Rhamnolipid-enhanced Pseudomonas putida biofilm formation on hydrophilic surfaces with toluene as the bacterium's sole carbon source

2018 ◽  
Vol 127 ◽  
pp. 87-94 ◽  
Author(s):  
Haim Katz ◽  
Ravit Farber ◽  
Gilad Chaniel ◽  
Yaakov Ankar ◽  
Haim Cohen ◽  
...  
2016 ◽  
Vol 27 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Mihaela Carmen Eremia ◽  
Irina Lupescu ◽  
Mariana Vladu ◽  
Maria Petrescu ◽  
Gabriela Savoiu ◽  
...  

Abstract Polyhydroxyalcanoates (PHAs) are specifically produced by a wide variety of bacteria, as an intracellular energy reserve in the form of homo- and copolymers of [R]-β-hydroxyalkanoic acids, depending on the C source used for microorganism growth, when the cells are grown under stressing conditions. In this paper we present microbiological accumulation of poly-3-hydroxyoctanoate (PHO) by using a consortium of bacterial strains, Pseudomonas putida and Bacillus subtilis, in a rate of 3:1, grown on a fermentation medium based on sodium octanoate as the sole carbon source. The experiments performed in the above mentioned conditions led to the following results: from 18.70 g sodium octanoate (7.72 g/L in the fermentation medium) used up during the bioprocess, 3.93-3.96 g/L dry bacterial biomass and 1.834 - 1.884 g/L PHA, containing 85.83 - 86.8% PHO, were obtained.


2007 ◽  
Vol 73 (9) ◽  
pp. 3105-3108 ◽  
Author(s):  
Giomar Rivera-Cancel ◽  
Daniela Bocioaga ◽  
Anthony G. Hay

ABSTRACT Pseudomonas putida DTB grew aerobically with N,N-diethyl-m-toluamide (DEET) as a sole carbon source, initially breaking it down into 3-methylbenzoate and diethylamine. The former was further metabolized via 3-methylcatechol and meta ring cleavage. A gene from DTB, dthA, was heterologously expressed and shown to encode the ability to hydrolyze DEET into 3-methylbenzoate and diethylamine.


2019 ◽  
Author(s):  
Mitchell G. Thompson ◽  
Luis E. Valencia ◽  
Jacquelyn M. Blake-Hedges ◽  
Pablo Cruz-Morales ◽  
Alexandria E. Velasquez ◽  
...  

ABSTRACTPseudomonas putida is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that P. putida is able to use valerolactam as a sole carbon source, as well as degrade caprolactam. Lactams represent important nylon precursors, and are produced in quantities exceeding one million tons per year[1]. To better understand this metabolism we use a combination of Random Barcode Transposon Sequencing (RB-TnSeq) and shotgun proteomics to identify the oplBA locus as the likely responsible amide hydrolase that initiates valerolactam catabolism. Deletion of the oplBA genes prevented P. putida from growing on valerolactam, prevented the degradation of valerolactam in rich media, and dramatically reduced caprolactam degradation under the same conditions. Deletion of oplBA, as well as pathways that compete for precursors L-lysine or 5-aminovalerate, increased the titer of valerolactam from undetectable after 48 hours of production to ~90 mg/L. This work may serve as a template to rapidly eliminate undesirable metabolism in non-model hosts in future metabolic engineering efforts.


2002 ◽  
Vol 57 (3-4) ◽  
pp. 356-360 ◽  
Author(s):  
Borjana K. Tuleva ◽  
George R. Ivanov ◽  
Nelly E. Christova

Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by the newly isolated and promising strain Pseudomonas putida 21BN. The biosurfactants were identified as rhamnolipids, the amphiphilic surface-active glycolipids usually secreted by Pseudomonas spp. Their production was observed when the strain was grown on soluble substrates, such as glucose or on poorly soluble substrates, such as hexadecane, reaching values of 1.2 g l-1. When grown on hexadecane as the sole carbon source the biosurfactant lowered the surface tension of the medium to 29 mN m-1 and formed stable and compact emulsions with emulsifying activity of 69%


Author(s):  
Vivek Kumar Ranjan ◽  
Shriparna Mukherjee ◽  
Subarna Thakur ◽  
Krutika Gupta ◽  
Ranadhir Chakraborty

2008 ◽  
Vol 5 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Jing Wang ◽  
Guiwen Yan ◽  
Mingquan An ◽  
Jieli Liu ◽  
Houming Zhang ◽  
...  

1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.


1985 ◽  
Vol 5 (5) ◽  
pp. 1111-1121
Author(s):  
S B Ellis ◽  
P F Brust ◽  
P J Koutz ◽  
A F Waters ◽  
M M Harpold ◽  
...  

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.


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