Chapter 9 - Onward.
First and second Room with the Feeders.
Kill all feeders, use a gun that conserves ammo like the ripper, pick up goodies, ransack lockers and then immediately save and exit DO NOT pick up your suit to end mission.
Reload enter rooms, rinse and repeat.
This method can be combined this with the farming glitch of setting your bots down on the high yield points, of which there is an infinite one on the surface.