California-based biotech company Chi Botanic is one of a new wave of start-ups seeking to unlock the potential of plant cell culture for the ingredient industry through the development of high value botanical compounds such as vanilla extract, citrus flavours, and aloe.
October 5, 2023
It is often said that oil rules the world, but scientists Jonathan Meuser and Robert Jinkerson, who seven years ago founded biotech firm Chi Botanic, have found botanical extracts to be a more lucrative application than fuel for cell culture technology.
“Robert and I both worked in the field of second-generation biofuel, applying high throughput biotechnology to algae to make renewable fuel. A huge amount of funding went into this, but it became clear after ten years or so that the operational and capital cost of creating the infrastructure to grow these algae was going to be far greater than the cost of the fuel,” Meuser explained.
However, the pair were not willing to give up on their research and instead turned their attention to higher value food, beverage and beauty ingredients including vanilla, aloe, and citrus flavours and fragrances.
“On a per litre basis, fuel is only a couple of dollars, but the price of aloe is $1,000 per kg, vanilla extract is $400 per kg and citrus oils are in the range of $50-$200, so we are talking about orders of magnitude more valuable than fuel. We realised that we could grow these ingredients via plant cell culture, using the same tools and knowledge,” said Meuser.
And in doing so, Chi Botanic is hopeful that it can solve some of the supply chain issues associated with these ingredients.
For example, the parts of the world where vanilla is grown are prone to extreme climate events, which makes it susceptible to price volatility - a situation that is exacerbated by the very limited availability of vanilla extract.
“Our goal is to bring a plant-based vanilla flavour that sits somewhere between a synthetic flavour and a true vanilla extract. If we can do that we can up-end the market,” said Meuser.
With citrus oils, it is disease that poses a threat to supply stability.
“Citrus greening has become a huge challenge for the industry and it is unclear what will happen with that. Our technology offers an alternative to flavours and fragrances sourced from trees,” he explained.
Instead of growing the whole plant, Chi Botanic takes the source plant and converts it into a cell culture, which is then grown via fermentation in a bioreactor, using sugar as a feedstock.
According to Meuser, there are compelling reasons for producing extracts in this way:
“The number one factor is how fast they grow – 30 times faster than a normal plant, plus every single cell is used in the product, whereas in conventional production, these high value products are only found in a specific part of the plant.”
He continued: “Most of these products come from tropical regions where deforestation occurs in order to grow them. We can grow them anywhere, so we can delocalise production. We don’t need any pesticides or herbicides either as they are grown in a bioreactor in the same way as beer, yoghurt, or kombucha."
In many respects, plant cell culturing is similar to precision fermentation, but there are some fundamental differences too. In precision fermentation, additional plant genes are inserted into the microbe’s genome, whereas plant cell culture involves taking cells from the plant and scaling them.
“What we are doing differently is developing a cell customisation pipeline whereby we are evolving the cells to be like that specific tissue. We are activating the plant’s natural ability to make that tissue. So, in that sense we are applying biotech but are not doing reverse genetics where you insert a set of genes to make one molecule,” he explained.
One of the advantages of growing plant cells rather than microbes is their greater capacity for complexity. As an example, microbes can make vanillin - a single chemical compound that is extracted from vanilla beans and can also be synthesised using petrochemicals - but they can’t make vanilla extract, which contains approximately 65 flavour chemicals.
“We are not trying to reduce the cells to make one specific molecule; we are looking to replicate a heterogenous mixture of molecules that give the full flavour, so it is a much larger fraction of the plant cell,” explained Meuser.
For example, he said that Chi Botanic’s aloe uses the entire soluble fraction of the cell, which includes 50% of the biomass and hundreds of valuable bioactives.
The key to making these ingredients economically viable is optimising the concentrations of valuable bioactives, according to Meuser.
“For us, the priority is hitting KPIs [Key Performance Indicators] in terms of cell composition, so upping the overall concentration of those compounds that give the citrus or vanilla flavour. We are applying automation to look through millions of cells for the ones that have the traits we want.”
As yet, none of Chi Botanic’s ingredients are on the market although aloe is the closest.
“Our aloe contains hundreds of bioactives because is a raw product - it doesn’t have to be processed to remove the toxins like conventionally produced aloe. We have found a company who sees the value in that and is finalising the last steps towards using it in a lotion,” said Meuser.
Chi Botanic sees major potential for using aloe in beverages too, but Meuser said this was more complex from a regulatory perspective.
He confirmed that Chi Botanic is working with “one of the largest drink companies in the world” to incorporate its citrus flavours into beverages, which involves delivering the cells in an oil format.
“Something we have learned is that companies want a ‘drop in’ replacement for an existing formula – they don’t want the cells,” said Meuser.
