Microscopic bacteria under pressure in a food processing plant, symbolizing food safety.

Can High Pressure Food Processing Wipe Out Bacteria? The Truth About Food Safety

Soraya Malik in Science & Nature September 2025 • 4 min read.

"Discover how high hydrostatic pressure (HHP) affects foodborne pathogens, and what genes play a role in bacterial resistance for safer food processing."

In our quest for healthier and safer food options, the food processing industry is constantly evolving. High hydrostatic pressure (HHP) has emerged as a promising method. It's a non-thermal technique that aims to eliminate harmful microorganisms while preserving the quality and nutritional value of our food. But how effective is it, and what are its limitations?

HHP works by applying intense pressure, up to several thousand times atmospheric pressure, to food products. This pressure disrupts the cellular functions of bacteria, viruses, and other microorganisms, leading to their inactivation. Unlike traditional heat treatments, HHP preserves the food's natural flavors, colors, and vitamin content, making it an attractive alternative for many food manufacturers.

While HHP is effective, some microorganisms exhibit resistance. Understanding the mechanisms behind this resistance is vital for optimizing HHP processes and ensuring food safety. Recent studies have focused on identifying the genes involved in high-pressure resistance in common foodborne pathogens like Escherichia coli, shedding light on how bacteria adapt and survive under extreme pressure.

What Makes Bacteria Resist High Pressure?

Microscopic bacteria under pressure in a food processing plant, symbolizing food safety.

Scientists have been diving deep into the genetic makeup of bacteria to understand how they withstand high-pressure processing. One key study focused on Escherichia coli (E. coli), a common bacterium found in food. Researchers screened thousands of E. coli mutants to find those that were either more sensitive or more resistant to HHP. This helped pinpoint specific genes that play a role in pressure resistance.

The study revealed several genes that, when disrupted, altered the bacteria's ability to survive HHP. Some genes, like rbsK, rbsR, hdfR, and crl, were found to decrease HHP resistance when disrupted. On the other hand, disrupting genes like sucC and sucD actually increased the bacteria's resistance to high pressure.

rbsK and rbsR: These genes are involved in ribose metabolism and transport. When these genes are disrupted, the bacteria become more vulnerable to HHP.
hdfR: This gene encodes a transcriptional regulator that affects acid resistance and flagellum formation. Disrupting hdfR significantly reduces the bacteria's ability to withstand high pressure.
crl: This gene enhances the activity of RpoS, a general stress response sigma factor. Disrupting crl makes the bacteria more sensitive to HHP.
sucC and sucD: These genes encode subunits of succinyl-CoA synthetase, an enzyme in the tricarboxylic acid cycle (TCA). Disrupting these genes surprisingly increased HHP resistance.

Further research zoomed in on the tricarboxylic acid cycle (TCA), a critical metabolic pathway in bacteria. The study found that disrupting genes like sucA and sucB, which encode subunits of the 2-oxoglutarate dehydrogenase complex, significantly decreased the survival rate of E. coli under high pressure. This suggests that the TCA cycle plays a vital role in how bacteria respond to HHP.

What's Next for High-Pressure Processing?

Understanding how bacteria resist high-pressure processing is a game-changer for the food industry. By identifying the genes and metabolic pathways involved in pressure resistance, we can develop more effective HHP strategies. This includes using HHP in combination with other preservation methods to ensure food safety while maintaining quality. Future research will likely explore ways to enhance the effectiveness of HHP by targeting these resistance mechanisms, leading to safer and more nutritious food for everyone.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.fm.2018.10.007, Alternate LINK

Title: Identification Of Novel Genes Involved In High Hydrostatic Pressure Resistance Of Escherichia Coli

Subject: Microbiology

Journal: Food Microbiology

Publisher: Elsevier BV

Authors: Elisa Gayán, Nele Rutten, Jan Van Impe, Chris W. Michiels, Abram Aertsen

Published: 2019-04-01

Everything You Need To Know

What is High Hydrostatic Pressure (HHP) and how does it work in food processing?

High Hydrostatic Pressure, or HHP, is a non-thermal food processing technique that uses intense pressure to inactivate microorganisms like bacteria and viruses in food products. The pressure, which can be several thousand times atmospheric pressure, disrupts cellular functions, leading to the inactivation of these microorganisms. Unlike heat treatments, HHP can preserve the food's natural flavors, colors, and vitamin content. HHP does not address issues like enzymatic spoilage, which may require additional preservation methods.

Why is it important to understand how some microorganisms resist High Hydrostatic Pressure (HHP)?

The resistance of some microorganisms to High Hydrostatic Pressure (HHP) is significant because it impacts the effectiveness of the food processing technique. Understanding the genetic mechanisms behind this resistance, such as the roles of genes like rbsK, rbsR, hdfR, crl, sucC, and sucD in E. coli, allows for the development of more targeted and effective HHP strategies. Overcoming resistance ensures food safety while maintaining food quality.

What are some of the genes that make bacteria resistant to High Hydrostatic Pressure (HHP)?

Several genes have been identified that influence High Hydrostatic Pressure (HHP) resistance in bacteria like E. coli. For example, rbsK and rbsR are involved in ribose metabolism, hdfR affects acid resistance and flagellum formation, and crl enhances a general stress response. Disrupting these genes generally makes bacteria more sensitive to HHP. Conversely, disrupting sucC and sucD, which are part of the tricarboxylic acid cycle, can surprisingly increase HHP resistance. Identifying these genes helps to understand how bacteria adapt and survive under high pressure.

What is the role of the tricarboxylic acid cycle (TCA) in bacterial resistance to High Hydrostatic Pressure (HHP)?

The tricarboxylic acid cycle (TCA), also known as the Krebs cycle, is a critical metabolic pathway in bacteria. It plays a vital role in how bacteria respond to High Hydrostatic Pressure (HHP). Studies have shown that disrupting genes like sucA and sucB, which encode subunits of the 2-oxoglutarate dehydrogenase complex within the TCA cycle, significantly decreases the survival rate of E. coli under high pressure. This indicates that the TCA cycle is important for bacterial survival and stress response under extreme pressure conditions.

What are the next steps for improving High Hydrostatic Pressure (HHP) in the food industry?

Future research and development in High Hydrostatic Pressure (HHP) processing will likely focus on enhancing its effectiveness by targeting the resistance mechanisms of bacteria. This includes using HHP in combination with other preservation methods to ensure food safety while maintaining quality. The goal is to develop strategies that can overcome bacterial resistance, leading to safer and more nutritious food options.