Nanobubbles in Microbial Culture & Fermentation

In aerobic culture processes where oxygen supply limits productivity, oxygen nanobubbles can be considered as a way to improve the growth environment of microorganisms and raise productivity.

Aerobic microorganisms consume oxygen as they grow and metabolize. If the oxygen transfer rate cannot keep up with their oxygen demand, growth and production of the target product can be limited.

Nanobubble systems can be used to improve this oxygen supply environment. The actual effect is best evaluated by comparing microbial growth rate, product yield and oxygen supply as well as dissolved oxygen change; Honour Tech's microbial culture and fermentation application is currently at the "validation" stage.

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No. Culture and fermentation processes need different gases depending on the microorganism and production purpose, so it is important to choose the gas that suits the process.

Oxygen supply is important in aerobic microbial culture, but in anaerobic fermentation it can actually work against the process. In some microalgae cultures, carbon dioxide supply plays a key role.

Honour Tech reviews a suitable gas and system configuration based on the culture target and process purpose. Where needed, gas transfer performance and productivity changes can be evaluated against the existing culture method.

Pressure changes and shear forces in nanobubble generation can affect some culture targets, so a supply method suited to the microorganism is important.

Nanobubble systems generally use a pump and a gas mixing device. If the culture broth is circulated directly, the target microorganisms or cells may be mechanically affected.

For shear-sensitive cell cultures in particular, it may be better to pretreat the supply water or set up a separate gas supply path rather than passing the broth directly through the nanobubble system. Honour Tech checks the culture target and operating conditions to review a suitable connection method.

In most cases, a nanobubble system can be considered as an addition while keeping the existing fermenter and aeration and agitation equipment.

The nanobubble system reinforces gas transfer to the broth. Existing agitators, however, perform several functions, such as uniform distribution of temperature and nutrients and preventing settling, and these roles must also be considered.

If the culture can tolerate mechanical effects, a circulation line is used; for sensitive cultures, other connection methods such as pre-gassing the supply water are considered. Once the operating conditions of existing equipment are confirmed, the system can be configured to minimize process changes.

HTV is the first recommendation for culture and fermentation processes that need hygienic wetted parts, and small-scale comparison tests can be considered before commercial-scale adoption.

HTV is a product series with stainless steel (All SUS) internal modules, making it a strong candidate for processes where hygiene and equipment materials matter. This alone does not guarantee aseptic operation or sterilization-in-place (SIP) compatibility, however, so the cleaning and sterilization requirements of the process and the properties of the broth are checked together.

In small-scale tests, a research nanobubble system can be used to compare dissolved oxygen, oxygen transfer performance, microbial growth rate and product yield against existing operating conditions. Honour Tech checks the test purpose, target microorganism, broth viscosity and properties, and gas to be used to review a suitable test method and commercial system configuration.

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