Direct Observation of Bacterial Growth in Giant Unilamellar Vesicles: A Novel Tool for Bacterial Cultures.

Invited for this month's cover picture are Dr. Masamune Morita, Dr. Kaoru Katoh and Dr. Naohiro Noda from the Biomedical Research Institute at the National Institute of Advanced Industrial Science and Technology (AIST, Japan). The cover picture shows direct monitoring of real-time activity of bacterial growth at the single-cell level inside giant unilamellar vesicles (GUVs); entrapped single bacterial cells are actively increasing to a great number of cells inside GUVs. This study shows new applications for GUVs, and can offer a novel tool for culturing bacteria in bacterial studies. Read the full text of their Communication at https://doi.org/10.1002/open.201800126.

What is the most significant result of this study?

The most significant result of this study is that living bacterial cells were cultured inside giant unilamellar vesicles (GUVs), which are artificial cell‐like systems. GUVs are unilamellar liposomes, specifically artificial vesicles averaging 1–100 μm in diameter; they are bounded by a single layer of amphiphilic lipids (or a mixture of such lipids) and contain an aqueous solution within the vesicles. One advantage of GUVs is their high retention of entrapped materials. Although the simple entrapment of bacteria inside GUVs had already been reported, we believe that our study is the first to describe entrapped bacteria successfully being cultured inside GUVs.

What future opportunities do you see?

The method we present in this study is the first step toward culturing living cells inside artificial cell‐like systems. We can design novel, artificial cell‐like systems by combining various (non‐)biomolecules based on GUVs. Artificial cell‐like systems offer unique possibilities in the development of cell‐culture systems for a wide range of fields, including biotechnology, microbiology, and synthetic biology. We call these new cell‐culture systems “artificial cell‐based incubators.” We are working furthering their development and continuing to research their possibilities.

How did the collaboration on this project start?

In a unique program that started within our institute last year, experts from the different fields participated in an ongoing collaboration that is researching “artificial cell‐based incubators.” Experts from the different fields are materials science and biophysics (M. Morita), biophysics and bioimaging (K. Katoh), and bioengineering (N. Noda).