Mahasweta Saha

Mahasweta Saha
Plymouth Marine Laboratory | PML · Marine Ecology and Biodiversity

PhD in Marine Chemical Ecology
Exciting fully funded PhD position coming up soon, email me 4 details!

About

59
Publications
17,775
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773
Citations
Introduction
I am a marine chemical ecologist and a senior scientist at PML with an expertise in chemical "language" that mediates communication in the marine environment and the effect of climate change. Available Fully funded PhD position: https://www.exeter.ac.uk/study/funding/award/?id=4297 To know more about our team: https://sahamahasweta.wixsite.com/chemicalecology
Additional affiliations
March 2019 - November 2020
Plymouth Marine Laboratory
Position
  • Senior Researcher
November 2017 - February 2019
GEOMAR Helmholtz Centre for Ocean Research Kiel
Position
  • Researcher
April 2016 - October 2017
University of Essex
Position
  • Fellow

Publications

Publications (59)
Article
Full-text available
It was demonstrated previously that polar and non-polar surface extracts of the brown alga Fucus vesiculosus collected during winter from the Kiel Bight (Germany) inhibited bacterial attachment at natural concentrations. The present study describes the bioassay-guided identification of the active metabolites from the polar fraction. Chromatographic...
Article
Full-text available
The chemical defence against microfouling in the brown seaweed Fucus vesiculosus was investigated and an inhibitor of bacterial settlement was isolated by bioassay-guided fractionation of non-polar surface extracts. UV-vis and mass spectrometry were used to identify the compound as the carotenoid fucoxanthin. The metabolite was tested at the natura...
Article
Full-text available
Seaweed surface provides a suitable substratum for the settlement of microorganisms (bacteria, viruses, and plankton). These microbial partners may have either beneficial or detrimental effects on the host since surface microbiota can act either as a protective layer to the macroalgae (symbiotic beneficial relations) or, under changing environmenta...
Article
Volatiles are important ‘infochemicals’ that play a crucial role in structuring life on our planet, fulfilling diverse functions in natural and artificial systems. Algae contribute significant quantities to the global budget of volatiles, but the ecological roles of aquatic volatiles are not well understood. In this review, we discuss the current k...
Article
Full-text available
Chemical communication via infochemicals plays a pivotal role in ecological interactions, allowing organisms to sense their environment, locate predators, food, habitats, or mates. A growing number of studies suggest that climate change‐associated stressors can modify these chemically mediated interactions, causing info‐disruption that scales up to...
Article
Full-text available
Marine macroalgae are important ecosystem engineers in marine coastal habitats. Macroalgae can be negatively impacted through excessive colonization by harmful bacteria, fungi, microalgae, and macro-colonisers and thus employ a range of chemical compounds to minimize such colonization. Recent research suggests that environmental pH conditions poten...
Article
Full-text available
Despite an increasing awareness of disease impacts on both cultivated and native seaweed populations, the development of marine probiotics has been limited and predominately focused on farmed animals. Bleaching (loss of thallus pigmentation) is one of the most prevalent diseases observed in marine macroalgae. Endemic probiotic bacteria have been ch...
Article
Full-text available
Diseases of the commercially cultivated brown seaweed Saccharina japonica have been noticed since the 1960s in China. However, the usually opportunistic nature of the pathogenic bacteria of seaweeds is still a main obstacle for isolating and identifying pathogenic bacteria responsible for causing diseases of the cultivated S. japonica. In this stud...
Article
Saccharina japonica is a commercially farmed seaweed of global importance. However, disease occurrence during different stages of cultivation can result in substantial economic losses. Identification of the causative agents of disease remains a significant bottleneck to the large scale cultivation of S. japonica. In this study, an aerobic heterotro...
Article
Full-text available
Both in terrestrial and aquatic realms, organisms communicate and interact with each other via volatile and non‐volatile infochemicals. Terrestrial plants and seaweeds, known as prolific producers of volatiles, harbour a plethora of microbes on their surfaces like phyllosphere of plant leaves and eco‐chemosphere of seaweeds, respectively where comp...
Article
Full-text available
The supply of healthy sporelings plays a crucial role in the successful aquaculture of commercially cultivated brown kelp Saccharina japonica. Epibacteria are of critical importance for maintaining seaweed health and development. Thus, this study aimed to investigate the epibacterial community associated with mature sporophytes and 1.5- and 2.0-mon...
Article
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems. However, we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help to describe and understand these co...
Article
Full-text available
Is it well-accepted that communication among organisms including land plants and aquatic macrophytes in terrestrial and aquatic ecosystems is largely achieved using information-conveying chemicals or infochemicals which should be seen as a chemical language of life. Marine macrophytes and phytoplankton are dominant primary producers in marine ecosy...
Article
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This is the Editorial introducing the Research Topic "Chemically mediated interactions between macrophytes and microbes" in "Frontiers in Marine Science".
Article
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Terrestrial plants are known to "garden" the microbiota of their rhizosphere via released metabolites (that can attract beneficial microbes and deter pathogenic microbes). Such a "gardening" capacity is also known to be dynamic in plants. Although microbial "gardening" has been recently demonstrated for seaweeds, we do not know whether this capacit...
Article
Full-text available
Since the holobiont concept came into the limelight ten years ago, we have become aware that responses of holobionts to climate change stressors may be driven by shifts in the microbiota. However, the complex interactions underlying holobiont responses across aquatic and terrestrial ecosystems remain largely unresolved. One of the key factors drivi...
Article
Full-text available
Climate change is characterized not only by an increase in mean temperature, but also an increase in the variability around the means causing extreme events like marine heatwaves. These events are expected to have strong influence on the ecology of marine foundation species such as the eelgrass Zostera marina. Bacterial and macroscopic foulers are...
Article
Full-text available
A new member of the family Flavobacteriaceae was isolated from the biofilm of a stone at Nordstrand, a peninsula at the German North Sea shore. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain ANORD1 T was most closely related to the validly described type strains Polaribacter porphyrae LNM-20 T (97.0 %) and Polaribacter reich...
Article
Cadmium (Cd) pollution is a widespread threat to marine life, and ongoing ocean acidification (OA) is predicted to impact bio-toxicity of Cd compounds. However, the cascading effects of changed Cd toxicity to marine primary producers are not well characterized. Here, we studied the impact of OA on Cd toxicity responses in a globally important diato...
Preprint
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems. However, we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help to describe and understand these co...
Article
Full-text available
This working group gathers 31 scientists from ten different countries, with expertise covering different scientific disciplines including philosophy, evolution, computer sciences, marine biology, ecology, chemistry, and microbiology, who participated in a workshop on marine holobionts, organized at the Roscoff Biological Station in March 2018. Thei...
Article
Full-text available
The establishment of epibacterial communities is fundamental to seaweed health and fitness, in modulating ecological interactions and may also facilitate adaptation to new environments. Abiotic factors like salinity can determine bacterial abundance, growth and community composition. However, influence of salinity as a driver of epibacterial commun...
Article
Full-text available
Marine heatwaves have been observed worldwide and are expected to increase in both frequency and intensity due to climate change. Such events may cause ecosystem reconfigurations arising from species range contraction or redistribution, with ecological, economic and social implications. Macrophytes such as the brown seaweed Fucus vesiculosus and th...
Article
Full-text available
“Infochemicals” (information-conveying chemicals) dominate much of the underwater communication in biological systems. They influence the movement and behavior of organisms, the ecological interactions between and across populations, and the trophic structure of marine food webs. However, relative to their terrestrial equivalents, the wider ecologi...
Article
Full-text available
Abstract In the course of the ongoing global intensification and diversification of human pressures, the study of variation patterns of biological traits along environmental gradients can provide relevant information on the performance of species under shifting conditions. The pronounced salinity gradient, co‐occurrence of multiple stressors, and a...
Preprint
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex sy...
Article
Full-text available
Our oceans host more than , species of marine life. Did you ever wonder how these organisms communicate? What you saw in "Finding Nemo" is clearly not the way it works in the real world! Marine plants and animals, even those that can see and hear like Nemo and Dory mostly "talk" using special signaling compounds collectively called infochemicals. I...
Article
Full-text available
1. Epimicrobial communities on seaweed surfaces usually contain not only potentially pathogenic but also potentially beneficial microorganisms. Capacity of terrestrial plants for chemically mediated recruitment, that is, "gardening" of bacterial communities in the rhizosphere was recently demonstrated. Empirical evidence directly linking such chemi...
Article
Full-text available
Featured Application: The development of new antifouling methods gives increasing attention to biomimicry, which could provide nontoxic or less toxic solutions for the deterrence of unwanted settlers. Natural mechanisms against fouling are often highly dynamic and future applications may need to mimic not only defensive compounds, but also their dy...
Preprint
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex sy...
Preprint
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex sy...
Preprint
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex sy...
Article
Full-text available
Host-microbe interactions play crucial roles in marine ecosystems. However, we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help to describe and understand these co...
Article
Full-text available
Marine biofouling is a paramount phenomenon in the marine environment and causes serious problems to maritime industries worldwide. Marine algae are known to produce a wide variety of chemical compounds with antibacterial, antifungal, antialgal, and anti-macrofouling properties, inhibiting the settlement and growth of other marine fouling organisms...
Article
Full-text available
The article “Minireview: algal natural compounds and extracts as antifoulants”, written by Mahasweta Saha, Franz Goecke, and Punyasloke Bhadury, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on November 6, 2017 without open access.
Article
Full-text available
Climate change will not only shift environmental means but will also increase the intensity of extreme events, exerting additional stress on ecosystems. While field observations on the ecological consequences of heat waves are emerging, experimental evidence is rare, and lacking at the community level. Using a novel "near-natural" outdoor mesocosms...
Chapter
All organisms and ecosystems emit and consume volatile organic compounds (VOCs). Traditionally, these have been qualitatively and quantitatively described in isolation without full consideration of the 'signatures’ produced by the totality of all volatiles released. Here, we suggest that volatilomics, a research area applied to medical diagnostics,...
Article
Full-text available
A new member of the Flavobacteriales was isolated from the surface of a stone collected on the German North Sea shore. The bacterium, strain ANORD5T, is a mesophilic, chemoheterotrophic aerobic, typical marine bacterium. Optimal growth was observed at 20-30 °C, pH 7.0-8.5 and 1-2 % sea salt. The 16S rRNA gene sequence revealed a distant relationshi...
Article
Full-text available
Biotic interactions underlie life’s diversity and are the lynchpin to understanding its complexity and resilience within an ecological niche. Algal biologists have embraced this paradigm, and studies building on the explosive growth in omics and cell biology methods have facilitated the in-depth analysis of nonmodel organisms and communities from a...
Article
Full-text available
A bioassay-guided approach was used to identify defense compounds that are present on the surface of Zostera marina and which inhibit settlement of microfoulers at natural concentrations. Moderately polar eelgrass surface extracts inhibited the settlement of seven marine bacteria and one yeast that originated from non-living substrata. In contrast,...
Article
Full-text available
Contents 1 I. 2 II. 2 III. 7 IV. 9 9 References 9 SUMMARY: Biotic interactions underlie life's diversity and are the lynchpin to understanding its complexity and resilience within an ecological niche. Algal biologists have embraced this paradigm, and studies building on the explosive growth in omics and cell biology methods have facilitated the in-...
Article
Full-text available
1. Rapid adaptation to novel biotic interactions and abiotic factors in introduced ranges can be critical to invasion success of both exotic terrestrial and aquatic plants. Seaweeds are extremely successful biological invaders in marine environments. Along with herbivores, foulers � ubiquitous enemies in the marine environment � have the potential...
Article
Full-text available
Large scale patterns of ecologically relevant traits may help identify drivers of their variability and conditions beneficial or adverse to the expression of these traits. Antimicrofouling defenses in scleractinian corals regulate the establishment of the associated biofilm as well as the risks of infection. The Saudi Arabian Red Sea coast features...
Article
Full-text available
The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubate...
Technical Report
GEOMAR biologists show a functioning defense system in Fucus vesiculosus despite environmental changes 31 October 2014/Kiel. The bladderwrack Fucus vesiculosus is actually one of the most important species of brown algae along the North Atlantic coasts. But for years their populations in the Baltic Sea were declining. Looking for the reasons, biolo...
Data
The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against microfoulers in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubat...
Article
Full-text available
The important role of marine epibiotic biofilms in the interactions of the host with its environment has been acknowledged recently. Previous studies with the temperate brown macroalga Fucus vesiculosus have identified polar and non-polar compounds recovered from the algal surface that have the potential to control such biofilms. Furthermore, both...
Thesis
Full-text available
Summary Bacteria are omnipresent in the marine environment. For example, in the Kiel Fjord (Baltic Sea) 0.7 to 2.24 x 106 bacterial cells are present in one ml of seawater. Marine organisms are thus continuously exposed to high densities of bacteria, some of which tend to settle and colonise living surfaces. Some associations between host and bacte...
Article
Full-text available
The impact of moderate environmental stress may be modulated by stress-induced shifts of biotic interactions such as host-epibiont relationships. We studied the stress regime in shallow Western Baltic habitats, the variability of fouling at different temporal and spatial scales, and whether common stressors-low light, high temperature and grazing-a...

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Question
I am looking for a software that does automated retention time allignment of GCFID data. Can anybody suggest?

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