Month: February 2025

DMS sophomore to study if tiny algae grow calcium carbonate crystals

Posted on February 12, 2025February 12, 2025 by Hannes Baumann

Evelyn Lewis glances at the well plates full of colorful slime in Prof. Visscher’s lab and smiles. The life thriving in there is invisible to the naked eye, but she knows how to keep the microscopic critters happy. For almost a year now, she has helped taking care of them, and this has helped others in the lab with their research projects.

But now, Evelyn is starting a project of her own. Her soft voice betrays the nascent excitement, as she examines a well plate full of what looks like crusty, white dust.

“These are calcium carbonate crystals, and they look so beautiful under the microscope”, she says.

Thanks to a new supply grant from UConn’s Office for Undergraduate research, she will now have the opportunity to look at many more of these crystals. Evelyn’s research will focus on some of the smallest photosynthetic organisms in world, cyanobacteria. When they bloom they often coat themselves in slime that they can chemically manipulate. The conditions in this extracellular slime might then become favorable to bind carbon dioxide (CO₂) in form of calcium carbonate (CaCO₃), ultimately removing it from the atmosphere. In other words, cyanobacteria may be tiny but mighty as a natural tool for combating the increase of heat-trapping CO2 in the atmosphere.

“These natural options of using microbial slime for CO₂ removal remain surprisingly underexplored”, explains Visscher. “The slime binds calcium and when it sinks to the bottom, it supports CaCO₃ formation in sediments for thousands of years. This recently discovered mechanism provides novel insights into the global carbon cycle.”

So over the course of the next months, Evelyn will culture cyanobacteria again – but this time for her project. In small well plates, she will measure their CaCO₃ production for about two weeks in relation to differing amounts of calcium. Yet the arguably coolest part will come after that, when the collected crystals will be examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS).

Ultimately, the gathered data will allow testing the overarching hypothesis that the presence of cyanobacteria increases CaCO₃ precipitation.

At DMS phytoplankton are now on IFCB-TV

Posted on February 5, 2025February 6, 2025 by Hannes Baumann

The team of DMS researchers Dr. Zofia Baumann, Dr. Kate Randolph and Hazel Levine are happy to share that a major new instrument has begun its long anticipated work. The Imaging Flow Cytobot - or IFCB for short - is for now installed in the Rankin Seawater lab, after being purchased with a UConn-CLAS shared equipment grant nearly two years ago (Dierssen, Baumann et al.).

The instrument has the capacity to monitor and display in real time the breath-taking diversity of microscopic life in the ocean. Our IFCB focuses on the smaller size classes 5 - 150 um, which mostly represent single cell algae and small mixotrophs.

Leveraging additional NSF support, we were able to overcome challenges with operating the IFCB on a routine basis. The IFCB now accesses the intake line of the Rankin Lab (a very small fraction of it) and then photographs any particles and characteristic shapes. The compilation below shows a given size range to illustrate some of the diversity. The IFCB now records these images and displays them on a public-facing online Dashboard, which can be mesmerizing to watch.

Plankton-composite — The composition of some of the larger phytoplankton as captured by the IFCB on February 6th 2025.

The implementation of the IFCB in Rankin Lab was led by Kate Randolph and greatly supported by Hazel Levine, Bob Dziomba, Charlie Woods, Todd Fake, and Chris Mills! Thank you.

The next step is to develop an AI-based classification system for automatic species identification. This will still take time, but we are collaborating with other IFCB users, including its inventors, and are optimistic about the progress ahead.

We hope you enjoy the stunning images of phytoplankton on what we like to call

"IFCB TV" !

Posted on February 5, 2025February 5, 2025 by Hannes Baumann

Reposted from UConn Today by Sarah Al-Arshani | January 28, 2025

A study led by marine sciences Ph.D. student Hannah Collins found that Novamont’s Mater-Bi, a starch-based polymer, degraded significantly faster than traditional plastics—showing promise for reducing marine pollution

Plastic pollution has become a global crisis, with the United Nations Environment Programme estimating between 19 and 23 million tons of plastic waste leak into aquatic ecosystems each year. A partnership between UConn marine sciences researchers and a leading bioplastics manufacturer is showing promise in addressing this issue.

A recent study published in the Journal of Polymers and the Environment found that Mater-Bi, a starch-based polymer produced by Italian company Novamont, degraded by as much as nearly 50% over nine months in a marine environment—significantly more than traditional plastics.

Novamont, which has a U.S. office in Shelton, collaborated with the UConn team to evaluate the product’s biodegradation.

tanks-hannah-and-larissa-3-998x665 — Marine sciences Ph.D. candidate Hannah Collins and Larissa Tabb '22 evaluate the lab tanks to check on degradation progress. (Contributed by Hannah Collins)

The study was led by Hannah Collins, a marine sciences Ph.D. candidate. Collins and her co-author, Larissa Tabb ’22 (CLAS), highlighted research done as part of the Marine Environmental Physiology Laboratory under the guidance of her advisor, professor and head of marine sciences Evan Ward.

“I’ve always been interested in how marine animals interact with their environment,” Collins says. “When our lab started looking at microplastics, it was clear how pervasive and damaging this problem is.”

Collins says the findings could have meaningful implications for reducing plastic pollution in aquatic environments. For example, products like Mater-Bi could replace traditional plastics used in aquatic structures, such as kelp farm lines, to reduce the possibility of plastic pollution.

“We’ve seen the pictures of sea turtles with plastic around their heads,” she says. “We have a lot of evidence of the negative effects of plastic pollution.”

Collins, who grew up visiting Cape Cod and the beaches of Long Island Sound, has long been fascinated by marine life. After earning a degree in biology from Gettysburg College and working in Alaska’s salmon fisheries, she decided to combine her passion for marine organisms and the environment, first in her master’s program and now for her Ph.D.

She says the collaboration with Novamont has helped her feel like she is making a difference in addressing marine pollution. It also provided her with hands-on experience examining real-world product applications.

Biodegradable plastics like Mater-Bi degrade much faster than traditional plastics, reducing risks to aquatic environments. However, Collins notes that many of these products are often tested under controlled conditions, not in real-world marine environments.

Collins’ research on Mater-Bi was conducted in a semi-controlled environment at the John S. Rankin Laboratory on the Avery Point campus. The lab filters seawater from the surrounding area to keep large organisms, like crabs, out. This allowed Collins and her team to test how much the product degraded in natural conditions while ruling out the impact of interference from those large organisms.

Her team tested samples of a Mater-Bi compostable bag, a traditional plastic bag, and a known biodegradable plastic in the lab. Every two weeks, they checked and measured how much each sample degraded by either mass or area. After nine months, they found that the Mater-Bi samples lost between 25% and 47% of their mass or area. Additionally, they found that the rate of degradation increased during warmer months.

“Microbial activity tends to increase in warmer conditions, which likely contributed to the faster degradation rates we observed,” Collins says.

Collins says she is hopeful that these findings could lead to future uses of Mater-Bi in aquaculture, especially for products where temporary or disposable materials are often used, such as oyster grow-out bags or kelp farming lines.

“If something breaks loose, it won’t persist in the water for decades,” she says.

Collins and Tabb have maintained connections with Novamont. Collins will attend the World Aquaculture Conference in New Orleans this March, where she hopes to connect industry leaders with biodegradable products like those produced by Novamont.

“Addressing plastic pollution requires a range of solutions,” she says. “Biodegradable plastics are just one piece of the puzzle.”

Marine Sciences