Abstract

Lipopolysaccharides (LPS) are surface glycoconjugates embedded in the external leaflet of the outer membrane (OM) of the Gram-negative bacteria. They consist of three regions: lipid A, core oligosaccharide (OS), and O-specific polysaccharide or O-antigen. Lipid A is the glycolipid endotoxin domain that anchors the LPS molecule to the OM, and therefore, its chemical structure is crucial in the maintenance of membrane integrity in the Gram-negative bacteria. In this paper, we reported the characterization of the lipid A and OS structures from Pseudoalteromonas nigrifaciens Sq02-Rifr, which is a psychrotrophic Gram-negative bacterium isolated from the intestine of Seriola quinqueradiata. The immunomodulatory activity of both LPS and lipid A was also examined.

Highlights

  • Accepted: 17 November 2021Psychrophiles and psychrotrophs, called cold-adapted bacteria, are microorganisms that thrive at low temperatures in permanently cold environments (0–10 ◦ C)

  • Figure 1. 14% DOC-Polyacrylamide gel electrophoresis (PAGE) analysis stained with silver nitrate of (a) smooth-LPS from E. coli O55:B5 used as a standard and (b) PCP extract from P. nigrifaciens Sq02

  • The monosaccharide and fatty acid composition of the PCP extract was determined through their derivation as acetylated methyl glycosides (AMG) and fatty acids methyl esters (FAME), respectively

Read more

Summary

Introduction

Psychrophiles and psychrotrophs, called cold-adapted bacteria, are microorganisms that thrive at low temperatures in permanently cold environments (0–10 ◦ C). Lipid A is the glycolipid domain that anchors the LPS molecule to the OM, and its chemical structure is crucial in the maintenance of membrane integrity and the enhancement of the membrane fluidity in cold-adapted bacteria. The of lack the O-specific polfrom cold-adapted bacteria lack this portion [6] In this case, the LPS is named rough ysaccharide could enhance the flexibility and stability of the OM. The lipid structural variation in the number or immune responses are mediated by the activation of the TLR-4 and subsequent activation length of the acyl chain can markedly affect host immune responses. Pseudoalteromonas nigrifaciens Sq02-Rifr is a psychrotrophic Gram-negative bacterium structural characterization of the LOS molecule produced from P. nigrifaciens Sq02-Rifr isolated from the intestine of a Seriola quinqueradiata. We compared structures withhaloplanktis those reported [13], which are psychrophilic bacteria isolated from the Antarctic. LPS treatments were evaluated on a gut inflammation model of [14]. and THP-1 cells co-culture to assess the potential immune-modulation activity [14]

Results
LOS Chemical Analysis
MALDI-TOF Analysis
Structural Characterization of the Lipid A
OH-treated mass spectrum recorded in reflector mode of the NHNH
LOS De-Acylation and NMR Analysis
C3 A5 A6
TLR-4 Activation and IL-6 mRNA Expression Evaluated by qRT-PCR
QUANTI-THP-1 Blue Assay
QUANTI-THP-1
Cells Growth
LPS Isolation and Purification
DOC-PAGE Analysis
Chemical Analysis
Deacylation of LOS
Mass Spectrometry Analysis
Cell Culture
3.10. TLR-4 and IL-6 mRNA Analyses Using qRT-PCR Analyses
Conclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.