The health benefits of blue green algae are well-know: it is one of the most nutrient-dense foods on the planet. Microalgae is also used to produce biodiesel, animal feed and is an invaluable ingredient in the food industry. Algal biotechnology uses cryopreservation at extreme low temperatures to ensure the viability of the algae is preserved, however not all algae can survive this technology. A review in Emerging Science explores this process.
By John G. Day and Roland A. Fleck
Algal biotechnology requires stable, function-fulfilling stock-cultures. Conventionally microalgae and cyanobacteria – bacteria that obtain their energy through photosynthesis – are transferred to a fresh medium and held under controlled environmental conditions.
Cryopreservation at ultra-low temperatures is the only methodology that can provide this level of security to master stock-cultures; however, many algae are resistant to cryopreservation with low or no survival.
In a review published in the Open Access journal Microalgae Biotechnology, the authors explore the reasons of this cryo-recalcitrance on the application of conventional colligative, two-step cryopreservation protocols and points towards the options available to enhance postcryopreservation viability.
The researchers show that extending the knowledge on acclimation potential across key algal groups could lead to improved cryopreservation outcomes by developing cryopreservation protocols that embrace reversible environmentally regulated changes in algae able to mitigate against cryo-injury and/or stress.
Considerable methodological development is still needed to increase the diversity of taxa to which cryopreservation is applicable and to ensure that recovered material remain functionally and genetically representative of the original sample.
As the method becomes a mainstay of the biotechnology sector, it will need to scale up to ensure the consistency of batch-to-batch production. For the foreseeable future the authors conclude that cryopreservation employing colligative approaches will continue to be the preferred method of conserving both master – and working – cultures of biotechnologically exploited/exploitable algae. This is because it is procedurally less complex and the frozen material is less sensitive to temperature fluctuations.
Read the original article here
This article was originally published on Energy Today