Fish Waste Fermentation Produces High Value Products

Marine Bioproducts AS (Biomega AS) is a Norwegian production and research company focusing on gentle and natural processing of fresh raw materials of marine origin. Although several fish species are used as raw materials, Marine Bioproducts specialises in the processing of salmonids, and the present product line includes hydrolysates, peptides, amino acids, digested protein meals, minerals and oil from salmon.

Marine Bioproducts AS purchase salmon by-products (heads, backbones, intestines) of food quality from local salmon slaughter houses. A continuous enzymatic hydrolysis method is employed to digest the salmon in a manner which is less harsh than chemical methods, thus preserving more nutrients. This is followed by separation steps giving high quality protein, lipid and bone derived products.

he project, referred to as Marine IB, set out to assess how MB peptone might serve as a nutrient for growing microorganisms, showing that a sustainable co-product of the Norwegian salmon industry could potentially be applied in industrial biotechnology to produce high- value products, thereby raising its value. This project was co-funded by the Technology Strategy Board and Innovation Norway.

MB peptone competed well against a range of commercial peptones in supporting the growth of a variety of industrial biotech organisms and was particularly good for the growth of industrially important yeasts.

In assessing the ability of MB peptone to support growth of a genetically modified (GM) organism and production of a GM enzyme, CPI cloned a model enzyme, glucose dehydrogenase, into Escherichia coli BL21, the most established industry standard GM microorganism. MB peptone was compared against popular all-purpose peptones from two other suppliers.

Growth was significantly better with MB peptone, particularly after protein expression was ​“switched on”, when cells are under greatest metabolic stress. Most importantly, the model enzyme yields were at least an order of magnitude higher on MB peptone than on the other two peptones. This work thus clearly demonstrates the huge potential of MB peptone for industrial biotech GM processes.

To demonstrate that the MB peptone could be used at a pilot scale to grow a non-GM organism to produce an industrially useful enzyme, the protease-producing bacterium Bacillus licheniformis was examined.

CPI developed the fermentation and downstream processing at lab scale and transferred the process to its NIBF1 pilot plant for production at 750L scale. The protease product was tested in pilot trials by MB as a potential replacement for the proteases currently purchased and used in their manufacturing process. The quality of the product made using CPI protease was at least as high as that made using the commercial proteases, thus demonstrating the potential application of MB peptone in a real industrial process.