Solid-state anaerobic fermentation of crayweed (Phyllospora comosa) biomass for nutrient stabilisation

The temperate Australian brown seaweed value chains and value chain developments necessitates sufficient characterisation of seaweed compositional changes imparted during preservation methods. In this study, two solid state anaerobic fermentation methods using natural seaweed microbiota and lactic acid bacteria (3.3 × 10 7 CFU/g Lactobacillus plantarum and Lactobacillus rhamnosus ) were carried out for sixty days on a freshly collected Phyllospora comosa biomass. The lipid composition of the fermentates were reduced by 12–13 % during the fermentations. The leading losses in the fatty acids were observed for 20:4n-6 (arachidonic acid) and 16:0 (palmitic acid) likely through the selective microbial β-oxidation and the de novo microbial polyketide fatty acid synthesis. The selective β-oxidation process depends on the degree of saturation, and chain lengths of fatty acids. The reduction of toxic arsenic also signifies the industrial importance of the solid-state fermentation process. However, the major portion of the P. comosa biomass was unchanged indicating the stabilising effects of the solid-state anaerobic fermentations for long term preservation facilitating enhanced applications in the Australian brown seaweed value chains. • Phyllospora comosa biomass was preserved using anaerobic solid state fermentation methods. • The only losses incurred during the storage were 12–13 % losses to lipids. • Fatty acid compositional changes were led by β-oxidation and de novo fatty acid synthesis.