β-glucanase

β-glucanase

Beta Glucanase is an enzyme that hydrolyzes β-glucans. The most important β-glucanases for brewing are those that break down the β-glucans located in the cell walls of the barley endosperm. High levels of β-glucans in brewing raw materials are to be avoided as they can cause problems, particularly in wort production and beer filtration. β-Glucanases are important in that they are needed to break down the complex β-glucan molecules to smaller units. There is a wide range of such enzymes, differing in the specific bonds that are broken.

Figure 1. Protein structure of XAO.

Introductions

The most important such enzymes in barley are endo-β→3, 1→4-glucanase (sometimes called endo-barley β-glucanase), which can enhance the β1→4 bond adjacent to the β1→3 bond Hydrolysis, resulting in a rapid decrease in the viscosity of the β-glucan solution. This enzyme is basically absent in barley, but it is synthesized during germination and plays a role in malt modification to remove problematic β-glucans. The enzyme is very sensitive to heat. If the enzyme is needed in the grains of the brewery, for example, to process the residual β-glucan in raw grains or β-glucan-rich adjuvants, such as raw, roasted, Baked or flaked barley or oats, then the green malt must be gradually warmed to the final solidification temperature at a lower initial temperature. In addition, if β-glucanase is to function at this stage, it is necessary to start saccharification at a reduced temperature (for example, 40°C–50°C or 104°F–122°F). Alternatively, more heat-resistant microorganism β-glucanase can be added to the mash. These include enzymes from Bacillus subtilis, whose specificity is very similar to enzymes from malt or glucanases derived from fungi such as Aspergillus, Trichoderma or Penicillium, they contain mixtures of enzymes with different specificities, including endo- and exo-β1-3-and β1-4-glucanase. As a result, they are more comprehensive in removing dextran.

Functions

• Beta-Glucanase represents a group of carbohydrate enzymes which break down glycosidic bonds within beta-glucan. These glucans also create up to 60% of the cell wall of many forms of fungal organisms such as Candida albicans and candidal biofilm (the common experience of candida in the gut).
• Beta glucans are a polysaccharide made of glucose molecules linked together into long chains that humans cannot readily digest. In more familiar terms they are cellulose plant fiber, cereal bran fiber, and parts of certain types of fungi, yeast, and bacteria. As a kind of indigestible fiber, they may become viscous in the intestinal tract and slow peristalsis (intestinal contractions).
• Beta-glucans are health-promoting in that they act as intestinal fiber, which may help reduce high serum cholesterol levels and help create regularity through bulk formation. Water-soluble fibers may also help to regulate blood sugar and reduce the likelihood of developing colon related diseases.

Health benefits of β-glucanase

People with candida overgrowth (also known as candidiasis) may benefit from taking β-glucanase. Although it is a fungal or yeast infection, it is difficult to eliminate due to its inherent antimicrobial capabilities. Unfortunately, many people use long-term and high-dose antibiotics to treat digestive diseases and infections. In fact, this can increase the resistance of Candida. Beta-glucanase is an enzyme that has been found to be particularly useful in reducing the coating or biofilm of Candida that can grow in the digestive tract. When intestinal bacteria or candidate cells secrete too much β-glucan, a biofilm will form in the organism. At present, the scientific community is studying the connection between these biofilms, the overgrowth of fungal organisms, and the increased resistance of fungi to drug treatment. The accumulation of excess β-glucan is also associated with increased antibiotic resistance.

Reference

1. Hrmova, M. Structure-function relationships of β-D-glucan endo- and exohydrolases from higher plants. Plant Molecular Biology. 2001, 47(1/2), 73–91.