John Helmann

FACULTY POSITION: We are seeking an Assistant Professor to join our growing and vibrant Department of Microbiology at Cornell! FOCUS: Using bacteria to address 21st century challenges. (part of a cohort hire in SynBio). *please repost* academicjobsonline.org/ajo/jobs/33098 #MicroSky

Bacillus subtilis biofilm formation is strongly stimulated by manganese. New results from Sachla et al. show that a Mn export protein (MeeY) and YybP are important for biofilm regulation, maturation, and proper matrix metalation 🎉🧪🦠 #Microsky www.nature.com/articles/s41...

Most cells require carbonic anhydrase and/or bicarbonate import to sustain pools of soluble inorganic carbon (SIC=CO2+HCO3-). Here, we identify proteins required for SIC homeostasis in Bacillus subtilis and identify a mutation that bypasses their requirement. www.biorxiv.org/content/10.6...

New in JB: Rangarajan and Waters review the role of divalent metals, particularly Mn2+, Mg2+, Zn2+, Ca2+, and Fe2+, in c-di-GMP signaling, including how these metals impact DGC and PDE enzyme activity. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol @microsky.bsky.social

A great review by the great @staceyheaver.bsky.social - all about bacterial lipids and their interactions with the host 🧪🧫🦠

Our new paper in PNAS reports the presence of Na+ and Li+ #aptamer RNAs in mammals. The latter hints at natural roles for #lithium in humans and provides direct links to #BipolarDisorder. Now seeking funding to study Li+ biology and create new therapeutics.

A beautiful perspective on science and the global impact of journals like JB. A journal that grows older and stays young | Journal of Bacteriology journals.asm.org/doi/10.1128/...

This is now published! For those interested in microbial mechanotransduction: www.cell.com/current-biol...

Excited to share our lab's first paper on the evolution of a c-di-GMP-controlled sigma factor: journals.asm.org/doi/10.1128/...

Yesha Patel here reviews how mutations in RNAP contribute to antibiotic resistance, with examples from both laboratory evolution and clinical settings. www.sciencedirect.com/science/arti... This work builds on two of her prior papers (PMIDs: 36779708 and 39908144). #MicroSky #antibiotics

1/ Out today in Science (@science.org): a result a decade in the making, and one that changed how I think about what cells are doing when they grow. We found a bacterium that grows slower than it could. And we found the molecular switch that lets us reverse it.

🫴 Cannibalism shapes biofilm structure and composition in Bacillus subtilis: | mBio journals.asm.org/doi/10.1128/... @mbio.bsky.social #subtiwiki

Published in Infection and Immunity, Gracious Donkor and I explore the diverse mechanisms microbes employ to withstand ROS-mediated stress and discuss recent efforts to harness oxidative stress responses as a potential strategy for developing new antimicrobials. journals.asm.org/doi/10.1128/...

New insights into copper physiology in Bacillus subtilis. The outlines of the pathway for copper import and trafficking to support aerobic growth are emerging. Work led by Grayson Barnes, with support from our collaborators. doi.org/10.1128/mbio... #microsky #metalsinbiology

@agnese75.bsky.social's work is out. She shows that under iron starvation M. tuberculosis splits flux through the Krebs cycle and secretes metabolites, akin of fermentation. Why is this important? Metabolic flexibility is what makes it so hard to kill in vivo. elifesciences.org/reviewed-pre...

See our new latest pre-print for a study led by grad student Ian Reynolds, with current and former undergrads Isabel Westin and Caleb Wood in the lab. A study that goes to show how so many cell surface processes are connected to each other in bacteria. www.biorxiv.org/content/10.6...

Now out in @pnas.org 🥳 "DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity" --> bad timing can kill you, even as a virus. www.pnas.org/doi/10.1073/... @spp2330.bsky.social, @mibinet.bsky.social, @dfg.de

The latest from the lab. Manikomycin, a new cyclic depsipeptide antibiotic from an 'old' source, the oxytetracycline producer Streptomyces rimosus. Still lots to be learned from this genus! Manikomycin blocks the E-site of the bacterial ribosome. A first. links.springernature.com/f/a/Q0JMeeZK...

Please RT: Registration is ongoing for our International Symposium "Microbial Networking - from organelles to cross-kingdom communities" organized as highlight of the first funding period of CRC 1535 @mibinet.bsky.social www.sfb1535.hhu.de/internationa... @dfg.de, @hhu.de, @fz-juelich.de

A redox- and proton-coupled inner membrane transporter mediates copper import to the bacterial cytoplasm www.pnas.org/doi/10.1073/... #jcampubs

Mutations in MreB suppress β-lactam sensitivity upon c-di-AMP accumulation in Listeria monocytogenes https://www.biorxiv.org/content/10.64898/2026.05.14.724990v1

Excited to share our work uncovering SNOR, a ribosome-associated factor that promotes translation restart after dormancy published in Nature!! This was, as usual, a wonderful collaborative effort between our group and the Mattei Lab @simonemattei.bsky.social @embl.org www.nature.com/articles/s41...

New paper out in @cp-cellhostmicrobe.bsky.social! Microbes evolving with modern lifestyles 🧬🦠 S. copri uses PerR to manage oxygen stress, but some strains acquired OxyR via HGT, boosting oxygen tolerance. These strains are enriched in industrialized populations. www.cell.com/cell-host-mi...

5/ Awardee @heatherfeaga.bsky.social is investigating how bacteria decide when to go dormant💤 (ie, form spores). Her project could lead to important new advancements in the management of spore-forming bacteria in the environment, hospitals, & food supply. 🎉 Congrats Dr. Feaga! 🙏 #HFScout Dipti Nayak

tagging @doerrlab.bsky.social New work from Tobi Dorr's lab (Cornell): Beta-lactam exposure can deplete nucleotide levels, and targeting nucleotide synthesis synergizes with β-lactam-mediated killing in V. cholerae, Klebsiella pneumoniae and E. coli.

Convergent MurJ flippase inhibition by phage lysis proteins www.nature.com/articles/s41...

See our newest manuscript dissecting emergent functions in a multispecies biofilm (metabolite cross-feeding, siderophore induction and cross-species utilization) that translates to plant growth promotion Great work by @jiyuxie.bsky.social and Xinli Sun www.biorxiv.org/content/10.6...

At long last! Check out the link to our publication in @nature.com to learn more. doi.org/10.1038/s415... 12/12

Thank you for highlighting our paper on how septal PG hydrolysis licenses a second wave of PG transpeptidation during cell separation! www.nature.com/articles/s41.... I will do a thread when the page set version is out.

@ewarman.bsky.social has followed up on her discovery of bidirectional promoters in bacteria by defining their basic rules for regulation and links to gene expression noise... academic.oup.com/nar/article/...

#Microbiology The anti-tuberculosis drug bedaquiline targets the mycobacterial ATP synthase, but how that leads to bacterial death is unclear Here the authors clarify how bedaquiline works @jnblab.bsky.social @morwan.me #TBSky #antibiotics #AMR http://dlvr.it/TQjZ0W

A gift of an article from the inimitable Colin Kleanthous as he says a moving farewell to his laboratory. A brave, unrepentant and scientifically brilliant journey is described - please have a read, friends. www.jbc.org/article/S002...

Why should microbiologists be interested in historical infection remedies, and how can we best investigate them for antimicrobial discovery? Thoroughly enjoyed co-writing this Microbiology Primer with @tosinorababa.bsky.social www.microbiologyresearch.org/content/jour... #MicroSky #Ancientbiotics

www.planktoscope.org

CuiT is a Cu importer required for metal homeostasis in Salmonella enterica https://www.biorxiv.org/content/10.64898/2026.01.22.701185v1

Congrats @regolab.bsky.social! www.pnas.org/doi/10.1073/...

Regulatory divergence and functional diversification of a c-di-GMP-controlled sigma factor in Actinomycetota https://www.biorxiv.org/content/10.64898/2026.01.14.699351v1

The Bacillus subtilis class A penicillin-binding protein 4 (PBP4) requires an accessory protein RpdA www.biorxiv.org/content/10.6...

🫴 A mechanotransduction mechanism for antibiotic defense in Gram-positive bacteria (Bacillus subtilis, with some interesting suppressor mutants): In Structure www.cell.com/structure/fu... #subtiWiki #subtilis

Thrilled to share our latest study, led by @reikatei.bsky.social, in @natchembio.nature.com! We began by asking a simple question—how do cells know if they have too much of a lipid in a particular membrane, and how do they respond to rectify this imbalance? www.nature.com/articles/s41... More info 👇

Registration is open for the 2026 Gordon Research Conference on Microbial Stress Response to be held on July 19-24 2026!! Submit your abstract by February 15th to be considered for a short talk. Apply now before it fills up!! Hope to see you there!! www.grc.org/microbial-st...

🧪HAPPY 2026 EVERYONE!!!! 🥂🍾🥳 When you enjoy your bubbly this evening, do spare a thought about carbonic anhydrase - it's an amazing enzyme (almost as fast as 2025 felt! 😜), and it turns out, it's also responsible for tasting CO2's "fizziness"!!! 🍾 www.science.org/doi/10.1126/...

This work was also our first time doing membrane localization (way to go Cassidy)! And so proud of Bella’s gorgeous Paenibacillus tree showing the distribution of the transmembrane containing Spo0B! Also it’s the lab’s first paper without ribosomes 🫨, but don’t worry - the ribosomes made the Spo0B!

Interesting new paper on Enterococcus lactis (the species formerly known as Clade B E. faecium) 'The Mannose Phosphotransferase System in Enterococcus lactis Is Essential for Gastrointestinal Colonization' onlinelibrary.wiley.com/doi/abs/10.1...

Our recent paper in npj Antimicrobials and Resistance is a great example of scientific serendipity: after staring at thousands of bacterial growth curves over many studies, we started wondering whether the curve shapes themselves carry mechanistic information 1/9 🦠🧪 www.nature.com/articles/s44...

We’re excited to share our latest study that reshapes our understanding of Mycobacterium tuberculosis (Mtb) lipid composition, with major implications for drug discovery, immunity, and vaccine development. www.nature.com/articles/s41... A thread.

The FsrA-Mediated Iron-Sparing Response Regulates the Biosynthesis of the Epipeptide EPE in Bacillus subtilis #MolMicrobiol by Sarah Miercke, Rabea Ghandour, Kai Papenfort and Thorsten Mascher onlinelibrary.wiley.com/doi/10.1111/...

Contribution of the Bacillus subtilis ytrGABCDEF operon to antibiotic stress adaptation Microbiology Spectrum from from Michaela Wenzel at Chalmer University of Technology, Gothenburg journals.asm.org/doi/10.1128/...

Spx inhibits expression of the SwrA•DegU master flagellar activator in Bacillus subtilis -in JBacteriol journals.asm.org/doi/10.1128/...