Development of a buffer system for dialysis of bovine spermatozoa before freezing. II. Effect of sugars and sugar alcohols on posthaw motility

Two experiments were conducted to evaluate the effect of different levels of sugars (glucose, lactose and raffinose) and the effect of those sugars (C(3) to C(6)) or their correspondent sugar alcohols on the dialysis of bovine semen. First, the effect of isosmotic solutions of glucose, lactose or raffinose at five different levels (0, 25, 50, 75, 95% V/V) on sperm motility of semen dialyzed prior to freezing were studied. These levels were used in extenders and dialysates, and the final volume was complemented with Piperazine-N-N-BIS (2-ethane sulfonic acid (PIPES) titrated to pH 7.0 with TRIS (hydroxymethyl) amino-methane (TRIS) to form PIPEST or a 1:1 (V/V) combination between PIPEST and sodium citrate solutions. In the second experiment, 30% of the buffer volume contained solutions of sugars (C(3) or C(6)) or their correspondent sugar alcohol, and the final volume was completed with PIPEST-citrate buffer. Semen aliquots were extended (1:10) and dialyzed (1:50) for 2 h while cooling from 37 to 5 degrees C in semipermeable dialysis bags of 12,000 to 14,000 molecular weight cut off. The samples were frozen in pellets 1 h after dialysis was terminated. Sperm survival was significantly higher in PIPEST-citrate than in PIPEST buffer alone (P<0.05). No significant difference (P>0.05) was obtained between the use of glucose or lactose or between lactose and raffinose. High levels of sugar appeared to be detrimental to sperm motility of fresh and thawed semen samples. Motility of cells extended in buffers containing 30% (V/V) isosmotic solutions of glucose, galactose, ribose, xylose, arabinose or their correspondent sugar alcohols was significantly higher (P<0.05) than their motility in extenders without sugar.     

Antibacterial Effect of Irradiated Sugar Solution

Effects of irradiated sugar solutions on the growth and viability of E. coli B were investigated on glucose, fructose and sucrose. The antibacterial effect was demonstrated to be classified into two types; the bactericidal effect was developed in every sugar solutions irradiated in air, while the bacteriostatic effect was found especially in fructose irradiated in air free. The bactericidal activity was abolished by heating, pH change to alkali, and addition of catalase or ferrous ions, suggesting its entity is a peroxide products(s). No appreciable activity was observed with the radiation produced hydrogen peroxide and low molecular carbonyl compounds with each alone and even with their combination. Behaviours of the bacteriostatic activity on similar treatments indicate that the entity is unlikely a peroxide compound but a more thermostable and thiol reactive product.     

Mutagenic effects of sodium azide in Drosophila melanogaster.

The mutagenic effects of sodium azide (NaN3) were studied at low pH in male Drosophila melanogaster using the sex-linked recessive-lethal test. No significant increase in the mutation frequency was observed after abdominal injection of azide solutions buffered at either pH 3.8 OR 4.6. However, a weak mutagenic effect was noticed in the flies fed for 3 days on 0.1 mM azide (pH 4.6) solution.     

Effects of feeding frequency and sugar concentrations on lifetime reproductive success of Meteorus pulchricornis (Hymenoptera: Braconidae)

Many species of parasitoids can increase their reproduction through feeding on supplemental sugar sources. We evaluated the longevity both with and without hosts and progeny production of a uniparental strain of Meteorus pulchricornis by varying concentration of the sugar solution and feeding frequency. A 1:1:1 sucrose–glucose–fructose-mixture was tested in a range of concentrations (0–70% (w/v)). The parasitoid lifespan did not increase with the concentration of sugar solutions, but parasitoids feeding on a 30% sugar solution attained greater longevity than parasitoids feeding on other sugar concentrations in the absence of hosts. The same effect of sugar concentration was also observed on progeny production, where when the parasitoid was fed 30% (w/v) sugar solution, its lifetime progeny production doubled in comparison to that fed water, and increased by 50% compared to those fed the other sugar solutions. In the last experiment, we studied the effect of feeding intervals on the longevity and progeny production of M. pulchricornis. Parasitoids fed with a 30% (w/v) 1:1:1 sucrose–glucose–fructose-mixture continuously lived six times longer than unfed parasitoids, three times longer than parasitoids fed only once and two times longer than parasitoids fed once every two days in the absence of hosts. Parasitoids with continuous access to the sugar solution produced considerably more progeny than those with fewer feeding frequencies. This increasing progeny production was accomplished more through an increase in daily offspring production rather than through extending reproductive lifespan.     

Radioprotective effect of melatonin assessed by measuring chromosomal damage in mitotic and meiotic cells.

This study was taken to evaluate the radioprotective effects of melatonin. Male adult albino mice were treated (intraperitoneal, i.p.) with 10 mg/kg melatonin either 1 h before or 1/2 h after exposure to 1.5 Gy of gamma-irradiation. Control, melatonin, irradiated and melatonin plus irradiation groups were sacrificed 24 h following treatment. The incidence of micronuclei (MN) in bone marrow cells was determined in all groups. The results show that melatonin caused a significant reduction in micronuclei polychromatic erythrocytes (MNPCE) when animals were treated with melatonin before and not after exposure to radiation. Mitotic and meiotic metaphases were prepared from spermatogonial and primary spermatocytes, respectively. Examination and analysis of metaphases showed no mutagenic effect of melatonin on chromosomal aberration (CA) frequency in spermatogonial chromosomes. Administration of one single dose of melatonin to animals before irradiation lowered total CA from 46 to 32%. However, no significant effect was observed when melatonin was given after irradiation. Similarly, the frequency of CA in meiotic metaphases decreased from 43.5% in the irradiated group to 31.5% in the irradiated group treated with melatonin 1 h before irradiation, but no change was observed when melatonin was administered after irradiation. The data obtained in this study suggest that melatonin administration confers protection against damage inflicted by radiation when given prior to exposure to irradiation and not after, and support the contention that melatonin radioprotection is achieved by its ability as a scavenger for free radicals generated by ionizing radiation.     

Mutation induction with UV- and X-radiations in spores and vegetative cells of Bacillus subtilis.

Spores and vegetative cells of Bacillus subtilis strains with various defects in DNA-repair capacities (hcr-, ssp-, hcr-ssp-) were irradiated with UV radiation or X-rays. Induced mutation frequency was determined from the observed frequency of prototrophic reversion of a suppressible auxotrophic mutation. At equal physical dose, after either UV- or X-irradiation, spores were more resistant to mutations as well as to killing than were vegetative cells. However, quantitative comparison revealed that, at equally lethal doses, spores and vegetative cells were almost equally mutable by X-rays whereas spores were considerably less mutable by UV than were vegetative cells. Thus, as judged from their mutagenic efficiency relative to the lethality, X-ray-induced damage in the spore DNA and the vegetative DNA were equally mutagenic, while UV-induced DNA photoproducts in the spore were less mutagenic than those in vegetative cells. Post-treatment of UV-irradiated cells with caffeine decreased the survival and the induced mutation frequency for either spores or vegetative cells for all the strains. In X-irradiated spores, however, a similar suppressing effect of caffeine was observed only for mutability of a strain lacking DNA polymerase I activity.     

Sugar Concentrations in Guard Cells of Vicia faba Illuminated with Red or Blue Light : Analysis by High Performance Liquid Chromatography

Concentrations of soluble sugars in guard cells in detached, sonicated epidermis from Vicia faba leaves were analyzed quantitatively by high performance liquid chromatography to determine the extent to which sugars could contribute to changes in the osmotic potentials of guard cells during stomatal opening. Stomata were illuminated over a period of 4 hours with saturating levels of red or blue light, or a combination of red and blue light. When stomata were irradiated for 3 hours with red light (50 micromoles per square meter per second) in a solution of 5 millimolar KCl and 0.1 millimolar CaCl₂, stomatal apertures increased a net maximum of 6.7 micrometers and the concentration of total soluble sugar was 289 femtomoles per guard cell (70% sucrose, 30% fructose). In an identical solution, 2.5 hours of irradiation with 25 micromoles per square meter per second of blue light caused a maximum net increase of 7.1 micrometers in stomatal aperture and the total soluble sugar concentration was 550 femtomoles per guard cell (91% sucrose, 9% fructose). Illumination with blue light at 25 micromoles per square meter per second in a solution lacking KCl caused a maximum net increase in stomatal aperture of 3.5 micrometers and the sugar concentration was 382 femtomoles per guard cell (82% sucrose, 18% fructose). In dual beam experiments, stomata irradiated with 50 micromoles per square meter per second of red light opened steadily with a concomitant increase in sugar production. Addition of 25 micromoles per square meter per second of blue light caused a further net gain of 3.7 micrometers in stomatal aperture and, after 2 hours, sugar concentrations had increased by an additional 138 femtomoles per guard cell. Experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were performed with epidermis illuminated with 50 micromoles per square meter per second of red light or with 25 micromoles per square meter per second of blue light in solutions containing or lacking KCl. DCMU completely inhibited sugar production under red light, had no effect on guard cell sugar production under blue light when KCl was present, and inhibited sugar production by about 50% when guard cells were illuminated with blue light in solutions lacking KCl. We conclude that soluble sugars can contribute significantly to the osmoregulation of guard cells in detached leaf epidermis of V. faba. These results are consistent with the operation of two different sugar-producing pathways in guard cells: a photosynthetic carbon reduction pathway and a pathway of blue light-induced starch degradation.     

Photoregulation of hypocotyl growth: geotropic evidence for the operation of two photosystems

Abstract. The rate of curvature of etiolated cress ( Lepi-dium sativum L. ) hypocotyls in response to gravity (negative geotropism) was retarded by red or blue light; far-red irradiation was without effect. The timing of the irradiation period in relation to the presentation for geostimulus markedly affected the response. When seedlings were irradiated during the 1–2 h period of geostimulus, blue light was more effective than red at retarding curvature; when seedlings were irradiated prior to geostimulus, only red light affected geocurvature. These results are interpreted as a further example of the kinetically distinct effects of red and blue light on hypocotyl development. Blue light elicited a rapid, immediate response effective only during the period of irradiation; red light induced a response characterized by a lag period and persistence in subsequent darkness. Etiolated mustard seedlings showed similar responses to light and gravity. The results are discussed in relation to the possibility that two photosystems operate in hypocotyl growth.     

Mutagenicity of rat-liver S9 to L5178Y mouse lymphoma cells

Rat-liver S9 preparations became highly mutagenic to cultured L5178Y mouse lymphoma cells when the exposure period was increased to 18-24 h or when S9 mix was preincubated in Fischer's medium at 37 degrees C for 19 h and then used to treat the cells for 4 h. Five different S9 preparations (from untreated and Aroclor 1254-treated Fischer 344 or Sprague-Dawley male rats) behaved similarly. S9 mix, which contained 1 mM NADP and 5 mM isocitrate as cofactors, was more mutagenic than S9 alone. Heat treatment of S9 did not destroy its mutagenic activity, but the addition of cofactors no longer stimulated an increase in mutagenicity, as observed with native S9. Treatment with cofactors was not mutagenic. These results implied the involvement of both energy-independent and NADPH-dependent enzymatic changes in S9 mix in producing mutagenic substances. The mutagenic treatments with S9 or S9 mix induced predominantly small TFT-resistant mutant colonies, which suggested that these treatments should be clastogenic to cultured mammalian cells. A warning was given that test chemicals evaluated as mutagenic only in the presence of S9 mix may instead be accelerating the decomposition of S9 mix into mutagens, and it may become necessary to experimentally distinguish between these two mechanisms before a chemical can be regarded as mutagenic.     

The effect of ribose pre-treatment of cortical bone on γ-irradiation sterilization effectiveness

Reconstruction of large skeletal defects is a significant and challenging issue. Tissue banks often use γ-irradiation (15–35 kGy) to sterilize bone allografts, which, however, drastically impairs the post-yield mechanical properties. In previous studies, we reported the development of a method that protects human bone collagen connectivity through ribose crosslinking while still undergoing γ-irradiation. Given these promising results, the next step was to determine if the presence of ribose within the bone tissue would interfere with the effectiveness of the γ-irradiation sterilization against bacteria. This study had two stages. The aim of the first stage was to assess the protective effect of ribose in solution using a Bacillus pumilus spore strip model. The aim of the second stage was to assess the protective effect of ribose (R) on spores within a human cortical bone model in comparison to conventionally irradiated bone (I). Treatment of B. pumilus spore strips with ribose in solution led to temperature-dependent effects on spore viability versus spore strips treated with PBS alone. Ribose solution at 60 °C led to a notable two logs decrease in spore count relative to PBS at 60 °C. In the human bone model, the number of spores in the I and R groups were greatly decreased in comparison to the non-irradiated N group. No spore colonies were detected in the R group (n = 4) whereas two of the four plates of group I formed colonies. This study provides evidence that the method of pre-treating bone with ribose crosslinking prior to irradiation sterilization, while improving irradiation sterilized bone allograft quality, also may improve the effectiveness of the sterilization process.     

Effects of irradiated medium with or without cells on bystander cell responses

Recent studies have indicated that extranuclear or extracellular targets are important in mediating the bystander genotoxic effects of alpha-particles. In the present study, human-hamster hybrid (A(L)) cells were plated on either one or both sides of double-mylar dishes 2-4 days before irradiation, depending on the density requirement of experiments. One side (with or without cells) was irradiated with alpha-particles (from 0.1 to 100 Gy) using the track segment mode of a 4 MeV Van de Graaff accelerator. After irradiation, cells were kept in the dishes for either 1 or 48 h. The non-irradiated cells were then collected and assayed for both survival and mutation. When one side with cells was irradiated by alpha-particles (1, 10 and 100 Gy), the surviving fraction among the non-irradiated cells was significantly lower than that of control after 48 h co-culture. However, such a change was not detected after 1h co-culture or when medium alone was irradiated. Furthermore, co-cultivation with irradiated cells had no significant effect on the spontaneous mutagenic yield of non-irradiated cells collected from the other half of the double-mylar dishes. These results suggested that irradiated cells released certain cytotoxic factor(s) into the culture medium that killed the non-irradiated cells. However, such factor(s) had little effect on mutation induction. Our results suggest that different bystander end points may involve different mechanisms with different cell types.     

Discrimination between A-type and B-type conformations of double helical nucleic acid fragments in solution by means of two-dimensional nuclear Overhauser experiments

The solution structure of two double helical nucleic acid fragments, viz, r(CGCGCG) and d(CGCGCG), was probed by means of two-dimensional nuclear Overhauser effect spectroscopy. The two compounds were selected as models for the A-type and B-type double helical conformations, respectively, and it is shown that for each of the two model compounds the intensities of the NOE cross peaks between base- and H2' (deoxy)ribose proteins are qualitatively in correspondence with the relative NOE intensities expected on basis of the supposed duplex conformations. Thus our results indicate that NOE-data can be used to differentiate between A-and B-type double helical conformations in solution. Coupling constant data show that, except for G(6), all ribose rings in r(CGCGCG) adopt pure N (C3'-endo) conformations thereby manifesting that this molecule takes up a regular A-type double helical conformation in solution. In contrast, the deoxyribose rings in d(CGCGCG) retain conformational freedom in the duplex state, albeit that the N/S-equilibrium is biased towards the S (C2'-endo) sugar conformation. This finding indicates that in solution the B-DNA backbone is highly dynamic.     

A procedure for the rapid screening of Maillard reaction inhibitors

A procedure for the rapid screening of inhibitors of glycation reaction, based on their ability to protect RNase against sugar induced inactivation of the enzyme is described. Glycation is implicated in variety of disorders including diabetes, atherosclerosis various micropathies yet is a slow process both in vivo and in vitro. In order to speed up glycation, the reaction was carried out at 60 °C using a thermostable protein RNase and ribose, a sugar that is known to react rapidly than glucose in the glycation reaction. It was observed that incubation of RNase with ribose at 60 °C in rapid inactivation of the enzyme with a parallel decrease in tyrosine fluorescence, enhancement in new fluorescence and hyperchromicity in the UV-region. No such alterations in the enzyme activity were observed when the incubation was carried out in absence of the sugar. Compounds and drugs that are known to act as inhibitors of glycation reaction restricted the ribose-induced inactivation of RNase. RNase immobilized on CNBr-activated Sepharose was also sensitive to exposure to ribose and appeared a better system to screen inhibitors of glycation from natural sources that contain substances that interfere with the assay of enzyme as well as in the study of post Amadori inhibitors of glycation.     

Effect of sodium fluoride on radiation sensitivity of barley seeds

Barley seeds soaked in 0.01 M sodium fluoride (NaF) in phosphate buffer (pH7) or in buffer alone for 18 h were dried and equilibrated to 10% moisture, either in air or in nitrogen. Pre-treated and re-dried seeds were irradiated in air or in nitrogen with 0, 13, 20, 26 and 32 kR of γ rays, and were immediately hydrated in oxygen- or nitrogen-bubbled water. Parameters of radiation effect considered were seedling injury, mitotic and meiotic cells with bridge aberrations at anaphase and pollen fertility in M₁, and the frequency of chlorophyll mutations in M₂. NaF at 0.01 M was not mutagenic by itself. Pre-treatment with NaF significantly enhanced the radiation effect, when the irradiation was done in air, in comparison with the buffer soaked seeds. The increased effect due to NaF was additional to the oxygen effect. In nitrogen, NaF pre-treatment increased the mutagenic effect but it was not always significant. Post-soaking of irradiated seeds in 0.01 M NaF for 5 h increased seedling injury in comparison with the irradiated seeds soaked in buffer alone or in 0.01 M NaCl. At least a part of the sensitizing effect of NaF may be due to the inhibition of repair.     

Migration and the effect of three environmental factors on the pre-reproductive period of the cotton-boliworm moth, Helicoverpa armigera

ABSTRACT. Migration by noctuid moths generally occurs while the adults are sexually immature, and so the pre-reproductive period provides an indication of the time available for migratory flight. Helicoverpa armigera (Hb.) (Lepidoptera: Noctuidae) is considered to be a facultative migrant, emigrating in response to a deterioration in local environmental conditions for adult survival and larval development; hence the effects of temperature, vapour-pressure deficit and the availability of sugar solution on the duration of the pre-reproductive period are investigated. Temperatures below 28^oC lengthened female pre-reproductive periods but, contrary to the findings of Isley (1935) for Helicoverpa zea (Boddie), temperatures above 28^oC shortened them. Females maintained at a vapour-pressure deficit of 23.7 ± 0.5 mmHg (c. 12% r.h.) and 6.45 ±0.15mmHg (c. 76% r.h.) did not have significantly different pre-reproductive period distributions. The availability of 10% w/v sugar solution (provided ad libitum ) had a marked effect on both the survival and the pre-reproductive period of both sexes. Moths given water for four nights followed by sugar solution thereafter, took significantly longer to reach reproductive maturity than those given sugar solution from emergence. Survival to reproductive maturity of moths given water only throughout their lives was poor (c. 20%). The significance of these findings to the migratory behaviour of H. armigera is discussed.     

The control of the proventriculus in the honeybee (Apis mellifera carnica L.) II. Feedback mechanisms

The mechanisms underlying the control of solution transport rates through the proventriculus in foraging honeybees were investigated in individuals trained to collect defined amounts of sugar solutions. Following feeding, bees were injected either with metabolisable (glucose, fructose, trehalose), or non-metabolisable (sorbose) sugars, in order to distinguish between haemolymph osmolarity and haemolymph sugar levels as factors controlling the solution transport rates through the proventriculus. After a fixed period, workers were dissected in order to measure crop content and haemolymph sugar titers. Between feeding and dissection, the metabolic rate of every investigated forager was measured using open-flow respirometry. Bees injected with metabolisable sugars 15 min after feeding were observed to reduce their solution transport rates through the proventriculus, but injection of non-metabolisable sugars had no influence on them. This suggests that the solution transport rate through the proventriculus is controlled by the concentration of metabolisable compounds in the haemolymph, and not by the haemolymph osmolarity. A period of 10 min after injection of metabolisable sugars was enough to observe reduced solution transport rates. However, if bees were injected only 5 min after feeding, no reduced solution transport rates were observed 10 min after injection.     

Factors affecting total dissolved solids concentration of γ-ray-irradiated aqueous hexamethylenetetramine solution: A dosimetric study

A new γ-ray-radiation dosimetric system (TDS-HMTA), comprising a 'total dissolved solids (TDS)' meter and 0.02 M aqueous hexamethylenetetramine (HMTA) solution, is introduced for medical and biological applications. Gamma-ray radiolysis of aqueous HTMA solutions increases the concentrations (ppm) of TDS, which is measured by the TDS meter. The effects of HMTA concentration, absorbed radiation dose, absorbed dose rate, and storage time on the TDS concentration of irradiated HMTA solutions were studied. It was found that 0.02 M aqueous HMTA solution yields the highest sensitivity to γ-ray-radiation according to TDS concentration measurements. The effect of absorbed radiation dose was studied in the range 1.64–435.5 kGy. The TDS concentration increases linearly up to the maximum of the studied absorbed radiation dose range (R² = 0.9965). The overall coefficient of variation (CV %) associated with TDS concentration measurements of 0.02 M HMTA solution as a function of absorbed dose was found to be 0.732%. The effect of dose rate on the TDS concentration was studied in the range 0.33–3.31 kGy/h. It was found, also, that the TDS concentration is relatively stable over a storage period of 144 h after irradiation with different doses. The tissue equivalency of 0.02 M aqueous HMTA solutions allow it to be used for radiation dose measurement during sterilization in human tissue banks. Therefore, this system (TDS–HMTA) could be considered as a promising candidate for γ-ray radiation dosimetry in technical, medical and research fields.     

Interaction of La (III) and Tb (III) ions with purine nucleotides: evidence for metal chelation (N-7-M-PO3) and the effect of macrochelate formation on the nucleotide sugar conformation.

The interaction of the La (III) and Tb (III) ions with adenosine-5'-monophosphate (5'-AMP), guanosine-5'-monophosphate (5'-GMP), and 2'-deoxyguanosine-5'-monophosphate (5'-dGMP) anions with metal/nucleotide ratios of 1 and 2 has been studied in aqueous solution in acidic and neutral pHs. The solid complexes were isolated and characterized by Fourier transform ir and 1H-nmr spectroscopy. The lanthanide (III)-nucleotide complexes are polymeric in nature both in the solid and aqueous solutions. In the metal-nucleotide complexes isolated from acidic solution, the nucleotide binding is via the phosphate group (inner sphere) and an indirect metal-N-7 interaction (outer-sphere) with the adenine N-1 site protonated. In the complexes obtained from neutral solution, metal chelation through the N-7 and the PO3(2-) group is prevailing. In aqueous solution, an equilibrium between the inner and outer sphere metal-nucleotide interaction has been observed. The ribose moiety shows C2'-endo/anti pucker in the free AMP anion and in the lanthanide (III)-AMP complexes, whereas the GMP anion with C2'-endo/anti sugar conformation exhibits a mixture of the C2'-endo/anti and C3'-endo/anti sugar puckers in the lanthanide (III)-GMP salts. The deoxyribose has O4'-endo/anti sugar pucker in the free dGMP anion and a C3'-endo/anti, in the lanthanide (III)-dGMP complexes.     

Insecticidal sugar baits for adult biting midges

The mixing of an insecticide with sugar solution creates an oral toxin or insecticidal sugar bait (ISB) useful for reducing adult insect populations. The ability of ISBs to kill the biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), a vector of bluetongue virus, epizootic hemorrhagic disease and vesicular stomatitis viruses, was tested. The commercial insecticide formulations (percentage active ingredient) tested included bifenthrin, cyfluthrin, deltamethrin, permethrin, dinotefuran, imidacloprid, thiamethoxam and spinosad. Mortality rates were determined for various concentrations of commercial formulations (0.01, 0.05, 0.1, 1, 2 and 3%) and observed at 1, 4, 10 and 24 h post‐exposure to the ISB. In the first set of assays, laboratory‐reared midges were fed sugar ad libitum and then exposed to insecticide‐treated sugar solutions to measure mortality. The second assay assessed competitive feeding: midges were provided with a control sugar solution (10% sucrose) in one vial, and a sugar and insecticide solution in another. Pyrethroid treatments resulted in the greatest mortality in the first hour at the lowest concentrations and spinosad consumption resulted in the least mortality. Biting midges were not deterred from feeding on the 1% ISB solutions despite the presence of an insecticide‐free alternative source of sugar.     

弗里熊蜂蜜罐中糖液成分分析

【目的】熊蜂是众多植物的重要传粉昆虫,以采集并贮藏花蜜和花粉为主要食物。本研究旨在探究熊蜂的营养需求及明确其对采集的食物是否存在酿制过程。【方法】利用白砂糖溶液(糖浓度50%)饲喂弗里熊蜂Bombus friseanus蜂群,收集并检测其贮藏在蜜罐中1~7 d的糖液,作为处理组样品;同时将上述白砂糖溶液置于灭菌离心管中,排除熊蜂取食,作为对照组样品,测定贮藏期间处理组和对照组糖液的pH值、糖浓度、糖组分及α-淀粉酶和转化酶活性。【结果】弗里熊蜂B. friseanus贮藏在蜜中1~7d的糖液pH值平均为3.74±0.13,显著低于对照组(6.55±0.15);糖浓度与贮藏时间显著正相关,贮藏6d后糖浓度显著高于贮藏1~3 d时的;糖液组分更加丰富,除蔗糖外利用HPLC还检出果糖、葡萄糖、麦芽糖和海藻糖,贮藏4~5 d的糖液中己糖含量极显著高于贮藏1~3 d和6~7 d时的,己糖和麦芽糖含量分别与蔗糖含量极显著负相关,总糖中果糖和麦芽糖含量与贮藏时间极显著负相关,葡萄糖、蔗糖和海藻糖的含量分别与贮藏时间极显著正相关。贮藏6 d的糖液中α-淀粉酶活性显著高于其他时间,其他贮藏时间样品间α-淀粉酶活性差异不显著,而所有样本的转化酶活性在21.17~38.05 U/g FW之间,随贮藏时间的延长差异不显著。【结论】弗里熊蜂B. friseanus采集人工饲喂的糖溶液贮藏在蜜罐中,经其加工后发生了物理和生物化学变化,揭示熊蜂存在酿蜜能力。本研究的结果为熊蜂生物学及繁育研究提供了参考。