Xanthan gum production from acid hydrolyzed broomcorn stem as a sole carbon source by Xanthomonas campestris

The importance of acetate, pyruvate, and citrate feeding times in improving xanthan production by Xanthomonas citri

Xanthan gum is a microbial polysaccharide produced by Xanthomonas and widely used in various industries. To produce xanthan gum, the native Xanthomonas citri-386 was used in a cheese-whey-based culture medium. The culture conditions were investigated in batch experiments based on the response surface methodology to increase xanthan production and viscosity. Three independent variables in this study included feeding times of acetate, pyruvate, and citrate. The maximum xanthan gum production and viscosity within 120 h by X. citri-386 using Box-Behnken design were 25.7 g/l and 65 500 cP, respectively, with a 151% and 394% increase as compared to the control sample. Overall, the findings of this study recommend the use of X. citri-386 in the cheese-whey-based medium as an economical medium with optimal amounts of acetate, pyruvate, and citrate for commercial production of xanthan gum on an industrial scale. The adjustment of the pyruvate and acetate concentrations optimized xanthan gum production in the environment.

Production and application of xanthan gum-prospects in the dairy and plant-based milk food industry: a review

Xanthan gum (XG) is an important industrial microbial exopolysaccharide. It has found applications in various industries, such as pharmaceuticals, cosmetics, paints and coatings, and wastewater treatment, but especially in the food industry. The thickening and stabilizing properties of XG make it a valuable ingredient in many food products. This review presents a comprehensive overview of the various potential applications of this versatile ingredient in the food industry. Especially in the plant-based food industries due to current interest of consumers in cheaper protein sources and health purposes. However, challenges and opportunities also exist, and this review aims to identify and explore these issues in greater detail. Overall, this article represents a valuable contribution to the scientific understanding of XG and its potential applications in the food industry.

Production of Bacterial Exopolysaccharides: Xanthan and Bacterial Cellulose

Recently, degradable biopolymers have become increasingly important as potential environmentally friendly biomaterials, providing a wide range of applications in various fields. Bacterial exopolysaccharides (EPSs) are biomacromolecules, which due to their unique properties have found applications in biomedicine, foodstuff, textiles, cosmetics, petroleum, pharmaceuticals, nanoelectronics, and environmental remediation. One of the important commercial polysaccharides produced on an industrial scale is xanthan. In recent years, the range of its application has expanded significantly. Bacterial cellulose (BC) is another unique EPS with a rapidly increasing range of applications. Due to the great prospects for their practical application, the development of their highly efficient production remains an important task. The present review summarizes the strategies for the cost-effective production of such important biomacromolecules as xanthan and BC and demonstrates for the first time common approaches to their efficient production and to obtaining new functional materials for a wide range of applications, including wound healing, drug delivery, tissue engineering, environmental remediation, nanoelectronics, and 3D bioprinting. In the end, we discuss present limitations of xanthan and BC production and the line of future research.

Articulating the exuberant intricacies of bacterial exopolysaccharides to purge environmental pollutants

Microbial exopolysaccharide (EPS) is composed of a mixture of macromolecules such as proteins, polysaccharides, humic-like compounds, and nucleic acids, which encase microbial cells in a three-dimensional matrix. The literature shows that the EPS possess significant properties such as renewable, biodegradable, eco-friendly, non-toxic, and economically valued product, representing it as a green alternative to the synthetic polymer. The cost-effective and green synthesis of the EPS must be encouraged by using agro-waste as a raw material. The main objective of the manuscript is to provide a comprehensive update on the various aspects pertaining to EPS, including the economic aspects of EPS production, provide an insight into the latest tools and techniques used for detailed structural EPS characterization along with updates in the integration of CRISPR/Cas9 technology for engineering the modification in EPS production, the role of newly discovered EPR3 as a signalling molecule in plant growth-promoting properties (PGP) or agricultural microbiology. Furthermore, the EPS achieved prospective interest prevailing potential environmental issues which can be subject to EPS treatment including, landfill leachate treatment, decolourization of dye from the effluent or waste generated by an industry, removal of radionuclides, heavy metals and toxic compounds from the various environments (aquatic and terrestrial), industry effluents, waste waters etc. are comprehensively discussed.

Bio-synthesis of food additives and colorants-a growing trend in future food

Food additives and colorants are extensively used in the food industry to improve food quality and safety during processing, storage and packing. Sourcing of these molecules is predominately through three means: extraction from natural sources, chemical synthesis, and bio-production, with the first two being the most utilized. However, growing demands for sustainability, safety and "natural" products have renewed interest in using bio-based production methods. Likewise, the move to more cultured foods and meat alternatives requires the production of new additives and colorants. The production of bio-based food additives and colorants is an interdisciplinary research endeavor and represents a growing trend in future food. To highlight the potential of microbial hosts for food additive and colorant production, we focus on current advances for example molecules based on their utilization stage and bio-production yield as follows: (I) approved and industrially produced with high titers; (II) approved and produced with decent titers (in the g/L range), but requiring further engineering to reduce production costs; (III) approved and produced with very early stage titers (in the mg/L range); and (IV) new/potential candidates that have not been approved but can be sourced through microbes. Promising approaches, as well as current challenges and future directions will also be thoroughly discussed for the bioproduction of these food additives and colorants.

Fruit and vegetable waste management: Conventional and emerging approaches

Valorization of Fruit and Vegetable Wastes (FVW) is challenging owing to logistic-related problems, as well as to their perishable nature and heterogeneity, among other factors. In this work, the main existing routes for food waste valorization are critically reviewed. The study focuses on FVW because they constitute an important potential source for valuable natural products and chemicals. It can be concluded that FVW management can be carried out following different processing routes, though nowadays the best solution is to find an adequate balance between conventional waste management methods and some emerging valorization technologies. Presently, both conventional and emerging technologies must be considered in a coordinated manner to enable an integral management of FVW. By doing so, impacts on food safety and on the environment can be minimized whilst wasting of natural resources is avoided. Depending on the characteristics of FVW and on the existing market demand, the most relevant valorization options are extraction of bioactive compounds, production of enzymes and exopolysaccharides, synthesis of bioplastics and biopolymers and production of biofuels. The most efficient emergent processing technologies must be promoted in the long term, in detriment of the conventional ones used nowadays. In consequence, future integral valorization of FVW will probably comprise two stages: direct processing of FVW into value-added products, followed by processing of the residual streams, byproducts and leftover matter by means of conventional waste management technologies.

Repeated cultures of Saccharomyces cerevisiae SC90 to tolerate inhibitors generated during cassava processing waste hydrolysis for bioethanol production

Large amount of cassava pulp is produced as by-product of industrial tapioca production. The value-added process of this low-cost waste is to use it as a substrate for bioethanol production. However, during the pulp pretreatment by acidification combined with steam explosion, many yeast inhibitors including acetic acid, formic acid, levulinic acid, furfural and 5-hydroxymethylfurfural are generated and these compounds have negative effects on the subsequent fermentation step. Therefore, the objective of this study was to investigate whether the repeated cultures of Saccharomyces cerevisiae SC90 could alleviate this problem. To obtain the inhibitor tolerable cells, the repeated culture was performed by growing yeast cells to a specific growth rate (µ) of 0.22 h-1 or higher (80% of the µ in control) and then transferring them to progressively higher concentrations of hydrolysate ranging from 20 to 100% (v/v). The results showed a tendency of longer lag phase as well as time to reach maximum cell number (t maxc) with an increase in hydrolysate concentration. However, the repeated culture at the same hydrolysate concentration could shorten both lag period and t maxc. Interestingly, the growth and fermentation efficiency of adapted cells in 100% hydrolysate were significantly higher (p ≤ 0.05) than those of non-adapted cells by 38% and 27%, respectively.