Nav: Home

A genetic nano-toolkit for the generation of new biomaterials

March 24, 2020

Magnetic bacteria might soon be used for the production of novel biomaterials. A team of microbiologists at the University of Bayreuth led by Prof. Dr. Dirk Schüler developed a modular system for the genetic reprogramming of bacteria, thereby turning the organisms into cell factories for multifunctional magnetic nanoparticles that combine various useful functions and properties. Because of their exceptional magnetic properties and good biocompatibility, these nanoparticles might be a promising new material in the biomedical and biotechnological field. In the journal "Small" the scientists presented their findings.

From magnetosomes to versatile nanoparticles

Magnetic bacteria of the species Magnetospirillum gryphiswaldense align their swimming behaviour along the Earth's magnetic field. Within the cells, magnetic nanoparticles, the magnetosomes, are arranged in a chain-like manner, thereby forming an intracellular compass needle. Each magnetosome consists of a magnetic iron oxide core surrounded by a membrane. In addition to lipids, this membrane also contains a variety of different proteins. The microbiologists of the University of Bayreuth have now succeeded in the coupling of biochemically active functional groups, which originate from various foreign organisms, to these proteins. The method used here starts at the stage of the genes that are responsible for the biosynthesis of the membrane proteins. These bacterial genes are fused to foreign genes from other organisms that control the production of the respective functional proteins. As soon as the genes are re-integrated into the genome, the reprogrammed bacteria produce magnetosomes that display these foreign proteins permanently installed on the particle surface.

In the study, four different functional groups (i.e. foreign proteins) were coupled to the membrane proteins. These include the enzyme glucose oxidase from a mould fungus, which is already used biotechnologically, for example as a "sugar sensor" in diabetes diseases. In addition, a green fluorescent protein from a jellyfish and a dye-producing enzyme from the bacterium Escherichia coli, whose activity can be easily measured, were installed on the surface of the magnetosomes. The fourth functional group is an antibody fragment from a lama (Alpaca) that was used as a versatile connector. Thus, all these properties including the superb magnetization of the magnetosomes are genetically encoded in the bacteria.

"Using this genetic strategy, we reprogrammed the bacteria to produce magnetosomes that glow green when irradiated with UV light and at the same time display novel biocatalytic functions. Various biochemical functions can be precisely installed on their surfaces. Thereby, magnetosomes from living bacteria are transformed into multifunctional nanoparticles with fascinating functions and properties. Moreover, the particles remain fully functional when they are isolated from the bacteria - which can be easily performed by taking advantage of their inherent magnetic properties," says Professor Dirk Schüler, who led the research team.

A genetic toolkit for applications in biomedicine and biotechnology

Functionalization of the magnetosomes by no means is limited to the functional groups that were installed on the particle surface by the Bayreuth microbiologists. Instead, these proteins can easily be replaced by other functions, thus providing of a highly versatile platform. Genetic reprogramming therefore opens up a broad spectrum to design the magnetosome surface. It provides the basis for a "genetic toolkit" that allows the production of tailored magnetic nanoparticles, combining different useful functions and properties. Each of these particles is between three and five nanometres in size.

"Our genetic engineering approach is highly selective and precise, compared to, for instance, chemical coupling techniques which are not as efficient and lack this high degree of control", explains the Bayreuth microbiologist Dr. Frank Mickoleit, the first author of the study. He points to a decisive advantage of the new biomaterials: "Previous studies show that the magnetic nanoparticles are likely not harmful to cell cultures. Good biocompatibility is an important prerequisite for the future application of the particles in biomedicine, for instance as contrast agents in magnetic imaging techniques or as magnetic sensors in diagnostics. In the future, for example, similar particles might help to detect and destroy tumour cells. Bioreactor systems are another field of application. Magnetic nanoparticles equipped with tiny catalysts would be highly suitable for this purpose and enable complex biochemical processes.

"There is an enormous application potential for nanoparticles that display different functional groups on the surface, particularly in the fields biotechnology and biomedicine. The magnetic bacteria now may serve as a platform for a versatile nano-toolkit, inspiring scientific creativity in the field of Synthetic Biology. It will initiate further interesting research approaches", adds the microbiologist Clarissa Lanzloth B.Sc., who was involved in the new study as co-author during completion of her Master thesis in "Biochemistry and Molecular Biology" in Bayreuth.
-end-


Universität Bayreuth

Related Bacteria Articles:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.
How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.
Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.