Photosynthetic physiology of Scenedesmus sp. (Chlorophyceae) under photoautotrophic and molasses-based heterotrophic and mixotrophic conditions

Manoj Kamalanathan, Thi Hai Ly Dao, Panjaphol Chaisutyakorna, Ros Gleadow, John Beardall

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

Abstract

Heterotrophically grown cells of a newly isolated strain of Scenedesmus sp. retained their photosynthetic pigment content after prolonged darkness. When these cells had reached an apparent stationary phase and were subsequently exposed to light (mixotrophy), growth rapidly resumed and the biomass increased by 5.5-fold relative to photoautotrophically grown cultures and doubled compared with heterotrophic cultures. Although it is expected, and supported by the majority of reports in the literature, that dark acclimation of algal cultures should lead to eventual loss of photosynthetic pigments, some algae defy these expectations and synthesize and retain their photosynthetic pigments independent of light, despite the high associated maintenance costs. Here we examined the photosynthetic activity of heterotrophically grown cells in an attempt to explain this variance, using Scenedesmus sp. as a model organism. The photosynthetic capacity of heterotrophically grown cells was comparable with that of autotrophically grown cultures, associated with an interesting set of changes to the photosynthetic apparatus that includes lower nonphotochemical quenching, chlorophyll content, absorption cross-sectional area, higher connectivity between reaction centers, higher electron transport flux per reaction center, and probability at t = 0 that a trapped exciton moves an electron into the electron transport chain beyond the primary quinone electron acceptor, and performance index. As a result, when these heterotrophically grown cultures were transferred back to light, they were still able to perform photosynthesis and enhance overall growth, which was otherwise limited in complete darkness.

Original languageEnglish
Pages (from-to)666-674
Number of pages9
JournalPhycologia
Volume56
Issue number6
DOIs
Publication statusPublished - 8 Aug 2017

Keywords

  • Biomass
  • Heterotrophy
  • Light-independent chlorophyll biosynthesis
  • Mixotrophy
  • Photosynthesis

Cite this

@article{aaa053bd42fd4dadb5313c19e792feb0,
title = "Photosynthetic physiology of Scenedesmus sp. (Chlorophyceae) under photoautotrophic and molasses-based heterotrophic and mixotrophic conditions",
abstract = "Heterotrophically grown cells of a newly isolated strain of Scenedesmus sp. retained their photosynthetic pigment content after prolonged darkness. When these cells had reached an apparent stationary phase and were subsequently exposed to light (mixotrophy), growth rapidly resumed and the biomass increased by 5.5-fold relative to photoautotrophically grown cultures and doubled compared with heterotrophic cultures. Although it is expected, and supported by the majority of reports in the literature, that dark acclimation of algal cultures should lead to eventual loss of photosynthetic pigments, some algae defy these expectations and synthesize and retain their photosynthetic pigments independent of light, despite the high associated maintenance costs. Here we examined the photosynthetic activity of heterotrophically grown cells in an attempt to explain this variance, using Scenedesmus sp. as a model organism. The photosynthetic capacity of heterotrophically grown cells was comparable with that of autotrophically grown cultures, associated with an interesting set of changes to the photosynthetic apparatus that includes lower nonphotochemical quenching, chlorophyll content, absorption cross-sectional area, higher connectivity between reaction centers, higher electron transport flux per reaction center, and probability at t = 0 that a trapped exciton moves an electron into the electron transport chain beyond the primary quinone electron acceptor, and performance index. As a result, when these heterotrophically grown cultures were transferred back to light, they were still able to perform photosynthesis and enhance overall growth, which was otherwise limited in complete darkness.",
keywords = "Biomass, Heterotrophy, Light-independent chlorophyll biosynthesis, Mixotrophy, Photosynthesis",
author = "Manoj Kamalanathan and Dao, {Thi Hai Ly} and Panjaphol Chaisutyakorna and Ros Gleadow and John Beardall",
year = "2017",
month = "8",
day = "8",
doi = "10.2216/17-45.1",
language = "English",
volume = "56",
pages = "666--674",
journal = "Phycologia",
issn = "0031-8884",
publisher = "International Phycological Society",
number = "6",

}

Photosynthetic physiology of Scenedesmus sp. (Chlorophyceae) under photoautotrophic and molasses-based heterotrophic and mixotrophic conditions. / Kamalanathan, Manoj; Dao, Thi Hai Ly; Chaisutyakorna, Panjaphol; Gleadow, Ros; Beardall, John.

In: Phycologia, Vol. 56, No. 6, 08.08.2017, p. 666-674.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Photosynthetic physiology of Scenedesmus sp. (Chlorophyceae) under photoautotrophic and molasses-based heterotrophic and mixotrophic conditions

AU - Kamalanathan, Manoj

AU - Dao, Thi Hai Ly

AU - Chaisutyakorna, Panjaphol

AU - Gleadow, Ros

AU - Beardall, John

PY - 2017/8/8

Y1 - 2017/8/8

N2 - Heterotrophically grown cells of a newly isolated strain of Scenedesmus sp. retained their photosynthetic pigment content after prolonged darkness. When these cells had reached an apparent stationary phase and were subsequently exposed to light (mixotrophy), growth rapidly resumed and the biomass increased by 5.5-fold relative to photoautotrophically grown cultures and doubled compared with heterotrophic cultures. Although it is expected, and supported by the majority of reports in the literature, that dark acclimation of algal cultures should lead to eventual loss of photosynthetic pigments, some algae defy these expectations and synthesize and retain their photosynthetic pigments independent of light, despite the high associated maintenance costs. Here we examined the photosynthetic activity of heterotrophically grown cells in an attempt to explain this variance, using Scenedesmus sp. as a model organism. The photosynthetic capacity of heterotrophically grown cells was comparable with that of autotrophically grown cultures, associated with an interesting set of changes to the photosynthetic apparatus that includes lower nonphotochemical quenching, chlorophyll content, absorption cross-sectional area, higher connectivity between reaction centers, higher electron transport flux per reaction center, and probability at t = 0 that a trapped exciton moves an electron into the electron transport chain beyond the primary quinone electron acceptor, and performance index. As a result, when these heterotrophically grown cultures were transferred back to light, they were still able to perform photosynthesis and enhance overall growth, which was otherwise limited in complete darkness.

AB - Heterotrophically grown cells of a newly isolated strain of Scenedesmus sp. retained their photosynthetic pigment content after prolonged darkness. When these cells had reached an apparent stationary phase and were subsequently exposed to light (mixotrophy), growth rapidly resumed and the biomass increased by 5.5-fold relative to photoautotrophically grown cultures and doubled compared with heterotrophic cultures. Although it is expected, and supported by the majority of reports in the literature, that dark acclimation of algal cultures should lead to eventual loss of photosynthetic pigments, some algae defy these expectations and synthesize and retain their photosynthetic pigments independent of light, despite the high associated maintenance costs. Here we examined the photosynthetic activity of heterotrophically grown cells in an attempt to explain this variance, using Scenedesmus sp. as a model organism. The photosynthetic capacity of heterotrophically grown cells was comparable with that of autotrophically grown cultures, associated with an interesting set of changes to the photosynthetic apparatus that includes lower nonphotochemical quenching, chlorophyll content, absorption cross-sectional area, higher connectivity between reaction centers, higher electron transport flux per reaction center, and probability at t = 0 that a trapped exciton moves an electron into the electron transport chain beyond the primary quinone electron acceptor, and performance index. As a result, when these heterotrophically grown cultures were transferred back to light, they were still able to perform photosynthesis and enhance overall growth, which was otherwise limited in complete darkness.

KW - Biomass

KW - Heterotrophy

KW - Light-independent chlorophyll biosynthesis

KW - Mixotrophy

KW - Photosynthesis

UR - http://www.scopus.com/inward/record.url?scp=85033599444&partnerID=8YFLogxK

U2 - 10.2216/17-45.1

DO - 10.2216/17-45.1

M3 - Article

AN - SCOPUS:85033599444

VL - 56

SP - 666

EP - 674

JO - Phycologia

JF - Phycologia

SN - 0031-8884

IS - 6

ER -