Brettanomyces lambicus is a species of yeast, often informally referred to as “Brett.” This microorganism plays a significant role in fermentation, particularly in brewing and winemaking. It is highly valued in traditional Belgian-style beers, such as Lambic, where its metabolism contributes complex, distinctive aromas described as “funky.” However, this yeast is frequently considered a spoilage agent in wine, where its volatile compounds produce undesirable notes. Understanding how B. lambicus navigates and spreads in liquid environments is important for controlling its presence in beverages.
Does Brettanomyces Lambicus Move Actively?
The direct answer is no: Brettanomyces lambicus is classified as a non-motile organism, like nearly all other yeast species. Active movement, or motility, requires specialized cellular structures such as flagella (whip-like appendages) or cilia (shorter, hair-like structures).
B. lambicus cells lack these mechanisms for self-propulsion. They are inert particles suspended in the fermentation environment. Any distance a cell travels depends entirely on external forces acting upon it. The cell’s movement is always passive. This non-motile nature shapes how the yeast is distributed and controlled in commercial settings.
Mechanisms of Passive Spread
Since active movement is not possible, the spread of Brettanomyces lambicus relies on growth mechanisms and physical transport. The population increases through asexual cell division, known as budding.
During budding, a mother cell grows a daughter cell, which eventually separates to become an independent organism, increasing the overall cell count. This process increases the concentration of the yeast population within a vessel but does not move the cells across any distance.
Movement across distances relies on fluid dynamics and physical intervention. In fermenters, barrels, or tanks, the yeast cells are readily transported by liquid currents. These currents include convection, stirring, pumping, or the force of gravity as liquid is transferred. Any equipment, tubing, or filter used to move a liquid containing B. lambicus can become a vector for its spread to a new batch or vessel.
Biofilm Formation
A significant mechanism for its persistence and spread is its ability to adhere to surfaces and form biofilms. A biofilm is a complex community of microorganisms encased in a self-produced matrix of sugars and proteins. This allows the cells to stick firmly to surfaces like wood, rubber, plastic, and stainless steel. These biofilms enable the yeast to survive harsh cleaning protocols and persist in microscopic cracks and pores of equipment.
The cells within a biofilm can be released into a new batch of liquid when the vessel is refilled, spreading the organism from one production cycle to the next. This adherence makes the yeast difficult to eradicate once established, requiring specialized sanitation agents to penetrate the protective biofilm matrix. The yeast can also be passively carried by insect vectors, such as fruit flies, further facilitating its spread.