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Effect of serial subculturing on the adaptive potential of Dunaliella Salina strain KU11
Author(s)
Date Issued
June 1, 2017
Type
Conference Paper
Abstract
Dunaliella is a halotolerant green microalga. It has the great potential for commercially generating nutraceutical, pharmaceutical and biofuel products. Dunaliella salina strain KU11 was isolated from hypersaline soil in Nakorn Ratchasrima province, Thailand [1,2]. In this study, we aimed to explore the adaptive potential of D. salina KU11 growth and biomass by using “Natural selection” that was previously successful on Chlamydomonas reinhardtii growth rate improvement [3]. In our experiments, we started growing D. salina KU11 in liquid Ramaraj’s medium [1]. The first Dunaliella population was called Progenitor Dunaliella (PD), then the alga was evolved for 100 populations (from March 2016 to February 2017) by serial subculturing and the transferred Dunaliella population was called Evolved Dunaliella (ED). We randomly analyzed growth of ED-34, ED-64 and ED-100 (the transferred Dunaliella at 34, 64, and 100 times, respectively) compared with PD. We found that ED-34 had cell density accumulation ~ 1.25 fold greater than PD in the late-log and stationary phase and a longer log phase. This result was confirmed by growth analyses of ED-64 and ED-100, they showed an increase of their cell density accumulation in log and stationary phase ~ 2-3 fold and their log phases were longer than PD about 2-5 days. We also measured cell size and found that ED-100 cells were ~1.2 fold smaller than PD cells and biomass of PD and ED-100 population was not signicant difference. Our preliminary results demonstrated that the natural selection technique affected on Dunaliella‘s cell division (or cell cycle) resulting in the higher cell density accumulation and a longer log phase. This change could be regulated by some genes changed during the selection. We further planned to study on genomic and transcriptomic analyses that will give us to better understand in cell cycle regulation of D. salina.
Citation
European Biomass Conference and Exhibition Proceedings, 2017(25thEUBCE), 313-318, 2017