Periodic Reporting for period 4 - SYNTOMAGX (A synthetic biology approach for magnetization of foreign organisms by genetic engineering and transplantation of bacterial magnetosome biosynthesis)
Berichtszeitraum: 2021-03-01 bis 2022-08-31
An immensely valuable asset to the field of synthetic biology would be a means to genetically endow magnetism to living organisms. Biomagnetism is innate to magnetotactic bacteria, mud-dwelling microbes which as geomagnetic sensors biomineralize iron nanocrystals with exceptional properties, the magnetosomes. However, transplantation of magnetosome biosynthesis has remained unachieved for many years, owing to its complexity and lack of knowledge of genetic determinants. In this project, we followed a systematic approach for the genetic magnetization of diverse microorganisms. To this end, the magnetosome biosynthesis pathway was analyzed and its essential gene set was delineated. We studied and engineered the functional expression of magnetosome gene clusters in the native donor Magnetospirillum gryphiswaldense and in a multitude of foreign microorganisms, which could be successfully ‘magnetized’. This was exploited for bioproduction of engineered magnetic nanomaterials with novel and tunable properties, which were utilized for a number of biotechnical and biomedical applications. In future work, this can be further utilized to generate intracellular labels, tracers and actuators for magnetic manipulation and analysis of other cells and organisms.
IIn the first part of the project, we analyzed the magnetosome biosynthesis pathway in the model organism Magnetospirillum gryphiswaldense and other magnetotactic bacteria. Then we engineered different prokaryotic hosts for the expression of magnetosome gene clusters from foreign bacteria and began to explore the expression of magnetosome biosynthetic genes in eukaryotic cells.
We identified novel candidate genes and regulators involved in the biosynthesis of functional magnetosomes. We also discovered several unexpected auxiliary cellular processes (for example involved in cell division, subcellular organization, and biosynthesis of bioactive compounds by magnetic bacteria). Further functionalities could be added to magnetosome particles by synthetic biology approaches. We showed that magnetosome genes from different donors can be expressed in various bacterial chassis strains. We expect that magnetosome biosynthesis can be further engineered in various expression hosts with respect to novel properties and additional functions.