I think this was just a bad summarization of the selling point for spas. This solution, coming from yeast, is carbon net negative (as they mention further down

I think this was just a bad summarization of the selling point for spas. This solution, coming from yeast, is carbon net negative (as they mention further down in the article) and reduces demand for a product of petroleum which might lead to more staying in the ground. The spa can then claim a lower carbon footprint which I imagine is very marketable.