Michelle Rudden

The University of York · Department of Biology

Body odour is a characteristic trait of Homo sapiens, however its role in human behaviour and evolution is poorly understood. Remarkably, body odour is linked to the presence of a few species of commensal microbes. Herein we discover a bacterial enzyme, limited to odour-forming staphylococci that are able to cleave odourless precursors of thioalcoh...

ELife digest Human body odour contains a number of chemicals, but the most pungent and recognisable are thioalcohols. These molecules are created through a series of chemical reactions that start with an odourless precursor, a compound produced in glands located in our armpits. Then, a type of bacteria called Staphylococcus hominis takes in these m...

At present, anti-virulence drugs are being considered as potential therapeutic alternatives and/or adjuvants to currently failing antibiotics. These drugs do not kill bacteria but inhibit virulence factors essential for establishing infection and pathogenesis through targeting non-essential metabolic pathways reducing the selective pressure to deve...

Background Our understanding of the skin microbiome has dramatically improved since the pioneering studies and the improvements in sequencing technologies. Species of the genus Corynebacterium are known to form a major part of the human skin microbiome but most detailed studies have focussed on other similarly prevalent genera like Staphylococcus a...

Located at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host-microbe interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These bacteria rely on specific transporters for the a...

Their biochemical versatility and biotechnological importance make actinomycete bacteria attractive targets for ambitious genetic engineering using the toolkit of synthetic biology. But their complex biology also poses unique challenges. This mini review discusses some of the recent advances in synthetic biology approaches from an actinomycete pers...

Pseudomonas aeruginosa uses quorum sensing (QS) to modulate the expression of several virulence factors that enable it to establish severe infections. The QS system in P. aeruginosa is complex, intricate and is dominated by two main N-acyl-homoserine lactone circuits, LasRI and RhlRI. These two QS systems work in a hierarchical fashion with LasRI a...

25 26 Located at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host-microbe 27 interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous 28 bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These 29 bacteria rely on specific transpo...

Optimising detergency at lower temperatures is of increasing interest due to environmental and economic factors, and requires a greater understanding of the effects of temperature on the adsorption of surfactant mixtures at interfaces. The adsorption properties of surfactant mixtures and biosurfactant/surfactant mixtures have been studied at room t...

List of strains used in this study

List of oligonucleotides used in this study

List of plasmids used in this study

The composition of an adsorbed layer at the air--water interface of a quinary mixture consisting of three conventional surfactants, octa-ethylene glycol monododecyl ether (C12E8), dodecane-6-p-sodium benzene sulfonate (LAS6), and diethylene glycol monododecyl ether sodium sulfate (SLE2S) mixed with two biosurfactants, the rhamnolipids L-rhamnosyl-L...

This chapter focusses on the biodiversity of microbial biosurfactants and the organisms that produce them. Specific attention is given to the low molecular weight glycolipids and lipopeptides produced by bacteria such as Pseudomonas, Burkholderia, Bacillus, Rhodococcus, and Alcanivorax in addition to other glycolipids synthesized by eukaryotic orga...

The self-assembly of dilute aqueous solutions of a ternary surfactant mixture and rhamnolipid biosurfactant / surfactant mixtures has been studied by small angle neutron scattering. In the ternary surfactant mixture of octaethylene glycol monododecyl ether, C12E8, sodium dodecyl 6-benzene sulfonate, LAS, and sodium dioxyethylene monododecyl sulfate...

Burkholderia thailandensis E264 is a rhamnolipid (RL)-producing gram-negative bacterium first isolated from the soils and stagnant waters of central and north-eastern Thailand. Growth of B. thailandensis E264 under two different incubation temperatures (25 and 30 °C) resulted in a significantly higher dry cell biomass production at 30 °C (7.71 g/l)...

Abstract Olive mill waste (OMW) creates a major environmental problem due to the difficulty of further waste processing. In this work we present an approach to give OMW added value by using it for the production of biosurfactants. Two bacterial species, Pseudomonas aeruginosa and Bacillus subtilis, were grown with OMW as the sole carbon source. Gly...

Rhamnolipids (RLs) are synthesised as a complex mixture of congeners comprising either one or two molecules of rhamnose glycosidically linked to a dimer of 3-hydroxy fatty acids varying in chain length and degree of saturation. Currently, HPLC-MS/MS is the most precise and accurate method for RL determination, while accurate quantification is limit...

High molecular weight biosurfactants are produced from a number of different bacteria and comprise lipoproteins, proteins, polysaccharides, lipopolysaccharides or complexes containing several of these structural types, many of which have yet to be fully characterised. Lipopeptide biosurfactants are cyclic peptides with varying attached lipid chains...

Microbial-produced biosurfactant glycolipids consist of four major groups: rhamnolipids, sophorolipids, trehalose lipids and mannosylerythritol lipids. Extensive research has been carried out on the production and analysis of rhamnolipids and sophorolipids, with significantly less research publications in the area of trehalose lipids and mannosyler...

A range of isolates of Pseudomonas aeruginosa from widely different environmental sources were examined for their ability to synthesise rhamnolipid biosurfactants. No significant differences in the quantity or composition of the rhamnolipid congeners could be produced by manipulating the growth conditions. Sequences for the rhamnolipid genes indica...

- Regulation of rhamnolipid biosynthetic cluster in Pseudomonas aeruginosa - Antimicrobial activities of rhamnolipids