The extremely thermophilic bacterium Thermus thermophilus HB27 displays lipolytic activity for the hydrolysis of triglycerides. In this study we performed a mutational in vivo analysis of esterases and lipases that confer growth on tributyrin. We interrupted 10 ORFs suspected to encode lipolytic enzymes. Two chromosomal loci were identified that resulted in reduced hydrolysis capabilities against tributyrin and various para-nitrophenyl acyl esters. By implementation of a convenient new one-step method which abstains from the use of selectable markers, a mutant strain with multiple scar-less deletions was constructed by sequentially deleting ORFs TT_C1787, TT_C0340, TT_C0341 and TT_C0904. The quadruple deletion mutant of T. thermophilus exhibited significantly lower lipolytic activity (approximately 25% residual activity compared to wild type strain) over a broad range of fatty acyl esters and had lost the ability to grow on agar plates containing tributyrin as the sole carbon source. Furthermore, we were able to determine the impact of each gene disruption on the lipolytic activity profile in this model organism and show that the esterase activity in T. thermophilus HB27 is due to a concerted action of several hydrolases having different substrate preferences and activities. The esterase-less T. thermophilus multi-deletion mutant from this study can be used as a screening and expression host for esterase genes from thermophiles or metagenomes.
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http://dx.doi.org/10.1016/j.jbiotec.2014.07.448 | DOI Listing |
RSC Chem Biol
December 2024
SSPC - The Science Foundation Ireland Research Centre for Pharmaceuticals, Department of Chemical Sciences, Bernal Institute, University of Limerick Limerick Ireland
Small, stable biomedicines, like peptides and hormones, are already available on the market as spray dried formulations, however large biomolecules like antibodies and therapeutic enzymes continue to pose stability issues during the process. Stresses during solid-state formation are a barrier to formulation of large biotherapeutics as dry powders. Here, we explore an alternative avenue to protein stabilisation during the spray drying process, moving away from the use of excipients.
View Article and Find Full Text PDFInt Microbiol
September 2024
Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain.
Plasmid
December 2024
Department of Applied Chemistry, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan.
We previously reported the development of a Cre/lox-based gene disruption system for multiple markerless gene disruption in Thermus thermophilus; however, it was a time-consuming method because it functioned at 50 °C, the minimum growth temperature of T. thermophilus HB27. In the present study, we improved this system by introducing random mutations into the cre-expressing plasmid, pSH-Cre.
View Article and Find Full Text PDFBiochim Biophys Acta Biomembr
October 2024
Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany. Electronic address:
The natural transformation system of the thermophilic bacterium Thermus thermophilus comprises at least 16 competence proteins. Recently we found that the outer membrane (OM) competence protein PilW interacts with the secretin channel, which guides type IV pili (T4P) and potential DNA transporter pseudopili through the OM. Here we have used biochemical techniques to study the interactions of cytoplasmic, inner membrane (IM) and OM components of the DNA transporter in T.
View Article and Find Full Text PDFBiochemistry
May 2024
Department of Chemical Sciences, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland.
Aldehyde dehydrogenase enzymes (ALDHs) are widely studied for their roles in disease propagation and cell metabolism. Their use in biocatalysis applications, for the conversion of aldehydes to carboxylic acids, has also been recognized. Understanding the structural features and functions of both prokaryotic and eukaryotic ALDHs is key to uncovering novel applications of the enzyme and probing its role in disease propagation.
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