Selection of tomato tissue cultures able to grow on ribose as the sole carbon source

1995 ◽  
Vol 14 (12) ◽  
Author(s):  
RobertD. Locy
2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Rodolfo García-Contreras ◽  
Daniel Loarca ◽  
Caleb Pérez-González ◽  
J Guillermo Jiménez-Cortés ◽  
Abigail Gonzalez-Valdez ◽  
...  

ABSTRACT Pseudomonas aeruginosa is one of the main models to study social behaviors in bacteria since it synthesizes several exoproducts, including exoproteases and siderophores and release them to the environment. Exoproteases and siderophores are public goods that can be utilized by the individuals that produce them but also by non-producers, that are considered social cheaters. Molecularly exoprotease cheaters are mutants in regulatory genes such as lasR, and are commonly isolated from chronic infections and selected in the laboratory upon serial cultivation in media with protein as a sole carbon source. Despite that the production of exoproteases is exploitable, cooperators have also ways to restrict the growth and selection of social cheaters, for instance by producing toxic metabolites like pyocyanin. In this work, using bacterial competitions, serial cultivation and growth assays, we demonstrated that rhamnolipids which production is regulated by quorum sensing, selectively affect the growth of lasR mutants and are able to restrict social cheating, hence contributing to the maintenance of cooperation in Pseudomonas aeruginosa populations.


1996 ◽  
Vol 42 (1) ◽  
pp. 87-91 ◽  
Author(s):  
ESTEBAN C. DELL'ANGELICA ◽  
DANIEL MILIKOWSKI ◽  
DANIEL A. SAENZ ◽  
CARLOS A. STELLA ◽  
EUGENIA H. RAMOS ◽  
...  

1972 ◽  
Vol 50 (6) ◽  
pp. 1399-1404 ◽  
Author(s):  
Calvin Chong ◽  
C. D. Taper

Callus cultures from 1-year-old twigs of the apple, Malus pumila, cultivars McIntosh, Cortland, and Red Delicious, and of the crabapple rootstock, Malus robusta No. 5, were successfully isolated and maintained on a medium with sorbitol as the sole carbon source. Investigation with various carbon sources, each at 3% concentration, showed that McIntosh callus grew equally well on sorbitol, sucrose, and glucose. Cortland and Robusta cultures responded equally to sorbitol and glucose but poorly to sucrose. The relative growths of the callus cultures on sorbitol were in the decreasing order, McIntosh, Cortland, and Robusta. Sorbitol served as an excellent carbon source for all three cultures.


2011 ◽  
Vol 3 ◽  
pp. 56
Author(s):  
Raimundo Cosme Silva Filho ◽  
Sérgio Carvalho Santana ◽  
Naveed Khan Khan ◽  
Everaldo Silvino Santos ◽  
Gorete Ribeiro Marcedo

In this work it was performed a selection of fungal strains able to grow in a specific medium containing chitosan (Chitosan Detector Agar) as the sole carbon source at 0.2%, and a kinetic study was performed to evaluate the best conditions for production of chitosanase from the best producing strain. The selection was made from five strains, previously isolated from soil. In the evaluation of kinetics was accompanied by cell concentration, the protein concentration (mg/mL), the enzyme activity (U/mL) for two volumes of fermentation broth (0.05 and 0.10 mL). The results showed a significant increase in all parameters studied in the first 12 hours of culture. Comparing the activity values for the two volumes of fermentation broth was observed that the volume of 0.05 mL broth showed enzymatic activity always greater than the volume of 0.1 mL


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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