Culturing microorganisms, the process of growing them in a lab, is a fundamental technique in microbiology research. Typically, this involves a liquid medium that supplies essential nutrients, but for aerobic microorganisms, an additional challenge arises: they need oxygen, which doesn’t dissolve readily in liquid. Traditionally, researchers solve this by aerating the medium, often by shaking it to enhance oxygen absorption. While effective, this approach exposes microorganisms to physical shear stress, potentially affecting their behavior and growth.

Figure 1. The Proposed Method.

To improve oxygen availability without shaking, scientists have developed specialized tools like “baffled” shake flasks, which use indentations to boost oxygen transfer, and air-bubbling bioreactors. However, these methods do not eliminate the stress caused by agitation. Figure 1 shows Kindai university researchers devise a new method of culturing microorganisms that can enable sustainable breakthroughs across science and industry.

Now, in a groundbreaking study published in Scientific Reports on October 10, 2024, researchers from Kindai University, led by Professor Motomu Akita and Dr. Kenji Ito, have introduced a novel "static" culturing technique. Using a unique polymer called TPX, which allows oxygen to permeate more readily, the team designed a bag that enables culturing without agitation. The TPX film bag, containing a small volume of liquid medium and inoculated with bacteria, was placed flat to create a thin layer, ensuring adequate oxygenation in a calm environment.

This approach proved successful:

Escherichia coli showed comparable growth in both the TPX film bags and conventional shake cultures. Testing with Komagataella phaffi, an oxygen-demanding microorganism, revealed slightly lower growth in the film bag than in shaken cultures, but it still demonstrated promising results for oxygen supply [1].

Prof. Akita highlights the advantages:

“Our method enables easy observation of biological phenomena that were previously unobservable. Until now, microorganisms have not been cultured in liquid conditions where sufficient oxygen was supplied and physical stress was absent.” Without agitation, microorganisms can be observed in a stress-free environment, allowing researchers to explore behaviors like biofilm formation—a gel-like layer created when microorganisms adhere to a surface. In this study, static culturing enabled biofilm formation by Bacillus species along the bag’s bottom, a phenomenon typically suppressed in shake cultures [2].

Prof. Akita emphasizes the potential of this method:

“The possibilities for this new culturing method are enormous. For starters, reducing the space, energy and resources needed to culture bacteria could promote more sustainable research activities.” This simplified, space-saving approach could support microbiology research in settings with limited resources or equipment constraints, and it opens up possibilities for research in remote locations, from polar research stations to space missions. It also holds promise for affordable educational and field research, as well as more accessible medical testing [3].

With these advances, the team’s findings are set to spark a wave of innovation across microbiology and biotechnology!

Source: Ruhr-University Bochum

References:

1. https://phys.org/news/2024-11-method-culturing-microbes-static-liquid.html
2. https://www.europeanpharmaceuticalreview.com/news/235696/innovative-static-culturing-method-developed/
3. https://www.eurekalert.org/news-releases/1064048

Cite this article:

Hana M (2024), A New Method for Culturing Microorganisms Without Shaking, AnaTechmaz, pp. 1040