How to cure the infection in Subnautica

While exploring the vast oceanscapes of Subnautica, you might have encountered a weird infection that spreads and eventually kills any creature it infects — even our protagonist. Whatever the method of contraction, this infection is a major part of the larger story in the lore of Subnautica. Designed on purpose, this infection, also known as the Kharaa Bacterium, has only one known cure. It is possible to piece the curing process from the game itself, but if you don’t mind spoilers, follow our guide to find out how to cure the infection in Subnautica.

What is Khara Bacterium infection in Subnautica?

The Kharaa Bacterium manifests as cyst-like growths over the infected organism, glowing a baleful green color. There’s a pronounced veiny discoloration around the cysts. The further the infection spreads, the more pronounced the discoloration and the green glow becomes, and the much closer the infected organism comes to dying.

What is the cure for the infection?

Following the storyline of the infection, it becomes apparent that the Precursors have tried to synthesize a cure but were unable to gain the needed resource called Enzyme 42. To create the vaccine for the infection, this enzyme needs to be extracted from the juvenile Sea Emperor Leviathans (the adults won’t work for this). Luckily for the protagonist, there is a facility that allows them to spawn just the organisms they need in order to create the cure.

How and where to get Enzyme 42?

If you’ve been playing through the game’s storyline, then by now, you have found the Primary Containment Facility and interacted with the Sea Emperor trapped there by the Precursors. You will need to enlist his help to get the enzyme. Talk to the Sea Emperor and pick up the “mission” to help in hatching five Sea Emperor Leviathan juveniles. That will open up the next part of the process — the acquisition of the Hatching enzyme.

The facility itself has portals that will allow you to collect the resources you need for the first stage of the process. In total, you will need to use four portals, which means that you will need to have four Ion Blocks with you to power them up — so make sure to bring enough and all the other sustenance for a longer stay away from the base.

For the Hatching enzyme, you will need to find the following resources with the help of the portals:

• Eye Stalk Seed: collected by slashing an Eye Stalk plant
• Sea Crown Seed: found near the Moonpool of the Primary Containment Facility
• Fungal Sample: collected by slashing the Tree Mushroom
• Ghost Weed Seed: collected by slashing a Ghost Weed plant
• Bulb Bush Sample: collected by slashing a Common Bulb Bush plant

After you’ve collected all the needed ingredients, go to a Fabricator, and you will be able to create the Hatching enzymes. With the enzymes crafted, bring them back to the Primary Containment Facility.

Dive from the facility’s Moonpool and swim to the base until you find the eggs. There is a control panel there that you can interact with. Insert the enzymes you’ve crafted, and that will hatch the eggs, spawning five juvenile Sea Emperor Leviathans.

The hatching will begin a cutscene during which you can interact with the enzyme that the juveniles produce. That enzyme is the Enzyme 42 we’ve been looking for and the ultimate cure for the Kharaa Bacterium infection.

With the curing process completed, you will get a nifty achievement and would have essentially completed the game’s storyline of curing the nasty infection that has almost ruined the world of Subnautica.