• Korean Journal of Microbiology
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• v.45 no.4
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• pp.332-338
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• 2009

A xylan-decomposing bacterium, HY-20, was isolated from the gut of a honeybee, Apis mellifera, and identified as Bacillus sp. The extracellular GH11 xylanase (XylP) gene (687-bp) of strain HY-20 encoded a protein of 228 amino acids with a deduced molecular mass of 25,522 Da and a calculated pI of 9.33. The primary structure of XylP was 97% identical to that of B. pumilus xylanase (GenBank accession no.: AY526092) that has not been characterized yet. The recombinant His-tagged enzyme (rXylP) overexpressed in Escherichia coli BL21 harboring pET-28a(+)/xylP was purified to electrophoretic homogeneity by cation exchange and gel permeation chromatographies. The purified enzyme exhibited the highest catalytic activity toward birchwood xylan at pH 6.5 and $50^{\circ}C$ and retained approximately 50% of its original activity when pre-incubated at $55^{\circ}C$ for 15 min. The recombinant enzyme was completely inactivated by $Hg^{2+}$ (1 mM) and N-bromosuccinimide (5 mM), while its activity was slightly stimulated by approximately 10% in the presence of $Mn^{2+}$ (1 mM), $Fe^{2+}$ (1 mM), and sodium azide (5 mM). rXylP was able to efficiently degrade various polymeric xylose-based substrates but PNP-sugar derivatives and glucose-based polymers were not susceptible to the enzyme.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.271-276
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• 2013

The Asian honeybee, Apis cerana, is a native honeybee species in Korea which is important in agriculture for pollination and honey production. For better understanding of the physiology of A. cerana, high-throughput Illumina transcriptome sequencing was performed to analyze the gene expression profiles of queen, worker, and larva. A total of 219,799,682 clean reads corresponding to 22.2 Gb of nucleotide sequences was obtained from the whole body total RNA samples. The Apis mellifera reference mRNA sequence database was used to measure the gene expression level with Bowtie2 and eXpress software, and the Illumina short reads were then mapped to 11,459 out of 11,736 A. mellifera reference genes. Total of 9,221 genes with FPKM value greater than 5 of each sample group were subjected to eggNOG with BLASTX for gene ontology analysis. The differential gene expression between queen and worker, and worker and larva were analyzed to screen the overexpressed genes in each sample group. In the queen and worker sample group, total of 1,766 genes were differentially expressed with 887 and 879 genes overexpressed over two folds in queen and worker, respectively. In the worker and larva sample group, total of 1,410 genes were differentially expressed with 1,009 and 401 genes overexpressed over two folds in worker and larva, respectively.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.39-44
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• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.99-107
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• 1989

The study was conducted to obtain some basic information to establish the system of performance-tests and selection of honeybee queens(Apis mellifera) under Korean circumstances, Colony performances were tested with thirty colonies of Apis mellifera at two apiaries in Taegu, Korea from September, 1988 to August 1989. The results of performance-testing on the colonies are summarized as follows : The colony weight measured before wintering was averaged $23.6{\pm}1.90kg$ and the colony weight was decreased by $2.9{\pm}0.82kg$ in average during winter season. Thirteen colonies were entered in two story hive from thirty single box colonies from April 17 to May 5, 1989 with increase of bee population and, consequently, the ability of enter-supers of the colonies apperared to be low. The ability of collecting pollen was measured to be $14.8{\pm}2.15gr$ per colony during 24 hours in April, and the number of swarm cells was counted $12.5{\pm}3.43$ cells per colony in aveage. Tendency to use propolis appeared to be moderate, and the number of returning foragers for a minute per colony was counted $108.7{\pm}18.31$ bees in average. Brood area was measured $2,464{\pm}628,67cm^2$ per colony in the post nectar flow season of acasia, and 30.8 percent of the colonies appeared to be infected with chalkbrood disease, The amount of honey production was $14.9{\pm}8.49kg$ per colony, which was harvested two times during the main nectar flow season of acasia.

• BMB Reports
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• v.36 no.6
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• pp.572-579
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• 2003

An expressed sequence tag (EST) library was established from the hypopharyngeal glands of Apis cerana. Sixty-six recombinant clones, possessing inserts >500 bp, were randomly selected and unidirectional sequenced. Forty-two of these (63.6%) were identified as homologues of Major Royal Jelly Proteins families 1, 2, 3, and 4 of A. mellifera (AmMRJP) for which MRJP1 was the most abundant family. The open-reading frame of the MRJP1 homologue (AcMRJP1) was 1299 nucleotides that encoded 433 deduced amino acids with three predicted N-linked glycosylation sites. The AcMRJP1 sequence showed 93% and 90% homologies with nucleotide and deduced amino acid sequences of AmMRJP1, respectively. Two complete transcripts of apisimin, and one and two partial transcripts of $\alpha$-glucosidase and glucose oxidase, were also isolated. In addition, the royal jelly proteins of A. cerana were purified and characterized using Q-Sepharose and Sephadex G-200 column chromatography. The native forms of protein peaks A1, A2, B1, and C1 were 115, 55, 50, and 300 kDa, respectively. SDS-PAGE analysis indicated that A1 and C1 were dimeric and oligomeric forms of the 80 kDa and 50 kDa subunits, respectively. The ratio of the total protein quantities of A1 : A2 : B1 : C1 were 2.52 : 4.72 : 1 : 12.21. Further characterization of each protein, using N-terminal and internal peptide sequencing, revealed that the respective proteins were homologues of MRJP3, MRJP2, MRJP1, and MRJP1 of A. mellifera.

• Journal of Sericultural and Entomological Science
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• v.52 no.2
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• pp.134-141
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• 2014

This study was examined the pollinating activity and the economical effect according to numbers released of Apis mellifera in the $825m^2$ strawberry (Seolhyang var.) vinyl-houses. The time-zone of pollinating activity relative to numbers of honeycomb released at the strawberry (Seolhyang var.) vinyl-houses was together from 9A.M. to 4P.M., and the peak time of pollinating activity was 11A.M.. The effects on pollinating activity relative to the honeycomb numbers in the honeybee hive released at the strawberry houses were ordered 5 honeycombs (11,000 heads), 4 honeycombs (8,800 heads) and 3 honeycombs (6,600 heads). The rate of workers lost in A. mellifera hives with 5 honeybee combs and 4 honeycombs during the strawberry cultivating period were lower than that of 3 honeycombs. The rates of fruit set by pollinating activity relative to the honeycomb numbers in the honeybee hive released at the strawberry vinyl-houses were same level with over 98%. The fruit qualities; No. of seeds, sugar content and rate of normal fruit set were same level, but fruit weights were ordered 5 honeycombs in 37.2 g, 4 honeycombs in 35.6 g and 3 honeycombs in 32.6 g. The marketing incomes of 4 honeycombs and 5 honeycombs were 9% to 13% higher than that of 3 honeycombs, respectively. Therefore, when the strawberry (Seolhyang var.) was planted at $825m^2$ of a vinyl-houses, it was surveyed that the most suitable numbers of honeycomb were over 4 honeycombs (8,800 heads).

• Journal of Apiculture
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• v.32 no.3
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• pp.155-162
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• 2017

This research was carried out to evaluate the royal jelly production in Apis mellifera through the selection of superior honeybee lines. For the study, two inbred honeybee lines A and C were evaluated for the production of royal jelly by their workers, royal jelly production per colony (g), and the acceptance percentage of grafted larvae (%). The results showed that, the average royal jelly production per colony was highest ($33.7{\pm}7.41g$) in the inbred line C in comparison to other lines and the percentage of larvae acceptance ($87.8{\pm}7.5%$) was also highest in the inbred line C in comparison to other liens. The royal jelly produced by the three honeybee lines was analyzed for their trans-10-hydroxy-2-decenoic acid (10-HDA) content using a column liquid chromatography technique. Chromatographic results showed that the royal jelly produced by the inbred honeybee line C had the maximum amount of 10-HDA. We also observed age-dependent alterations of the major royal jelly proteins (MRJPs), which were differentially expressed in the two inbred lines and the commercial line, using quantitative real time-PCR (qRT-PCR).

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.382-390
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• 2008

This study was performed to evaluate the acute toxicity and residual toxicity of the 69 kinds of agrochemicals (41 insecticides, 18 fungicides, and 10 acaricides) against honeybee, Apis mellifera and bumblebee, Bombus terrestris. According to the IOBC standard, the toxicity showed below 30% was classified as non-toxic. Among 41 insecticides, five insecticides (acetamiprid, chlorfenapyr, thiacloprid, milbemectin, and buprofezin+amitraz) against the honeybee; eight insecticides (methomyl, thiodicarb, acetamiprid, chlorfenapyr, thiacloprid, abamectin, spino sad, buprofezin+amitraz) against the bumblebee did not show any toxic effect. Therefore, it thought to being safe. Other 18 fungicides and 10 acaricides were safe against the honeybee and bumblebee. In residual toxicity against the honeybee, eight insecticides (dichlorvos, methomyl, imidachlorprid, emamectin benzoate, spinosad, cartap hydrochloride, chlorfenapyr, and endosulfan) among 41 insecticides tested were safe at three days after treatment; however, sixteen insecticides (dimethoate, fenitrothion, fenthion, methidathion, phenthoate, pyraclofos, fenpropathrin, clothianidin, dinotefuran, thiamethoxam, abamectin, acetamiprid+ethofenprox, acetamiprid+indoxacarb, bifenthrin+imidacloprid, ethofenprox+phenthoate, imidacloprid+methiocarb) still remain high toxicity at eleven days after treatment. Against the bumblebee, residual toxicity showed as safe in seven insecticides (dimethoate, methidation, a-cypermethion, ethofenprox, indoxcarb, chlorpyrifos+a-cypennethrin, esfenvalerate+fenitrochion) at three days after treatment; however, eight insecticides (fenitrothion, pyraclofos, clothianidin, fipronil, acetamiprid+ethofenprox, chlorpyrifos+bifenthrin, ethofenprox+phenthoate, imidacloprid+methiocarb) still showed high toxicity at seven days after treatment. From above results, it will be useful information to select insecticides being safe and effective against the honeybee and bumblebee.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.228-233
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• 2017

The aim of the current study was to examine genotoxicological safety of purified bee venom (Apis mellifera L.) The bacterial reverse mutation in Salmonella typhimurium (TA100, TA1535, TA98, and TA1537) and Escherichia coli (WP2 uvrA) were evaluated with purified bee venom at concentrations of 0, 1.5, 5, 15, 50, 150, and $500{\mu}g/plate$. Purified bee venom was negative in Ames test with both in the presence and absence of rat liver microsomal enzyme. According to these results, we concluded that purified bee venom did not cause bacterial reverse mutation. The safety of the purified bee venom at practical doses needs to be further evaluated in in vivo genotoxicity assays.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.154-160
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• 2022

Background: The mango is one of the essential fruit trees for the economy of Thailand. Mango pollination relies primarily on insects. Other external forces, such as wind, are less efficient since pollen is sticky and aggregating. There is only one report from Thailand on the use of bees as mango pollinators. The study of the behavior and pollination efficiency of honey bees (Apis mellifera) and stingless bees (Tetragonula laeviceps species complex) was conducted in Nam Dokmai mango plantings in Phrao and Mae Taeng districts, Chiang Mai province, between February and March 2019. Results: Our results reveal that the honey bees commenced foraging earlier than the stingless bee. The number of flowers visited within 1 minute by honey bees was higher than that visited by stingless bees. The average numbers of honey bees and stingless bees that flew out of the hive per minute from 7 a.m. and 6 p.m. in the Phrao district were 4.21 ± 1.62 and 9.88 ± 7.63 bees/min, respectively, i.e., higher than those observed in Mae Taeng, which were 3.46 ± 1.13 and 1.23 ± 1.20 bees/min, respectively. The numbers of fruits per tree were significantly higher in the honey bee and stingless bee treatments (T1 and T2) than in the open pollination treatment (T3). The number of fruits between T1 and T2 treatments was not different. In the pollinator exclusion treatment (T4), no fruit was produced. Fruit size factors were not significantly different among T1, T2, and T3 treatments. Conclusions: Our results showed that insect pollination is crucial for mango production, especially with the Nam Dokmai variety in Northern Thailand. As pollinator exclusion treatment showed no fruit set, and pollinator treatment significantly increased the fruit sets compared to open access plots, a managed pollinator program would benefit the mango growers for better productivity. Both the honey bee and the stingless bee were shown to be effective as pollinators.