Effectiveness of Parachlorella kessleri cell disruption evaluated with the use of laser light scattering methods

Abstract

The main objective of this study is to demonstrate the possibilities of using laser light scattering methods, dynamic light scattering and laser Doppler electrophoresis, as suitable methods in investigations of algal production biosystems and biotechnology. This paper highlights the innovative use of the dynamic light scattering (DLS) methods for monitoring the destruction of Parachlorella kessleri cells. Additionally, these results indicate electrophoretic mobility as a new parameter to investigate the effectiveness of cell disruption prior to extraction conducted to optimise the biotechnological processes of recovery of microalgal intracellular metabolites. The efficacy of P. kessleri cell disintegration by ultrasound was determined by measurements of the number of cells with the algal cell reduction (CR ns), relative mean hydrodynamic diameter (Rd t) and electrophoretic mobility after applying different lengths of ultrasound exposure to a cell suspension. It was found that stationary-phase cells were the most resistant to the ultrasound treatment, especially at low values of the optical density. Both the relative hydrodynamic diameter and the electrophoretic mobility of cells were correlated statistically significantly with the time of sonication (t) and the algal cell reduction. The relationships allowed estimation of the sonication time needed for total cell disruption.

Effect of ultrasonication, high pressure homogenization and their combination on efficiency of extraction of bio-molecules from microalgae Parachlorella kessleri

“…These methods can be chemical, enzymatic, or different physical treatments, such as ultrasonication (US), microwaves, pulsed electric fields, and mechanical stresses (high pressure homogenization (HPH), bead milling (BM) etc…) [13,[16][17][18][19]. The efficacy of P. kessleri cell disintegration by US treatment was evaluated by laser light scattering methods [20]. In the US treatment, the cell walls can be damaged by the bursting of cavitation bubbles outside the cells and the development of extremely high pressures.…”

Agro-industrial by-product in photoheterotrophic and mixotrophic culture of Tetradesmus obliquus: Production of ω3 and ω6 essential fatty acids with biotechnological importance

“…During the cultivation in the photobioreactors, spectrophotometric measurements of optical density (OD 650 ) were carried out every 24 h using a Cary 300/Biomelt spectrophotometer. Based on the calibration curve equation for T. obliquus (DCW = 303.21 × OD 650 − 2.354, R 2 = 0.9958) and the determined optical density values, the theoretical dry cell weight (expressed in g L −1 ) was determined during the consecutive days of cultivation, demonstrating the growth of the cultured T. obliquus cells 52 .…”

“…determined in the algal biomass with the gravimetric method, which is a modification of the Bligh and Dyer method 18,52 . An ultrasound-assisted lipid extraction method with the use of a chloroform and methanol mixture in a volume ratio of 1:2 v/v was employed.…”

Morphological Change and Cell Disruption of Haematococcus pluvialis Cyst during High-Pressure Homogenization for Astaxanthin Recovery

“…Therefore, a synergistic combination of these methods is recommended for the development of practical H. pluvialis biorefinery processes that co-produce various bio-products, including lipids, proteins, carbohydrates, chlorophyll, and astaxanthin. Several analytical techniques have been reported in order to evaluate the disintegration efficiency of algal biomass by mechanical treatments: particle-size analyzer (homogenization for Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata [28]; bead beating for C. reinhardtii [29]), dynamic light scattering (ultrasonication for Parachlorella kessleri [30]), and flow cytometer (bead milling for Chlorella species [31,32]). However, after cell disruption, the morphological characteristics of the algal cell and/or the internal target substance(s) have not been studied in detail.…”