TY  - JOUR
A1  - Müller, Janina
A1  - Beckers, Mario
A1  - Mußmann, Nina
A1  - Bongaerts, Johannes
A1  - Büchs, Jochen
T1  - Elucidation of auxotrophic deficiencies of Bacillus pumilus DSM 18097 to develop a defined minimal medium
JF  - Microbial Cell Factories
N2  - Background
Culture media containing complex compounds like yeast extract or peptone show numerous disadvantages. The chemical composition of the complex compounds is prone to significant variations from batch to batch and quality control is difficult. Therefore, the use of chemically defined media receives more and more attention in commercial fermentations. This concept results in better reproducibility, it simplifies downstream processing of secreted products and enable rapid scale-up. Culturing bacteria with unknown auxotrophies in chemically defined media is challenging and often not possible without an extensive trial-and-error approach. In this study, a respiration activity monitoring system for shake flasks and its recent version for microtiter plates were used to clarify unknown auxotrophic deficiencies in the model organism Bacillus pumilus DSM 18097.

Results
Bacillus pumilus DSM 18097 was unable to grow in a mineral medium without the addition of complex compounds. Therefore, a rich chemically defined minimal medium was tested containing basically all vitamins, amino acids and nucleobases, which are essential ingredients of complex components. The strain was successfully cultivated in this medium. By monitoring of the respiration activity, nutrients were supplemented to and omitted from the rich chemically defined medium in a rational way, thus enabling a systematic and fast determination of the auxotrophic deficiencies. Experiments have shown that the investigated strain requires amino acids, especially cysteine or histidine and the vitamin biotin for growth.

Conclusions
The introduced method allows an efficient and rapid identification of unknown auxotrophic deficiencies and can be used to develop a simple chemically defined tailor-made medium. B. pumilus DSM 18097 was chosen as a model organism to demonstrate the method. However, the method is generally suitable for a wide range of microorganisms. By combining a systematic combinatorial approach based on monitoring the respiration activity with cultivation in microtiter plates, high throughput experiments with high information content can be conducted. This approach facilitates media development, strain characterization and cultivation of fastidious microorganisms in chemically defined minimal media while simultaneously reducing the experimental effort.
Y1  - 2018
U6  - http://dx.doi.org/10.1186/s12934-018-0956-1
SN  - 1475-2859
VL  - 17
IS  - 1
SP  - Article No. 106
PB  - BioMed Central
ER  - 
TY  - JOUR
A1  - Wilming, Anja
A1  - Begemann, Jens
A1  - Kuhne, Stefan
A1  - Regestein, Lars
A1  - Bongaerts, Johannes
A1  - Evers, Stefan
A1  - Maurer, Karl-Heinz
A1  - Büchs, Jochen
T1  - Metabolic studies of γ-polyglutamic acid production in Bacillus licheniformis by small-scale continuous cultivations
JF  - Biochemical engineering journal
Y1  - 2013
SN  - 1873-295X (E-Journal); 1369-703X (Print)
VL  - Vol. 73
SP  - 29
EP  - 37
PB  - Elsevier
CY  - Amsterdam
ER  -