Statistical Optimization of Medium for Pullulan Production by Aureobasidium pullulans NCPS2016 Using Fructose and Soybean Meal Hydrolysates

Abstract

Pullulan, with its excellent characteristics of film-forming, water solubility, and biodegradability, is attracting more and more attention in agricultural products preservation. However, high pullulan production cost largely restricts its widely application due to its low production. In order to improve pullulan production by Aureobasidium pullulans NCPS2016, the medium was optimized using single factor experiment and response surface methodology. Based on the single factor experiments, the contents of soybean meal hydrolysates (SMHs), (NH4)2SO4, and K2HPO4·3H2O were considered to be main factors influencing the extracellular polysaccharide (EPS) production, and were further optimized by Box–Behnken design. The optimal content of SMHs of 7.71 g/L, (NH4)2SO4 of 0.35 g/L, and K2HPO4·3H2O of 8.83 g/L were defined. Finally, EPS production of 59.8 g/L was obtained, 39% higher in comparison with the production in the basal medium. The purified EPS produced by NCPS2016 was confirmed to be pullulan. This is the first time fructose is reported to be the optimal carbon source for pullulan production by Aureobasidium pullulans, which is of great significance for the further study of the mechanism of the synthesis of pullulan by NCPS2016. Also, the results here have laid a foundation for reducing the industrial production cost of pullulan.

Improved Pullulan Production and Process Optimization Using Novel GA–ANN and GA–ANFIS Hybrid Statistical Tools

“…It has also been claimed by many researchers that carbon source might be a significant factor in melanin pigmentation found in many strains of the microbe [28]. Sucrose, fructose, maltose, xylose, and glucose were the most common time and tested carbon sources for fermentative production of pullulan [29]. Through extensive study of the metabolic pathway of sucrose in pullulan fermentation, it was found that sucrose did not cleave into glucose and fructose in the medium [30,31].…”

Exclusive Biosynthesis of Pullulan Using Taguchi’s Approach and Decision Tree Learning Algorithm by a Novel Endophytic Aureobasidium pullulans Strain

“…In addition, the statistical optimization of the central composite design was applied for using molasses as a carbon source for pullulan production by A. pullulans , with a yield of 45 g/L [ 13 ]. A more recent study investigated the use of soybean meal hydrolysate as a nitrogen source and found that pullulan production by A. pullulans reached 59.8 g/L [ 14 ].…”

“…However, genetic engineering methods can be time-consuming and expensive, and the stability of the modified strains can be a limitation. Optimization of the medium composition, as well as the different process parameters (e.g., temperature, pH, and agitation) for pullulan production by varying the level of each variable, can be challenging and have conflicting effects; this is due to the biosynthesis process needs an accurate balance of the fermentation conditions and very sensitive to the interactions among components [ 12 , 13 , 14 ].…”

Pullulan Oxidation in the Presence of Hydrogen Peroxide and N-Hydroxyphthalimide

“…The large and strong absorption band at 3436 cm −1 indicated the OH stretching vibrations in the pullulan structure [ 41 ]. The other strong absorption at 2924 cm −1 indicated an sp 3 C–H stretching vibration [ 42 ]. The peak at 1381 cm −1 confirmed the C–O–H bending at the C-6 position [ 43 ].…”