Chemical Structure of the Lipid A component of Pseudomonas sp. strain PAMC 28618 from Thawing Permafrost in Relation to Pathogenicity

• Published in: Scientific Reports
• Main Authors: Park, Han-Gyu, Sathiyanarayanan, Ganesan, Hwang, Cheol-Hwan, Ann, Da-Hee, Kim, Jung-Ho, Bang, Geul, Jang, Kyoung-Soon, Ryu, Hee Wook, Lee, Yoo Kyung, Yang, Yung-Hun, Kim, Yun-Gon
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2017
• Subjects: Article; Arctic; Climate change; permafrost
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5438365/; http://www.ncbi.nlm.nih.gov/pubmed/28526845; https://doi.org/10.1038/s41598-017-02145-w

Climate change causes permafrost thawing, and we are confronted with the unpredictable risk of newly discovered permafrost microbes that have disease-causing capabilities. Here, we first characterized the detailed chemical structure of the lipid A moiety from a Pseudomonas species that was isolated from thawing arctic permafrost using MALDI-based mass spectrometric approaches (i.e., MALDI-TOF MS and MALDI-QIT-TOF MSn). The MALDI multi-stage mass spectrometry (MS) analysis of lipid A extracted from the Pseudomonas sp. strain PAMC 28618 demonstrated that the hexaacyl lipid A ([M−H]− at m/z 1616.5) contains a glucosamine (GlcN) disaccharide backbone, two phosphates, four main acyl chains and two branched acyl chains. Moreover, the lipid A molecule–based structural activity relationship with other terrestrial Gram-negative bacteria indicated that strain PAMC 28618 has an identical lipid A structure with the mesophilic Pseudomonas cichorii which can cause rot disease in endive (Cichorium endivia) and that their bacterial toxicities were equivalent. Therefore, the overall lipid A validation process provides a general strategy for characterizing bacteria that have been isolated from arctic permafrost and analyzing their respective pathogenicities.