…vanillin also can be made synthetically using chemicals derived from petroleum. To create it from plastic, instead, researchers genetically modified a strain of E. coli bacteria so that it can make vanillin from terephthalic acid (TA)—a raw material used in the production of plastic bottles, which can be broken down using special enzymes that reduce them to their basic chemical components.2 Because it uses microbial fermentation, the chemistry is similar to that of brewing beer.
According to the paper, approximately 85% of the world’s vanillin is synthesized from chemicals that are derived from fossil fuels, including crude oil.
Being able to create vanillin with plastic instead of petroleum means increasing vanillin supply while mitigating plastic waste, reducing industrial reliance on fossil fuels, and preserving forests.
There most definitely are byproducts. Like you say you couldn’t grow a flower without creating byproducts. I think the critical thing would be not whether there are byproducts, but is this more desirable than using first generation petroleum products. That would take full carbon accounting, a chemical comparison of both systems, and analysis of impacts on the larger world including human consequences/benefits.
Indeed that’s the bottom line.