title: Impact of UV-B radiation on thylakoid membrane and fatty acid profile of Spirulina platensis.
abstract: Ultraviolet-B (UV-B) radiation to thylakoid membrane and fatty acid profile has been investigated in cyanobacterium, Spirulina platensis. The thylakoid membrane was isolated by mechanical disruption of the freeze-dried and lysozyme-treated cells followed by differential density gradient centrifugation and morphological variations were examined. UV radiation distorted the membrane on the outer side with reduced chlorophyll a (chl a) content compared to its untreated counterpart. Liquid chromatography-mass spectrometry (LC-MS) was used for characterization of chl a of the thylakoid membrane. UV-B exposure resulted in alterations in the pigment-protein complexes 47 kDa and 43 kDa. Furthermore, 94 kDa and 20 kDa protein appeared in UV-B-exposed thylakoid membrane of S. platensis. The composition of fatty acid in response to UV-B radiation was detected by gas chromatography-mass spectrometry having 23.5% saturated fatty acid (SFA), 76.4% monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA). In contrast to its UV-B-untreated counterpart, SFA was 46.6%, and MUFA and PUFA were 53.3%. Our findings suggest that UV-B radiation not only affects membrane morphology and its protein profile but also reduces saturated fatty acid and increases unsaturated fatty acids in S. platensis.
authors.affiliation: Department of Biotechnology, Madhav Institute of Technology & Science, Race Course Road, Gwalior 474005, India.
authors.forename: Radha
authors.initials: R
authors.lastname: Gupta
authors.forename: Pratiksha
authors.initials: P
authors.lastname: Bhadauriya
authors.forename: Vinay Singh
authors.initials: VS
authors.lastname: Chauhan
authors.forename: Prakash Singh
authors.initials: PS
authors.lastname: Bisen
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002853:Chromatography, Liquid; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D053545:Spirulina / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D020524:Thylakoids / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D002734:Chlorophyll