Hydrogel culture bacterial system

Encapsulates the cells, allowing researchers to conduct lengthy experiments
in a hydrated environment.
However, cell growth under these conditions puts a lot of pressure on the encapsulated case, causing cell leakage
.
In a new study, researchers at the University of Illinois at Urbana-Champaign have developed modified alginate hydrogels that tolerate the growth of bacteria, allowing them to synthesize important enzymes
.

Hydrogels are polymers reinforced by different chemical bonds that absorb water and expand without decomposition
.
Therefore, biotechnology researchers often turn to these structures to provide stability and structural support
for their cell cultures.

"Hydrogel shells have been used for more than 50 years
.
By combining different kinds of cells in different hydrogel environments, many different types can be made," said
Yoon Jeong, a graduate student in Irudayaraj (CGD/EIRH) lab.
"The problem with combining microbes with hydrogel capsules is that they leak out
.
"

To solve this problem, Jeong decided to focus on alginate, a naturally edible compound
found in brown algae.
Although it has been studied before, it has been challenging
to encapsulate bacteria with it.

Professor Jeong said: "My strategy is to make a hydrogel membrane
on the surface of the hydrogel structure.
Although the changes may seem small, they work well
.
Testing Lactococcus lactis with genetically modified methods, he found that without this membrane, bacteria would leak out and be unable to form a biofilm, a collection
of microbes that stick to each other.
On the other hand, colonies of L.
lactis in modified hydrogels can grow for more than 10 days; The hydrogel provides a stable platform that does not break.

Jeong also studied genetically modified E.
coli, which synthesizes a number of different molecules
only when it can reach high cell density.
He looked at E.
coli cells, which produce green fluorescent protein, which emits green signals
when the cells are exposed to ultraviolet light.
"While it's simple to grow GFP-producing E.
coli, they die
quickly," Jeong said.
I found that inside the hydrogel, they form colonies, which increase in size, produce GFP, and do not leak.

”

He achieved the same result
when he used bioluminescent E.
coli cells.
These bacteria code for the lux gene, causing blue cells to glow
in the dark.
The researchers found that once the bacteria reached a certain cell density, the luminescence continued to increase
over the next 3 days.

The main purpose of fabricating these hydrogels is to develop bioreactors that can support bacterial growth while making important compounds
.
To test whether the modified hydrogel could sustain such a process, Jeong also tested L.
Lactis makes lactic acid protein, a peptide
used as a food preservative.
Consistent with their previous results, the bacteria were able to grow well in the modified hydrogel and were able to produce compounds
.

"While at first glance it may seem simple to make these hydrogel structures, it's actually difficult
.
You have to control their size, thickness and prevent clumping because these capsules will stick together
.
Researchers with diverse scientific backgrounds find this process difficult
.
We plan to release a detailed protocol soon so people can use this cheap and simple technology
.
”

The researchers are also interested in continuing testing in humans and cancer cells, hoping that hydrogels will provide a reliable platform
for a wide range of applications.

Soft hydrogel-shell confinement systems as bacteria-based bioactuators and biosensors