Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Wageningen Universiteit, VLAG Graduate School, Food Process Engineering, Hollanda
Tezin Onay Tarihi: 2021
Tezin Dili: İngilizce
Öğrenci: Xinyuan Cao
Asıl Danışman (Eş Danışmanlı Tezler İçin): Murat Yanat
Özet:
Recently chitin and chitosan nanoparticles have been taking attention due to their broad applications. They can be added into the polymers to enhance the mechanical properties of the nanocomposite. Besides, both chitin and chitosan showed antimicrobial activity against bacteria, fungi and yeast. It is supposed that by adding chitin and chitosan nanoparticles into polymers, the nanocomposite can obtain the antimicrobial property. Many factors such as degree of deacetylation of chitin/chitosan, molecular weight, type of microorganism (i.e. G+ or G- bacteria) influence the antimicrobial activity of chitin and chitosan. Besides, the current studies are not satisfied in terms of understanding the mechanism of antimicrobial activity of chitin and chitosan. In this study, an experiment plan to investigate the antimicrobial activity of chitin and chitosan nanoparticles and chitin/chitosan nanoparticle-PLA composite was developed, in order to further investigate the antimicrobial activity of chitin/chitosan nanoparticle-PLA composite in following up studies. Besides, a meta-analysis was conducted. Data of minimum inhibitory concentrations (MIC) of chitin/chitosan, degree of deacetylation (DD), molecular weight of chitin/chitosan (MW) and information of G+/G- bacteria were collected from primary studies. These data were analyzed to investigate which factors influence the antimicrobial activity of chitin and chitosan and how are the impacts. Multiple linear regression analyses were done for data with both degree of deacetylation and molecular weight information as factors affecting the MIC. Firstly, data of all definitions of MIC were analyzed, then two main definitions of MIC were selected and logarithmic transformation was done for MIC in order to normalize the data. The results showed that different definitions of MIC led to different results. MIC of G- bacteria was lower than MIC of G+ bacteria, which means G- bacteria are more sensitive to chitin/chitosan. This result might be caused by the interaction between the positive charges of chitosan and negative charges of lipopolysaccharide component in cell membrane of G-bacteria.