Lactose is present in milk at approximately 4.6%. For it to be properly absorbed in the intestines, lactose must be broken down into glucose and galactose by the enzyme lactase. Most infants have high levels of lactase activity, allowing them to digest milk efficiently. However, as people age—typically between 3 to 5 years—their lactase production decreases significantly, often by 90% to 95%. This decline is believed to be genetically controlled, following a recessive inheritance pattern, and is considered a normal physiological process. Studies have shown that even with repeated exposure to lactose, lactase activity cannot be increased, indicating that this reduction is irreversible.
This gradual decrease in lactase activity is referred to as Lactase Nonpersistence (LNP). In adults, the lack of sufficient lactase leads to undigested lactose passing into the large intestine, where it serves as a substrate for gut bacteria. The fermentation of lactose by these microbes can result in symptoms such as bloating, gas, abdominal pain, and diarrhea—collectively known as lactose intolerance.
Lactose intolerance affects a significant portion of the global population, though it is less common among Asians. As a result, there is growing interest in solutions to manage this condition. One potential approach involves using probiotics like *Lactobacillus acidophilus*, which can produce β-galactosidase, an enzyme that helps break down lactose. However, since β-galactosidase is an intracellular enzyme, its activity must be measured after breaking the cell walls. Common methods for cell disruption include physical grinding or chemical treatments, but these may not always yield consistent results or accurately reflect enzyme activity.
To address this challenge, this experiment employs ultrasonic cell disruption to effectively measure β-galactosidase activity in *Lactobacillus acidophilus*. This method is preferred because it allows for more precise control over the process, making it a valuable tool for evaluating the enzyme's performance. By understanding how to optimize this technique, researchers aim to support the use of *Lactobacillus acidophilus* as a functional strain in dairy products, ultimately helping to alleviate lactose intolerance in affected individuals.
The effectiveness of ultrasonic disruption depends on several factors, including frequency, energy level, processing time, cell concentration, and cell type. It’s important to carefully control the intensity of the ultrasound to avoid excessive foaming, which can lead to protein denaturation. At power levels above 240W, foam formation becomes noticeable, so the experiment uses a power range between 200W and 220W. This ensures optimal cell disruption without compromising the integrity of the enzymes being studied.
Jiangmen Vanky Stainless Steel Products Co., Ltd. , https://www.vankystar.com