Biochemical and Elemental Composition of Pelagic Sargassum Biomass Harvested across the Caribbean

Thierry Tonon,Eduardo Mora Jimenez,Michael J Allen,Julio V Suarez,Deanna Webber,Leopoldo Herrera-Rodriguez,Carla Botelho Machado,Amy Pilsbury,Frederick Gonzalez,James Smith,Michael Ahearn,Félix Cicéron,Mona Webber

doi:10.3390/phycology2010011

Abstract

Massive and recurrent strandings of pelagic Sargassum biomass have become the new norm in the Caribbean and the Western Africa since 2011, and there is no sign of this abating. These Sargassum events have negative environmental, socioeconomic and health impacts in the affected countries. In the meantime, various processing techniques and applications have been suggested for valorisation of this biomass. However, variability in quantity, quality and location creates substantial uncertainty for the development of reliable and robust industrial processes. As part of ongoing efforts to better characterise seasonal and geographical variations in the biochemical and elemental composition of the pelagic Sargassum biomass across the Caribbean, we analysed samples from Mexico, Jamaica and the Dominican Republic harvested during summer 2020 and winter 2021. Different degrees of variation were observed in the contents of ash, metals and metalloids, vitamins, fatty acids, amino acids and biogenic amines, and monosaccharides. Our results indicate that biomass is of highly variable quality depending on season and location. In this context, we suggest that biorefinery approaches geared towards controlled metal removal and focused on the extraction and purification of amino acids, fatty acids and vitamins should be prioritised to assess the potential valorisation of pelagic Sargassum biomass into standardised and high-value outputs.

Highlights

The impact of unwanted pelagic Sargassum on the environment, human health and tourist economies is legion [1–3]
Little is currently known about the polysaccharide composition of these specific species of Sargassum, especially in regard to laminarin content, and their cell walls
We observed an important abundance of fucose in our monosaccharide analysis

Summary

Introduction

The impact of unwanted pelagic Sargassum on the environment, human health and tourist economies is legion [1–3]. Recovered biomass is sent to landfill or left to rot in piles near to (or on) the beach It is perhaps one of life’s little ironies that the onset and continued prevalence of problematic Sargassum seaweed blooms over the past decade in the Caribbean region has been mirrored by a blooming global interest in exploiting seaweed as a sustainable and ecologically friendly biomass source for generating bulk commodity products, such as biofuels, fertilisers and chemical precursors. Local geographies and infrastructures influence the ability to retrieve and process biomass effectively, further exacerbating variation in the quality of potential input biomasses. This will undoubtedly impact on any truly scalable industrial process seeking to exploit this biomass

Methods

Results

Conclusion