In May of 2021, researchers at the School of Fundamental Sciences at Massey University in New Zealand published a paper which included research using the CDC Biofilm Reactor (CBR). This research looked at dairy biofilm isolates obtained from an evaporator of a dairy powder manufacturing facility in New Zealand. Several strains of Geobacillus stearothermophilus were collected and spores were grown using the CBR. The heat resistance and calcium content of the spores were found and compared to eachother. The goal was to provide data for future research and to assist with designing better heat treatment equipment for the dairy industry, and perhaps the greater food industry.
     New Zealand was home to 4.92 million dairy cows in 2020, and is a NZ$13.4 billion industry. The importance of dairy processing to the New Zealand economy is clear.  Because of this, lots of research is being done to increase yields, make milk products safer, and overall better the industry that so much of the country relies on. A major part of dairy processing (and processing in many other areas of the food industry) is properly sterilizing the milk products before selling them. This step is critical in ensuring consumer health and safety, and involves heating the product to temperatures that will kill potentially harmful pathogenic microbes.
     During pasteurization, the food product is heated to kill pathogens, but cannot be heated to a point which destroys the product. This narrow window of temperature (usually around 100 °C) is usually sufficient to kill most pathogens, along with any bacteria that may cause spoilage to the food product. However, it is known that many bacterial spores can survive much higher temperatures. This is why milk and other food processing plants must incorporate additional heating steps to help with killing or removing heat resistant spores.
     The findings presented in this study regarding dairy biofilm isolates provide valuable data to food industry engineers which will help them to incorporate the necessary steps in processing plants to safely remove all harmful bacteria, including their heat resistant spores. In an ever-changing global climate, it is increasingly important to be increasing food product yields and food safety while eliminating waste due to spoiled foods during shipping. This research offers an important step in that direction.

     The CDC Biofilm Reactor is one of BioSurface Technologies’ core reactors. It has been used around the world to study countless biofilms like the one discussed in this paper. More publications involving CDC Biofilm Reactor research can be found by searching “CDC Biofilm Reactor” on Google Scholar.


Read the full publication on dairy biofilm isolates:

Kumar, Murali, et al. “A comparison of the spore heat resistance of dairy isolates of Geobacillus stearothermophilus obtained using a CDC biofilm reactor and a sporulating medium.” International Dairy Journal 116 (2021): 105000 (