División de Ingeniería Química y Bioquímica, Tecnológico de Estudios Superiores de Ecatepec, Av. Tecnológico S/N, Valle de Anáhuac, Ecatepec de Morelos, Estado de México 55210, Mexico; Departamento de Ingeniería y Tecnología, Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Cuautitlán-Campo Uno, Av. 1° de mayo s/n Colonia Santa Ma. Las Torres, Cuautitlán Izcalli, Estado de México C.P. 54740, Mexico.
División de Ingeniería Química y Bioquímica, Tecnológico de Estudios Superiores de Ecatepec, Av. Tecnológico S/N, Valle de Anáhuac, Ecatepec de Morelos, Estado de México 55210, Mexico.
Int J Biol Macromol. 2023 Mar 1;230:123204. doi: 10.1016/j.ijbiomac.2023.123204. Epub 2023 Jan 10.
Two lactic bacteria were used in sequential co-cultures to demineralize (DM) and deproteinize (DP) shrimp shells (SS) to obtain chitin. During the first 24 h, Lactobacillus delbrueckii performed the DM in a minimal medium containing 100 g/L SS and 50 g/L glucose. Then, three different conditions were assayed to complete DM and perform the DP stage: 1) Bifidobacterium lactis was added with 35 g/L of glucose (Ld-G → Bl-G); 2) only B. lactis was added (Ld-G → Bl); and 3) a 35 g/L pulse of glucose was added, and at 48 h, B. lactis was inoculated (Ld-G → G → Bl). The highest DM (98.63 %) and DP (88 %) were obtained using a glucose pulse in the DM step and controlling the pH value above 6.0 in the DP step. Finally, a deacetylases cocktail produced by Aspergillus niger catalyzed the deacetylation of the resulting chitin. The chitosan samples had a deacetylation degree higher than 78 % and a solubility of 25 % in 1.0 N acetic acid. The deacetylation yield was 74 % after a mild chemical treatment, with a molecular weight of 71.31 KDa. This work reports an entirely biological process to get chitin and chitosan from SS with high yields.
两种乳酸菌被用于顺序共培养，以脱矿质（DM）和脱蛋白（DP）虾壳（SS）来获得壳聚糖。在最初的 24 小时内，德氏乳杆菌（Lactobacillus delbrueckii）在含有 100 g/L SS 和 50 g/L 葡萄糖的最小培养基中进行 DM。然后，为了完成 DM 和 DP 阶段，测试了三种不同的条件：1）添加 35 g/L 葡萄糖的长双歧杆菌（Bifidobacterium lactis）（Ld-G→Bl-G）；2）仅添加 B. lactis（Ld-G→Bl）；3）添加 35 g/L 葡萄糖脉冲，在 48 小时时接种 B. lactis（Ld-G→G→Bl）。在 DM 步骤中使用葡萄糖脉冲并在 DP 步骤中控制 pH 值高于 6.0 时，可获得最高的 DM（98.63%）和 DP（88%）。最后，黑曲霉（Aspergillus niger）产生的脱乙酰酶混合物催化所得壳聚糖的脱乙酰化。壳聚糖样品的脱乙酰度高于 78%，在 1.0 N 乙酸中的溶解度为 25%。经过温和的化学处理后，脱乙酰化收率为 74%，分子量为 71.31 KDa。这项工作报道了一种完全生物过程，可从 SS 中获得具有高产量的壳聚糖和壳聚糖。
