Production of Microbial Exopolysaccharide by Cost-effective Medium Opimization Method

Abstract

Microbial exopolysaccharide (EPS) emerged as a fast and high yielding sustainable polymeric substance which can be used as an alternative to synthetic polymer in industry. In this study, the influence of various nutritional and environmental factors of fermentation medium on bacterial growth and EPS production was evaluated by one factor at a time optimization. Efficient production medium was chosen from four different basal media and its carbon and nitrogen substrates were varied among organic and inorganic sources. Feasibility of bacterial utilization of some agricultural wastes as carbon and nitrogen sources to synthesize exopolysaccharide was compared. Carbon source of the fermentation medium was replaced with hydrolysates of sugarcane baggasse (SCB), sweet potato peels (SPP) or ripe plantain peels (RPP) at various concentrations while the nitrogen substrates was replaced with extracts of poultry droppings (PP), groundnut pod (GP) or beans bran (BB). Response results observed from single factor optimization were explored as center points to Nwosu et al.; JAMB, 19(2): 1-13, 2019; Article no.JAMB.52290 2 design a model for Response Surface Methodology study. Cell growth was determined from the biomass population of the fermentation broth after 5 days of incubation in a rotary shaker at 120 rpm at 30ºC. EPS was precipitated with pre-chilled ethanol (at 4ºC) from cell-free broth and overnight incubation at 4ºC. Total carbohydrate content was estimated by phenol-sulphuric acid method. Result obtained showed that 2% concentration Hydrolysate of SPP containing medium gave maximum yield of 2.26 g EPS/l of the medium as compared to sucrose containing medium with yield of 1.25 g EPS/l of the medium while highest production yield of 9.46 gEPS/l of the medium was obtained from 10 g/l BB extract medium as compared to yeast extract medium (5.41 gEPS/l). Results indicated that agricultural wastes such as sweet potato peel hydrolysate and bean bran extract could be developed as inexpensive alternative route to synthesize EPS from bacteria than inorganic substrates. Original Research Article

Importancia de las bacterias ácido lácticas como productoras de exopolisacáridos

“…Los primeros son todos aquellos parámetros proporcionados a la célula bacteriana para mejorar su crecimiento y biosíntesis de polisacárido de manera óptima; entre estos podemos mencionar a los sustratos empleados en el medio de cultivo los cuales tienen un efecto sustancial en el metabolismo microbiano y el costo de producción (Sheng et al, 2010). Dentro de estos se ha propuesto el uso de fuentes de carbono económicas; tal es el caso de las melazas de caña de azúcar, suero de leche, aguamiel, jugo de sidra y las cáscaras de frutas y verduras (Galindo-Rodríguez y Cruz-Nicolas, 2016; Nwosu et al, 2019). Asimismo, fuentes de nitrógeno de bajo costo como las cascarillas de trigo, harina de maíz, pasta de soya y urea (Hernández-Rosas et al, 2021;Muhammadi y Afzal, 2014;Yang et al, 2018).…”

Extremophilic Exopolysaccharides: Biotechnologies and Wastewater Remediation

“…Moreover, it is necessary to have a clear pollutant recovery strategy throughout the flocculation and separation processes, column elution, metal-biomass burning, or a disposal/reuse strategy (e.g., life-cycle assessment studies and catalyst use of metal-EPS/biomass complex; Alipanah et al, 2020). Finally, a cost assessment of the microbial biomass/EPS production (Nwosu et al, 2019) and the whole biosorption process would be required. This is because various highly available, low-cost bio-sorbents from nature (e.g., macro/ microalgae, mosses, plants, and animals), and others obtained as industrial by-products, can be used for the same purposes but may have the drawback of seasonal scarcity, target pollutant non-selectivity, and structure variability between batches that would limit their application.…”