Algal Biomass Constituent Analysis: Method Uncertainties and Investigation of the Underlying Measuring Chemistries

Abstract

Algal biomass compositional analysis data form the basis of a large number of techno-economic process analysis models that are used to investigate and compare different processes in algal biofuels production. However, the analytical methods used to generate these data are far from standardized. This work investigated the applicability of common methods for rapid chemical analysis of biomass samples with respect to accuracy and precision. This study measured lipids, protein, carbohydrates, ash, and moisture of a single algal biomass sample at 3 institutions by 8 independent researchers over 12 separate workdays. Results show statistically significant differences in the results from a given analytical method among laboratories but not between analysts at individual laboratories, suggesting consistent training is a critical issue for empirical analytical methods. Significantly different results from multiple lipid and protein measurements were found to be due to different measurement chemistries. We identified a set of compositional analysis procedures that are in best agreement with data obtained by more advanced analytical procedures. The methods described here and used for the round robin experiment do not require specialized instrumentation, and with detailed analytical documentation, the differences between laboratories can be markedly reduced.

Biochemical characterization of microalgal biomass from freshwater species isolated in Alberta, Canada for animal feed applications

“…Vast diversity in species/strains, isolate geographical environment, culture conditions, harvesting/processing techniques and poorly defined biomass characterization methods have resulted in data that is difficult to reproduce and confidently apply to industrial applications [1,23,[35][36][37]. The present study generated new data on the biochemical composition of four novel freshwater microalgae isolates identified as promising candidates for industrial CO 2 conversion in Northern climates.…”

“…Biochemical composition of algal biomass was conducted according to Laurens et al [23] with minor alterations. Moisture and ash levels were determined gravimetrically after heating at 105°C and after incineration at 550°C, respectively until constant weight.…”

Application of Algae as Cosubstrate To Enhance the Processability of Willow Wood for Continuous Hydrothermal Liquefaction

“…The N-factor was determined as an average of 10 marine microalgae species with a standard deviation of 0.11. The content of lipid in algal biomass was determined by extraction with a chloroform-methanol mixture in a Soxhlet extractor 31,32 . 19,23 .…”

Analysis of Fatty Acid Content and Composition in Microalgae

“…The latter include fatty acids with nutritional benefits (ω-3 fatty acids) like C20:5 (eicosapentaenoic acid; EPA) and C22:6 (docosahexaenoic acid; DHA) for which no vegetable alternatives , the main difference between commonly used lipid extraction procedures is in the solvent-systems that are used. Because of the large variety of lipid classes present in microalgae, each varying in polarity, the extracted lipid quantity will vary with solvents used [10][11][12] . This leads to the inconsistencies in the lipid content and composition presented in literature 9,10 .…”

“…Because of the large variety of lipid classes present in microalgae, each varying in polarity, the extracted lipid quantity will vary with solvents used [10][11][12] . This leads to the inconsistencies in the lipid content and composition presented in literature 9,10 . Depending on the solvent system used, methods based on solvent extraction without cell disruption through, for example, bead beating or sonication, might not extract all lipids because of the rigid structure of some microalgae species 9,13 .…”