Establishment of a cryopreserved biobank for the Culture Collection of Freshwater Microalgae (CCMA-UFSCar), São Paulo, Brazil

Abstract

The Culture Collection of Freshwater Microalgae (CCMA-UFSCar, Coleção de Culturas de Microalgas de Água-Doce), based at the Universidade Federal de São Carlos, plays an important role in underpinning Brazilian microalgal research, providing biological materials, substrates and training personnel for a large proportion of the past and current projects in this area. However, recent efforts to expand the culture catalogue/holdings have reached a ceiling because of the logistical practicality of maintaining actively growing cultures. In order to reduce the costs associated with the maintenance regime of cultures, efforts were initiated on the establishment of a cryopreserved biobank for long term maintenance of cultures, thus minimizing the efforts associated with handling of material, as successfully frozen cultures, in theory, could be maintained effectively indefinitely, with the advantage of the stability of cells characteristics. Initial tests were performed on 93 strains including exemplar taxa across the different taxonomic groups in the collection catalogue. The highest levels of success were achieved for the smaller taxa, such as the small green algae; while for the larger and more complex organisms limited to no success was obtained. For the strains tested, over 70% had positive good levels of post-thaw viability and regenerated phenotypically normal cultures.

A simple and effective cryopreservation protocol for the industrially important and model organism, Euglena gracilis

“…Cryopreservation is a leading strategy for long-term cell-line storage that limits genetic drift, storage space, strain loss, cross-contamination, and permits facile clone transfer between facilities. Over the years, cryopreservation has been developed for a plethora of autotrophically grown microalgae and cyanobacteria, including Euglenophytes, by optimizing cryoprotectant solutions, freezing parameters, and recovery steps ( Morris and Canning, 1978 ; Fleck et al., 2006 ; Day, 2007 ; Bui et al., 2013 ; Tessarolli et al, 2017 ; Kapoore et al., 2019 ). For example, Morris and Canning (1978) developed a method for E. gracilis but only achieved 30% cell recovery.…”

BIOFIJACIÓN DE CO₂ POR DOS ESPECIES DE MICROALGAS CULTIVADAS EN FOTOBIORREACTORES

“…El cultivo de las microalgas posee variables que deben ser consideradas ya que podrían afectar su desarrollo, por tanto, cada especie tiene sus propias condiciones ideales de cultivo que dependen de su sitio de origen, como la intensidad de luz y la temperatura los cuales son factores determinantes para el crecimiento (Tessarolli et al, 2017). Los nutrientes más importantes para el adecuado desarrollo de las microalgas son en primer lugar el carbono, obtenido principalmente del CO 2 atmosférico (Walter et al, 2011), el nitrógeno, que afecta en la síntesis de proteína, ácidos nucleicos y clorofila, así como la productividad de lípidos (Menegol et al, 2017).…”

Cellular feasibility study of Acutodesmus obliquus

“…Microalgae biomass can be effectively preserved through storage, however, there are few studies that show cell viability techniques when the biomass is refrigerated, or even frozen for long periods of time. The freezing method becomes unfeasible mainly due to the formation of ice crystals, being responsible for cell expansion, causing cell wall disruption (Hanashiro et al 2019;Kapoore et al 2019;Tessarolli, Day, Vieira 2017;Umamaheswari e Shanthakumar, 2016).…”