• Journal of Life Science
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• v.32 no.12
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• pp.997-1004
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• 2022

To verify the nutritional superiority and safety of Protaetia brevitarsis larvae fed a food source containing soybean curd cake, the nutrients and harmful substances of larvae reared only with fermented oak sawdust and a food source containing soybean curd cake were comparatively analyzed. The crude protein content was 50.0% in the larvae fed with a food source containing soybean curd cake (SCC), which was 1.1 times higher than that of the larvae fed with fermented oak sawdust (FOS) at 44.7%. Potassium, which showed the highest content among macrominerals, was 2.5 times higher in SCC (3,169.6 mg/100 g) than in FOS (1,245.9 mg/100 g). Among trace minerals, zinc showed 12.6 times higher content than FOS (8.2 mg/100 g) in SCC (103.0 mg/100 g). As a result of the analysis of harmful substances, all heavy metals met the edible insect control standards, and pathogenic microorganisms, such as E. coli and Salmonella spp, were not detected. According to the above study, the larvae of P. brevitarsis fed soybean curd cake contain various nutrients, and safety has also been confirmed, so it is judged to be suitable for use as food.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.447-454
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• 2023

In the environment in which humans live, there are various antigens that invade the human body and interfere with humans leading a healthy life, so the immune system recognizes the antigen then removes them through a complex mechanism. Macrophages are widely distributed immune cells involved in the innate immune system, and produce various immune modulators such as inducible nitric oxide synthase-induced nitric oxide, cyclooxygenase-2 induced prostaglandin E2 and proinflammatory cytokines such as tumor necrosis factor-alpha. On the other hand, Protaetia brevitarsis seulensis larvae are a type of edible insect that have emerged as an alternative to the future food supply problem. The immuno-modulatory effect through the activation of murine macrophage RAW264.7 cell via mitogen-activated protein kinases (MAPKs)/nuclear factor-kappa B (NF-κB) signaling pathways has been reported. Based on this report, in this study, we confirmed how the expression of immune modulators induced by Protaetia brevitarsis seulensis larvae extracts in RAW264.7 cells was changed by treatment with pharmacological inhibitors of toll-like receptor 4 (TLR4), MAPKs and NF-κB signaling pathways. As a result, reduction of immune modulators was confirmed in the c-Jun N-terminal kinase (JNK) inhibitor treatment group and NF-κB inhibitor treatment group among the Protaetia brevitarsis seulensis larvae-treated RAW264.7 cell. Furthermore, in the TLR4 inhibitor-treated group, decreases in phosphorylation of JNK and NF-κB factors were confirmed in Protaetia brevitarsis seulensis larvae-treated RAW264.7 cell, as well as decreases in immune modulators. This results suggest that Protaetia brevitarsis seulensis larvae activates RAW264.7 cells by the engagement of TLR4-JNK/NF-κB signaling pathway.

• Journal of Life Science
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• v.32 no.6
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• pp.455-462
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• 2022

This study examined changes in the body composition of Protaetia brevitarsis larvae fed sulfur and selenium. Among the general chemical components, an increase in protein was observed in the sulfur-fed group, whereas an increase in fatty acid was found in the groups fed selenium and sulfur/selenium. The structural amino acid showed some tendency to be increased compared to the control group, but this was especially true in the sulfur-fed group. The free amino acid were increased in the groups fed selenium and sulfur/selenium, with GABA, Glu, and Pro, in particular, being increased in the group fed sulfur/selenium. Among the essential amino acids, Met, Trp, and Val tended to be increased in selenium and sulfur/selenium groups. Saturated and polyunsaturated fatty acids showed a tendency to increase in the group fed sulfur/selenium, but monounsaturated fatty acid tended to be decreased in the group. In particular, no oleic acid was detected in the sulfur/selenium group, whereas palmitic acid, palmitoleic acid, and linoleic acid were increased. From observations of these body composition changes associated with the feeding of sulfur and selenium, it is estimated that the group fed sulfur/selenium would likely undergo a pronounced change in body composition. Therefore, we suggest that it is possible to manufacture a food that has enhanced functionality by appropriately adjusting the diet of Protaetia brevitarsis larvae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.397-402
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• 2013

The pharmacological efficacy of Protaetia (P.) brevitarsis larvae has been described in the Dongui Bogam. It is believed that the larvae are particularly useful for hepatic disorders. However, natural aversion has made it difficult to consume these larvae as food. Thus, we sought to make an eatable form of the larvae by establishing optimal conditions for larvae preparation. Larvae were selectively bred, sterilized, and a powder of larvae generated by freeze-drying. Afterward, the CellTiter $96^{(R)}$ AQueous Non-Radioactive Cell Proliferation Assay (MTS) with the RAW 264.7 cell line was used to validate the safety of the powder as a food ingredient. We determined that oak sawdust sterilized by water vapor for 5 minutes could be used for larvae feed, and a feeding for 3~5 days followed by a fasting for 3 days were optimal conditions for larvae preparation. In addition, sterilization of larvae at $115^{\circ}C$ and $0.9kgf/cm^3$ (to avoid contamination of pathogenic bacteria and fungi) was successfully applied in the production of edible powder from P. brevitarsis. The optimized processes established in our experiments can be used in the industrial production of P. brevitarsis as a food ingredient.

• Korean journal of applied entomology
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• v.55 no.3
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• pp.215-221
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• 2016

In this study, we used electron microscopic analysis to characterize the hemocytes in the last larva of Protaetia brevitarsis seulensis (Colbe) (Cetoniidae, Coleoptera). Granulocytes (GR), plasmatocytes (PL), oenocytoids (OE), spherulocytes (SP), prohemocytes (PR) and adipohemocytes (AD) were classified based on their size and ultrastructural differences in the circulating hemocytes. Many dark granules (<$1{\mu}m$ in diameter) in the GR's cytoplasm were observed and well-developed mitochondria, endoplasmic reticulum (ER), nucleus, and Golgi complex were also seen. After microorganisms infected, the GRs were morphologically activated and phagocytosed them. Especially, dark granules (lysosomes) were fused themselves and these bigger granules finally agglomerate together with microorganisms. Other hemocytes seem to have no immune functions.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.1
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• pp.83-85
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• 2007

A glycine and proline-rich antibacterial protein was cloned from larvae of a beetle, Protaetia brevitarsis. The DNAs encoded a deduced propeptide of 127 amino acid residues with predicted molecular weight of 14.0 kDa and PI of 7.89. Structural analysis of this protein indicated the presence of a recognition sequence for the cleavage site within the constitutive secretory pathway(Arg-Xaa-Lys/Arg-Arg), suggesting that mature portion(72 amino acid residues) is produced by cleavage of signal peptide and propeptide from 127 amino-acid-long precursor protein. Mature portion sequence of this protein showed 72% similarity to that of Oryctes rhinoceros Rhinocerosin and 91% to that of Holotrichia diomphalia holotricin 2. The mRNA expression was reached the highest level at 4 hrs after E. coli injection and then declined gradually.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.131-135
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• 2008

A cDNA encoding a defensin-like peptide (Protaetiamycine) from the larvae of a beetle, Protaetia brevitarsis was cloned. The DNAs encoded the deduced propeptide of 79 amino acid residues with the predicted molecular weight of 8.4 kDa and PI of 8.24. Overall amino acid sequence of this protein has 39% similarity to that of Rhodnius prolixus defensin, 43% similarity to that of Acalolepta luxuriosa defensin, and 72% similarity to that of Oryctes rhinoceros defensin, suggesting that this gene is an insect defensin. In an attempt to apply the anti-bacterial peptide to the development of therapeutic agents, a 12-mer peptide amidated at its C-terminus, ACAAHCLAIGRG-$NH_2$ (Ala55-Lys66-$NH_2$, 12Pbn) was synthesized. This peptide showed some antifungal activity against Candida albicans. To increase antifungal activity, six 9-mer peptides were synthesized by modifying amino acid sequences of 12Pbn fragment. Among these peptides, 9Pbm3-9Pbm6 exhibited strong activity compared with Cecropin B and mellitin.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.1
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• pp.1-9
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• 2018

The purpose of this study was to determine the best method for minimizing the occurrence of Metarhizium anisopliae infection of Protaetia brevitarsis seluensis during mass breeding on agricultural farms. There is a high demand for the use of P. b. seluensis larvae in animal feed and as food for humans. However, mass breeding results in the entomopathogenic fungal (usually M. anisopliae) infection of P. b. seluensis. A mixture of microorganisms (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) delayed fungal infection by M. anisopliae, which infected fewer P. b. seluensis when the microorganism mixture was added to sawdust as feed for P. b. seluensis. When sawdust with the effective microorganisms (EM) was given to P. b. seluensis for 30 d, their mortality rate was approximately 35 % less than that of the control group, which was fed sawdust without the EM. In addition, the growth of M. anisopliae on agar media spread with each bacterium as inhibited by up to 80 % more than those spread with 4 % sodium hypochlorite, which is a harmless fungal inhibitor generally used in agricultural farms for disinfection.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.471-478
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• 2021

Effective microorganisms (EM), which are sources of fermentation byproducts in herbal medicine, were compared with oyster mushrooms(OM) to identify alternative larval feeds for white-spotted flower chafer (Protaetia brevitarsis seulensis). The nutritional composition of each fermented feed was analyzed. The content of crude protein, crude fat, and fiber was higher in the OM fermented feed, except for crude ash. No difference in nutritional content of larvae based on fermented feed was observed. A comparative weekly analysis of the live weights of larvae was based on the fermented feed used. The average weight was significantly higher in the feeds using EM and OM from third week of observation. The larval survival rate in the presence of fermented feed was 96.7% compared with 9.8% with non-fermented feed. The results suggest that fermented food source is essential for the growth of white-spotted flower chafer, and OM was a stable alternative to EM as a fermentation source for the survival of white-spotted flower chafer.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.374-379
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• 2020

The white-spotted flower chafer (Protaetia brevitarsis) larva is one of the insects widely-used for edible and medicinal purposes in Eastern Asia. As a result of increasing demand for P. brevitarsis, massrearing systems in domestic farms have become necessary. However, the mass-rearing of larvae under confined rearing conditions could provide conditions unsuitable for preventing entomopathogenic diseases. Metarhizium anisopliae is the strongest fatal entomopathogenic fungus against P. brevitarsis. For inhibition of M. anisopliae, we used a Rhus verniciflua Stokes extract that has antifungal components. We investigated the inhibitory effect of the R. verniciflua extract at 1%, 5%, and 10% concentrations. The results showed that a 1% R. verniciflua extract added to sawdust produced a significantly low P. brevitarsis mortality rate. Moreover, extract-treated groups were heavier and had a shorter larval period than those of the untreated group. Consequently, we suggest that using an R. verniciflua extract can reduce the P. brevitarsis fatality rate from entomopathogenic fungi (e.g. M. anisopliae), resulting in more effective mass-rearing systems for P. brevitarsis.