Soybean oil refinery effluent treatment and its utilization for bacterial cellulose production by Gluconacetobacter xylinus

Removal of heavy metal vanadium from aqueous solution by nanocellulose produced from Komagataeibacter europaeus employing pineapple waste as carbon source

Environmental concerns have taken a center stage in our lives driving the society towards biorefinery. Bioprocess development to produce valuable products utilizing waste has its own significance in circular bioeconomy and environmental sustainability. In the present study, production of bacterial cellulose using pineapple waste as carbon source by Komagataeibacter europaeus was undertaken and it was applied for removal of vanadium, a heavy metal which is generated as waste by semiconductors industry in Taiwan. Highest yield of bacterial cellulose (BC) e.i. 5.04 g/L was obtained with pineapple core hydrolysate (HS-PC) replacing glucose in HS medium. The vanadium adsorption capacity by BC produced by HS medium was 5.24 mg/g BC at pH 4 and 2.85 mg/g BC was observed on PCH medium. BC was characterised via SEM, FTIR and XRD.

Optimization and physicochemical characterization of bacterial cellulose by Komagataeibacter nataicola and Komagataeibacter maltaceti strains isolated from grape, thorn apple and apple vinegars

Bacterial cellulose (BC) is a valuable biopolymer that is increasingly used in medical, pharmaceutical and food industries with its excellent physicochemical properties as high water-holding capacity, nanofibrillar structure, large surface area, porosity, mechanical strength and biocompatibility. Accordingly, the isolation, identification and characterization of potent BC producers from grape, thorn apple and apple vinegars were performed in this study. The strains isolated from grape and apple vinegars were identified as Komagataeibacter maltaceti and the strain isolated from thorn apple vinegar was identified as Komagataeibacter nataicola with 16S rRNA analysis. Optimized conditions were found as 8% dextrin, 1.5% (peptone + yeast extract) and 10% inoculation amount at pH 6.0 with a productivity rate of 1.15 g/d/L, a yield of 8.06% and a dry weight of 6.45 g/L for K. maltaceti, and 10% maltose, 1% (peptone + yeast extract) and 10% inoculation amount at pH 6.0 with a productivity rate of 0.96 g/L/d, a yield of 5.35% and a dry weight of 5.35 g/L for K. nataicola. Obtained BC from K. maltaceti and K. nataicola strains was more than 2.56- and 1.86-fold when compared with BC obtained from HS media and exhibited 95.1% and 92.5% WHC, respectively. Based on the characterization results, BC pellicles show characteristic FT-IR bands and have ultrafine 3D structures with high thermal stability. By means of having ability to assimilate monosaccharides, disaccharides and polysaccharide used in this study, it is predicted that both isolated Komagataeibacter species can be used in the production of biopolymers from wastes containing complex carbon sources in the future.

Bacterial cellulose as an oleaginous yeast cell carrier for soybean oil refinery effluent treatment and pyrolysis oil production

Bacterial cellulose produced from soybean oil refinery effluent is a good immobilization carrier because of the large pores in its fiber network, its high water-holding capacity, and its good biocompatibility. In this study, it was applied to immobilization of oleaginous yeasts for treating soybean oil refinery effluent. The immobilization percentage reached 50%, and the removal of chemical oxygen demand and oil content reached 92.1% and 93.1%, respectively, during dynamic immobilization using a mass percentage of bacterial cellulose of 30% and an immobilization time of 24 h, which were significantly higher than those of free oleaginous yeasts or yeasts immobilized by bacterial cellulose from rich medium. The immobilized oleaginous yeasts facilitated the recovery of the yeasts and effectively treated three batches of soybean oil refinery effluent. The immobilized oleaginous yeasts recovered after soybean oil refinery effluent treatment were pyrolyzed to produce bio-oil, which contributed to more alkanes and a higher calorific value of bio-oil in the pyrolysis products as compared to those of free oleaginous yeasts. As bacterial cellulose used as an oleaginous yeast cell carrier is produced from soybean oil refinery effluent, no waste of immobilization materials is involved and an efficient waste-into-oil bioprocess is developed.

Evaluation of Different Methods for Cultivating Gluconacetobacter hansenii for Bacterial Cellulose and Montmorillonite Biocomposite Production: Wound-Dressing Applications

Bacterial cellulose (BC) has received considerable attention due to its unique properties, including an ultrafine network structure with high purity, mechanical strength, inherent biodegradability, biocompatibility, high water-holding capacity and high crystallinity. These properties allow BC to be used in biomedical and industrial applications, such as medical product. This research investigated the production of BC by Gluconacetobacter hansenii ATCC 23769 using different carbon sources (glucose, mannitol, sucrose and xylose) at two different concentrations (25 and 50 g∙L⁻¹). The BC produced was used to develop a biocomposite with montmorillonite (MMT), a clay mineral that possesses interesting characteristics for enhancing BC physical-chemical properties, at 0.5, 1, 2 and 3% concentrations. The resulting biocomposites were characterized in terms of their physical and barrier properties, morphologies, water-uptake capacities, and thermal stabilities. Our results show that bacteria presented higher BC yields in media with higher glucose concentrations (50 g∙L⁻¹) after a 14-day incubation period. Additionally, the incorporation of MMT significantly improved the mechanical and thermal properties of the BC membranes. The degradation temperature of the composites was extended, and a decrease in the water holding capacity (WHC) and an improvement in the water release rate (WRR) were noted. Determining a cost-effective medium for the production of BC and the characterization of the produced composites are extremely important for the biomedical applications of BC, such as in wound dressing materials.