RESUMO
One of the well-known postoperative complications that requires a number of prophylactic and curative treatments is infection. The implications of postsurgical infections are further exacerbated by the emergence of antibiotic-resistant strains. Reduced effectiveness of synthetic antibiotics has led to an interest in plant-based substances. Extracts obtained from Nigella sativa have been shown to possess effective anti-infectious agents against bacteria frequently seen in bone infections. In this study, a fiber-based bone scaffold containing polycaprolactone, poly(lactic acid), and hydroxyapatite with N. sativa oil at varying concentrations was developed. Solvent electrospinning was used to fabricate the fibers with the specified composition. According to FE-SEM analysis, fibers with average diameters of 751 ± 82, 1000 ± 100, 1020 ± 90, and 1223 ± 112 nm were formed and successful integration of N. sativa oil into the fiber's structure was confirmed via FTIR. Staphylococcus aureus showed moderate susceptibility against the fibers with a maximum inhibition zone diameter of 11.5 ± 1.6 mm. MTT assay analysis exhibited concentration-dependent cell toxicity against fibroblast cells. In short, the antibacterial fibers synthesized in this study possessed antibacterial properties while also allowing moderate accommodation of CDD fibroblast cells at low oil concentrations, which can be a potential application for bone healing and mitigating postsurgical infections.
RESUMO
Hazelnut husk is one of the most abundant agricultural residue in Turkey. Valorization of this lignocellulosic biomass would provide a promoting alternative for economical production of pullulan. In this study, dried hazelnut husk hydrolysate was used directly as fermentation medium for pullulan production by a domestic strain of Aureobasidium pullulans. The aim of this work was the optimization of some fermentation medium parameters by central composite design using response surface methodology (RSM). The effects of (NH4)2SO4 concentration, the volume of concentrated H2SO4 and the amount of ground hazelnut husk on pullulan production were optimized by RSM. The optimum levels of the fermentation parameters defined as 7.2 gL-1, 2.5 mL and 20 g, respectively. The maximum pullulan and exopolysaccharide concentrations were determined as 74.39 and 75.95 gL-1, respectively in the optimum conditions. Specific growth rate of the strain was found as 0.097 h-1. FTIR spectral attributes confirmed the structure of pullulan. Thermal decomposition temperature of synthesized pullulan was found as 247.15 °C. This study showed that hazelnut husk was one of the novel substrate for production of the pullulan by A. pullulans AZ-6. No previous work was found to utilize dried hazelnut husk as fermentation medium for pullulan production by A. pullulans.
Assuntos
Corylus , Glucanos , FermentaçãoRESUMO
Agro-industrial wastes are rich sources of some nutrients. Thus, utilization of wastes seems to be ecologically sound and economically advantageous. The aim of this work was to investigate the potential usage of various agro-industrial wastes as fermentation medium for pullulan production by a domestic strain; Aureobasidium pullulans AZ-6. In this study, different agro-industrial wastes; various citrus peels, grape pomace, the hydrolysates of hazelnut and chestnut shells, sugarcane molasses residue, dried and fresh hazelnut husks and pumpkin peel, were used as fermentation media without adding any extra nutritional component for pullulan production by A. pullulans AZ-6. As a result, among the tested media, the maximum pullulan concentration was obtained as 33.59 gL-1 using the sugarcane molasses residue, and followed by the corresponding value of 30.02 gL-1 obtained in the dried hazelnut husk hydrolysate medium. Therefore, the usage of agro-industrial wastes as fermentation media is considered to make pullulan production cost effective. In addition, waste treatment from this aspect solves a relevant environmental problem. In this study, sugarcane molasses residue and dried hazelnut husk hydrolysate were used directly as fermentation media for pullulan production for the first time. Pullulan production from sugarcane molasses residue and dried hazelnut husk hydrolysate media might be a promising substrate for economical point of view.
