| dc.description.abstract | There is an increasing demand for agricultural land and other resources necessary to feed an expanding world population. This has led to a growing interest in using sustainable feedstocks to produce value-added compounds using microbial processes. Most of these processes commonly rely on sugar-based feedstocks as carbon and energy sources. However, the use of sugars as feedstock becomes progressively less feasible for microbial processes as it is in direct competition with the feed and food industry, and thus a steady price increase is to be expected. Therefore, the switch to alternative carbon sources for microbial fermentation is sought after.
The primary goal of this Ph.D. thesis was to explore the use of methanol and brown seaweed as alternative and sustainable feedstocks for the microbial production of riboflavin, a water-soluble vitamin that is commonly used in animal feed and in dietary supplements and/or pharmaceuticals for humans. To achieve this goal, three secondary objectives were pursued: to update and expand the current knowledge of bacterial formaldehyde metabolism in context of methanol assimilation; to demonstrate the overproduction of riboflavin from methanol by genetic engineering of the methylotrophic bacterium Bacillus methanolicus; and to explore the potential of brown seaweed biomass as a sustainable feedstock for microbial riboflavin production by genetic engineering of the bacterium Corynebacterium glutamicum.
Overall, this Ph.D. thesis has provided new insights into the understanding of formaldehyde metabolism in methylotrophic and non-methylotrophic bacteria, revealed a novel formaldehyde dissimilation system in Bacillus subtilis, and demonstrated methanol and brown seaweed as potential alternative and sustainable feedstocks for microbial overproduction of riboflavin. | en_US |
