If you can make money off open source, you can make money off curing every cavity in the world... But the company decided instead.... To sell mouthwash?
But you know how money is made off open source? Usually by support subscriptions (which, to be fair, is also how money was/is made on low-volume, high-value proprietary software, like e.g. SDKs for obscure and ancient industrial protocols). Beyond that, there is no general way to turn open source into money. Instead, open source is used by companies:
- To lower their costs - by outsourcing a chunk of development and testing to free volunteers; also by improving quality and reducing on-boarding costs of new hires (as you can select for those who already spent significant personal time learning your tech stack);
- For marketing purposes - mostly in terms of marketing to prospective employees, but for companies targeting technical audience, also marketing to customers;
- As a weapon against competition - the code you open-source is code your competitors can't sell; this is useful both in breaking into a legacy market, as well as restricting the kind of competition you'll get from those who started after you;
Where does the money come from then? Usually some combination of venture capital, rent-seeking and advertising. Open source destroyed the viability of the simple, honest model of providing value in exchange for payment. The alternative business models are much worse for end-users and society at large.
Assuming the bacteria story is true, your open source analogy is wrong. Anyone can copy the bacteria (similar to open source) but there's no maintenance needed once the bacteria is released to the public. Anyone in any country can offer to give you the bacteria. It's naive to think that anyone but a non-profit would release something like this.
This is an obvious scam