(German title: Optimierung der Produktion antimikrobieller Wirkstoffe von terrestrischen Cyanobakterien - Vom Screening bis zur Reaktorentwicklung)

The discovery of penicillin in 1928 by Alexander Fleming made the treatment of bacterial infections possible. Penicillin-resistant pneumococci were discovered in Australia in 1967 and the multi-resistant form was described in South Africa in 1977. In the case of an infectious disease with multi-resistant pathogens (MRE), conventional medication is ineffective. Bacterial resistance develops primarily due to the widespread use of broad-spectrum antibiotics and the resulting selection pressure. Multi-resistant pathogens develop as a result of mutations or the uptake of resistance genes from other organisms. From 2008 to 2013, multi-resistant E. coli bacteria tripled in the outpatient sector and doubled in the inpatient sector [Robert Koch Institute: ARS, ars.rki.de, data status: 19 October 2016].

In order to combat MRE, it is extremely important to find new antibiotics and establish them on the market. Organisms that have been little researched biotechnologically, such as cyanobacteria, are particularly suitable for this purpose. Cyanobacteria are one of the richest and most promising sources of bioactive primary and secondary metabolites. These organisms often live in biofilms that attach to surfaces embedded in a matrix of extracellular polymeric substances (EPS). Cyanobacteria are among the oldest known microorganisms and have evolved over a period of more than three billion years. In addition to aquatic cyanobacteria, there are also a large number of terrestrial strains. Terrestrial cyanobacteria generally live in biofilms, which protect them from drying out, among other things. Based on the traditional medicine of some indigenous peoples, microorganisms have long been specifically analysed for potent compounds. In this way, many pharmacologically interesting compounds have already been isolated and identified. Cyanobacteria (especially Nostoc sp.) were used as early as 1500 BC to treat gout, cancer and fistulas.

In this project, terrestrial cyanobacteria will be analysed for the production of antimicrobial agents. The aim is to elucidate the structure of the identified active substances. By varying the process conditions in different cultivation systems (shake flasks, bioreactor) and with regard to the energy and carbon supply (photoautotrophic, chemoorganotrophic and mixotrophic), the initial titres of the model strains will then be improved. 

The aim of this project is to establish a process model for the production of active ingredients for at least one model strain in different reactor systems.