heterolaktisk

Heterolaktisk is a term used in microbiology and biochemistry to describe a metabolic pathway in certain bacteria, primarily lactic acid bacteria. It refers to a type of fermentation where both lactic acid and other end products, such as ethanol, carbon dioxide, acetic acid, or formic acid, are produced from the fermentation of a carbohydrate, typically glucose. This contrasts with homolaktisk fermentation, where lactic acid is the sole or predominant end product.

The key characteristic of heterolaktisk fermentation is the pentose phosphate pathway, also known as the hexose monophosphate shunt. This pathway is essential for the production of precursors like NADPH, which are necessary for various biosynthetic reactions. When these bacteria ferment glucose through the pentose phosphate pathway, it leads to the generation of intermediates that can be further metabolized into a mixture of products. For example, certain heterolaktisk bacteria can convert a molecule of glucose into one molecule of lactic acid, one molecule of ethanol, and one molecule of carbon dioxide.

The specific ratio and types of end products can vary depending on the species of bacteria and the conditions of fermentation, such as pH and temperature. This metabolic flexibility allows heterolaktisk bacteria to thrive in diverse environments and play significant roles in various ecological niches and industrial processes, including the production of certain fermented foods and beverages. Understanding whether a bacterium is heterolaktisk or homolaktisk is important for optimizing fermentation processes and for the classification of microorganisms.