Adaptation of marine plankton to environmental stress by glycolipid accumulation

Gašparović, Blaženka; Godrijan, Jelena; Frka, Sanja; Tomažić, Igor; Penezić, Abra; Marić, Daniela; Djakovac, Tamara; Ivančić, Ingrid; Paliaga, Paolo; Lyons, Daniel Mark; Precali, Robert; Tepić, Nataša (2013) Adaptation of marine plankton to environmental stress by glycolipid accumulation. Marine Environmental Research, 92 . pp. 120-132. ISSN 0141-1136

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Abstract

A systematic investigation of non-phosphorus containing glycolipids (GL) was conducted in the northern Adriatic Sea during two years at two stations with different nutrient loads. GL concentration varied both spatially and temporally, with values of 1.1-21.5 g/L and 0.4-44.7 g/L in the particulate and the dissolved fraction, respectively. The highest concentrations were measured during summer in surface waters and at the more oligotrophic station, where GL yields (% of total lipids) were often higher than 20% and 50% in the particulate and dissolved fractions, respectively. To obtain more insight into factors governing GL accumulation autotrophic plankton community structure (pico-, nano- and microplankton fractions), chlorophyll a, heterotrophic bacteria and nutrient concentrations were measured together with hydrographic parameters and sunlight intensity. During the investigated period smaller autotrophic plankton cells (pico- and followed by nanoplankton) prevailed in abundance over larger cells (microplankton), which were found in large numbers in freshened surface samples. Several major findings resulted from the study. Firstly, during PO4 limitation, particularly at the oligotrophic station, enhanced glycolipid instead of phospholipid accumulation takes place, representing an effective phosphate-conserving mechanism. Secondly, results suggest that at seawater temperatures >19ºC autotrophic plankton considerably accumulate GL, probably to achieve thermal stability. Thirdly, high sunlight intensities seem to influence increased GL accumulation ; GL possibly plays a role in cell mechanisms that prevent/mitigate photooxidation. And finally, substantial accumulation of GL detected in the dissolved fraction could be related to the fact that GL do not contain biologically relevant elements, like phosphorus, which makes them an unattractive substrate for enzyme activity. Therefore, substantial portion of CO2 could be removed from the atmosphere in P-limited regions during summer via its capture by plankton and conversion to GL.

Item Type:	Article
Uncontrolled Keywords:	glycolipids; PO4 limitation; temperature; sunlight; microplankton; nanoplankton; picoplankton
Subjects:	NATURAL SCIENCES > Interdisciplinary Natural Sciences > Marine Science
Divisions:	Division for Marine and Enviromental Research
Projects:	Project title Project leader Project code Project type Mehanizam dugoročnih promjena u ekosustavu sjevernog Jadrana- Robert Precali 098-0982705-2731 MZOS Struktura i fiziologija mikrobnih zajednica frontalnih zona sjevernog Jadrana- Mirjana Najdek-Dragić 098-0982705-2729 MZOS Matematičko modeliranje cirkulacije i satelitska detekcija graničnih procesa- Milivoj Kuzmić 098-0982705-2707 MZOS Priroda organske tvari, interakcije s mikrokonstituentima i površinama u okolišu- Irena Ciglenečki-Jušić 098-0982934-2717 MZOS
Depositing User:	Blaženka Gašparović
Date Deposited:	21 May 2018 14:38
URI:	http://fulir.irb.hr/id/eprint/4044
DOI:	10.1016/j.marenvres.2013.09.009

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