GREEN CHEMISTRY
Their extensive use across diverse applications – from personal care and household cleaning to crop protection and industrial processes – makes them a prime target for engineering biology.
Conventional surfactants are generally petroleum-based or derived from palm oil, which brings its own sustainability concerns linked to intensive agriculture and loss of habitats and biodiversity. Therefore, the development of biosurfactants produced via the fermentation of yeast or bacteria is attracting a great deal of attention.
There are several commercial examples of fermentationbased production of rhamnolipid biosurfactants. Stepan has acquired a plant with 20,000 tonnes / year capacity. 4 Evonik opened a 10,000 tonnes / year plant in January 2024.5 Holiferm is scaling its capacity to 15,000 tonnes / year and has also managed to address cost-related challenges linked to downstream processes. 6
Overall, the biosurfactants market is predicted to grow rapidly from $ 1.2
billion in 2022 to $ 2.3 billion by 2028.7 Yet this only represents around 10 % of the overall surfactants market. A significant barrier to widespread use is cost, which is estimated to be 20-30 % higher than for conventional surfactants. 8 There are two key reasons for this: the high cost of substrates used as feedstocks and the necessary purification steps, which can account for 50-60 % of overall production costs.
Overcoming production challenges
While engineering biology reduces the need for petrochemical feedstocks, the sustainability credentials of biological feedstocks can also be problematic. Most commercial-scale bio-manufacture depends on sugarbased feedstocks, but sugar cane cultivation is resource-intensive and is often associated with deforestation.
The reliance on fossil fuels for energy to power the production of sugar-based feedstock is an additional sticking point. Another is the high cost of processing, especially for the purification stage.
Chemical manufacturers looking to begin or extend use of engineering biology might resolve some of these issues with alternative sourcing and novel techniques( Figure 2). However, there is another major limiting factor: the technical challenges that hinder effective scale-up of metabolic engineering processes.
While processes can be very effective in the laboratory, adapting them for commercial production is not straightforward. Overcoming the challenges demands focused attention and specialist expertise from disciplines including physics, engineering and data science.
Challenges often centre on production costs and yield because the productivity of metabolic pathways generally decreases as scale increases. It can also be difficult to maintain the stability and performance of chemicals produced from GMOs. This can have a detrimental impact on their functionality and efficacy downstream.
Nevertheless, it is possible to address these matters and enhance the viability and feasibility of
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