Dr. Chandni Sidhu

My research investigates the complex ecological processes underpinning the breakdown of algal polysaccharides by marine bacteria during North Sea algal blooms. While these blooms are often visually striking, they represent dynamic ecosystems where a diverse array of microorganisms interact with complex algal compounds. Beyond the well-studied carbon cycling, I explore the crucial roles of sulfur and nitrogen cycling in these microbial communities.

By employing advanced genomic, transcriptomic, and molecular techniques, I aim to unravel the genetic and biochemical mechanisms that enable bacteria to degrade these complex algal compounds, especially polysaccharides and organosulfonate compounds. This includes identifying specific enzymes and elucidating the metabolic pathways involved in the assimilation of released nutrients. These insights are essential for comprehending the involved interaction between bacteria and algal blooms, and their impact on nutrient cycling, energy flow, and the overall health of marine ecosystems.

In collaboration with other scientists, I extend my research to the Western Antarctic Peninsula, a region undergoing rapid environmental change. Here, I investigate the resource utilization strategies of bacterioplankton communities and their contribution to biogeochemical cycles. By examining the microbial interactions within these sensitive environments, we gain a deeper understanding of their role in shaping ecosystem dynamics, carbon sequestration, and their potential influence on global climate patterns. This research provides valuable insights into the resilience and adaptability of marine ecosystems in the face of climate change.

Current Position(s)

Independent Researcher (DFG-Fellow) - Institut für Chemie und Biologie des Meeres (ICBM), University of Oldenburg, Oldenburg, Germany (Webpage)

Senior Scientist - Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Oldenburg, Germany (Webpage)

Publications

• Chandni Sidhu*, Daniel Bartosik, Vaikhari Kale, Anke Trautwein-Schult, Dörte Becher, Thomas Schweder, Rudolf Amann, Hanno Teeling. “Resource partitioning in organosulfonate utilization by free-living heterotrophic bacteria during a North Sea microalgal bloom”. bioRxiv. https://doi.org/10.1101/2024.12.10.627767 (In-review)
• Gunjan Vasudeva, Chandni Sidhu, Kalyan Vaid, Pragya Priyadarshini, Vanish Kumar, Muthu Krishnan, Balvinder Singh, Anil Kumar Pinnaka. “Bioremediation of catecholic pollutants with novel oxygen-insensitive catechol 2, 3-dioxygenase and its potential in biomonitoring of catechol in wastewater”. Environmental Pollution (2025). https://doi.org/10.1016/j.envpol.2024.125613
• Joris Krull, Conor J Crawford, Chandni Sidhu, Vipul Solanki, Margot Bligh, Leonard Rößler, Rajat K Singh, Guoyin Huang, Craig S Robb, H Teeling, Peter H Seeberger, Thomas Schweder, Jan-Hendrik Hehemann. “Polyelectrolyte mannan from diatoms reshapes sunlit ocean microbiome”. bioRxiv. https://doi.org/10.1101/2024.07.03.601839 (In-review)
• Feng-Qing Wang, Daniel Bartosik*, Chandni Sidhu*, Robin Siebers, De-Chen Lu, Anke Trautwein-Schult, Dörte Becher, Bruno Huettel, Johannes Rick, Inga V. Kirstein, Karen H. Wiltshire, Thomas Schweder, Bernhard M. Fuchs, Mia M. Bengtsson, Hanno Teeling & Rudolf I. Amann. “Particle-attached bacteria act as gatekeepers in the decomposition of complex phytoplankton polysaccharides”. Microbiome (2024). https://doi.org/10.1186/s40168-024-01757-5
• Jan D Brüwer, Chandni Sidhu, Yanlin Zhao, Andreas Eich, Leonard Rößler, Luis H. Orellana, and Bernhard M. Fuchs. "Globally occurring pelagiphage infections create ribosome-deprived cells." Nature Communications 15, no. 1 (2024): 3715.
• Irena Beidler, Nicola Steinke, Tim Schulze, Chandni Sidhu, Daniel Bartosik, Marie-Katherin Zühlke, Laura Torres Martin, Joris Krull, Theresa Dutschei, Borja Ferrero-Bordera, Julia Rielicke, Vaikhari Kale, Thomas Sura, Anke Trautwein-Schult, Inga V Kirstein, Karen H Wiltshire, Hanno Teeling, Dörte Becher, Mia Maria Bengtsson, Jan-Hendrik Hehemann, Uwe T Bornscheuer, Rudolf I Amann, Thomas Schweder. “Alpha-glucans from bacterial necromass indicate an intra-population loop within the marine carbon cycle”. Nature Communications (2024). https://doi.org/10.1038/s41467-024-48301-5
• Chandni Sidhu, Inga V. Kirstei , Cédric L. Meunier, Johannes Rick, Vera Fofonova, Karen H. Wiltshire, Nicola Steinke, Silvia Vidal‐Melgosa, Jan‐Hendrik Hehemann, Bruno Huettel, Thomas Schweder, Bernhard M. Fuchs, Rudolf I. Amann and Hanno Teeling. "Dissolved storage glycans shaped the community composition of abundant bacterioplankton clades during a North Sea spring phytoplankton bloom". Microbiome (2023). https://doi.org/10.1186/s40168-023-01517-x
• Luis H Orellana, Karen Krüger, Chandni Sidhu, Rudolf Amann. "Comparing genomes recovered from time-series metagenomes using long-and short-read sequencing technologies". Microbiome (2023). https://doi.org/10.1186/s40168-023-01557-3
• Jan D Brüwer, Luis H Orellana, Chandni Sidhu, Helena CL Klip, Cédric L Meunier, Maarten Boersma, Karen H Wiltshire, Rudolf Amann, Bernhard M Fuchs. "In situ cell division and mortality rates of SAR11, SAR86, Bacteroidetes, and Aurantivirga during phytoplankton blooms reveal differences in population controls". mSystems (2023). 10.1128/msystems.01287-22#
• Nevena Maslać, Chandni Sidhu, Hanno Teeling, Tristan Wagner. "Comparative Transcriptomics Sheds Light on Remodeling of Gene Expression during Diazotrophy in the Thermophilic Methanogen Methanothermococcus thermolithotrophicus". Mbio (2022). 13(6), e02443-22
• Gunjan Vasudeva, Chandni Sidhu, Nidhi Kalidas, Anil Kumar Pinnaka. "Shape-function of a novel metapyrocatechase, RW4-MPC: Metagenomics to SAXS data based insight into deciphering regulators of function". International Journal of Biological Macromolecules (2021), 1012-1024
• Chandni Sidhu, Mohit Kumar Saini, Naga Radha Srinivas Tanuku, and Anil Kumar Pinnaka. "Arenibacter amylolyticus sp. nov., an amylase-producing bacterium of the family Flavobacteriaceae isolated from marine water in India". International journal of systematic and evolutionary microbiology (2021), 71, no. 3: 004664.
• Dipesh Kumar Verma, Gunjan Vasudeva, Chandni Sidhu, Anil K Pinnaka, Senthil E Prasad, Krishan Gopal Thakur. "Biochemical and taxonomic characterization of novel Haloarchaeal strains and purification of the recombinant halotolerant α-amylase discovered in the isolate". Frontiers in Microbiology (2020).
• Dipesh Kumar Verma, Chetna Chaudhary, Latika Singh, Chandni Sidhu, Busi Siddhardha, Senthil Prasad, Krishan Gopal Thakur. "Isolation and taxonomic characterization of novel phototropic Haloarchaeal isolates from Indian solar saltern: A brief review on distribution of bacteriorhodopsins and V-type ATPases in Haloarchaea". Frontiers in Microbiology (2020).
• Chandni Sidhu, Vipul Solanki, Anil Kumar Pinnaka, Krishan Gopal Thakur. "Structure Elucidation and Biochemical Characterization of Environmentally Relevant Novel Extradiol Dioxygenases Discovered by a Functional Metagenomics Approach". Msystems (2019).
• Vasundhera Gupta, Shalley Singh, Chandni Sidhu, Vishakha Grover, Anil Kumar Pinnaka, Suresh Korpole.“Virgicin, a novel lanthipeptide from Virgibacillus sp. strain AK90 exhibits inhibitory activity against Gram-positive bacteria”.  World Journal of Microbiology and Biotechnology (2019).
• Ramkrushna Ashok Salunke, Chandni Sidhu, Ashok Kumar, Anil Kumar Pinnaka, Baldev Raj Bansal, Manmohan Chhibber. "Enhanced Antibacterial Activity of Endo-nortropine Substituted (C-7) Fluoroquinolones Against V. cholerae, S. aureus and B. subtilis" Letters in Drug Design & Discovery (2018).
• Chandni Sidhu, Surendra Vikram, and Anil Kumar Pinnaka. “Unraveling the microbial interactions and metabolic potentials in pre-and post-treated sludge from a wastewater treatment plant using metagenomic studies”. Frontiers in Microbiology 8 (2017): 1382.
• Chandni Sidhu, Suresh Thakur, Gunjan Sharma, Naga Radha Srinivas Tanuku, Anil Kumar Pinnaka. “Oceanospirillum sanctuarii sp. nov., isolated from a sediment sample”. IJSEM (2017), doi: 10.1099/ijsem.0.002132.
• Ananya Mehta, Chandni Sidhu, Anil Kumar Pinnaka, Anirban Roy Choudhury."Extracellular polysaccharide production by a novel osmotolerant marine strain of Alteromonas macleodii and its application towards biomineralization of silver”. PlosOne (2014).

Research Grant

• 2025-2028 - DFG Research Grant for the project WindFluX

Fellowships and Awards

• 2017-2012 - CSIR-UGC Junior and Senior Research Fellowship for PhD (Govt. of India)
• 2017 - Travel Grant, Department of Biotechnology (DBT, Govt. of India)
• 2017 - Best Poster Prize, International Congress on microbial interaction and applications of Beneficial microbes, Munich, Germany.
• 2006 - Winner of Science fest on Interschool, Tehsil and District levels.

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ORCID: https://orcid.org/0000-0003-1386-1881

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