A Data-Driven Comparison of Commercially Available Testing Methods for Algae Characterization

Algal biomass composition is often the primary driver of economic viability of research and commercial algae-based product development. As the commercial algae production field is expanding, there is a growing need for a standardized language across producers and markets in terms of biomass characterization. Similarly, to establish and design collaborative or cross-institutional algae research projects, groups need to harmonize reported compositional analysis data to ensure comparable and reproducible results. In order to provide a consistent foundation of algae quality assessment, we are working towards closely coordinated, harmonized and objective operational protocols across the algae community. We present here a demonstration of biomass composition data from different commercial analytical laboratories, specifically applied to a reference biomass material. The data highlights a lack of consistency across laboratories in methods that are available for analysis. The data presented here illustrate variability in reported biomass measurements of protein, lipids and carbohydrate content causing differences of up to 1.36, 1.43, and 3.37-fold respectively, when expressed on a dry biomass basis. When the same methods are used between the laboratories, e.g. for protein and ash measurements, the data are consistent across laboratories. However, the reported lipid content varies with the method chosen at each laboratory, and causes the calculated carbohydrate content to then absorb the remaining difference from full mass balance closure. A suggestion of a common set of analytical standard methods available commercially is provided and can help to alleviate some of the challenges the algae community faces in terms of biomass descriptive reporting. This work sets the stage for and identifies critical niches to build on an established framework for understanding and harmonizing analytical methodologies for compositional analysis of algal biomass.