Direct ESI-MS analysis of O-acyl glycosylated cardiolipins from the thermophilic bacterium Alicyclobacillus acidoterrestris

Analysis of glycosylated cardiolipins from thermophilic bacteria using GC-MS and LC-ESI-MS/MS methods

Unusual glucose-substituted cardiolipins (Glcx-CLs) in three genera of thermophilic bacteria, having more than one glycosidically linked glucose to the hydroxyl of the central glycerol of Glcx-CLs were identified for the first time in thermophilic bacteria of the genera Geobacillus, Meiothermus, and Thermus. The number of glucoses reached up to five units. The structure of glycosidically linked oligosaccharides was determined based on shotgun analysis MS (electrospray high-resolution tandem mass spectrometry), partially methylated alditol acetates were identified by GC-MS, both electron ionization (EI) and positive chemical ionization (PCI), hydrophilic interaction liquid chromatography (HILIC) separation and identification of CLs glycosides by high resolution MS-ESI, and digestion by specific glycosidases.

Application and potential of multifrequency ultrasound in juice industry: Comprehensive analysis of inactivation and germination of Alicyclobacillus acidoterrestris spores

The majority of acidic fruits are perishable owing to their high-water activity, which promotes microbial activity, thus exhibiting metabolic functions that cause spoilage. Along with sanitary practices, several treatments are used during processing and/or storage to inhibit the development of undesirable bacteria. To overcome the challenges caused by mild heat treatment, juice manufacturers have recently increased their involvement in developing novel non-thermal processing procedures. Ultrasonication alone or in combination with other hurdle technologies may be used to pasteurize processed fruit juices. Multifrequency ultrasound has gained popularity due to the fact that mono-frequency ultrasound has less impact on bacterial inactivation and bioactive compound enhancement of fruit juice. Here, we present and discuss the fundamental information and technological knowledge of how spoilage bacteria, specifically Alicyclobacillus acidoterrestris, assemble resistant spores and inactivate and germinate dormant spores in response to nutrient germinants and physical treatments such as heat and ultrasound. To the authors' knowledge, no prior review of ultrasonic inactivation and germination of A. acidoterrestris in fruit juice exists. Therefore, this article aims to provide a review of previously published research on the inactivation and germination of A. acidoterrestris in fruit juice by ultrasound and heat.

Simultaneous analysis of cardiolipin and lipid A from Helicobacter pylori by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Cardiolipin (CL) is an anionic tetraacylphospholipid found in mammalian tissues, inner membrane of mitochondria and in the cytoplasmic membrane of Gram-positive and -negative bacteria. Lipid A is the principal structural component responsible for the range of biological activities of lipopolysaccharides. Here we report a MALDI-MS-based method for the sensitive simultaneous analysis of CL and lipid A from Helicobacter pylori cells. The sensitivity was demonstrated by the analysis of CL and lipid A from a single bacterial colony of in vitro grown H. pylori strain NCTC 11637 (ATCC 43504). We then characterized the CL and lipid A structures in H. pylori cells grown under three different conditions, on agar-horse blood plates, in liquid culture and ex vivo. The results revealed the presence of high amounts of myristic (C14:0) and 19-carbon cyclopropane (C19:0cyc) fatty acids. Alterations in CL structure were observed in H. pylori cells cultivated on plates as compared with the bacteria grown in broth culture. Furthermore, significant changes in lipid A acylation pattern were detected in H. pylori cells during formation of coccoids. In contrast, structural analysis of CL from ex vivo H. pylori cells recovered from the stomachs of infected Mongolian gerbils demonstrated only minor changes in acyl chain combination. This is the first report of simultaneous analysis of CL and lipid A from ex vivo cells of H. pylori.

Toward total structural analysis of cardiolipins: multiple-stage linear ion-trap mass spectrometry on the [M - 2H + 3Li]+ ions

ESI multiple-stage linear ion-trap (LIT) mass spectrometric approaches for a near-complete structural characterization of cardiolipins (CLs), including identification of the fatty acyl substituents, assignment of the fatty acid substituents on the glycerol backbone, and location of the double-bond(s) or cyclopropyl group along the fatty acid chain are described. Upon collisionally activated dissociation (CAD) on the [M - 2H + 3Li](+) ions of CL in an ion-trap (MS(2)), two sets of fragment ions (designated as (a + 136) and (b + 136) ions) analogous to those previously reported for the [M - 2H + 3Na](+) ions were observed, leading to assignment of the phosphatidyl moieties attached to 1'- or 3'-position of the central glycerol. Further dissociation of the (a + 136) (or (b + 136)) ions (MS(3)) gives rise to the (a + 136 - R(1(or 2))CO(2)Li) (or b + 136 - R(1(or 2))CO(2)Li) ion pairs that identify the fatty acid moieties and their position on the glycerol backbone. This is followed by MS(4) on the (a + 136 - R(1(or 2))CO(2)Li) (or b + 136 - R(1(or 2))CO(2)Li) ion to eliminate a tricyclic glycerophosphate ester residue (136 Da) to yield the (a - R(1(or 2))CO(2)Li) ion, which is then subjected to MS(5). The MS(5) spectrum contains the structural information that locates the double-bond(s) or cyclopropyl group of the fatty acid substituents. Finally, the subsequent MS(6) on the dilithiated fatty acid ions generated from MS(5) also yields feature ions that confirm the assignment.