Study on the roles and quantification of 3-hydroxy fatty acids in the soma and supernatant of cultured Burkholderia cepacia complex

• Main Authors: Hong-yi Liu, 劉鴻毅
• Other Authors: Ya-Lei Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/78dh4t

碩士 === 國立高雄師範大學 === 生物科學研究所 === 97 === Study on the roles and quantification of 3-hydroxy fatty acids in the soma and supernatant of cultured Burkholderia cepacia complex Abstract Although Burkholderia cepacia complex (BCC) divided into 9 of recA genomovars in present, the virulence to hosts in these genomovars were still undifferentiated. We hypothesized that, in cultural supernatants, the amounts of C14:0 3-OH fatty acids, the unique components of BCC lipopolysaccharides (LPS), acted as a biomarker for virulence, were related to the degrees of pathologically inflammatory effects on animals with BCC infection. Thirty-two strains were identified to BCC gonomorvarⅢa by the outcomes of biochemical and molecular tests, and typed to their genetic independence by the profiles of cellular fatty acid and randomly amplified polymorphic DNA (RAPD), respectively. To determine the concentration of fatty acids in supernatants, the quantitative profiles of each fatty acid methyl ester (FAME) analyzed by gas chromatography mass spectrometry (GC/MS) was developed. In this study, the instrument detection limits were reached to 26 ng/ml. The optimal reaction was defined as >90% in esterification for each fatty acid. The processing of samples were performed as that, after a 7 d-incubation, the cultural supernatants were acted as reactants and sequentially reacted to alkaline hydrolysis for 30 min and esterification for 10min. Among of the cultures of these isolates, the concentration of C14:0 3-OH fatty acid in supernatants was ranged from 19.3±0.4 to 133.7±3.6ng/ml. The molar ratio of C14:0/C16:0 3-OH fatty acid was calculated to be 1.78±0.3. With multiple regression analysis, a positive correlation was shown that the concentration of 3-OH fatty acids in supernatants of each isolates was against some levels of pathological effect (area of cell debris in liver) of Balb/c mice with tested BCC infection individually (R2=0.682). Results suggested that the concentration of C14:0 3-OH fatty acid in BCC cultural supernatants was acted as an indicator of virulence to the mice with the bacterial infection for 2 d. Keywords：Burkholderia cepacia complex, lipopolysaccharides, C14:0 3-OH fatty acid, Gas chromatography mass spectrometry