Contact
Viggó Marteinsson
Research Group Leader
viggo@matis.is
Bacterial diversity in the processing environment of fish products
The report seeks to address the diversity and species composition of micro-organisms in fish processing environments. The research work began with the installation and development of methods for scanning microbial composition using molecular biological methods, and then at a later stage, work began on examining selected environments from the fishing industry. Two fish processing plants were visited, each twice where an evaluation was made of the processing and approx. 20 samples taken in each trip. A diverse community of bacteria was found, where known harmful bacteria were usually in a high proportion along with various other species. Microbial counts showed high levels of bacteria on the surface of production lines during processing with few bacterial groups in excess but also numerous other species in smaller quantities. The main groups of bacteria found belong to Photobacterium phosphoreum, which was in the highest proportion overall throughout the study, along with Flavobacterium, Psychrobacter, Chryseobacter, Acinetobacter and Pseudoalteromonas. All of these species are known fish bacteria that live in the redness and intestines of live fish. This is the first known project where molecular biological methods are used to scan the bacterial ecosystem of fish processing plants. A knowledge base has therefore been laid here for bacterial ecosystems in different conditions in fish processing, which will be used permanently in research and development of improved processing processes and storage methods for fish.
In this report we seek answers on diversity and species composition of bacteria in fish processing environment. The study initiated method development to screen microbial systems using molecular methods followed by analysis of samples from 2 fish processing plants. This research shows the presence of a diverse microbial community in fish processing environment where known spoilage microorganisms are typically in high relative numbers along with various other bacterial species. Total viable counts showed the presence of bacteria in high numbers on processing surfaces during fish processing where few species typically dominated the community. Photobacterium phosphoreum was the most apparent species followed by genera such as Flavobacterium, Psychrobacter, Chryseobacter, Acinetobacter and Pseudoalteromonas. All these species are known fish associated bacteria that live on the skin and in the digestive tract of a living animal. To our knowledge, this is the first study where molecular methods are used to screen microbial communities in fish processing plants. This research has therefore contributed a database on bacterial diversity in fish processing plants that will be used in the future to improve processing and storage methods in the fish industry.