Bacteria as factories of the biobased economy

(Nanowerk News) In the nearby future, the raw materials for plastics and fibres that are currently derived from petroleum could be obtained from renewable green resources such as corn straw or wood. The work will be done by bacteria that function as microscopic factories. In his inaugural lecture on 23 March, Richard van Kranenburg, special professor of Bacterial Cell Factories, explained how the bacteria will contribute to the new biobased economy . Prof. Van Kranenburg’s chair is funded by Corbion.
The microworld of bacteria that can function as mini factories is fascinating, says Prof. Van Kranenburg during his inaugural lecture ‘Bacterial cell factories – Applying thermophiles to fuel the biobased economy’ at Wageningen University & Research.
‘Bacteria produce useful products such as lactic acid out of plant sugars. After this microbial process, which we call fermentation, we can purify the resulting products and use them to produce bioplastics and other materials,’ explains the professor. ‘This is an important step in the transition from a fossil economy to an economy based on green chemistry and biotechnology solutions that use renewable raw materials such as corn stover, wheat straw or wood.’

Compost heap

Bacteria are not able to convert these raw materials directly into usable products. The raw material first needs to be pre-treated to release the fermentable sugars. Some bacteria have special enzymes that do this.
‘We found an important bacterium in a compost heap that has such activity. In this warm environment (50 to 60°C), we found a heat tolerant Bacillus species that contains the enzymes needed to release the sugars, allowing the sugars to be used for the fermentation process.’

Industrial fermentation

Fermentation has been used in the production of foods such as bread, wine and soy sauce for thousands of years. Industrial fermentation only arose sometime around 1881 with the production of lactic acid. This process should be improved to further contribute to the biobased economy. For example, most fermentation processes result in byproducts next to the intended products.
‘This is why we are developing a toolkit so that we can genetically modify the bacterium to carry out the industrial fermentation process as efficiently as possible. For example, we could modify it to produce only lactic acid, or a more products with a more complex production pathway, such as succinic acid. One such tool is Cas9. This enzyme can be applied to target and eliminate less productive wild-type bacteria, while ignoring the desired optimized bacteria. These are exciting times for biotechnologists!’ concludes Prof. van Kranenburg.
Source: Wageningen University