A rapid and general method for measurement of protein in micro-algal biomass

Abstract

A convenient small-scale extraction method for lyophilized micro-algae is described that dispenses with labor-intensive homogenization and is widely applicable to algae from different phyla. The procedure employs an optimized sequential extraction in trichloroacetic acid (TCA) and NaOH to achieve chemical lysis. Conditions were tested using several micro-algal strains to develop a method that was generally applicable. Incubation of lyophilized material in 24% (w/v) TCA at 95 °C followed by a hot alkaline treatment was found to be effective for strains that are resistant to conventional extraction approaches, such as the Chlorella and the Eustigmatophycean species. The single-tube extraction procedure can be complete in 4h and is conveniently followed by the Lowry assay, requiring a further 30 min. Overall, this method proved to be generally applicable and ideal either for single samples or for high-throughput screening of multiple algal strains for protein content.

pH-shift processing of Nannochloropsis oculata microalgal biomass to obtain a protein-enriched food or feed ingredient

“…Protein content in all freeze-dried fractions was determined according to [18]. The method is based on that of Lowry [19] and extracts proteins using trichloroacetic acid precipitation and spectrophotometric quantification (Cary Win UV 50, Varian, Australia, with either a quartz suprasil flow-cuvette, Hellma, Germany, or 0.5 ml disposable plastic cuvettes, Kartell, Italy, for samples with volumes b 3 ml).…”

Nitrogen-to-protein conversion factors revisited for applications of microalgal biomass conversion to food, feed and fuel

“…In the case of the Lowry spectrophotometric procedure, the color development is based on the reduction of the Folin reagent (Cu 2+ to Cu + ) by aromatic residues and peptide bonds in protein, after which the Cu + is chelated by bicinchoninic acid (BCA) to form the detected color [21][22][23]. Because the Folin reagent will react with other reducing substances in solution, this assay is susceptible to algae species-and growth condition-specific interferences which often cause a high bias [15,24].…”

From the Ancient Tribes to Modern Societies, Microalgae Evolution from a Simple Food to an Alternative Fuel Source

“…So far, the research team has screened 2700 microalgae strains from culture collections in order to define promising strains for lipid production. The team has published a few papers, mostly dealing with climate change and global warming risks, alternative species for lipid production and strain screening, strain improvement, reviews about biogas production, techno-economic development , and research on biogas production from seaweeds (Allan, 2011;Callaway et al, 2012;Day et al, 2012;Hughes et al, 2012;Roleda et al, 2013;Dave et al, 2013;Slocombe et al, 2013aSlocombe et al, , 2013bVanegas and Bartlett, 2013).…”