Extractor

The Zerg Extractor is essentially a giant organ that sits atop a Vespene geyser and packages the gas into small flesh/wrapped sacs that can be easily carried by Zerg Drones to a nearby Hatchery for absorption. Through this structure, the Zerg convert raw Vespene Gas into a form that is more beneficial for their organic systems. The refined Vespene Gas it produces becomes a necessity in the later evolutions of the Zerg Breeds. As the Extractor lives off Vespene Gas itself, it does not need to be built on an area already covered in Creep.

StarCraft II
The Extractor is set to appear in StarCraft II. It functions almost identically to its predecessor.

Restore Gas
If the Extractor is depleted, at a cost of 100 minerals, the player can gain 600 Vespene gas. Doing so prevents gas collection for 45 seconds. The player must balance their need for gas against the immediacy of this need. "Restore Gas" can be used any number of times.