Antibacterial activity inducible in the haemolymph of the silkworm, Bombyx mori, by injection of formalin-treated Escherichia coli K-12 during the fifth larval instar and pharate adult development

1992 ◽  
Vol 101 (1-2) ◽  
pp. 165-171 ◽  
Author(s):  
Motoyuki Sumida ◽  
Hiromasa Ichimori ◽  
Shiroh Johchi ◽  
Atsushi Takaoka ◽  
Tamon Yuhki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Bombyx Mori ◽  
Adult Development ◽  
Larval Instar ◽  
K 12 ◽  
Pharate Adult ◽  
Silkworm Bombyx Mori

scholarly journals Ib-M6 Antimicrobial Peptide: Antibacterial Activity against Clinical Isolates of Escherichia coli and Molecular Docking

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
J. M. Flórez-Castillo ◽  
P. Rondón-Villareal ◽  
J. L. Ropero-Vega ◽  
S. Y. Mendoza-Espinel ◽  
J. A. Moreno-Amézquita ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Molecular Docking ◽  
Outer Membrane ◽  
Docking Simulations ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Membrane Components ◽  
K 12 ◽  
Susceptibility Assay

The Ib-M6 peptide has antibacterial activity against non-pathogenic Escherichia coli K-12 strain. The first part of this study determines the antibacterial activity of Ib-M6 against fourteen pathogenic strains of E. coli O157:H7. Susceptibility assay showed that Ib-M6 had values of Minimum Inhibitory Concentration (MIC) lower than streptomycin, used as a reference antibiotic. Moreover, to predict the possible interaction between Ib-M6 and outer membrane components of E. coli, we used molecular docking simulations where FhuA protein and its complex with Lipopolysaccharide (LPS–FhuA) were used as targets of the peptide. FhuA/Ib-M6 complexes had energy values between −39.5 and −40.5 Rosetta Energy Units (REU) and only one hydrogen bond. In contrast, complexes between LPS–FhuA and Ib-M6 displayed energy values between −25.6 and −40.6 REU, and the presence of five possible hydrogen bonds. Hence, the antimicrobial activity of Ib-M6 peptide shown in the experimental assays could be caused by its interaction with the outer membrane of E. coli.

scholarly journals STUDIES ON THE POSTERIOR SILK GLAND OF THE SILKWORM, BOMBYX MORI

1968 ◽  
Vol 38 (3) ◽  
pp. 574-588 ◽  
Author(s):  
Yutaka Tashiro ◽  
Takashi Morimoto ◽  
Shiro Matsuura ◽  
Sunao Nagata
Keyword(s):  
Bombyx Mori ◽  
Early Stage ◽  
Larval Instar ◽  
Silk Gland ◽  
Exponential Increase ◽  
Wet Weight ◽  
Rough Er ◽  
Electron Microscopical ◽  
Silkworm Bombyx Mori ◽  
Posterior Silk Gland

Growth of the posterior silk gland and biosynthesis of fibroin during the fifth larval instar of the silkworm, Bombyx mori, have been studied. In accordance with the exponential increase in the wet weight of the gland, the amounts of DNA, RNA, protein, and lipids per animal increased rapidly in the early stage of the fifth instar (0–96 hr). Biosynthesis of fibroin, on the contrary, mainly proceeds in the later stage of the fifth instar (120–192 hr). Electron microscopical observations have shown that, in the very early stage (0–12 hr), a number of free ribosomes exist in the cytoplasm. Rough endoplasmic reticulum (ER) with closely spaced cisternae was also observed. Then rough ER starts to proliferate rapidly, and at the same time lamellar ER is rapidly or gradually transformed into vesicular or tubular forms. In the later stage of the fifth instar (120–192 hr), the cytoplasm is mostly filled with tubular or vesicular ER. Golgi vacuoles, free vacuoles (fibroin globules), and mitochondria are also observed. It is concluded that in the early stage of the fifth instar the cellular structures necessary for the biosynthesis of fibroin are rapidly formed, while in the later stage the biosynthesis of fibroin proceeds at a maximum rate and utilizes these structures.

Proteolytic enzyme in the midgut of the pharate adult of the silkworm, Bombyx mori

1972 ◽  
Vol 18 (12) ◽  
pp. 2457-2467 ◽  
Author(s):  
Masaharu Eguchi ◽  
Shigeru Furukawa ◽  
Akiko Iwamoto
Keyword(s):  
Bombyx Mori ◽  
Proteolytic Enzyme ◽  
Pharate Adult ◽  
Silkworm Bombyx Mori

Studies on the Mode of Action of the Diapause Hormone in the Silkworm, Bombyx Mori L

1964 ◽  
Vol 41 (4) ◽  
pp. 855-863
Author(s):  
KINSAKU HASEGAWA
Keyword(s):  
Bombyx Mori ◽  
Adult Development ◽  
Mode Of Action ◽  
Sexual Difference ◽  
Pupal Stage ◽  
Suboesophageal Ganglion ◽  
Hormone Production ◽  
Bombyx Mori L ◽  
Diapause Hormone ◽  
Silkworm Bombyx Mori

1. The susceptibility of ‘non-diapause’ pupae to diapause hormone, the sexual difference in production of diapause hormone in the suboesophageal ganglion (SG), the changes in diapause hormone content of the SG during larval-pupal-adult development, and the hormone production in polyvoltine race, were studied by injecting diapause hormone extracts into pupae expected to produce non-diapause eggs. 2. The susceptibility of ‘non-diapause’ pupae of a bivoltine race (Daizo) was very low, or the hormone injected was almost inactivated. The susceptibility of ‘non-diapause’ race to diapause hormone is different in different races. 3. As for sexual differences in content of diapause hormone in moth heads, males are superior to females, which was further substantiated by injecting extracts from the SG of both sexes. 4. From the activity of diapause hormone extracts derived from larval, pupal and adult SG, the hormone production in SG is raised during the late pupal stage, especially in males. It is also observed that larval SG produces the hormone, and the hormone production in the SG of male moths after mating becomes weak. 5. Male moth heads of ‘non-diapause’ worms (polyvoltine race), as well as of ‘diapause’ worms, contain diapause hormone; though activity is less than in ‘diapause’ worms, which reflects the occurrence of diapause eggs caused by SG-transplantation. 6. It is highly probable that the bioassay by injecting diapause hormone extracts reveals the activity of the SG in the silkworm. 7. The activity of the SG in the polyvoltine race has been discussed from standpoint of diapause determination in the silkworm.

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