Brevibacterium represents a genus of bacteria found across many different environments, from the soil to the human body. These microorganisms possess specific characteristics that allow them to thrive in diverse conditions. Their unique metabolic activities have implications for various natural processes and industrial applications.
What is Brevibacterium?
Brevibacterium is a genus of bacteria characterized by its Gram-positive staining and rod-like shape, although some species can appear coccus-shaped in older cultures. These bacteria are aerobic, requiring oxygen to grow, and tolerate high salt concentrations, surviving in environments with up to 15% sodium chloride. They are commonly found in soil, water, and on the surface of human skin.
The genus Brevibacterium includes several species, such as Brevibacterium album and Brevibacterium epidermidis. Many members of this genus are non-pathogenic.
The Secret Behind Stinky Cheese
Brevibacterium linens plays a significant role in the ripening of certain cheeses, particularly smear-ripened varieties like Limburger, Port-du-Salut, and Muenster. This bacterium contributes to the distinctive aromas, flavors, and the characteristic orange or reddish color of the cheese rind. It is often applied to the cheese surface during ripening, sometimes through a brine wash.
During ripening, Brevibacterium linens breaks down proteins and fats in the cheese through enzymatic activities. These enzymatic actions release various compounds, including volatile sulfur compounds, which are largely responsible for the pungent, “stinky” aroma associated with these cheeses. The bacterium also produces carotenoid pigments, which give the rind its vibrant orange hue. The growth of Brevibacterium linens can also inhibit the growth of some foodborne bacteria, adding to the safety of these products.
Unraveling Body Odor
Certain species of Brevibacterium, particularly Brevibacterium epidermidis and Brevibacterium linens, are found on human skin and contribute to body odor. Human sweat is initially odorless, but bacteria on the skin interact with its components to produce volatile compounds. These compounds are responsible for the distinct smells we associate with body odor.
Brevibacterium species on the skin break down various substances present in sweat, such as amino acids and other organic compounds. This metabolic activity can lead to the production of volatile sulfur compounds and other short-chain fatty acids. For instance, the breakdown of leucine can result in isovaleric acid, which contributes a cheesy smell. While other bacteria like Corynebacterium and Staphylococcus also play significant roles, Brevibacterium’s presence contributes to the overall odor profile.
Beyond Cheese and Odor
Beyond its well-known roles in cheese ripening and body odor, the genus Brevibacterium has other applications. Most species are non-pathogenic, making them suitable for food production. They are found in diverse natural environments, including salt marshes and marine sediments.
They have been studied for their ability to produce enzymes, amino acids like L-lysine and L-glutamic acid, and carotenoids. Some species show promise in bioremediation efforts, such as the biotransformation of contaminants in wastewater. Certain Brevibacterium strains also show antimicrobial properties against other bacteria.