Best case for shareholders is the interest is an investment for...

Best case for shareholders is the interest is an investment for shares, which will just dillute existing shareholders and likely substantially lower the share price. The market cap was only about $4m, and they are probably going to need to raise at least $3m, so expect it may be at $0.01 territory. At least that would give it a chance to get the TGA approval and commercialise aqua phase (if anyone will deal with them now).

If they buy the business or part of it, you have shares in a company with less or no assets other than the proceeds of the sale. Those proceeds will be paid to creditors and any surplus (likely minimal, if any) will be distributed to shareholders if they wind up. They may also sit and become a shell for a backdoor listing.

Similar if its a takeover, likely the proceeds won't be enough to return anything of substance to shareholders.

Fingers crossed there are some interested parties willing to invest for shares, and just take a controlling interest in the Company.