Enhanced cholesterol removal ability of lactobacilli via alteration of membrane permeability upon ultraviolet radiation

• Published in: Annals of microbiology Vol. 62; no. 4; pp. 1709 - 1721
• Main Authors: Lye, Huey-Shi, Alias, Abdul-Karim, Rusul, Gulam, Liong, Min-Tze
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2012; Springer
• Subjects: Applied Microbiology; Biological and medical sciences; Biomedical and Life Sciences; cholesterol; fermentation; Fundamental and applied biological sciences. Psychology; Lactobacillus; Life Sciences; lipid bilayers; lipid peroxidation; Medical Microbiology; membrane permeability; membranes; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mycology; Original Article; tail; ultraviolet radiation; viability; Membrane; Incorporation; Ultraviolet; Lactobacilli; Cholesterol; Lactic acid bacteria; Ultraviolet radiation; Ultraviolet irradiation; Bacteria; Lactobacillaceae; Permeability; Lactobacillus
• ISSN: 1590-4261; 1869-2044
• DOI: 10.1007/s13213-012-0428-5

This study aimed to evaluate the effects of ultraviolet radiation (UVA, UVB, and UVC) on the cholesterol removal ability of lactobacilli and altered membrane properties. Viability of lactobacilli decreased (P < 0.05) immediately upon UV treatment due to oxidative damage of the cellular membrane, as induced by lipid peroxidation. UVB and UVC showed higher (P < 0.05) effects in inducing lipid peroxidation compared to UVA. However, the viability of lactobacilli increased significantly (P < 0.05) upon fermentation at 37°C for 20 h, which was attributed to the formation of transient pores and membrane permeabilization. These alterations also led to increased (P < 0.05) assimilation of cholesterol and incorporation of cholesterol into the cellular membrane upon fermentation. The ratio of membrane cholesterol:phospholipids (C:P) also increased upon UV treatment, accompanied by increased saturation of cholesterol in the polar head, apolar tail and the interface regions of the membrane lipid bilayer.