Bacillus
Bacillus is a Cursed mod for Fabric and NeoForge that remakes the original Bacteria mod by TeNNoX, adding bacteria blocks that spread and destroy other blocks.
What it does
Bacillus rebuilds the bacteria mechanics of the original Bacteria mod by TeNNoX and adds features on top of them for Minecraft 1.21.x. A bacteria block placed above a source block uses the block below it as a target and spreads, destroying the blocks it touches. A block directly above a source replaces the blocks below with a supplied block. Both bacteria types are activated with a redstone signal, and the block directly below a bacteria block is added to its target filter automatically.
Crafted jammer items counter the spread. The main hand holds a jamming item that halts bacteria in the world, and the off hand holds a killing item that removes them. Some textures come from the Bacterium mod by InEqualMeasure. The mod requires Architectury API, Fabric API, Fabric Language Kotlin and Kotlin for Forge, and it is published for Fabric and NeoForge for 1.21 – 1.21.3 under the GNU General Public License v2.0 or later. Client and server both need it.
Key features
Remade bacteria
The bacteria mechanics are rebuilt from the original TeNNoX mod and extended with new options.
Filtered spreading
Bacteria target only the block types chosen in their filter, leaving other blocks untouched.
Block replacement
A source block above a bacteria block can replace the blocks below it with a chosen block.
Redstone activation
Both bacteria types start spreading when a redstone signal reaches them.
Jamming and killing items
Crafted items stop bacteria in the world, with a jamming item in the main hand and a killing item in the off hand.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 3
How it compares
Bacterium by InEqualMeasure is a Fabric mod for 1.21.11 under a custom license and is not open source. Backrooms Through The Walls is a Fabric mod for 1.21.1 under All rights reserved and is not open source. Bacillus differs by covering 1.21 – 1.21.3 on both Fabric and NeoForge.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Bacillus | Fabric and NeoForge | 1.21 – 1.21.3 | Client and server | 2024-12-07 |
| Bacterium | Fabric | 1.21.11 | Client and server | 2026-04-10 |
| Backrooms Through The Walls | Fabric | 1.21.1 | Client and server | 2025-12-05 |
Questions
Does Bacillus need Fabric API on NeoForge?
Which loaders does Bacillus support?
Does Bacillus have to be installed on both sides?
In the catalog
Bacillus is one of 7,555 Cursed mods on ModsFinder, and one of 4,235 Cursed mods for Fabric. 13,252 mods support Minecraft 1.21.3.
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What the author says
Bacillus is a remake of the mod Bacteria by TeNNoX. Some textures used in the mod are from the Bacterium mod by InEqualMeasure.
Official listing
- Modrinth page
- modrinth.com/mod/bacillus
- Owner
- Bread Experts Group
- Published
- 2024-10-19
- Updated on Modrinth
- 2024-12-07
- Facts verified
- 2026-10-15