Microbiological degradation of macroalgae waste and its potential considerations for agricultural applications

The carbon, nitrogen, and phosphate contents of macroalgae suggest their favorable applications for agricultural uses, including soil enrichment through mulching or composting. Macroalgae contain complex and sulfated polysaccharides that are not found in the terrestrial environment and have heterogeneous sugar compositions. The biological process for algae degradation remains undefined. The dominant species of this study include Gracilaria salicornia, Avrainvillea amadelpha, and Acanthophora spicifera. A microbiological community comparison using PCoA analysis with Bray distances determined using the National Institute of Health (NIH) Nephele and Mothur pipeline analysis revealed that the communities between agricultural biomass piles containing terrestrial organic matter (waste biomass-WB1, WB2) were similar, however, distant in relation to the invasive algae pile (algae waste biomass-AWB). Determined using the Geneious software, 27% of the microorganisms in the AWB sample have clear marine origins at the phylogenic family level. Within these identified marine families, 61% have potential algae degradation metabolisms. In addition to the presence of trace metals found in the AWB sample, these are important considerations for agricultural applications.

Automated summary

The study suggests that macroalgae are suitable for agricultural use to enrich soil with carbon, nitrogen, and phosphate, containing complex polysaccharides and sulfated polysaccharides with diverse sugar compositions. The process of algae degradation remains unclear, but microbiological community analysis shows marine origins and potential algae degradation metabolisms in the algae waste biomass.