Glycogen-lead relationship in the earthworm Dendrobaena rubida from a heavy metal site

Summary Control individuals contained no lead in the chloragocytes but high -glycogen rosette reserves. Starvation of contaminated earthworms for 4d caused a lead loss and the chloragocytes possessed fewer debris vesicles than those of unstarved worms, suggesting that the debris vesicles may be the route for at least some of the lead loss. No glycogen deposits were observed in the chloragocytes of starved or unstarved earthworms from contaminated soil. Maintenance of contaminated earthworms in potting compost caused lead losses similar to those sustained by starvation, but the chloragocyte cytoplasm possessed -glycogen reserves. Specimens maintained in lead-spiked potting compost showed lead levels similar to those of earthworms taken directly from contaminated soil. No -glycogen accumulations were observed under this enriched regime.Although the possible interference of lead in carbohydrate metabolism is discussed, the results do not wholly support metabolic inhibition by lead. It is hypothesised that lead sequestration is energy-demanding and that in the absence of an energy-rich diet glycogen stores fail to accumulate. In the presence of an organic-rich medium, elevated lead levels preclude glycogen formation, because of the high sequestration-demand, but at lower lead levels -glycogen deposits occur if a high organic diet is available.     

The occurrence and localisation of heavy metals and glycogen in the earthwormsLumbricus rubellus andDendrobaena rubida from a heavy metal site

Summary The lead content of whole earthworms, highest in contaminated site specimens, was significantly higher inDendrobaena rubida thanLubricus rubellus and a species difference in zinc was also recorded. Selective feeding and differential absorption are discounted and a species difference in maximum tolerance to body lead is suggested. Copper was low in all specimens. Chloragocytes and intestinal tissue showed significantly higher lead levels in contaminated earthworms than in control material. Ultrastructurally, chlorgocytes from contaminated earthworms showed electron dense flecks associated with the chroragosome peripheries and within the debis vesicles. Very fine flecks occurred in the nuclei, but mitochondria and Golgi were indistinguishable from control material. Preliminary X-ray microanalysis of contaminated chloragocytes revealed lead and phosphorus. The deposits within the chloragocytes might represent unbound lead precipitated by phosphate buffer; flecks being absent from contaminated, citrate buffered material and from control material. The chloragosomes are proposed as possible sites for sequestered lead.Chloragocyte and intestinal glycogen levels were significantly higher in control material where the chloragocyte cytoplasm was rich in -glycogen rosettes, these being absent from lead contaminated cells. The glycogen-lead correlation suggests that the metabolism of contaminated chloragocytes is directed towards lead sequestration, though differing nutritional states cannot be ignored.The assistance of Mr. P.M. Webster, University of Keele, is gratefully acknowledged.     

Earthworms as vectors of Escherichia coli O157:H7 in soil and vermicomposts

Survival and movement of Escherichia coli O157:H7 in both soil and vermicompost is of concern with regards to human health. Whilst it is accepted that E. coli O157:H7 can persist for considerable periods in soils, it is not expected to survive thermophilic composting processes. However, the natural behavior of earthworms is increasingly utilized for composting (vermicomposting), and the extent to which earthworms promote the survival and dispersal of the bacterium within such systems is unknown. The faecal material produced by earthworms provides a ready supply of labile organic substrates to surrounding microbes within soil and compost, thus promoting microbial activity. Earthworms can also cause significant movement of organisms through the channels they form. Survival and dispersal of E. coli O157:H7 were monitored in contaminated soil and farmyard manure subjected to earthworm digestion over 21 days. Our findings lead to the conclusion that anecic earthworms such as Lumbricus terrestris may significantly aid vertical movement of E. coli O157 in soil, whereas epigeic earthworms such as Dendrobaena veneta significantly aid lateral movement within compost. Although the presence of earthworms in soil and compost may aid proliferation of E. coli O157 in early stages of contamination, long-term persistence of the pathogen appears to be unaffected.     

Earthworms as paratenic hosts of toxoplasmosis in eastern barred bandicoots in Tasmania

An experimental feeding study was designed to assess the role of earthworms in the transmission of Toxoplasma gondii infection to eastern barred bandicoots (Perameles gunnii). Six animals with no agglutinating antibodies to T. gondii were fed artificially cultured earthworms that had been maintained in autoclaved nutrient-enriched soil. Two animals were given earthworms that had been maintained in soil contaminated with T. gondii oocysts (P89/VEG strain); two animals were fed on earthworms, which initially had been exposed to soil containing T. gondii oocysts then transferred through three changes of sterile soil; two control bandicoots were fed earthworms maintained in sterile soil. Both bandicoots fed earthworms maintained in T. gondii contaminated soil died 11 and 14 days after feeding. The necropsy findings were consistent with acute toxoplasmosis. Bandicoots fed earthworms exposed to oocysts but then transferred through changes of sterilized soil remained healthy as did control animals. All surviving animals remained seronegative over the 6 wk observation period after feeding. These findings confirm that earthworms, a major component of the natural diet of P. gunnii, can transmit T. gondii infection. It appears that oocysts present in the alimentary tracts of the worms, rather than infective stages of T. gondii in worm somatic tissues, are responsible for these infections.     

Effects of pulp mill solids and three composts on early growth of tomatoes

Compost has been proposed as a means of simultaneously diverting organic materials from landfills while producing a valuable product that improves tilth, organic matter content and nutrient supply of agricultural soils. Composts manufactured from different source materials may have markedly different properties however, even if they meet all regulatory requirements. We compared the capacity of composts made from three different combinations of organic wastes (horse manure and bedding, mink farm wastes, municipal solid waste (MSW) and sewage sludge) along with clarifier solids from a chemo-thermomechanical pulp mill, to enhance the growth of tomato (Lycopersicon esculentum L.) seedlings grown in nutrient-poor organic potting soil. Germination and seedling emergence of tomatoes, cress (Lapidium sativum L.) or radish (Raphanus sativus L.) were tested to assess phytotoxicity of the four amendments. Mink farm compost and horse manure compost stimulated root and shoot growth of tomato seedlings but MSW compost and pulp mill solids were strongly inhibitory. MSW compost and unamended potting soil also inhibited seedling emergence and pulp mill solids produced stunting and deformities in radish and cress seedlings. Both toxic constituents and nutrient imbalances may be responsible for the growth-inhibiting effects of these amendments. Application of pulp mill solids to agricultural soil without composting may lead to deleterious effects on vegetable crops.     

Residues effects of isoproturon in mature earthworm (Aporrectodea caliginosa) under laboratory conditions

This study was conducted to investigate the residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin in soil and mature earthworms under laboratory conditions. Mature earthworms (Aporrectodea caliginosa) were exposed for various durations (7, 15, 30, and 60 days) to soils contaminated with isoproturon concentrations (2, 4, 6, 8, and 10 mg.kg(-1) soil). The decrease in isoproturon concentration in the soil depended on initial concentration it was slower at higher concentrations. The isoproturon and its metabolites accumulated in earthworms it increased during the first 15 days and decreased thereafter. Acute toxicity of isoproturon was determined together with total soluble protein content and glycogen of worms. These parameters were related to isoproturon concentration in soil and earthworms. No lethal effect of isoproturon was observed even at the concentration 1000 mg.kg(-1) soil after 60 days of exposure. A reduction of total soluble protein was observed in all treated worms (maximum 59.54%). This study is suggesting the use of the total soluble protein content and glycogen of earthworms as biomarker of exposure to isoproturon.     

Equipment Review

A quantitative survey of the fauna of a garden compost heap showed it to be similar to that of soil and leaf litter. The greatest biomasses of animals identified were earthworms, molluscs, and woodlice respectively. Animals were most abundant in the upper levels. The addition of various groups of animals to experimental composts allowed the direct estimation of their effect upon primary decomposition and of their role in the compost heap. Microbial populations played by far the greatest role in primary decomposition; earthworms and enchytraeids had smaller but significant roles. The addition of other animals had no significant effect.     

Freeze tolerance in Aporrectodea caliginosa and other earthworms from Finland

Earthworms that live in subarctic and cold temperate areas must deal with frost even though winter temperatures in the soil are often more moderate than air temperatures. Most lumbricid earthworms can survive temperatures down to the melting point of their body fluids but only few species are freeze tolerant, i.e. tolerate internal ice formation. In the present study, earthworms from Finland were tested for freeze tolerance, and the glycogen reserves and glucose mobilization (as a cryoprotectant) was investigated. Freeze tolerance was observed in Aporrectodea caliginosa, Dendrobaena octaedra, and Dendrodrilus rubidus, but not in Lumbricus rubellus. A. caliginosa tolerated freezing at -5 degrees C with about 40% survival. Some individuals of D. octaedra tolerated freezing even at -20 degrees C. Glycogen storage was largest in D. octaedra where up to 13% of dry weight consisted of this carbohydrate, whereas the other species had only 3-4% glycogen of tissue dry weight. Also glucose accumulation was largest in D. octaedra which was the most freeze-tolerant species, but occurred in all four species upon freezing. It is discussed that freeze tolerance may be a more common phenomenon in earthworms than previously thought.     

SERGE, the subcellular site of initial hepatic glycogen deposition in the rat: a radioautographic and cytochemical study

Hormonal control of hepatic glycogen and blood glucose levels is one of the major homeostatic mechanisms in mammals: glycogen is synthesized when portal glucose concentration is sufficiently elevated and degraded when glucose levels are low. We have studied initial events of hepatic glycogen synthesis by injecting the synthetic glucocorticoid dexamethasone (DEX) into adrenalectomized rats fasted overnight. Hepatic glycogen levels are very low in adrenalectomized rats, and DEX causes rapid deposition of the complex carbohydrate. Investigation of the process of glycogen deposition was performed by light and electron microscopic (EM) radioautography using [3H]galactose as a glycogen precursor. Rats injected with DEX for 2-3 h and [3H]galactose one hour before being killed displayed an increasing number of intensely labeled hepatocytes. EM radioautography revealed silver grains over small (+/- 1 micron) ovoid or round areas of the cytosome that were rich in smooth endoplasmic reticulum (SER) and contained a high concentration of small dense particles. These distinct areas or foci of SER and presumptive glycogen (SERGE) were most numerous during initial periods of glycogen synthesis. After longer exposure to DEX (4-5 h) more typical deposits of cytoplasmic glycogen were evident in the SERGE regions. Several criteria indicated that the SERGE foci contained glycogen or presumptive glycogen: resemblance of the largest dense particles to beta-glycogen particles in EM; association of 3H-carbohydrate with the foci; removal of particles and label with alpha-amylase; and positive reaction with periodic acid-chromic acid-silver methenamine. The concentration of SER in the small foci and the association of newly formed glycogen particles with elements of SER suggest a role for this organelle in the initial synthesis of glycogen.     

Fate of Salmonella enterica serovar Typhimurium on carrots and radishes grown in fields treated with contaminated manure composts or irrigation water

Three different types of compost, PM-5 (poultry manure compost), 338 (dairy cattle manure compost), and NVIRO-4 (alkaline-pH-stabilized dairy cattle manure compost), and irrigation water were inoculated with an avirulent strain of Salmonella enterica serovar Typhimurium at 10(7) CFU g(-1) and 10(5) CFU ml(-1), respectively, to determine the persistence of salmonellae in soils containing these composts, in irrigation water, and also on carrots and radishes grown in these contaminated soils. A split-plot block design plan was used for each crop, with five treatments (one without compost, three with each of the three composts, and one without compost but with contaminated water applied) and five replicates for a total of 25 plots for each crop, with each plot measuring 1.8 x 4.6 m. Salmonellae persisted for an extended period of time, with the bacteria surviving in soil samples for 203 to 231 days, and were detected after seeds were sown for 84 and 203 days on radishes and carrots, respectively. Salmonella survival was greatest in soil amended with poultry compost and least in soil containing alkaline-pH-stabilized dairy cattle manure compost. Survival profiles of Salmonella on vegetables and soil samples contaminated by irrigation water were similar to those observed when contamination occurred through compost. Hence, both contaminated manure compost and irrigation water can play an important role in contaminating soil and root vegetables with salmonellae for several months.     

Studies on the local dispersal of the New Zealand flatworm, a predator of earthworms, in Edinburgh between 1993 and 1999

The flatworm Artioposthia triangulata was found, from studies using weighted down plastic sheeting, to move predominantly through the soil rather than over it and to use earthworm burrows. Under compost‐filled plastic sacks the flatworm was most active at night although its numbers were similar to those during the day. The transfer of specimens into an area covered with weighted plastic sheeting had no lasting effect on their numbers. The flatworm was regularly removed over 6 years from under paving stones, sheets of newspaper and cardboard placed on the ground in a garden. The rise and fall of the numbers of the flatworm under this debris suggest a predator‐prey periodicity between the flatworm and earthworms of 3 years.     

Occurrence of Aspergillus fumigatus during composting of sewage sludge.

Aspergillus fumigatus, a medically important fungal opportunist and respiratory allergen, was isolated from woodchips and sewage sludge used in the production of compost at the U.S. Department of Agriculture's composting research facility in Beltsville, Md. It was also regularly isolated as a dominant fungus during forced aeration composting and after 30 days in an unaerated stationary curing pile; in both cases, the fungus was found in pile zones with temperatures less than 60 degrees C. Compost stored outdoors in stationary unaerated piles from 1 to 4 months after screening out of woodchips contained easily detectable amounts of A. fumigatus in the exterior pile zones (0- to 25-cm depths). Semiquantitative studies of the airspora at the composting site revealed that A. fumigatus constituted 75% of the total viable mycoflora captured. At locations 320 m to 8 km from the compost site, the fungus constituted only 2% of the total viable mycoflora in the air. Of 21 samples of commercially available potting soil, one had levels of A. fumigatus nearly equivalent to those of 1-month-old storage compost; 15 others had lower but detectable levels.     

The accumulation and intracellular compartmentation of cadmium,lead, zinc and calcium in two earthworm species (Dendrobaena rubida and Lumbricus rubellus) living in highly contaminated soil

Summary The earthworm Lumbricus rubellus contained more Ca and Zn, and less Pb and Cd, than Dendrobaena rubida living in the same contaminated disused-mine soil. Differences in the kinetics of Ca turnover may account for some of the inter-specific differences in heavy metal burdens, although the calciferous glands do not seem to be directly involved in heavy metal excretion. A comparison of the present findings with published data indicated that the concentration of soil Ca and the bioavailability of heavy metals, both factors being allied to soil pH, are important exogenous determinants of heavy metal accumulation by different earthworm populations. Electron microprobe X-ray analysis of air-dried smears of chloragogenous tissue showed that the metals were fairly specifically compartmentalized into two distinct organelles in both worms: Ca, Pb and Zn were found (associated with P) in the chloragosomes; Cd was found (with S and probably in stoichiometric association) in a more electron-lucent vesicular component, designated the cadmosome, but which may be identical with the debris vesicles which are characteristic inclusions in conventionally-fixed chloragocytes. The in vivo incorporation of Pb by the chloragosomes of D. rubida was accompanied by the loss of Ca, Zn and P.     

Occurrence of Aspergillus fumigatus during composting of sewage sludge.

Aspergillus fumigatus, a medically important fungal opportunist and respiratory allergen, was isolated from woodchips and sewage sludge used in the production of compost at the U.S. Department of Agriculture's composting research facility in Beltsville, Md. It was also regularly isolated as a dominant fungus during forced aeration composting and after 30 days in an unaerated stationary curing pile; in both cases, the fungus was found in pile zones with temperatures less than 60 degrees C. Compost stored outdoors in stationary unaerated piles from 1 to 4 months after screening out of woodchips contained easily detectable amounts of A. fumigatus in the exterior pile zones (0- to 25-cm depths). Semiquantitative studies of the airspora at the composting site revealed that A. fumigatus constituted 75% of the total viable mycoflora captured. At locations 320 m to 8 km from the compost site, the fungus constituted only 2% of the total viable mycoflora in the air. Of 21 samples of commercially available potting soil, one had levels of A. fumigatus nearly equivalent to those of 1-month-old storage compost; 15 others had lower but detectable levels.     

Fate of Salmonella enterica Serovar Typhimurium on Carrots and Radishes Grown in Fields Treated with Contaminated Manure Composts or Irrigation Water

Three different types of compost, PM-5 (poultry manure compost), 338 (dairy cattle manure compost), and NVIRO-4 (alkaline-pH-stabilized dairy cattle manure compost), and irrigation water were inoculated with an avirulent strain of Salmonella enterica serovar Typhimurium at 10⁷ CFU g⁻¹ and 10⁵ CFU ml⁻¹, respectively, to determine the persistence of salmonellae in soils containing these composts, in irrigation water, and also on carrots and radishes grown in these contaminated soils. A split-plot block design plan was used for each crop, with five treatments (one without compost, three with each of the three composts, and one without compost but with contaminated water applied) and five replicates for a total of 25 plots for each crop, with each plot measuring 1.8 × 4.6 m. Salmonellae persisted for an extended period of time, with the bacteria surviving in soil samples for 203 to 231 days, and were detected after seeds were sown for 84 and 203 days on radishes and carrots, respectively. Salmonella survival was greatest in soil amended with poultry compost and least in soil containing alkaline-pH-stabilized dairy cattle manure compost. Survival profiles of Salmonella on vegetables and soil samples contaminated by irrigation water were similar to those observed when contamination occurred through compost. Hence, both contaminated manure compost and irrigation water can play an important role in contaminating soil and root vegetables with salmonellae for several months.     

取食蜂蜜对棉铃虫齿唇姬蜂体内主要代谢物质的影响

为揭示食物在齿唇姬蜂Campoletis chlorideae Uchida生命中所起的作用,测定分析饱食蜂蜜和只取食清水的齿唇姬蜂体内糖类、脂肪和蛋白质随日龄增加的变化趋势。结果显示,取食蜂蜜对齿唇姬蜂体内主要代谢物质影响显著。10%蜂蜜水和清水饲养的齿唇姬蜂的雌蜂和雄蜂在刚羽化时体内都含有较高水平的糖原、总糖、脂肪和蛋白质。但随着日龄的增加,用清水饲养的雌、雄蜂体内的糖原和总糖含量迅速下降并达到最低水平;而用蜂蜜水饲养的雌、雄蜂随日龄的增加体内的糖原含量没有显著变化,并且与清水饲养的雌、雄蜂相比,其体内总糖含量反而有所上升。用蜂蜜水饲养的齿唇姬蜂的寿命显著长于用清水饲养的齿唇姬蜂。由于蜂蜜中含有丰富的果糖,所以冷蒽酮反应测定显示,用蜂蜜水饲养的齿唇姬蜂体内果糖含量较高,但却不能在清水饲养的齿唇姬蜂体内测出。2种食物处理的齿唇姬蜂在羽化后体内脂肪含量均有下降;并且随日龄的增加,清水饲养的齿唇姬蜂体内脂肪含量的下降速度明显快于蜂蜜水饲养的齿唇姬蜂。取食蜂蜜水的齿唇姬蜂体内蛋白质含量随日龄无显著变化;而用清水饲养的齿唇姬蜂在羽化后体内蛋白质含量随日龄的增长迅速下降并达到最低水平。     

Inability of glucagon to regulate glycogen metabolism in rat hepatocytes isolated after fasting and refeeding high-carbohydrate diets

Studies are described which demonstrate that the ability of glucagon, epinephrine, and dibutyryl-cAMP to stimulate glycogenolysis is impaired in rat hepatocytes isolated from animals starved for 24 h and then refed a sucrose-rich diet or refed standard rat chow. The impaired regulation of glycogenolysis by glucagon was observed within 24 h after refeeding and persisted for at least 3 days. The inability of glucagon to stimulate glycogen breakdown in the refed condition appeared to be due to a suppressed activation of glycogen phosphorylase and phosphorylase b kinase by the hormone. The capacity of glucagon to regulate pyruvate kinase and glycolysis was not altered by refeeding, suggesting that the defect lies beyond interaction of the hormone at its receptor. Prolonged incubation of hepatocytes from refed rats was accompanied by depletion of glycogen reserves and was accompanied by restoration of hormonal stimulation of glycogenolysis. Addition of glycogen to cell-free extracts was found to inhibit phosphorylase b kinase but not phosphorylase. The findings of this investigation are consistent with the interpretation that high levels of glycogen present of liver after refeeding may lead to a diminished activity of phosphorylase b kinase and its hormonal regulation.     

Transformation of buffalo manure by composting or vermicomposting to rehabilitate degraded tropical soils

The addition of composted buffalo manure may lead to qualitative and quantitative improvement of the organic matter content of degraded tropical agricultural soils in Northern Vietnam. The objectives of this study were to follow the biochemical changes occurring during composting of buffalo manure with and without earthworms during 3 months and to study the effect of the end products (compost and vermicompost) on soil biochemical parameters and plant growth after two months of incubation under controlled conditions in an open pot experiment. Our conceptual approach included characterisation of organic matter of the two composts before and after addition to soil by elemental, isotopic analysis and analytical pyrolysis and comparison with conventional fertilisation. We also analysed for lignin content and composition.Our results showed that composting in the presence of earthworms led to stronger transformation of buffalo manure than regular composting. Vermicompost was enriched in N-containing compounds and depleted in polysaccharides. It further contained stronger modified lignin compared to regular compost. In the bulk soil, the amendment of compost and vermicompost led to significant modification of the soil organic matter after 2 months of exposure to natural weather conditions. The lignin component of SOM was unaffected whatever the origin of the organic amendment. Compost and vermicompost amendments both enhanced aggregation and increased the amount of organic matter in water stable aggregates. However, vermicompost is preferable to compost due to its beneficial effect on plant growth, while having similar positive effects on quantity and quality of SOM.     

Succession of bacterial communities during early plant development: transition from seed to root and effect of compost amendment

Compost amendments to soils and potting mixes are routinely applied to improve soil fertility and plant growth and health. These amendments, which contain high levels of organic matter and microbial cells, can influence microbial communities associated with plants grown in such soils. The purpose of this study was to follow the bacterial community compositions of seed and subsequent root surfaces in the presence and absence of compost in the potting mix. The bacterial community compositions of potting mixes, seed, and root surfaces sampled at three stages of plant growth were analyzed via general and newly developed Bacteroidetes-specific, PCR-denaturing gradient gel electrophoresis methodologies. These analyses revealed that seed surfaces were colonized primarily by populations detected in the initial potting mixes, many of which were not detected in subsequent root analyses. The most persistent bacterial populations detected in this study belonged to the genus Chryseobacterium (Bacteroidetes) and the family Oxalobacteraceae (Betaproteobacteria). The patterns of colonization by populations within these taxa differed significantly and may reflect differences in the physiology of these organisms. Overall, analyses of bacterial community composition revealed a surprising prevalence and diversity of Bacteroidetes in all treatments.     

Tissue-specific inhibition and recovery of esterase activities in Lumbricus terrestris experimentally exposed to chlorpyrifos

Exposure and effect assessment of organophosphate (OP) pesticides generally involves the use of cholinesterase (ChE) inhibition. In earthworm, this enzyme activity is often measured in homogenates from the whole organism. Here we examine the tissue-specific response of ChE and carboxylesterase (CE) activities in Lumbricus terrestris experimentally exposed to chlorpyrifos-spiked field soils. Esterases were measured in different gut segments and in the seminal vesicles of earthworms following acute exposure (2 d) to the OP and during 35 d of a recovery period. We found that inhibition of both esterase activities was dependent on the tissue. Cholinesterase activity decreased in the pharynx, crop, foregut and seminal vesicles in a concentration-dependent way, whereas CE activity (4-nitrophenyl valerate) was strongly inhibited in these tissues. Gizzard CE activity was not inhibited by the OP, even an increase of enzyme activity was evident during the recovery period. These results suggest that both esterases should be determined jointly in selected tissues of earthworms. Moreover, the high levels of gut CE activity and its inhibition and recovery dynamic following OP exposure suggest that this esterase could play an important role as an enzymatic barrier against OP uptake from the ingested contaminated soil.