title: Facts and myths of antibacterial properties of silk.
abstract: Silk cocoons provide protection to silkworm from biotic and abiotic hazards during the immobile pupal phase of the lifecycle of silkworms. Protection is particularly important for the wild silk cocoons reared in an open and harsh environment. To understand whether some of the cocoon components resist growth of microorganisms, in vitro studies were performed using gram negative bacteria Escherichia coli (E. coli) to investigate antibacterial properties of silk fiber, silk gum, and calcium oxalate crystals embedded inside some cocoons. The results show that the previously reported antibacterial properties of silk cocoons are actually due to residues of chemicals used to isolate/purify cocoon elements, and properly isolated silk fiber, gum, and embedded crystals free from such residues do not have inherent resistance to E. coli. This study removes the uncertainty created by previous studies over the presence of antibacterial properties of silk cocoons, particularly the silk gum and sericin.
authors.affiliation: Australian Future Fibres Research & Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
authors.forename: Jasjeet
authors.initials: J
authors.lastname: Kaur
authors.forename: Rangam
authors.initials: R
authors.lastname: Rajkhowa
authors.forename: Tarannum
authors.initials: T
authors.lastname: Afrin
authors.forename: Takuya
authors.initials: T
authors.lastname: Tsuzuki
authors.forename: Xungai
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D012831:Bombyx; D004926:Escherichia coli; D005349:Fibroins; D047030:Sericins; D047011:Silk / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D047030:Sericins; D047011:Silk; D005349:Fibroins
keywords: antibacterial; calcium oxalate hydrate crystals; degumming; protection; sericin; silk cocoon; silk fiber