Growth and photosynthesis of Chlorella strains from polar,temperate and tropical freshwater environments under temperature stress  

作　　者：Kok-Keong LEE Phaik-Eem LIM Sze-Wan POONG Chiew-Yen WONG Siew-Moi PHANG John BEARDALL 

机构地区：[1]Institute of Ocean and Earth Sciences, University of Malaya [2]Institute of Graduate Studies, University of Malaya [3]School of Health Sciences, International Medical University [4]National Antarctic Research Centre, University of Malaya [5]Institute of Biological Sciences, University of Malaya [6]School of Biological Sciences, Monash University

出　　处：《Journal of Oceanology and Limnology》2018年第4期1266-1279,共14页海洋湖沼学报（英文）

基　　金：Supported by the HiCoE Grant(No.IOES-2014H)from the Ministry of Higher Education(MOHE),Malaysia;the University of Malaya Postgraduate Research Fund(No.PG121-2015A);the Knowledge Management Grant(No.RP001O-13SUS);the Antarctic Flagship Project(Nos.FP0712E012,PV002-2015)by the Ministry of Science,Technology&Innovation(MOSTI),Malaysia

摘　　要：Elevated temperatures as a consequence of global warming have significant impacts on the adaptation and survival of microalgae which are important primary producers in many ecosystems. The impact of temperature on the photosynthesis of microalgae is of great interest as the primary production of algal biomass is strongly dependent on the photosynthetic rates in a dynamic environment. Here, we examine the effects of elevated temperature on Chlorella strains originating from different latitudes, namely Antarctic, Arctic, temperate and tropical regions. Chlorophyll fluorescence was used to assess the photosynthetic responses of the microalgae. Rapid light curves(RLCs) and maximum quantum yield( F_v/F_m) were recorded. The results showed that Chlorella originating from different latitudes portrayed different growth trends and photosynthetic performance. The Chlorella genus is eurythermal, with a broad temperature tolerance range, but with strain-specific characteristics. However, there was a large overlap between the tolerance range of the four strains due to their "eurythermal adaptivity". Changes in the photosynthetic parameters indicated temperature stress. The ability of the four strains to reactivate photosynthesis after inhibition of photosynthesis under high temperatures was also studied. The Chlorella strains were shown to recover in terms of photosynthesis and growth(measured as Chl a) when they were returned to their ambient temperatures. Polar strains showed faster recovery in their optimal temperature compared to that under the ambient temperature from which they were isolated.Elevated temperatures as a consequence of global warming have significant impacts on the adaptation and survival of microalgae which are important primary producers in many ecosystems. The impact of temperature on the photosynthesis of microalgae is of great interest as the primary production of algal biomass is strongly dependent on the photosynthetic rates in a dynamic environment. Here, we examine the effects of elevated temperature on Chlorella strains originating from different latitudes, namely Antarctic, Arctic, temperate and tropical regions. Chlorophyll fluorescence was used to assess the photosynthetic responses of the microalgae. Rapid light curves（RLCs） and maximum quantum yield（ F_v/F_m） were recorded. The results showed that Chlorella originating from different latitudes portrayed different growth trends and photosynthetic performance. The Chlorella genus is eurythermal, with a broad temperature tolerance range, but with strain-specific characteristics. However, there was a large overlap between the tolerance range of the four strains due to their “eurythermal adaptivity”. Changes in the photosynthetic parameters indicated temperature stress. The ability of the four strains to reactivate photosynthesis after inhibition of photosynthesis under high temperatures was also studied. The Chlorella strains were shown to recover in terms of photosynthesis and growth（measured as Chl a） when they were returned to their ambient temperatures. Polar strains showed faster recovery in their optimal temperature compared to that under the ambient temperature from which they were isolated.

关 键 词：ANTARCTIC Arctic FV/FM MICROALGAE PIGMENTS recovery 

分 类 号：Q949.254[生物学—植物学] X16[环境科学与工程—环境科学]