Pohlschroder Lab

Prokaryotic Cell Surface Biogenesis


October 2021

We are excited to welcome Marco Garcia, our second FERBS student (Cris is from the inaugural cohort), in the lab. Great dinners – yup, back at the Biopond, an Oasis for outdoor “COVID time dinners” with the lab just before Bienfait left for Oxford, and with the 2021 FERBS fellows (photo), mentors and PIs.

September 2021

yup, outdoor events are NOT always at the Biopond – West Philly has lots of great places to hang out and celebrate ūüôā

August 2021

We are excited that Yirui Hong, who already worked with Stefan on a remote project, joined the lab for her first in-person rotation project, welcome Yirui!!!! Unfortunately, it was also a bittersweet get-together as Aldo’s 10-week summer program ended. Thanks for choosing to work with us this summer












July 2021

Great PennLENS student visit to Penn. Thanks to all the PennFERBS Fellows, including Cris, for helping make the day so informative with a campus tour and student panel. Victoria and Azullema, all the Best for the College application process – it was great having you with us even if it was mostly virtual.


June 2021

Lots of reasons to celebrate:

Congratulations Priyanka for being appointed to the Cell and Molecular Biology Training grant! We are excited that you will carry out your dissertation work in our lab!

Stefan Schulze’s work describing the largest archaeal glycoproteome to date: “Comprehensive glycoproteomics shines new light on the complexity and extent of glycosylation in archaea¬†was published in PlosBiology.

Welcome Penn SUIP student Aldo Trejos and PennLENS high school students Victoria Andrews and Azullema Ramirez, looking forward to working with you this summer!!!

PennFERBS¬†Fellows’ accomplishments were celebrated in this PennToday¬†article.



May 2021

Thanks, Cris for heading off the PennFERBS Fellows Seminar Event with a great presentation about your work in the lab this past semester!









April 2021

We are excited to welcome Priyanka Chatterjee from the MVP program in the lab for her third rotation. Priyanka is poised to find out more about how Haloferax volcanii cells communicate with each other.

Congratulations Michiyah for receiving the Rose Undergraduate Research Award for your research “Mutations Affecting HVO_1357 or HVO_2248 Cause Hypermotility in Haloferax volcanii, Suggesting Roles in Motility Regulation”. The¬†Rose Foundation recognizes outstanding undergraduate research projects completed by graduating seniors.

Last but not least, Heather received the Dissertation Research Award. This grant is a tribute to your outstanding academic record and impressive plan for dissertation research.” CONGRATULATIONS!!!!!

Definitely lots to celebrate at our first outdoor dinner at the Biopond













March 2021

Our collaborative work with the Duggin lab: “The impact of growth media on archaea morphology” was this month’s Microbiology Editor’s Choice.

February 2021

Congratulations Bienfait for being a Rhodes Finalist and for your acceptance as a Ph.D. student at Oxford!

Thanks to lab alumni, Evan Yan and Bienfait Igiraneza and current undergrads, Michiyah Collins and Zuha Mutan for participating in the panel to help your younger FGLI peers from the Penn FERBS program, “seeing themselves in science”!

The first Archaea Power Hour was fantastic – thanks Farid Abdul-Halim and Michiyah Collins for co-chairing this inaugural meeting with nearly 120 scientists interested in Archaea Biology from across the Americas coming together to hear three amazing talks and to network! Get more archaea news @archaea_power. Thanks Alex Bisson for setting this up and for working with great students to design the archaea webpage.

January 2021

More than three decades ago, the haloarchaeal S-layer glycoprotein was the first glycoprotein identified in any prokaryote and remained one of just a few archaeal glycoproteins until now. Check out Stefan’s work defining the most extensive archaeal glycoproteome in his article “Glycoproteomics of Haloferax volcanii reveals an extensive glycoproteome and concurrence of different N-glycosylation pathways” on¬†bioRxiv. Thanks Friedhelm Pfeiffer for yet another wonderful collaboration!


Michiyah Collins, Farid Abdul-Halim and I are excited to be part of the organizing committee of the “Archaea Power Hour“, a monthly meeting that gives students, postdocs and research scientists the chance to present their work and interact in a very informal way. Our goal is to strengthen, grow and diversify the Archaea community across the Americas! ¬†Join us on February 24th at 1pm for our first meeting!

We welcome sophomore Keya Patel, who’s also in the Biology Master’s submatriculation program to our lab and are excited to have Zuha and Taylor returning to the lab in person! We even had President Gutman attend our first lab meeting ūüôā Farid’s already published a first-author Methanogen paper in the Costa lab but his H. volcanii work still is being published – see¬†Microbiology research article describing a collaboration with the Duggin lab at the University of Technology in Sydney. Why does H. volcanii¬†only make rods in early log phase and how does it switch to disks? Stay tuned for the answers – we, together with some great H. volcanii groups across the Globe are trying to understand this cool morphological phenomenon. December 2020

The year ended beautifully thanks to amazing work from literally everyone in the lab Рcheck out the three papers that were published in December!  

1. Simi’s screen and Michiyah’s selection for hypermotile H. volcanii tn-mutants and the characterization of the “winners of the race” was published in¬†Genes. This work would have not been possible without great work of all the co-authors including our collaborators, Mike Dyall-Smith and Friedhelm Pfeiffer – thanks everyone!

2. Fantastic collaboration with the Hippler lab at the University of Muenster – check out the Bioinformatics publicationSugarPy facilitates the universal, discovery-driven analysis of intact glycopeptides“. Congrats, Stefan!

3. “Haloferax volcanii Immersed Liquid Biofilms Develop Independently of Known Biofilm Machineries and Exhibit Rapid Honeycomb Pattern Formation“, that also includes three undergraduate students from the Biol376 Microbial Diversity and Pathogenesis lab course ¬†is now published in mSphere! Oh, and let me not forget – check out Taylor’s amazing performance in the Penn Dance Group (if you don’t have time to watch all of the Glee Club/Dance collaboration, go to 15.5 min).

October 2021

Welcome to the lab Criston Young! Cris, who is part of the inaugural Penn Freshmen Exposure to Research in Biological Science (PennFERBS) cohort, will work with Heather to learn more about the liquid biofilms formation and dispersal. We look forward to working with you, Cris! Also, can’t wait to hear you perform in the Penn Band post-COVID!!!!!

September 2020 Welcome Dina Issakova, first year Biology graduate student, who is rotating in the lab this semester working with Stefan as well as Michiyah who, finally after six months is allowed back into the lab. We are excited that you can finish your exciting project on H. volcanii hyper motile mutants before graduating!

July 2020

Stefan Schulze mentored two amazing students from Carver Engineering and Science High school, Morgan Bryson and Sultanah Harper who were part of the LENS program. While we only got to know each other online this summer, we are hoping to meet you in in person to show you or lab very soon!!!!

Stefan’s recently published work on the Archaeal Proteome Project (see below) as well as his discovery and subsequent characterization of rapid liquid biofilm honeycomb pattern formation in collaborations with Heather Schiller was featured in PennToday. The manuscript describing latter work was also submitted to BioRxiv. Four undergraduate students contributed to this story and Theopy Rados from the Bisson lab at Brandeis University provided this beautiful Movie. June 2020

Our Archaeal Proteome Project (ArcPP), an international collaboration between 5 laboratories across 3 continents was just published in Nature Communications. The idea for this project was to more efficiently use existing proteomics data by combining not only resources but also expert knowledge across different fields of biology, in order to gain a deeper understanding of archaeal cell biology. Thanks and congratulations to Stefan Schulze, the postdoc in the lab who spearheaded this project, and collaborators who shared large amounts of proteome data, provided invaluable insight and carried out experiments. After demonstrating the usefulness of our approach, we made our results available in a web-database ( We are eager to work together with more laboratories in order to extend our analyses to other archaeal species or even bacteria, harvesting the synergistic effects of a broad scientific community.

Heather, congratulations for passing your Prelims during a very difficult period and while writing a manuscript that was only tangentially related to your prelim proposal!

Congratulations Taylor for graduating from Carver High School of Engineering and Science and for receiving the “Linda H Ahmed Award” for being an exceptional female student in the STEM fields – see you in the Fall!!!!


May 2020

Congratulations Bienfait – it’s been an honor to have had you in the lab and we hope that you will stay in touch. I can’t wait to see the great things you will continue to contribute to Science and Society! ¬† ¬†

April 2020

Michiyah, congratulations for receiving the¬†Jumpstart for Juniors¬†Research Fellowship – looking forward to working with you this summer – even if it’ll be virtual! While the poster presentation at the Delaware Tristate Science Fair had to be cancelled, Taylor won 3rd price in the highly competitive Microbiology category for the paper describing her research project – CONGRATULATIONS. Oh, and that’s not it, guess who will be a Freshman at Penn this Fall ūüôā Taylor, we can’t wait to see you again on campus, but this time with and “undergrad Penn ID!

March 2020

Congratulations Taylor for winning the 1st price in the Microbiology category of the City-wide Carver Science Fair, qualifying for the Delaware Tristate Science Fair AND winning the Eastern Branch ASM price for finding super-interesting H. volcanii persister mutants. The project was perfect for you: while challenging you persisted!!!   December 2019

End of the semester lab lunch including Jack Bletz who just finished his rotation in the lab and Cristy Almonte who will start her rotation in January (third and fourth from right, respectively). Elbren Montuya, a freshman at Penn also joined the lab this semester.

Our manuscript “Lipid anchoring of archaeosortase substrates and mid-cell growth in haloarchaea” a great collaborative effort with¬†Alex Bisson‘s lab (see his ArtA, PssA and PssD mid-cell localization movies above) was submitted to BioRxiv.¬†


September 2019

For the second time, Michiyah Collins presents her summer research at the Annual CURF Research Expo. Her project was also selected for a presentation at the upcoming family weekend – congratulations Michiyah!










July 2019

We keep the tradition going Рthis summer we have two high school students from Carver Engineering and Science РTaylor Bui as well as David Kouassi Рhelp out in the lab. Taylor, one of the 2019 LENS  students will also continue working with us this Fall!












May 2019

Lunch at Cierra Green to celebrate the end of the semester and welcome Heather Schiller (right) a first-year Biology Ph.D. student, to the lab – looks like her presence even moves the clouds ūüôā

April 2019

Georgio’s work “Limited Cross-Complementation Between Haloferax volcanii PilB1-C1 and PilB3-C3 Paralogs” was just published. These¬†in vivo data complement¬†in silico studies by¬†Makanrova et al.
Congratulations to Evan Yang who will leave Penn for Harvard. Enjoy grad school in Cambridge and please stay in touch!!!!!! Congratulations to Michiyah who received not one but two fellowships to work in the lab this summer, the Pincus Magaziner Family Research Award and the College Alumni Society Grant. Looking forward to having you in the lab this summer!!!!

March 2019

Congratulations to Sarah for being a semi-finalist at the Junior Science and Humanities Symposium and earning 4th place at the Carver Science Fair

November 2018

Haloferax volcanii is Trends in Microbiology’sMicrobe of the Month“!!!!

H. volcanii has emerged as an important archaeal model system. An extensive repertoire of genetic, molecular biological, and biochemical tools has been developed for this fast-growing, easily cultivated haloarchaeon, including expression vectors and gene-deletion strategies, including CRISPR. Its low mutation rate and ability to grow on defined media allow straightforward application of methods such as metabolic labeling, and the sequenced genome laid the foundation for transcriptomics and proteomics studies.


September 2018

Anthony Dilucido joined the lab as a Research Technician – welcome!


The FEMS Microbiology Reviews Thematic Issue on Archaea co-edited by Sonja Albers and Mecky, including our review on Archaeal Cell Surface Biogenesis is now published.

Bienfait received yet another award, the Seltzer Family Digital Media Award 2018 Рfelicitation encore une fois Bienfait!

Bienfait and Michiyah both presented posters about their summer work at the CURF Research Expo.

Zuha Mutan, an incoming freshman in the College joined the lab and right away helped Michiyah sort over 150 microscopes donated by Alpha and Omega Microscope Service in Maryland (thanks Peter Potter for delivering them on Saturday) for distribution to Philly teachers at our next Biology High School Professional Development session.


August 2018


Sarah Sawda, a rising senior from George Washington Carver Engineering and Science joined the lab for the summer as part of the LENS program. We are looking forward to having her in the lab this Fall as she is continuing the characterization of her hyper motile H. volcanii transposon mutants. June 2018 Bienfait Igiraneza received the Pincus-Magaziner Family Undergraduate Research and Travel Fund from the College Alumni Society Рfelicitation Bienfait!

May 2018

Vagelos student, David Yang,  joined the lab just after finishing his sophomore year Рwelcome David!

April 2018


Interested in how Mecky Pohlschroder’s career path from a small German farm via UMass and Harvard to UPenn? Check out this month’s Omnia article.


Simi and our halophiles are featured in “The Power of Penn” and “We Grow Inclusion” videos.


Anjana Sundarrajan was invited to attend the GapSummit.


Bienfait Iriganeza received the Pincus Magaziner Family Undergraduate Research Fellowship.

March 2018

Simi Afolayan was accepted into the Summer Research Internship Program at the CHOP Pediatric Center of Excellence in Nephrology.

Michiyah Collins received a Penn Undergraduate Research Mentoring Program Fellowship from the Center for Undergraduate Research and Fellowships.

February 2018 Farid Abdul-Halim’s characterization of the ArtA active site was published in Molecular Microbiology.

January 2018 Stefan was awarded a Deutsche Forschungsgemeinschaft postdoctoral fellwoship Рcongratulations Stefan!

December 2017 Lisa Valenti is moving on to her next rotation – thanks Lisa for great science AND art contributions ūüôā

October 2017

It’s been great to have Mariana Costa, from the University of Mar del Plata in Argentina visit the lab for a month. We are excited about our ongoing collaboration on the effects of rhomboid proteases on pili biosynthesis and function. We also had two new Masters of Biotechnology students, Anjana Sundarrajan and Kun Yun, as well as a a sophomore, Simisola (Simi) Afolayan and a freshman, Michiyah Collins, join the lab this Fall. Lisa Valenti, a first year Biology graduate student is rotating in the lab.

August 2017

Sending off Georgio Legerme to Med School at the University of Florida, Gainesville and Ronald Rodriguez to Grad School at Berkeley was a bittersweet event.

Laboratory Experiences in the Natural Sciences (LENS) students Tamera Stanley from George Washington Carver Engineering and Science High School spent the summer in the lab and screened nearly 4000 mutants for a motility defect. Her work was featured in the Penn News and she presented her mutants during the LENS poster session.

July 2017 Bienfait’s blog “A little closer to Burundi” about his incredible¬†CASI¬†internship at the Aravind Eye Care System in Madurai, India featured in Penn News igiraneza, aime bienfait May 2017

Stefan Schulze (postdoc) and Precious Nwanwa (undergraduate student)  joined the lab Рwelcome!

Farid Abdul Halim received his Ph.D.

and Evan received his Bachelor – Congratulations Evan and Farid!

March 2017

Aime Bienfait Igiraneza, freshman in the college, joined the lab – welcome Bienfait!

Ronald Rodriguez just obtained an NSF Graduate Research Fellowship – Congratulations, Ronald!!!!! Read more here

August 2016:

Jonathan Stoltzfus started his Assistant Professor position at Millersville University after just a year as a postdoc in the lab!

…he managed to attend the Halophile Meeting in Puerto Rico just before leaving though!


Jonathan presenting his work on ArtA-dependent surface anchoring at the Halophile meeting.

July 2016:

Rianne Esquivel started her post-doc at the Wistar Institute.  Her acceptance to the Lindau Nobel Laureates meeting was just one of the highlights during her extremely successful time as a graduate student in the lab!

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Rianne with Nobel Laureate Francoise Barre-Sinoussi and fellow students in Lindau, Germany.  

June 2016:

Farid Abdul Halim, after completing the Teece Fellowship, allowing him to participate in the Woods Hole Microbial Diversity Course in 2015, now also obtained an SAS Dissertation Completion Fellowship.


Farid, together with fellow students sampling in Woods Hole.

May 2016:

Georgio Legerme received a NASA post-baccalaureate fellowship. He also presented his work on identifying and characterizing H. volcanii adhesion transposon mutants at the ASM meeting in Boston.

img_20160618_134847    img_20160618_133500

Also check out:

Astrobiology Magazine‚Äôs research highlight featured our type IV pili work ‚ÄúAppendages Help Microbes Survive Harsh Conditions‚ÄĚ


A bacterium using type IV pili to walk on a surface. IMAGE CREDIT: GERARD WONG, UCLA BIOENGINEERING, CNSI.

March 2016:

Joshua Kouassi, freshman at Carver High School wins 1st place and 2nd place in Microbiology at the Carver and Delaware Science Fairs, respectively with his project “One in a Million“, a transposon screen that allowed him to identify intriguing hyper motile H. volcanii mutants. Thanks Evan for training Josh!


August 2016:

Penn News featured¬†Evan Yang¬†in the article: “Studying a Salt-loving Microbe, Penn Senior Evan Yang Imagines Life on Mars.

img_20160618_135707 img_20160618_133548

Evan presenting his work, supported by an ASM URF fellowship, on H. volcanii motility transposon mutants at the ASM Microbe meeting in Boston.

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