Highest Itaconic Acid Yield through Aspergillus terreus Filamentous Fungal Fermentation in the LAMBDA MINIFOR Benchtop Bioreactor. 

Itaconic acid (IA) found its importance in various industrial applications, such as serving as a cross-linking agent in synthetic latex production and as a monomer for unsaturated polyester resins. Production of IA through the fermentation of Aspergillus terreus is economical however large amounts of Biomass and water are generated as waste. To overcome this, a novel method with increased IA production and decreased waste generation has to be made.

Researchers from the Research Group on Bioengineering, Membrane Technology, and Energetics at the University of Pannonia, Hungary, were engaged in enhancing IA production through continuous fermentation using the LAMBDA MINIFOR Benchtop Bioreactor. The effluent of the fermentation broth containing Itaconic acid was purified using Bipolar membrane electrodialysis (EDBM) and reintroduced the diluate from EDBM back to the Bioreactor. The continuous fermentation process lasted 547 hours.

Continuous fermentation occurred in a LAMBDA MINIFOR bioreactor with an effective volume of 1.8 L, maintaining an operating temperature of 37°C. The necessary dissolved oxygen level was attained by introducing pure oxygen gas at 0.2 VVM.

Fig 1: The LAMBDA MINIFOR Fermenter's agitation mechanism provides optimal Aspergillus terreus clumps for Itaconic acid production. 

The LAMBDA MINIFOR Fermenter-Bioreactor played a crucial role in enhancing Itaconic Acid production. For increased production of IA, the morphology of Aspergillus terreus proved to be highly significant during fermentation. Researchers noted that clumps or loose pellets of mycelia ranging between 0.4-0.5 mm in diameter were optimal for acid production. The team also confirmed that the novel agitation mechanism of the LAMBDA MINIFOR Bioreactor provided effective mixing while maintaining the required mycelia morphology without compromising the perfect mycelia formation.

Reference: Hülber-Beyer, Éva, Nemestóthy, N., & Bélafi-Bakó, K. (2024). Case Study of Continuous Itaconic Acid Fermentation by Aspergillus Terreus in a Bench-Scale Bioreactor. Hungarian Journal of Industry and Chemistry, 51(2), 57–63. doi.org/10.33927/hjic-2023-19

At the 96th hour, continuous operation of the fermenter commenced and continued for 23 days (547 hours). The effluent was drained through a harvest cannula extending to the bottom of the reactor vessel.

The height-adjustable cannulas of the LAMBDA MINIFOR Bioreactor facilitated maintaining a distance of above 5cm from the surface of the culture for medium refilling. The dilution rate was maintained at 0.007 h-1.

Fig 2: Illustration of morphology of Aspergillus terreus and graphical overview of Oxygen update rate (OUR), Concentration of glucose and Itaconic acid in the fermenter. Reference: Hülber-Beyer, Éva, Nemestóthy, N., & Bélafi-Bakó, K. (2024). Case Study of Continuous Itaconic Acid Fermentation by Aspergillus Terreus in a Bench-Scale Bioreactor. Hungarian Journal of Industry and Chemistry, 51(2), 57–63. doi.org/10.33927/hjic-2023-19

Result:

During the Itaconic acid producing period spanning 16 days, a maximum product titer of 35 g·L-1 was successfully attained, surpassing those documented in prior continuous fermentations. The presence of oxygen and gentle agitation of the LAMBDA MINIFOR Fermenter played a role in fostering the formation of fungal clumps, which are favorable conditions for increased Itaconic acid production.

How does the LAMBDA MINIFOR Fermenter-Bioreactor achieve optimal agitation, not only for fungal fermentation but also for various types of cells?

Agitating cell cultures poses a challenge, as the large, shear sensitive cells like filamentous Fungai, mammalian and any Eukaryotic cells can be damaged by the sharp edges of conventional stirrers. Even the pitched blade impellers causes shear stress to the cells at a littler higher speed. This raises the question: Which approach is preferable?

a) Increasing impeller speed to improve medium oxygenation and gas exchange, albeit at the risk of partially damaging cells, or

b) Prioritizing cell protection and accepting suboptimal gas exchange in the medium?

Nature provides a solution that predates human existence: the design of the fish tail, which efficiently minimizes turbulence to maximize propulsion in water. When the fish tail is mobilized, water flows away with maximal efficiency. 

  

The LAMBDA MINIFOR Fermenter-Bioreactor agitation mechanism - Gentle and efficient mixing!

The slim and flexible fin of a fish tail lacks sharp edges yet moves faster in the water. By emulating this design, LAMBDA has developed a new mixing disc that achieves high stirring efficiency without mechanical damage to living cells. With the "Fish-Tail" stirring discs, cultures like filamentous fungai containing sensitive cells can be effectively aerated without compromising cell integrity.

For more details regarding the LAMBDA MINIFOR fermenter-bioreactor, please visit www.fermentador-bioreactor.com/features/ and explore the innovations of the LAMBDA MINIFOR fermenter-bioreactor at www.lambda-instruments.com/fermenter-bioreactor/innovations-of-minifor-fermentor-bioreactor/ 

If you have any inquiries, require a quotation, or need pricing information for our fermenter-bioreactor system, feel free to reach out to us athttps://www.lambda-instruments.com/contact-us/