From Guild Wars 2 Wiki
Double-click to combine the Volatile Spores, Bloodsucker Enzymes, Beetle Juice, Frothy Troll Saliva, Malodorous Mucus, and Salivary Stone in an Empty Hylek Flask to create the Concentrated Maguuma Bacteria.
— In-game description
- Hint: Activate the M-PEC before defeating a Champion Arrowhead at Arrowhead Vale in Auric Basin to gather its mucus.
- The Champion Arrowhead of the Hero Point east of Arrowhead Vale drops this item if you've not killed him that day. (Collection item is in the bouncy chest)
- Champion Arrowheads may spawn during the event Defend Dawkkurra as she gathers saurian eggs for her feast (80).
- Some times a Champion Arrowhead spawns near the north gate to Tarir. If you fail on the HP, try this one as an alternative to having to wait a day.