Ultrasound treatment enhances cholesterol removal ability of lactobacilli

• Published in: Ultrasonics sonochemistry Vol. 19; no. 3; pp. 632 - 641
• Main Authors: Lye, Huey-Shi, Alias, Karim Abdul, Rusul, Gulam, Liong, Min-Tze
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2012
• Subjects: Cholesterol; Cholesterol - isolation & purification; Cholesterol - metabolism; Dose-Response Relationship, Radiation; High-Energy Shock Waves; Incorporation; Lactobacillus; Lactobacillus - metabolism; Lactobacillus - radiation effects; Membrane; Metabolic Clearance Rate - radiation effects; Radiation Dosage; Sonication - methods; Ultrasound; Membrane; Incorporation; Ultrasound; Cholesterol; Lactobacillus
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2011.08.004

► Ultrasound enhanced membrane permeabilization that increased viability of cells. ► Increased in viability also increased the cholesterol removal ability of cells. ► Cholesterol was saturated in apolar and polar regions of the membrane bilayer. This study aimed to evaluate the effect of ultrasound treatment on the cholesterol removing ability of lactobacilli. Viability of lactobacilli cells was significantly increased ( P < 0.05) immediately after treatment, but higher intensity of 100 W and longer duration of 3 min was detrimental on cellular viability ( P < 0.05). This was attributed to the disruption of membrane lipid bilayer, cell lysis and membrane lipid peroxidation upon ultrasound treatment at higher intensity and duration. Nevertheless, the effect of ultrasound on membrane properties was reversible, as the viability of ultrasound-treated lactobacilli was increased ( P < 0.05) after fermentation at 37 °C for 20 h. The removal of cholesterol by ultrasound-treated lactobacilli via assimilation and incorporation of cholesterol into the cellular membrane also increased significantly ( P < 0.05) upon treatment, as observed from the increased ratio of membrane C:P. Results from fluorescence anisotropies showed that most of the incorporated cholesterol was saturated in the regions of phospholipids tails, upper phospholipids, and polar heads of the membrane bilayer.