Fecha de publicación: 01/12/2024 Fuente: Citrus Byproducts Extraction Abstract
Biological process to extract chitin from crustacean wastes may be an interesting and safe alternative than chemical process. The inoculation of lactic acid bacteria is an environmentally-friendly strategy to extract chitin especially if low-cost raw materials are utilized as fermentation substrates. The deacetylation of chitin by chemical or biological processes results in an important and multifaceted biopolymer, the chitosan, with a range of applications in diverse areas. A two-step process consisting of lactic fermentation (by Lactiplantibacillus plantarum) of shrimp wastes and chemical deacetylation of chitin to obtain chitosan was here proposed focusing on the replacement of the semi-synthetic medium MRS (de Man–Rogosa–Sharpe) by sugarcane molasses, on the variation in the concentration and drying of shrimp wastes in the fermentation step, and increased deacetylation times of chitin. Chitosan was characterized and assayed for antimicrobial activity, microsphere and film-forming properties. Diluted molasses containing 150 g/L of total reducing sugars and supplemented with 12 g/L yeast extract is a viable and cost-effective alternative to MRS to recover chitin from oven-dried shrimp wastes at a concentration of 5% w/v. A low molecular weight chitosan (95.3 kDa) was obtained after a 2-h chemical deacetylation (79.6% deacetylation degree). Molasses chitosan exhibited antibacterial and antifungal activities. Chitosan rough microspheres capable of loading antibiotic (monensin), and transparent and homogenous films were also obtained. The complete flow of operations until obtaining chitosan with considerable yields is here presented, also demonstrating the intrinsic properties of this polymer. The molasses chitosan, utilized without purification, has potential application in industry and agriculture as a biomaterial.