Evaluation of mixing effect and shear stress of different impeller combinations on nemadectin fermentation

Robust myco-composites: a biocomposite platform for versatile hybrid-living materials

Fungal mycelium, a living network of filamentous threads, thrives on lignocellulosic waste and exhibits rapid growth, hydrophobicity, and intrinsic regeneration, offering a potential means to create next-generation sustainable and functional composites. However, existing hybrid-living mycelium composites (myco-composites) are tremendously constrained by conventional mold-based manufacturing processes, which are only compatible with simple geometries and coarse biomass substrates that enable gas exchange. Here we introduce a class of structural myco-composites manufactured with a novel platform that harnesses high-resolution biocomposite additive manufacturing and robust mycelium colonization with indirect inoculation. We leverage principles of hierarchical composite design and selective nutritional provision to create a robust myco-composite that is scalable, tunable, and compatible with complex geometries. To illustrate the versatility of this platform, we characterize the impact of mycelium colonization on mechanical and surface properties of the composite. We found that our method yields the strongest mycelium composite reported to date with a modulus of 160 MPa and tensile strength of 0.72 MPa, which represents over a 15-fold improvement over typical mycelium composites, and further demonstrate unique applications with fabrication of foldable bio-welded containers and flexible mycelium textiles. This study bridges the gap between biocomposite and hybrid-living materials research, opening the door to advanced structural mycelium applications and demonstrating a novel platform for development of diverse hybrid-living materials.

Sustainable production and preparative purification of thermostable alkaline α-amylase by Bacillus simplex (ON754233) employing natural deep eutectic solvent-based extractive fermentation

Using PEG-based deep eutectic solvents (PDES), the current study proposes extractive fermentation as a sustainable process integration for the production and purification of α-amylase from Bacillus simplex (ON754233). Glucose: PEG 400 outperformed five PDES in terms of tie lie length (58) and slope value (1.23) against sodium sulphatt. Apple cider pomace was used as a low-cost, sustainable carbon source to produce-amylase, with a maximum enzyme production of 2200.13 U/mL. PDES concentration (20% w/v), salt (12.75 w/v), and apple waste (2.75 g/mL) were all optimized using response surface methodology. When scaled upto 3 L benchtop bioreactor, extractive fermentation was proved to be better technology with maximum recovery of 92.4% with highest partition coefficient (3.59). The partially purified enzyme was further purified using a Sephadex G 100 followed by DEAE-Sephadex anion exchange chromatography with a purity fold of 33. The enzyme was found to be thermostable at the temperature (60 °C), remains alkaline (pH 8), and the activity was stimulated in the presence of Mg2+ ions. With SDS PAGE electrophoresis, the molecular weight was found to be around 140 kDa. Finally, the enzyme kinetics parameters were evaluated with observed Km (0.00396 mM) and Vmax (37.87 U/mL). Thus scaling up extractive fermentation entails increasing production capacity with improved extraction efficiency using green solvents.

Microbubbles in Food Technology

Microbubbles are largely unused in the food industry yet have promising capabilities as environmentally friendly cleaning and supporting agents within products and production lines due to their unique physical behaviors. Their small diameters increase their dispersion throughout liquid materials, promote reactivity because of their high specific surface area, enhance dissolution of gases into the surrounding liquid phase, and promote the generation of reactive chemical species. This article reviews techniques to generate microbubbles, their modes of action to enhance cleaning and disinfection, their contributions to functional and mechanical properties of food materials, and their use in supporting the growth of living organisms in hydroponics or bioreactors. The utility and diverse applications of microbubbles, combined with their low intrinsic ingredient cost, strongly encourage their increased adoption within the food industry in coming years.

Effects of Impeller Geometry on the 11α-Hydroxylation of Canrenone in Rushton Turbine-Stirred Tanks

The 11α-hydroxylation of canrenone can be catalyzed by Aspergillus ochraceus in bioreactors, where the geometry of the impeller greatly influences the biotransformation. In this study, the effects of the blade number and impeller diameter of a Rushton turbine on the 11α-hydroxylation of canrenone were considered. The results of fermentation experiments using a 50 mm four-blade impeller showed that 3.40% and 11.43% increases in the conversion ratio were achieved by increasing the blade number and impeller diameter, respectively. However, with an impeller diameter of 60 mm, the conversion ratio with a six-blade impeller was 14.42% lower than that with a four-blade impeller. Data from cold model experiments with a large-diameter six-blade impeller indicated that the serious leakage of inclusions and a 22.08% enzyme activity retention led to a low conversion ratio. Numerical simulations suggested that there was good gas distribution and high fluid flow velocity when the fluid was stirred by large-diameter impellers, resulting in a high dissolved oxygen content and good bulk circulation, which positively affected hyphal growth and metabolism. However, a large-diameter six-blade impeller created overly high shear compared to a large-diameter four-blade impeller, thereby decreasing the conversion ratio. The average shear rates of the former and latter cases were 43.25 s^-1 and 35.31 s^-1, respectively. We therefore concluded that appropriate shear should be applied in the 11α-hydroxylation of canrenone. Overall, this study provides basic data for the scaled-up production of 11α-hydroxycanrenone.