Quantitative Analysis of Proteins Isolated from Cladophora glomerata Algal Biomass Using Bradford and Lowry Methods

Abstract

Background: Cladophora glomerata (C. glomerata) is a branched green alga belonging to the Cladophoraceae family [1]. The content of amino acids in Cladophora macroalgae is higher than in Spirulina cyanobacteria and Porphyra red seaweeds. Algal blooms caused by C. glomerata reduces biological diversity, as this species of green algae forms accumulations that decrease the recreational value of water bodies, thus causing harmful ecological and economic effects [1,2]. Therefore, excess biomass of C. glomerata could be collected as a source of proteins, and the waste could be adapted as raw material, creating a sustainable production chain. In this study, protein concentration was evaluated using Bradford and Lowry spectrophotometric microplate methods. Aim: To determine the protein content in C. glomerata biomass using Bradford or Lowry methods. Methods: C. glomerata biomass samples were collected from the Dūkšta river in Lithuania on August 25, 2023, and prepared for analysis by scientists at the Laboratory of Algology and Microbial Ecology (Nature Research Centre). Methods: extraction with 7.4 pH PBS aqueous buffer solution 0.01 M, protein precipitation method using ammonium sulfate salt, resuspension method using 7.4 pH PBS aqueous buffer solution (ratio 1:10), preparation of protein samples using the dialysis process [3]. For protein quantification analysis - spectrophotometric Bradford and Lowry methods [3]. The obtained research results were processed using the Microsoft Office Excel data analysis program (Microsoft Corporation, USA). Results: Using the Bradford spectrophotometric microplate method, it was determined that 1g of C. glomerata biomass material contains 0.833 (0.012) mg of proteins. Using the Lowry spectrophotometric microplate method, it was determined that 1g of C. glomerata biomass material contains 0.146 (0.002) mg of proteins. Conclusion: The Bradford method is more suitable for quantitative determination of proteins isolated from C. glomerata biomass material (0.833 (0.012) mg).