Grupo de Aplicaciones de Materiales Biocompatibles, Departamento de Química, Facultad de Ingeniería, Universidad de Buenos Aires (UBA), C1063ACV, CABA, Argentina; Instituto de Tecnología en Polímeros y Nanotecnología (ITPN), Facultad de Ingeniería, Universidad de Buenos Aires (UBA)-CONICET, C1127AAQ, CABA, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1425FQB, Godoy Cruz 2290, CABA, Argentina.
Grupo de Aplicaciones de Materiales Biocompatibles, Departamento de Química, Facultad de Ingeniería, Universidad de Buenos Aires (UBA), C1063ACV, CABA, Argentina; Instituto de Tecnología en Polímeros y Nanotecnología (ITPN), Facultad de Ingeniería, Universidad de Buenos Aires (UBA)-CONICET, C1127AAQ, CABA, Argentina.
Carbohydr Polym. 2018 Dec 15;202:409-417. doi: 10.1016/j.carbpol.2018.07.084. Epub 2018 Jul 30.
The study examines the use of macrobeads for the controlled-release of bacteria. Macrobeads were prepared by an easy dripping-technique using 20/80 wt/wt chitosan-starch blends and sodium tripolyphosphate as cross-linking agent. The resulting polymeric matrix was examined by SEM, XRD, TGA, and solid-RMN. The swelling-equilibrium, thermal behaviour, crystallinity, and size of macrobeads were affected by the autoclave-sterilization. The diameter of the sterilized xerogel was c.a. 1.6 mm. The results suggested that ionotropic-gelation and neutralization were the mechanisms underlying hydrogel formation. Plant growth-promoting bacteria (PGPB) were loaded into macrobeads separately or co-inoculated. Bacteria loaded macrobeads were dried and stored. Bacteria survived at least 12 months in orders of 10 CFU of A. brasilense/g and 10 CFU of P. fluorescens/g. Bacterial release in sterile saline solution tended to a super Case-II transport mechanism. Polymeric-matrix release efficiently both PGPB in natural soils, which uncovers their potential for the formulation of novel and improved biofertilizers.
该研究考察了大珠粒在细菌控制释放中的应用。大珠粒是通过使用 20/80wt/wt 壳聚糖-淀粉混合物和三聚磷酸钠作为交联剂的简单滴注技术制备的。用 SEM、XRD、TGA 和固体-RMN 对所得聚合物基质进行了研究。溶胀平衡、热行为、结晶度和大珠粒的大小受高压釜灭菌的影响。灭菌的干凝胶的直径约为 1.6mm。结果表明，离子凝胶化和中和是水凝胶形成的机制。植物促生菌（PGPB）分别或共同接种到珠粒中。将负载细菌的珠粒干燥并储存。细菌在 10 CFU 的 A. brasilense/g 和 10 CFU 的 P. fluorescens/g 的数量级下至少存活 12 个月。在无菌盐溶液中的细菌释放倾向于超 II 型传输机制。聚合物基质在天然土壤中有效地释放 PGPB，这揭示了它们在新型和改良生物肥料配方中的潜力。
