Kousheh Seyedeh Alaleh, Moradi Mehran, Tajik Hossein, Molaei Rahim
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
Int J Biol Macromol. 2020 Jul 15;155:216-225. doi: 10.1016/j.ijbiomac.2020.03.230. Epub 2020 Mar 30.
Microbial biomass, as an environmentally friendly resource, has drawn a lot of attention as green biomaterials for production of unique and functionalized carbon dots (CDs). However, the hydrophilicity and high porosity drive bacterial nanocellulose as a suitable matrix for CDs with antimicrobial, photoluminescent and ultraviolet blocking features. For the first time, antimicrobial CDs were synthesized by hydrothermal method from cell-free supernatant of Lactobacillus acidophilus and characterized. Antimicrobial performance of CDs was examined on Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive). Additionally, the as-prepared CDs embedded by ex-situ method into nanocellulose in order to fabricate antimicrobial/ultraviolet protective nanopaper. The photoluminescent CDs with an average size of 2.8 nm and high-hydroxylated groups were synthesized. The CDs at 500 mg mL concentration had antibacterial activity towards both bacteria. Moreover, nanopaper displayed a fluorescence appearance under ultraviolet. Nanocellulose with CDs loading capacity of 71.74 ± 4.13 mg cm represented an appropriate stretchability and flexibility in comparison to nanocellulose. The CDs incorporated nanopaper also depicted greater ultraviolet-blocking specifications and inhibitory activity on Gram-positive bacterium than Gram-negative one. CDs can be used as a novel fluorescence antimicrobial/ultraviolet protective material in the nanocellulose film in order to develop an antimicrobial and forgery-proof packaging due to their fluorescence appearance.
微生物生物质作为一种环境友好型资源，作为生产独特且功能化碳点（CDs）的绿色生物材料已备受关注。然而，亲水性和高孔隙率使细菌纳米纤维素成为具有抗菌、光致发光和紫外线阻挡特性的CDs的合适基质。首次通过水热法从嗜酸乳杆菌的无细胞上清液中合成了抗菌CDs并进行了表征。考察了CDs对大肠杆菌（革兰氏阴性菌）和单核细胞增生李斯特菌（革兰氏阳性菌）的抗菌性能。此外，通过异位法将制备好的CDs嵌入纳米纤维素中，以制备抗菌/紫外线防护纳米纸。合成了平均尺寸为2.8 nm且具有高羟基化基团的光致发光CDs。浓度为500 mg mL的CDs对两种细菌均具有抗菌活性。此外，纳米纸在紫外线下呈现荧光外观。与纳米纤维素相比，负载CDs能力为71.74±4.13 mg cm的纳米纤维素具有适当的拉伸性和柔韧性。掺入CDs的纳米纸对革兰氏阳性菌的紫外线阻挡性能和抑制活性也比对革兰氏阴性菌更强。由于其荧光外观，CDs可作为纳米纤维素膜中的新型荧光抗菌/紫外线防护材料，用于开发抗菌防伪包装。
