Paddy Meier

Anaerobic fungi are remarkable decomposition factories for plant biomass. They can decompose lignocellulosic biomass. In environmental biotechnology, this property can be utilised in the fermentation of lignocellulosic waste. However, the handling of anaerobic fungi

is laborious and to obtain isolated strains they must be subcultured weekly. A new method was therefore established in this work, based on previous lyophilisation processes. This means that the anaerobic fungi do not have to be subcultivated weekly and their handling can be made easier. Anaerobic fungi have also not yet been cultivated in bioreactors very often, so a

bioreactor is being set up, its cultivation trialled and the process adapted. Normal standard parameters such as pH value and temperature were therefore monitored to analyse the reactor process. However, HLPC analyses were also carried out. Many samples were also analysed

microscopically and recorded. 

This revealed that a cultivation process for anaerobic fungi requires significantly more care than other processes. For example, the process could not be continued contamination-free

without antibiotics. In addition, a glass bioreactor with a large number of openings proved to be unsuitable. It was not only the tightness that was a problem, but also maintaining the temperature. Glass is too weak when it comes to temperature transfer, which meant that the temperature could no longer be brought above 30°C after a few days. However, the pH could

be kept stable at around 6.6. Furthermore, even after almost a month, anaerobic fungi could still be found in the medium, which was also confirmed by the enzymatic activity. 

Important insights were gained from the lyophilisation experiments about the method itself, which was adapted through three repetitions so that it came close to success. In the third attempt, a small milestone was achieved for the first time and intact structures of anaerobic fungi were found, but these were still weak as far as further cultivation was concerned. Adapting the cryoprotectants and the preparation for freeze-drying could therefore deliver better results than before. However, this would require further research and experiments that could not be carried out in this work due to a lack of time.