultural, nutritional, medical, and ornamental value, little is known about its population genetics. This study uses random amplified polymorphic DNA to investigate the genetic diversity and population genetic structure of 13 natural populations of the subspecies sinensis. Fifteen primers amplified 107 reproducible bands, with 95 (88.79%) being polymorphic. The gene diversity within population was 0.168, considerably lower than that of tree species and most perennial, outcrossing species, but higher than that of annual or short-lived, selfing species. The Gst value showed that 18.3% of the total genetic variation resided among populations, a little lower than that of outcrossing species. The present results are quite similar to those previously reported in another subspecies, H ssp. . rhamnoides rhamnoides. The low genetic differentiation among populations in ssp. sinensis may be attributed to the long-distance dispersal of seeds facilitated by birds, in addition to its characteristics of outcrossing, wind pollination, and widespread distribution. No association between genetic distance and geographical distribution was found. The population relationships revealed by the UPGMA dendrogram parallel this result, in that genetic distance did not increase with geographic separation. This pattern of population differentiation may imply the adaptation of ssp. s populations to the local environment, given that its habitats vary greatly across its distribution.     

Developmental response of <Emphasis Type="Italic">Euplectrus comstockii</Emphasis> to ascorbic acid in the diet of the larval host, <Emphasis Type="Italic">Heliothis virescens</Emphasis>

Recent developments in genetic engineering have paved the way for researchers to produce crops of high nutritional and yield value, in addition to being resistant to diseases and pests. Ascorbic acid content is one of the parameters researchers are trying to enhance in plants. This study investigated the effect of different levels of dietary ascorbic acid of a beneficial wasp, Euplectrus comstockii Howard (Hymenoptera: Eulophidae), by measuring life history parameters of the wasp when reared on lepidopteran larvae fed a basal diet containing low and high levels of ascorbic acid. Odds and odds ratio analyses showed that the probability of egg hatch and adult emergence for the wasp increased with the amount of ascorbic acid in the diet of the host, and that the rate of development and probability of female or male progeny was similar for most levels of ascorbic acid tested. This would indicate that as the ascorbic acid concentration increases in the pest insect the effectiveness of the wasp is likely to increase and when, by comparison with other published findings, the effectiveness of microbial pathogens is likely to decrease.     

Microalgal feeds for aquaculture

The concurrent trends of increasing consumption of seafood and decreasing natural harvests will dictate that a larger portion of seafood must be derived from aquaculture in the 21st century. The difficulty of producing economically large quantities of microalgal feeds is currently one of the major impediments to the further development of the aquaculture industry. Traditional methods, which rely on photosynthetic growth in outdoor ponds or indoors under artificial lights, suffer from the phenomenon of light-limitation of biomass density. Certain species of microalgae are capable of heterotrophic growth to high density utilizing sugars or other organic compounds for energy and cell carbon. This paper reviews work with strains of heterotrophic algae that have demonstrated potential as both nutritional feeds and for economical production by fermentation.     

Selecting zinc-efficient cereal genotypes for soils of low zinc status

Deficiencies of zinc are well known in all cereals and cereal-growing countries. From physiological evidence reported elsewhere, it would appear that a critical level for zinc is required in the soil before roots will either grow into it or function effectively; it is likely the requirement is frequently not met in deep sandy, infertile profiles widespread in southern Australia. Because fertilizing subsoils is impractical, this paper presents arguments for breeding cereal varieties with root systems better able to mobilise zinc from soil sources of low availability. Other agronomic arguments are presented in support of breeding for zinc efficiency.Significant genetic variation for this character is described for wheat, barley and oats. Linkage to other efficiency traits (e.g., manganese) is poor suggesting independent mechanisms and genetic control not linked to gross root system geometry. Zinc efficiency traits for sandy and clayey soils appear to be genetically different. Zinc-efficient genotypes absorb more zinc from deficient soils, produce more dry matter and more grain yield but do not necessarily have the highest zinc concentrations in tissue or grain. Although high grain zinc concentration also appears to be under genetic control, it is not tightly linked to agronomic zinc efficiency traits and may have to be selected for independently. High grain zinc is considered a desirable quality factor which not only contributes to the seedling vigour of the next generation but could increase the nutritional value of the grain in areas where a high dependence on grains for food may result in zinc deficiency in humans.     

Composition and Nutritional Characteristics of Fungi Consumed by Callimico goeldii in Pando, Bolivia

Though ≥22 species of Primates consume fungi, most do so at low rates, comprising <5% of their feeding time. Goeldi's monkeys (Callimico goeldii), spend up to 29% of their feeding time year-round consuming fungal sporocarps, the fruiting bodies of fungi. We provide comprehensive data on the nutritional characteristics of 4 species of fungi consumed by Callimico goeldii (Ascopolyporus polyporoides, Ascopolyporus polychrous, Auricularia auricula, and Auricularia delicata). The composition of the fungi is similar to that of other fungi: predominantly fiber (66.2–83.0% dry matter) with small amounts of sugar (2.0–5.6% dry matter) and crude fat (0.9–1.6% dry matter). Though the crude protein content is substantial (5.5–13.4% dry matter), much of the nitrogen in the fungi is not likely to be available to Callimico goeldii because it is associated with indigestible food components or is in nonprotein form. The mineral content of the fungi are within the normal range for fungi generally and the calcium-to-phosphorus ratio is low (0.07–0.25). Fungi appear to be a low-quality food resource for Callimico goeldii and may contribute to their relatively large home ranges and low population density compared to other Callitrichinae. Research on the ability of Callimico goeldii to digest fungi is needed to understand fully the nutritional value of fungi to them. We discuss adaptations Callimico goeldii may have for improving their ability to obtain nutrients from fungi and potential ecological correlates of mycophagy.     

Prospects for a bio-based succinate industry

Bio-based succinate is receiving increasing attention as a potential intermediary feedstock for replacing a large petrochemical-based bulk chemical market. The prospective economical and environmental benefits of a bio-based succinate industry have motivated research and development of succinate-producing organisms. Bio-based succinate is still faced with the challenge of becoming cost competitive against petrochemical-based alternatives. High succinate concentrations must be produced at high rates, with little or no by-products to most efficiently use substrates and to simplify purification procedures. Herein are described the current prospects for a bio-based succinate industry, with emphasis on specific bacteria that show the greatest promise for industrial succinate production. The succinate-producing characteristics and the metabolic pathway used by each bacterial species are described, and the advantages and disadvantages of each bacterial system are discussed.     

Microbiological Characteristics of Medically Important <Emphasis Type="Italic">Trichosporon</Emphasis> Species

Trichosporon species are opportunistic pathogens associated with a high mortality rate in immunocompromised patients. Disseminated trichosporonosis is uncommon but reports are increasing. In this study, using 16 stock clinical isolates of suspected Trichosporon species and 4 known Trichosporon strains, we investigated the morphology, physio-biochemistry, molecular biology and antifungal susceptibility characteristics of these Trichosporon spp. and discovered that ITS sequence-based identification is a rapid and accurate identification alternative to most phenotypic or physio- biochemical methods. In vitro antifungal susceptibility tests showed high amphotericin B, itraconazole and terbinafine MIC value in these Trichosporon strains.     

Sporulation ofStreptomyces roseosporus in submerged culture

Summary A soil isolate ofStreptomyces roseosporus was found to produce spores in stirred submerged culture. Both biological mass and respiratory activity increased during the sporulation process. Contrary to other reports, the differentiation process was not purposefully initiated by critical manipulation of either nutritional or environmental conditions.     

Biotechnology and aquaculture of rotifers

Biotechnology can be defined as any technology that involves living organisms or their derivatives. In applying this definition to rotifers, we focus on their contribution in culturing of early larval stages of marine fish. After almost four decades of marine fish culture in captivity, the success of this worldwide industry is still quite dependent on mass culture of the species Brachionus plicatilis and B. rotundiformis. In mass culture, the rotifers are continuously driven to reproduce at high rates, in relatively extreme environmental conditions of high population density and high loads of organic matter. Therefore, the success of mass cultures and future improvements in these systems relies on a close interaction between basic and applied studies of rotifers. In the present review, we will attempt to analyze why rotifers are suitable for early life stages of fish and to describe, in general, methodologies that have been devised for reliable supply of rotifers in large quantities. Problems associated with rotifer production, nutritional quality and effect on fish health and nutrition, will be discussed. Research on B. plicatilis and B. rotundiformis has increased enormously during the past three decades and these two species are the best-studied rotifers so far. While much of the research on these species is directed or devoted to the needs of aquaculture industry, they are also used as models for addressing basic biological questions, due to the relative ease of culture and their availability. Studies on feeding, pheromones, speciation in rotifers, the occurrence and putative hormones involved in sexual and asexual reproduction and production of resting eggs, are few examples of such studies. Rotifers will probably maintain their role as food organism for fish larvae, in spite of attempts to replace them with more accessible formulated food. Development of new culture methods that will improve the nutritional quality and production efficiency of rotifers may result in more diversified and flexible tasks for these organisms in aquaculture.     

The first approach towards recognising allergy-provoking flora in Belluno and its relationship with allergic phenomena

Summary The town of Belluno has a high number of wild and cultivated plants whose pollen has various degrees of importance from an allergological point of view.In this preliminary study we have taken into consideration the distribution and the flowering period of these species, correlating them with the data on the quantity and type of pollen collected by a sampler placed on the roof of the City Hospital, and also with the results of the allergometric tests (Prick Tests) carried out in the Broncho-Pneumological Department during the first 9 months of 1990.The wild specis of spring-flowering trees which can be found in the woods surrounding the city (Fagaceae, Betulaceae, Corylaceae) and along the gravel banks of the Piave river (Salicaceae) as well as the Graminaceae which are widespread both in the urban area and in the fields outside the city and some cultivated species (Robinia, Tilia, Acer) which flower a little later, are the species which produce most pollen and which are held responsible for allergies. However, only the pollen of the Graminaceae gave rise to cases of mono-sensitivity (16%) (apart from one case of Betulaceae and Corylaceae and one case ofArtemisia as well asDermatophagoides) (9.7%). For the other species, the positive reactions were associated with the positive reactions to the pollen of other species belonging to different families and/or to other factors.     

Betalains in the era of global agri-food science, technology and nutritional health

Natural pigments from plants are of growing interest as substitutes for synthetic dyes in the food and pharmaceutical industry and they increase their added value if they possess positive effects on health. These pigments can be added as such if they are in the legal authorized lists of additives or can be added as phytochemical-enriched plant extract achieving the original product, which has received it, the new nomenclature of functional food. In this way, we comprise on this review a wide point of view of a group of natural pigments known as betalains. From a chemical point of view, betalains are ammonium conjugates of betalamic acid with cyclo-DOPA (betacyanins, violet) and aminoacids or amines (betaxanthins, orange or yellow), which are compounds present in our diet. Besides and taking into account that one type of betalain, betanin is approved as food colorant (E-162) by the European Union and that enlarges the specific weight of these compounds in the diet, we have evolved an overview from the biosynthesis, technology and promoting production, industrial uses as pigments up to physiological and nutritional biovailability or biological and health-promoting properties of betalains for accessible information to industrials, researchers and consumers.     

Airborne Pollen and Fungal Spores in Florist Shops in Worcester and in Bristol, UK: A Potential Problem for Occupational Health

Persistent allergies are common in workers in florist shops but little research has been done on the reasons for this. This paper reports an investigation of occupational exposure of florists to pollen and spores in three florist shops over a 2-week period in the autumn of 2000. In each shop three sampling methods were used: Burkard continuous volumetric samplers, deposition plates and low-tac tape for surface samples, including hands of the florists and leaves of a selection of the plants. The florists kept a record of the type of work they undertook each day and of the stock amounts of flowers in the shops. The volumetric traps collected 80 pollen and spore taxa. The average concentrations recorded through the working day were generally low but short-term peak (one hour mean) concentrations of some types were found to be relatively high or very high. For a few taxa these concentrations equalled or exceeded those typical for short-term peaks in wind dispersed pollen types in the ambient air. Fungal spore concentrations of several known allergenic types were also very high for peak periods. This was most notable for Aspergillus spp. which reached extremely high concentrations in one shop, compared with typical peak concentrations in the ambient atmosphere. Low-tac tape leaf samples demonstrated that the flowers' foliage is a major source of the fungal spores. Few pollen grains or fungal spores were found on the hands.     

Nutritional consequences of the transformation from subsistence to commercial agriculture in Tabasco,Mexico

Recent changes in the area of the Plan Chontalpa in Tabasco have greatly reduced the production of subsistence crops by rural families, resulting in decreased crop diversity and a concomitant increase in the degree of dependence on outside sources of food. Results from a nutrition survey of 149 families demonstrate that dietary diversity, dietary quality, and nutritional status of preschool children are negatively associated with lower crop diversity and increased dependence on purchased foods. Dietary deterioration is illustrated by the negative relationship found between nutritional status and increased sugar consumption. The assumption that a rise in income accompanying the adoption of commercial production will automatically lead to improved nutrition is challenged: income levels were not found to be consistently related to nutritional status. Children of families that have converted to cattle production, despite greater land availability and family incomes, do not have improved nutritional status. In the study area, where wages are low and food prices are very high, the value of a higher degree of self-sufficiency in food is recognized, yet families continue to switch to cash crops due to the environmental, economic, and time constraints imposed by the system of commercial agriculture in which they participate. The solution is not to return to traditional subsistence farming, however, but to determine under what conditions a more progressive form of agricultural change can occur.     

The spatial and temporal concentrations of choline in the lumen contents of the small intestine of uninfected and Hymenolepis diminuta infected rats

The spatial and temporal concentrations of free choline in the lumen of the small intestine of the uninfected and Hymenolepis diminuta-infected rat were investigated. In the unfed infected or uninfected rat, the choline concentrations ranged from approximately 500 microM in the duodenum to approximately 20 microM in the posterior ileum, with some segments in infected rats containing significantly higher choline levels than in uninfected rats. Following feeding, choline levels were significantly elevated to approximately 3 mM by 6 h, although these concentrations fell rapidly in transit down the intestine. By 12 h the choline levels were similar to those in the unfed rat. An initial small shift in the worm biomass toward the duodenum after feeding was followed by a redistribution of biomass along the length of the small intestine. The worm biomass, however, had little or no effect on the choline levels. The high concentrations of free choline observed in the anterior regions of the intestine are postulated to be predominantly determined by nutritional intake while the concentrations in the posterior region may in part be determined by blood choline levels. The high levels of choline indicate that choline is not limiting to support the growth of the worms.     

Gorillas (Gorilla gorilla gorilla) in the Likouala swamp forests of north central Congo: Preliminary data on populations and ecology

Until recently it was generally believed that gorillas avoid water. In two recent, independent faunal surveys in the Likouala swamp of north central Congo, we have found that gorillas occur at high densities, extending the known range of Gorilla gorilla gorillavery close to the Oubangui River. The gorillas in this area fed on the abundant ground vegetation of herbaceous monocotyledons in the swamp forest. In adjacent islands of terra firmathere was little evidence of gorilla nesting or feeding, indicating that they spend at least part of the year almost exclusively in the swamp forests. Recent reports from several sites in West Africa indicate that swamp forests may generally provide abundant food resources that are used regularly by gorillas.     

The impacts of vascular wilt disease of the takamaka tree Calophyllum inophyllum on conservation value of islands in the granite Seychelles

The takamaka tree Calophyllum inophyllum is animportant component of indigenous coastal forests in the granitic Seychelles,found on most islands of the archipelago. In 1994, a fungal pathogen previouslyunrecorded in the Seychelles (Leptographium calophylli) wasdetected on takamaka. Since the first cases of the disease were observed, spreadof the disease has been rapid, both within and between islands. Attempts tocontrol the disease, involving both legislation and forest management, appear tohave had little impact in controlling the spread. In the six yearssince the disease was first recorded in the Seychelles, it has reached10 islands, including most of the large islands of the archipelago. Mortality ratesand rates of spread between trees appear to vary in different islands andsituations, but in some cases both appear to be high. This paper describes thedistribution of the disease in the granitic Seychelles six yearsafter it was first recorded, reviews the potential impact of the disease onconservation value and discusses management strategies to minimise the impact ofthe disease on endemic vertebrates.     

稀有稻种长毛谷的民族植物学及营养成分研究

长毛谷(Changmaogu/Oryza sativa)是云南省兰坪白族普米族自治县白族支系拉玛人传统栽植的一个特有的有色稻种，是我国农家品种的典型代表，处于稀有濒危状态，但对该品种的研究较少。为促进长毛谷保护及可持续利用，该研究利用民族植物学及营养学的方法，对兰坪当地有关长毛谷品质特征、传统知识与文化、开发利用现状及存在的问题进行了调查和分析，并测定稀有农家品种长毛谷的营养成分，与普通常见稻种的营养成分进行对比，探究长毛谷的营养价值。结果表明：(1)长毛谷产地的白族支系拉玛人积累了丰富的关于长毛谷的传统知识和文化，包括传统耕作知识、相关历史典故、传统食用知识和种子的交换及保存文化。(2)长毛谷具有高含量的可利用碳水化合物、水分、灰分、总膳食纤维和花青素且含有一定量的原花青素，表明长毛谷具有较高的营养保健价值。综上认为，长毛谷的原生境保护模式可为其他农家品种的保护提供科学参考，有利于长毛谷等农家品种的可持续利用。