Algal Oxylipins Mediate the Resistance of Diatoms against Algicidal Bacteria

Algicidal bacteria can lyse microalgal blooms and trigger shifts within plankton communities. Resistant algal species can escape lysis, and have the opportunity to dominate the phytoplankton after a bacterial infection. Despite their important function in ecosystem regulation, little is known about mechanisms of resistance. Here, we show that the diatom Chaetoceros didymus releases eicosanoid oxylipins into the medium, and that the lytic algicidal bacterium, Kordia algicida, induces the production of several wound-activated oxylipins in this resistant diatom. Neither releases nor an induction occurs in the susceptible diatom Skeletonema costatum that is lysed by the bacterium within a few days. Among the upregulated oxylipins, hydroxylated eicosapentaenoic acids (HEPEs) dominate. However, also, resolvins, known lipid mediators in mammals, increase upon exposure of the algae to the algicidal bacteria. The prevailing hydroxylated fatty acid, 15-HEPE, significantly inhibits growth of K. algicida at a concentration of approximately 1 µM. The oxylipin production may represent an independent line of defense of the resistant alga, acting in addition to the previously reported upregulation of proteases.

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High CO2 increases lipid and polyunsaturated fatty acid productivity of the marine diatom Skeletonema costatum in a two-stage model

Journal of Applied Phycology ◽

10.1007/s10811-021-02619-5 ◽

2021 ◽

Author(s):

Min Wu ◽

Guang Gao ◽

Youwen Jian ◽

Juntian Xu

Keyword(s):

Fatty Acid ◽

Polyunsaturated Fatty Acid ◽

Skeletonema Costatum ◽

Marine Diatom ◽

Stage Model ◽

Two Stage ◽

High Co2 ◽

Acid Productivity ◽

Fatty Acid Productivity ◽

Diatom Skeletonema Costatum

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The Algicidal Bacterium Kordia algicida Shapes a Natural Plankton Community

Applied and Environmental Microbiology ◽

10.1128/aem.02779-18 ◽

2019 ◽

Vol 85 (7) ◽

Cited By ~ 1

Author(s):

Arite Bigalke ◽

Nils Meyer ◽

Lydia Alkistis Papanikolopoulou ◽

Karen Helen Wiltshire ◽

Georg Pohnert

Keyword(s):

North Sea ◽

Algal Blooms ◽

Plankton Community ◽

Algicidal Bacteria ◽

Important Species ◽

Substantial Impact ◽

The North ◽

Algicidal Bacterium ◽

The North Sea ◽

Plankton Communities

ABSTRACT Plankton communities consist of complex microbial consortia that change over time. These fluctuations can be only partially explained by limiting resources. Biotic factors such as herbivores and pathogens also contribute to the control of algal blooms. Here we address the effects of algicidal bacteria on a natural plankton community in an indoor enclosure experiment. The algicidal bacteria, introduced into plankton taken directly from the North Sea during a diatom bloom, caused the rapid decline of the bloom-forming Chaetoceros socialis within only 1 day. The haptophyte Phaeocystis, in contrast, is resistant to the lytic bacteria and could benefit from the removal of the competitor, as indicated by an onset of a bloom in the treated enclosures. This cascading effect caused by the bacterial pathogen accelerated the succession of Phaeocystis, which bloomed with a delay of only several weeks in the in situ waters at Helgoland Roads in the North Sea. The algicidal bacteria can thus modulate the community within the limits of the abiotic and biotic conditions of the local environment. Implications of our findings for plankton ecosystem functioning are discussed. IMPORTANCE Plankton communities change on a seasonal basis in temperate systems, with distinct succession patterns; this is mainly due to algal species that have their optimal timing relative to environmental conditions. We know that bacterial populations are also instrumental in the decay and termination of phytoplankton blooms. Here, we describe algicidal bacteria as modulators of this important species succession. Upon treatment of a natural plankton consortium with an algicidal bacterium, we observed a strong shift in the phytoplankton community structure, compared to controls, resulting in formation of a succeeding Phaeocystis bloom. Blooms of this alga have a substantial impact on global biogeochemical and ecological cycles, as they are responsible for a substantial proportion of primary production during spring in the North Sea. We propose that one of the key factors influencing such community shifts may be algicidal bacteria.

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Algicidal bacterium CZBC1 inhibits the growth of Oscillatoria chlorina, Oscillatoria tenuis, and Oscillatoria planctonica

AMB Express ◽

10.1186/s13568-019-0872-8 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Xiao-Juan Hu ◽

Yu Xu ◽

Hao-Chang Su ◽

Wu-Jie Xu ◽

Li-Hua Wang ◽

...

Keyword(s):

Algal Species ◽

Algicidal Bacteria ◽

Inhibitory Effects ◽

The Sustainable Development ◽

Initial Concentration ◽

Algicidal Bacterium ◽

Cyanobacteria Blooms ◽

Cell Counts ◽

Colony Forming Units ◽

Harmful Cyanobacteria

Abstract Frequent harmful cyanobacteria blooms limit the sustainable development of aquaculture. Algicidal bacteria can efficiently control harmful algae without secondary pollution. The algicidal bacteria CZBC1 can lyse Oscillatoria spp. and other harmful cyanobacteria, but its effector mechanism and algicidal threshold are unknown. In this study, we examined the algicidal effect of CZBC1 on O. chlorina, O. tenuis, and O. planctonica by microscopic enumeration and scanning electron microscopy observation. Then, we examined the alginolytic effects of CZBC1 (concentrations 103–106 colony forming units (cfu)/mL) on these three species (concentrations 103–106 cells/mL) to determine the effective concentrations of CZBC1 for Oscillatoria spp. alginolysis. Results showed that CZBC1 can directly lyse O. chlorina and O. tenuis but indirectly lyse O. planctonica. When the initial concentration of CZBC1 was 106 cfu/mL, alginolytic effects were high for all three species at all concentrations, and the alginolytic rate could reach 100% in 3–9 days. When the initial concentration of CZBC1 was lower (103 cfu/mL), its inhibitory effects were delayed by 2–5 days, but the cell counts were significantly decreased compared with the control, evidencing significant alginolysis. In addition, the higher the concentration of the algicidal bacteria suspension, the more significant the alginolytic effects. Our results indicate that CZBC1 has different alginolytic mechanisms for O. chlorina, O. tenuis, and O. planctonica, and that different initial concentrations of CZBC1 have different alginolytic effects on these algal species.

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Fatty Acid Distribution in Lipids of Marine Plankton

Journal of the Fisheries Research Board of Canada ◽

10.1139/f64-118 ◽

1964 ◽

Vol 21 (6) ◽

pp. 1379-1384 ◽

Cited By ~ 38

Author(s):

H. Brockerhoff ◽

M. Yurkowski ◽

R. J. Hoyle ◽

R. G. Ackman

Keyword(s):

Fatty Acid ◽

Skeletonema Costatum ◽

Fatty Acid Distribution ◽

Large Degree ◽

Typical Structure ◽

Animal Fats ◽

Lipid Fractions ◽

Marine Food ◽

Diatom Skeletonema Costatum ◽

Recent Demonstration

In the diatom, Skeletonema costatum, as well as in a zooplankton sample, the polyunsaturated fatty acids of the triglycerides were found accumulated in the β-position of the glycerol. This fatty acid distribution pattern is typical for animal fats, in particular for fish oils. Together with the recent demonstration that fish and invertebrates retain in part the structure of ingested triglycerides, the findings of the present study show that the typical structure of marine triglycerides originates in phytoplankton and is to a large degree retained through the marine food chains.The fatty acid composition of several other lipid fractions of the plankton samples was also determined.

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Origin of Marine Fatty Acids. I. Analyses of the Fatty Acids Produced by the DiatomSkeletonema costatum

Journal of the Fisheries Research Board of Canada ◽

10.1139/f64-067 ◽

1964 ◽

Vol 21 (4) ◽

pp. 747-756 ◽

Cited By ~ 95

Author(s):

R. G. Ackman ◽

P. M. Jangaard ◽

R. J. Hoyle ◽

H. Brockerhoff

Keyword(s):

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Laboratory Experiments ◽

Unsaturated Fatty Acids ◽

Skeletonema Costatum ◽

Marine Diatom ◽

Highly Unsaturated Fatty Acids ◽

Diatom Skeletonema Costatum

Analysis of the fatty acid composition of a marine diatom, Skeletonema costatum, shows that the longer-chain highly unsaturated fatty acids characteristic of fish lipids can be produced by some phytoplankton as well as through intermediary zooplankton. Comparison of cultures of various degrees of maturity indicates that the fatty acid composition of mature cultures in laboratory experiments is not necessarily typical of pelagic diatoms. The origin of atypical C16-polyunsaturated fatty acids is discussed.

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Isolation and Characterization of the Algicidal Bacterium DCJ-2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1065-1069.3077 ◽

2014 ◽

Vol 1065-1069 ◽

pp. 3077-3082 ◽

Cited By ~ 1

Author(s):

Ting Ting Liu ◽

Yu Fu Peng ◽

Li Liu ◽

Xue Shan Xia

Keyword(s):

Natural Waters ◽

Algal Species ◽

Algicidal Activity ◽

Algicidal Bacteria ◽

Plectonema Boryanum ◽

Lake Dianchi ◽

Algicidal Bacterium ◽

Isolation And Characterization ◽

Bloom Water

Algicidal bacteria as part of the microbial populations in natural waters, is possible toinhibit the growth of algae or kill algae, dissolve algal cells in a direct or indirect way. In this study,four algicidal bacteria were isolated from cyanobacteria bloom water of Lake Dianchi, designated asDCJ-1, DCJ-2, DCJ-3, DCJ-4 respectively. The algicidal range and algicidal activity assay of the fouralgicidal bacteria showed that they have different algicidal range on the 10 tested algal species, whichstrain DCJ-2 has the best algicidal activity. The results indicated that bacterial strain DCJ-2 has highalgicidal activity against the Plectonema boryanum and exhibited algicidal activity through directattack. The lytic effect of strain DCJ-2 against Plectonema boryanum was time-dependent. It could be a potential bio-agent to control the blooms of cyanobacteria.

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