If you keyword search the private equity portfolio companies or the professional bios, it is usually best to leave off the suffixes in your search terms. This way, your search results will contain all occurrences of the root form of the word that is important to you.
For example, if you are interested in searching for commercial printers, it would be better to search for commercial print. This way your search results will also include: print, printer, printers, printing, prints, etc.
This approach allows you to be targeted in your keyword choice, but broader in matching to the specific content within the database.