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Aims: Sanghuangporus vaninii (S. vaninii) is a rare medicinal mushroom that is rich in polysaccharides, triterpenes, flavonoids, and other bioactive compounds. It has good potential development value. Methods and Results: We performed single factor experiments and Box-Behnken response surface methodology to optimize the liquid fermentation medium formulation for S. vaninii with mycelial biomass as the indicator. The in vitro antioxidant and anti-cancer capacity of the exopolysaccharides of S. vaninii were estimated. The optimal liquid fermentation media composition for the MS-4, MS-6, and MS-8 strains of Sanghuangporus vaninii consisted of 25.86 ± 0.068 g/L maltose, 7.3 ± 0.043 g/L yeast extract, and 0.71 ± 0.005 g/L dandelion powder. The average mycelial biomass of S. vaninii under optimal conditions was 12.61 g/L. The mycelial biomass of the Sanghuangporus vaninii strains in the optimized formulation was 109–191% higher than that obtained with the basic potato dextrose broth (PDB). The exopolysaccharides of Sanghuangporus vaninii exhibited an ABTS radical scavenging activity with an EC50 of 0.021 ± 0.017 mg/mL and a DPPH radical scavenging activity with an EC50 of 0.076 ± 0.043 mg/mL. In anti-cancer assays, these exopolysaccharides demonstrated an IC50 value of 1.98 ± 0.36 mg/mL against PC-3 human prostate cancer cells, indicating significant bioactivity, highlighting their potential as functional food ingredients. Conclusions: In this study, the formula of liquid fermentation of S. vaninii strains was optimized, which lays a theoretical foundation for increasing the yield of S. vaninii and its application in industry. Moreover, our data showed the clinical potential of the S. vaninii exopolysaccharides as antioxidants and anti-cancer drugs. [ABSTRACT FROM AUTHOR]

Previous research has indicated that Pseudomonas aurantiaca ST-TJ4 possesses a notable antagonistic impact on Phytophthora cinnamomi and holds promising potential for biocontrol. In this study, a combination of a single-factor experiment, a Plackett–Burman design and a response surface approach was employed to investigate the optimal formula of ST-TJ4 fermentation medium. Furthermore, the stability of ST-TJ4 fermentation filtrate and its biocontrol effect on Ph. cinnamomi in vivo were also evaluated. The results revealed that the optimal culture conditions for ST-TJ4 involved the use of 20.59 g/L of glucose and 18.76 g/L of yeast extract powder. Following optimization, the fermentation filtrate of ST-TJ4 exhibited an inhibition rate of 76.5%, representing a 15% increase compared to previous levels. Additionally, phzA, phzB, phzD, phzE, phzF and phzO genes involved in the synthesis of phenazine-1-carboxylic acid (PCA) and 2-hydroxyphenazine (2-OH-PHZ) were also upregulated. The ST-TJ4 fermentation filtrate demonstrated strong alkali resistance, weak acid resistance and favorable temperature and UV light stability. Furthermore, in vitro inoculation experiments confirmed that optimizing the fermentation medium reduced Ps. cinnamomi's ability to infect the leaves of Rhododendron pulchrum. [ABSTRACT FROM AUTHOR]

Detailed knowledge of the flow characteristics, bubble movement, and mass transfer is a prerequisite for the proper design of multiphase bioreactors. Often, mechanistic spatiotemporal models and computational fluid dynamics, which intrinsically require computationally demanding analysis of local interfacial forces, are applied. Typically, such approaches use volumetric mass-transfer coefficient (kLa) models, which have demonstrated their predictive power in water systems. However, are the related results transferrable to multiphase fermentations with different physicochemical properties? This is crucial for the proper design of biotechnological processes. Accordingly, this study investigated a given set of mass transfer data to characterize the fermentation conditions. To prevent time-consuming simulations, computational efforts were reduced using a force balance stationary 0-dimension model. Therefore, a competing set of drag models covering different mechanistic assumptions could be evaluated. The simplified approach of disregarding fluid movement provided reliable results and outlined the need to identify the liquid diffusion coefficients in fermentation media. To predict the rising bubble velocities uB, the models considering the Morton number (Mo) showed superiority. The mass transfer coefficient kL was best described using the well-known Higbie approach. Taken together, the gas hold-up, specific surface area, and integral mass transfer could be accurately predicted. [ABSTRACT FROM AUTHOR]

Bacillus subtilis spores have important biological applications; however, high spore-cell densities and sporulation efficiencies in fermentation is poorly reported. This study systematically analyzed the spore densities and formation efficiency of B. subtilis BSNK-5 in different culture substrates. A response surface regression equation was established based on the results of single factor and Box–Behnken experimental designs. The optimal medium formulation, as predicted from the equation, consisted of soluble starch at 3 g·L−1, soybean flour at 12 g·L−1, and MgSO4 at 5 g·L−1. The spore yield reached 2.43 × 109 CFU·mL−1, and the sporulation rate was 83.3%, which was nearly three times higher than before optimization using an optimized medium at 36 °C and 200 rpm for 60 h. [ABSTRACT FROM AUTHOR]