Analysis of silks from silkworms reared with artificial diet and mulberry leaves
Objective In order to understand the quality differences between silk fibers produced by artificial diet feeding and mulberry leave feeding,and to investigate the possibility of substituting artificial diet for mulberry leaves in sericulture,this research systematically analyzed the differences in morphology,composition,chemical structure,and mechanical properties between artificial diet-fed silkworm silk and mulberry leaves-fed silkworm silk.Method In this study,two groups of silkworms were fed separately with artificial diet and mulberry leaves.The silk cocoons and fibers were carefully examined for their morphological characteristics using scanning electron microscopy.In order to evaluate the composition of the silk,elemental analysis,amino acid content analysis,and sodium dodecyl sulfate polyacrylamide gel electrophoresis testing were conducted to compare the two feeding methods.Additionally,infrared absorption spectroscopy,two-dimensional wide-angle X-ray scattering(2D-WAXS),and silk tensile testing were employed to elucidate the differences in chemical structure and mechanical properties between artificial diet-fed and mulberry leaves-fed silkworm silk.Results The silk with artificial diet feeding exhibited no significant differences in fiber appearance compared to the silk with mulberry leave feeding.Protein composition analysis showed that there was no difference in the type and content of silk fibroin heavy chain protein,silk fibroin light chain protein and sericin protein between the two groups of silk samples.However,notable differences were observed in terms of element content,proline content,secondary structure,and crystallinity.The element analysis revealed that,except for Na and Si,the artificial diet silk had significantly lower content of other elements compared to the mulberry leaves silk.Furthermore,artificial diet silk exhibited lower levels of trace elements such as Al,Cr,and B,while higher levels of Fe,Mn,Zn,and Cu were detected compared to the mulberry leaves silk.Analysis of amino acid content indicated a distinct variation of proline content between the two silk types,with significantly higher proline content in the artificial diet silk.The analysis of secondary structure and crystallinity demonstrated higher β-turn content and lower random coil content in the artificial diet silk compared to the mulberry leaves silk.2D-WAXS analysis revealed lower crystallinity(60.1％)in the artificial diet silk compared to the mulberry leaves silk(65.2％).Tensile testing showed that the artificial diet silk exhibited a higher average breaking strain(19.8±8.2)％,while the mulberry leaves silk demonstrated higher breaking strength(361.6±97.2)MPa,although the difference was not statistically significant.Conclusion The study findings indicated that the observed disparities in morphology,composition,chemical structure,and mechanical properties between artificial diet-fed and mulberry leaves-fed silk were not significant,suggesting the potential of artificial diet as a substitute for mulberry leaves feeding to obtain high-quality silk fibers.The two feeding methods have no significant impact on the quality of silk produced.In addition,artificial diet offered advantages such as the potential for adding beneficial substances and avoiding harmful substances,further highlighting its suitability as a replacement for mulberry leaves in silkworm feeding.Future research may focus on incorporating beneficial substances such as metal ions or proline into artificial diets,by optimizing the formula of artificial diets and adding appropriate amounts of beneficial elements for compensation,in order to selectively improve the mechanical properties of silk and enhance the wider value of artificial diet feeding silk in sericulture.Overall,this comprehensive analysis contributes valuable insights and directions for improving artificial diet in sericulture and enhancing the quality of silk and lays a solid foundation for further promoting the strategic goal of industrialized sericulture of whole age feeding in the future.
万方数据
维普
