Abstract

The extremophilic unicellular red microalga Galdieria sulphuraria (Cyanidiophyceae) is able to grow autotrophically, or mixo- and heterotrophically with 1% glycerol as a carbon source. The alga divides by multiple fission into more than two cells within one cell cycle. The optimal conditions of light, temperature and pH (500 µmol photons m−2 s−1, 40 °C, and pH 3; respectively) for the strain Galdieria sulphuraria (Galdieri) Merola 002 were determined as a basis for synchronization experiments. For synchronization, the specific light/dark cycle, 16/8 h was identified as the precondition for investigating the cell cycle. The alga was successfully synchronized and the cell cycle was evaluated. G. sulphuraria attained two commitment points with midpoints at 10 and 13 h of the cell cycle, leading to two nuclear divisions, followed subsequently by division into four daughter cells. The daughter cells stayed in the mother cell wall until the beginning of the next light phase, when they were released. Accumulation of glycogen throughout the cell cycle was also described. The findings presented here bring a new contribution to our general understanding of the cell cycle in cyanidialean red algae, and specifically of the biotechnologically important species G. sulphuraria.

Highlights

  • In the case of a mixotrophic regime, it was cultivated with the addition of 1% v/v glycerol to evaluate and optimize growth conditions of asynchronous cultures for potential biotechnological applications

  • The final dry matter (DM) ±SD values reached under the different conditions are listed in

  • For any cell cycle study, optimal growth conditions have to be determined for the model organism being used

Read more

Summary

Introduction

The genomes of three representatives of cyanidiales have been sequenced so far—Cyanidioschyzon merolae, G. sulphuraria and Galdieria phlegrea [2,3,4,5]. These extremophilic microalgae are adapted to thermo-acidophilic growth conditions, inhabiting hot sulfur springs and geothermal habitats [6,7,8]. They thrive in a wide range of temperatures up to 56 ◦ C and in acidic environments with pH values below 1.0 [9,10].

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call