Lagat Mevin Kiprotich, Were Samuel, Ndwigah Francis, Kemboi Violah Jepkogei, Kipkoech Carolyne, Tanga Chrysantus Mbi
Department of Botany, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-02000, Kenya.
Department of Food and Nutritional Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-02000, Kenya.
Microorganisms. 2021 Nov 23;9(12):2417. doi: 10.3390/microorganisms9122417.
Globally, the broad-spectrum antimicrobial activity of chitin and chitosan has been widely documented. However, very little research attention has focused on chitin and chitosan extracted from black soldier fly pupal exuviae, which are abundantly present as byproducts from insect-farming enterprises. This study presents the first comparative analysis of chemical and biological extraction of chitin and chitosan from BSF pupal exuviae. The antibacterial activity of chitosan was also evaluated. For chemical extraction, demineralization and deproteinization were carried out using 1 M hydrochloric acid at 100 °C for 2 h and 1 M NaOH for 4 h at 100 °C, respectively. Biological chitin extraction was carried out by protease-producing bacteria and lactic-acid-producing bacteria for protein and mineral removal, respectively. The extracted chitin was converted to chitosan via deacetylation using 40% NaOH for 8 h at 100 °C. Chitin characterization was done using FTIR spectroscopy, while the antimicrobial properties were determined using the disc diffusion method. Chemical and biological extraction gave a chitin yield of 10.18% and 11.85%, respectively. A maximum chitosan yield of 6.58% was achieved via chemical treatment. From the FTIR results, biological and chemical chitin showed characteristic chitin peaks at 1650 and 1550 cm-wavenumbers corresponding to amide I stretching and amide II bending, respectively. There was significant growth inhibition for , , and when subjected to 2.5 and 5% concentrations of chitosan. Our findings demonstrate that chitosan from BSF pupal exuviae could be a promising and novel therapeutic agent for drug development against resistant strains of bacteria.
在全球范围内，几丁质和壳聚糖的广谱抗菌活性已有广泛记载。然而，对于从黑水虻蛹蜕中提取的几丁质和壳聚糖，却很少有研究关注，而黑水虻蛹蜕作为昆虫养殖企业的副产品大量存在。本研究首次对从黑水虻蛹蜕中化学提取和生物提取几丁质和壳聚糖进行了比较分析。还评估了壳聚糖的抗菌活性。对于化学提取，分别使用1 M盐酸在100℃下处理2小时进行脱矿质处理，使用1 M氢氧化钠在100℃下处理4小时进行脱蛋白处理。生物几丁质提取分别通过产蛋白酶细菌和产乳酸细菌去除蛋白质和矿物质。提取的几丁质通过在100℃下用40%氢氧化钠脱乙酰化8小时转化为壳聚糖。使用傅里叶变换红外光谱对几丁质进行表征，同时使用纸片扩散法测定抗菌性能。化学提取和生物提取的几丁质产率分别为10.18%和11.85%。通过化学处理获得的壳聚糖最大产率为6.58%。从傅里叶变换红外光谱结果来看，生物几丁质和化学几丁质在1650和1550厘米波数处显示出特征性的几丁质峰，分别对应酰胺I伸缩振动和酰胺II弯曲振动。当壳聚糖浓度为2.5%和5%时，对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌有显著的生长抑制作用。我们的研究结果表明，来自黑水虻蛹蜕的壳聚糖可能是一种有前景的新型治疗剂，可用于开发抗耐药菌株的药物。
