Open AccessSimplified cryopreservation of the microalga Chlorella vulgaris integrating a novel concept for cell viability estimation
Author(s) -
Morschett Holger,
Reich Sebastian,
Wiechert Wolfgang,
Oldiges Marco
Publication year - 2016
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201500056
Subject(s) - chlorella vulgaris , cryopreservation , biochemical engineering , protocol (science) , biology , biological system , viability assay , microbiology and biotechnology , algae , computer science , process engineering , computational biology , botany , engineering , cell , biochemistry , embryo , medicine , alternative medicine , pathology
Microalgae currently receive growing attention as promising candidates for future bio‐economy concepts. However, the reliable maintenance of production strains remains challenging. The well‐established serial subculturing techniques suffer from low long‐time stability and high effort and are therefore stepwise being replaced by cryopreservation. Currently, available protocols are often deduced from cell culture technology and are rather complex. This study aimed to investigate if less complex approaches can be applied. We introduce an easy‐to‐use cryopreservation protocol based on the model organism Chlorella vulgaris . To overcome error‐prone viability estimation by plating techniques, an alternative method using growth pattern analysis was developed. As revealed by growth pattern analysis, the preservation of stationary phase cells proved superior to the commonly applied concept of freezing cells from the growing phase. Controlled‐rate cooling using simple devices resulted in reproducibly high post‐thawing viabilities in the range of 63 ± 2%. Moreover, the presented protocol highlights the potential of simplifying microalgal cryo‐preservation procedures, thereby reducing the required labor and material need to a minimum. Apart from the viability analysis of the cryopreserved microalga C. vulgaris , this approach seems to have the potential to be applied for other algae species and microorganisms, as well.