Preparation And Application Of Bacterial Cellulose-based Antibacterial Dressing PLBC

Bacterial cellulose is a natural biopolymer secreted by microorganisms.It is made up of ?-1,4 glycosidic bonds of glucose molecules.BC has such high purity,high crystallinity,excellent elastic modulus,and high tensile strength.BC has been widely used in food,paper,medical materials,acoustic diaphragms and other fields due to its strength and high water holding capacity.Bacterial cellulose itself has no antibacterial properties.In order to make it have antibacterial properties,tissue regenerative power and biocompatibility,and expand the application range of bacterial cellulose,various composite antibacterial dressings have been prepared.?-polylysine is a biological preservative with good antibacterial effect.?-PL can be decomposed into lysine,one of the eight essential amino acids in the human body.It is a nutritive bacteriostatic agent.In this paper,a new antibacterial dressing PLBC was prepared by combining ?-polylysine with bacterial cellulose,and the performance and bacteriostatic performance of the composite antibacterial dressing PLBC obtained by fermentation were investigated.The main research results were as follows:The effects of medium carbon source,glucose concentration,nitrogen source and ethanol concentration on fermentation were investigated.Based on the single factor experiment,the carbon sourceand nitrogen source were screened.Finally,the central response surface method was used to further optimize the medium formula.The optimal medium formula was: glucose 50 g / L,peptone 7.5 g / L,yeast extract 7g / L,ethanol 1.6%,the bacterial cellulose yield was 4.9 g / L.PLBC composite membranes were prepared.The physicochemical properties of composite membranes such as water absorption and dehydration rate,microstructure,infrared spectrum analysis,XRD analysis and mechanical properties were investigated.It was proved by analysis that PL and BC were well mixed,and the addition of PL did not affect.The crystal structure of BC,the addition of PL enhances the toughness and tensile strength of BC film,which will be beneficial to the application of PLBC film in medical dressings.The antibacterial activity of the PLBC composite membrane was verified by the inhibition zone method and the absorbance method.The experimental results showed that the PLBC composite membrane had good antibacterial activity.According to the PLBC composite membrane inhibition mechanism test(cell content dissolution test),the inhibition was confirmed.The mechanism of the bacteria is that PL in the PLBC composite membrane binds to the microbial cells and forms pores on the surface of the cell membrane,and the cell contents are released to kill the microbial cells.This bacteriostatic mechanism can be applied to G+ and G-bacteria.Based on the results of this test,it is foreseeable that PLBCcomposite membranes will have broad application potential in many fields such as medical dressings,food hygiene,infants and women's products.