• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.3
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• pp.107-113
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• 2024

The efficiency of protein extraction from Hongjam, a steamed mature silkworm, was quantitatively evaluated using various chemical buffers and physical methods. This study considers the difficulty of protein extraction yield due to the high content of hydrophobic amino acids in Hongjam compared to 5^th instar-3^rd day silkworm larvae. Results indicated that urea buffer enhanced protein yield more effectively than RIPA buffer. Additionally, the application of physical methods such as microwave treatment to samples treated with RIPA buffer increased yields by up to 22%, achieving concentrations as high as 3.9 mg/mL. Circular dichroism (CD) analysis showed that proteins extracted with urea buffer retained their structural integrity, exhibiting deeper and more prominent peaks associated with random coil structure. In addition, physical methods such as vortexing, sonication, microwave and homogenization increased the extraction yield of larger molecules without altering protein structures, suggesting their potential scalability for industrial applications. These results demonstrate the critical role of selecting appropriate extraction methods to optimize the yield and functionality of proteins from Hongjam, with implications for its use in biotechnological applications and nutraceuticals.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.45-50
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• 2007

Ethanol extract of 20 botanicals in 3 concentrations i.e., 2.5%, 5% and 10% were evaluated for their efficacy to improve reproductive performance of mulberry silkworm (Bombyx mod L.) through feeding botanical enriched mulberry leaves during $2^{nd}$ day of $4^{th}$ age as well as $1^{st}$ and $3^{rd}$ day of $5^{th}$ age larvae. The preliminary screening was done by ranking the botanicals based on influence in most important reproductive contributing parameters such as single cocoon weight, effective rate of rearing, pupation rate, fecundity and recovery of eggs/kg cocoon. Five botanicals viz., Asparagus recemosus, Achyranthes aspera, Tribulus terrestris, Withania somnifera, Parthenium histerophorus ranked first were further evaluated at 8% 5% and 3% concentrations to confirm their effectiveness and standardize effective concentration. Among the rearing parameters, mature larval weight, shell ratio and number of cocoons/kg were not significantly influenced by the treatments. However, reproductive parameters such as effective rate of rearing (wt), pupation rate (%), fecundity (No.) and egg recovery (g)/kg cocoon were significantly (P<0.05) influenced by the botanicals. Higher fecundity and egg recovery were obtained on treatment with Withania somnifera irrespective of concentrations. However at 5% concentration, pupation rate, fecundity as well as egg recovery were found significantly higher than that of other concentrations, confirming its effectiveness for improving reproductive efficiency.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.105-108
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• 2018

Recently matured silkworm powder was developed by RDA. In this study, the effect of pulverizing method on the particle size of matured silkworm powder was examined. FESEM was performed to observe the morphology and to measure the particle size of silkworm powder. Particle morphology of air-jet mill pulverized powder was round and smooth, however, those of roller-mill and hammer-mill pulverized mature silkworm was more harsh and square. Particle size was varied with pulverizing technique as follows; $1.1{\mu}m$ (air-jet mill), $10{\mu}m$ (roller mill), and $120{\mu}m$ (hammer mill), respectively. A proximate analysis results of air-jet mill powder showed that crude protein, crude lipid, crude fiber, and ash was 73%, 12%, 1.95%, and 3.4%, respectively. According to our results, air-jet mell technique might be used to make a tiny matured silkworm powder.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.45-51
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• 2014

A cecropin-A gene was isolated from the immunized larvae of the Japanese oak silkworm, Antheraea yamamai and designed Ay-CecA. The complete Ay-CecA cDNA consists of 419 nucleotides with 195 bp open reading frame encoding a 64 amino acid precursor that contains a putative 22-residue signal peptide, a 4-residue propetide and a 37-residue mature peptide with a theoretical mass of 4046.81. The deduced amino acid sequence of the peptide evidenced a significant degree of identity (62 ~ 78% identity) with other lepidopteran cecropins. Like many insect cecropin, Ay-CecA also harbored a glycine residue for C-terminal amidation at the C-end, which suggests potential amidation. To understand this peptide better, we successfully expressed bioactive recombinant Ay-CecA in Escherichia coli that are highly sensitive to the mature peptide. For this, we fused mature Ay-CecA gene with insoluble protein ketosteroid isomerase (KSI) gene to avoid the cell death during induction. The fusion KSI-CecA protein was expressed as inclusion body. The expressed fusion protein was purified by Ni-NTA immobilized metal affinity chromatography (IMAC), and cleaved by cyanogen bromide (CNBr) to release recombinant Ay-CecA. The purified recombinant Ay-CecA showed considerably antibacterial activity against Gram-negative bacteria, E. cori ML 35, Klebsiella pneumonia and Pseudomonas aeruginosa. Our results proved that this peptide with a potent antibacterial activity may play a role in the immune response of Japanese oak silkworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.2
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• pp.89-96
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• 2017

Various health promoting effects of steamed and freeze-dried mature silkworm powder (SMSP) have been reported. However, it is not still clear which substances in SMSP are responsible for those health promoting effects yet. In this study, we examined and compared the quantities of phytochemicals in SMSP and freeze-dried mulberry leave powder (FMLP). To investigate the optimal solvent for extracting phytochemicals from SMSP and FMLP, we used four different solvents. Among them, 80% ethanol extracts from SMSP and FMLP contained the highest amount of five flavonoids examined. In addition, FMLP had high contents of flavonoids compared with those of SMSP. The amounts of rutin, isoquercetin, astragalin, quercetin, and kaempferol in FMLP were $5.078{\pm}0.187mg/g$, $5.162{\pm}0.083mg/g$, $2.989{\pm}0.061mg/g$, $3.317{\pm}0.236mg/g$, and $2.243{\pm}0.237mg/g$, respectively, while the amounts of rutin, isoquercetin, astragalin, quercetin, and kaempferol in SMSP were $0.171{\pm}0.024mg/g$, $0.252{\pm}0.032mg/g$, $0.374{\pm}0.031mg/g$, $0.645{\pm}0.063mg/g$, and $0.0512{\pm}0.047mg/g$, respectively. Taken together, SMSP could be a source for providing various and readily absorbable flavonoids.

• Food Science and Industry
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• v.55 no.2
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• pp.154-165
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• 2022

Humans have been breeding the mulberry silkworm for the long period of time to obtain silk fabric and nutrient-rich pupae. Currently, silkworm larvae, pupae, and silk-Fibroin hydrolysates are registered as food raw materials, while silkworm feces and Bombyx batryticatus are registered as Korean traditional medicines. Among sericulture products, individually recognized health functional food ingredients include silk-protein acid-hydrolysates for immunity enhancement, Fibroin-hydrolysates for memory improvement, and freeze-dried 5^th instar and 3^rd-day-silkworm powder for lowering-blood sugar. Recently, HongJam produced by steaming and freeze-drying mature silkworms were reported to have various health-promoting effects such as preventing the onset of Alzheimer's disease and Parkinson's disease, enhancing gastro-intestinal functions, improving skin-whitening and hair growth, and extending healthspan. By consuming silkworm products with various health-promoting effects, it is possible to increase the healthspan of human beings, thereby reducing personal and national medical expenses, resulting in increasing the individual's happiness.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.69-78
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• 1965

1. In younger larval stages, the incubation period of Spicaria pracina was showed to generally last for 8 days after the inoculation of 1st instar, for 11 days after that of 2nd instar, and for 12 days after that of 3rd instar. 2. The more the inoculum of spore is, the more silkworm jundices appear severely throughout all stage except 1st instar. 3. Especially in matured larval stages, more death rate due to silkworm jundice was showed to appear than that due to green muscardine and the more the larvae became mature, the more the loss due to jundice were severe. 4. Among other inoculum, the control by 5 per cent cerisan lime resulted in getting the best economical effect while this chemicals did harm to the silkworms, being of 20.1 per cent death rate.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.72-77
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• 2021

Silkworms have traditionally been used to produce silk and textiles. However, steamed and freeze-dried mature silkworm larval powder (SMSP) contain large amounts of amino acids, vitamins, and essential minerals. In this study, we investigated the potential of SMSP as a hangover-relieving agent. Thirty individuals who met the selection criteria and exclusion criteria were included in the study and subsequently underwent a double-blind, randomized, placebo-controlled, cross-design human application test. Importantly, the test product containing SMSP (CKDHC) was proven to alleviate hangovers through a significant reduction in the plasma concentration of acetaldehyde in the context of an alcohol-induced hangover model. In particular, from 0.5 h after SMSP intake, the blood acetaldehyde concentration (mg/L), area under the time curve (AUC; indicating the degree of bioabsorption of blood acetaldehyde), and the highest blood acetaldehyde concentration (Cmax) were reduced. Altogether, these results suggest that the test product (CKDHC) exhibits an accelerated hangover-relieving effect.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.15-23
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• 1987

The strain differences in larval walking behavior of 39 silkworm varieties, Bombyy mori, have been investigated. larval walking distance in silkworm varieties were remakably different. The walking distance was the longest in the matured larvae following the newly hatched larvae and in the other larval stage the distance was very short. The means of the walking distance in larval stages were as follows ; newly hatched larvae was 2.58cm, 3rd instar 0.72cm, 5th instar 1.18cm and matured larvae 2.94cm. The length of relative walking distances in each variety was not always in proportion to each larval stage. Therefore, the controlling factor of walking behavior was assumed to be different by the each larval stage. In the newly hatched larvae, 3rd instar and 5th instar larvae, the distribution range of walking distance was very broad in European races, narrow in Chinese races and medium in Japanese races. There was not much differences in the walking distance of mature larvae among European, Chinese and Japanese races.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.169-178
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• 2014

In this study, we investigated genetic diversity of 22 microsporidian isolates infecting tropical tasar silkworm, Antheraea mylitta collected from various geographical forest locations in the state of Jharkhand, India, using polymerase chain reaction (PCR)-based marker assay: random amplified polymorphic DNA (RAPD). A type species, NIK-1s_mys was used as control for comparison. The shape of mature microsporidians was found to be oval to elongate, measuring 3.80 to $5.10{\mu}m$ in length and 2.56 to $3.30{\mu}m$ in width. Of the 20 RAPD primers screened, 16 primers generated reproducible profiles with 298 polymorphic fragments displaying high degree of polymorphism (97%). A total of 14 RAPD primers produced 45 unique putative genetic markers, which were used to differentiate the microsporidians. Calculation of genetic distance coefficients based on dice coefficient method and clustering with un-weighted pair group method using arithmetic average (UPGMA) analysis was conducted to unravel the genetic diversity of microsporidians infecting tasar silkworm. The similarity coefficients varied from 0.059 to 0.980. UPGMA analysis generated a dendrogram with four microsporidian groups, which appear to be different from each other as well as from NIK-1s_mys. Two-dimensional distribution based on Euclidean distance matrix also revealed considerable variability among different microsporidians identified from the tasar silkworms. Clustering of few microsporidian isolates was in accordance with the geographic origin. The results indicate that the RAPD profiles and specific/unique genetic markers can be used for differentiating as well as to identify different microsporidians with considerable accuracy.