If you’ll look at the cross reference link I provided, you’ll see the inventors and BioAmber were represented by a firm that specializes in handling the patents, VO. That also happens to be who the correspondence requesting the fee was addressed to. BioAmber was paying VO, and VO was paying for the renewal fees. BioAmber is dead, make no mistake about that. The patent was sold in the liquidation, it’s on page 77 of the 6th monitor’s report, and now belongs to LCYB.
The factual approach to anything with BioAmber’s name on it on the internet is to start with the court records. Everything listed was sold. The fairy tale approach is to find things with BioAmber’s name on them and assume the court records must somehow be false.