Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Advances in the characterisation of the oyster mushroom genes

16.03.2005


The oyster mushroom (Pleurotus ostreatus), apart from reducing cholesterol and having anticancerogenic properties, is characterised for its capacity for breaking down cellulose. Finding out which genes are responsible for this activity – the reason why the fungus is sometimes used as a decontaminating agent, was the aim of the PhD thesis by Arantza Eizmendi Goikoetxea, which she defended at the Public University of Navarre with the title, Molecular Characterisation of a family of genes of cellobiohydrolases in the “Pleurotus ostreatus” fungus.



Degradation of cellulose

In nature, the oyster mushroom grows on dead trunks of trees where the lignin and cellulose – the two principal components of wood - are being broken down. Degradation of lignin has been studied over the years by a number of research teams that have characterised the genes involved. But nobody, to date, has tackled the degradation of cellulose from a molecular perspective.


Cellulose is the most abundant biological polymer on the planet. It is made up of units of D-glucose united by means of glycosidic links that form long polymer chains. The breaking down by live organisms takes place through the action of three types of enzymes: endogluconases, cellobiohydrolases y b-glucosidases.

All these, necessary for the complete breaking down of cellulose, function by hydrolysing the glycoside links, but they vary in the specificity of substrate: the endoglucanases attack the glycosidic links within the cellulose molecule, the cellobiohydrolases act by liberating units of cellobiose from either end of the cellulose chain and the b-glucosidases hydrolyse the cellobiose molecules, producing glucose as end product.

In her PhD thesis Arantza Eizmendi Goikoetxea has analysed the activity of one of these types of enzymes: the cellobiohydrolases. To this end, she cloned, isolated and sequenced those genes of the oyster mushroom responsible for this activity and investigated the culture in which each of these genes expresses itself.

Five genes of one family

The PhD work resulted in the isolation of five genes of the oyster mushroom, of the Florida variety, and the expression thereof giving rise to different cellobiohydrolases, thus demonstrating the existence of a multigenic family responsible for the said enzymatic activity. Also, using such genomic sequences as a probe, it has been possible to detect what are the conditions under which the expression of each one of the genes is produced. This has enabled the synthesis of the cDNA of each gene and, by means of comparison with the corresponding genomic sequence, the characterisation of their structure.

Regarding their location on the linkage map, it has been found that four of the five genes are located on the same chromosome, quite near each other, and the other is located on a different chromosome. It is precisely this fifth gene that is structurally distinct from the others: it lacks a fragment at its end.

It should be pointed out that the genes that are together and the lone one are located on chromosomes where there are also genes responsible for the breaking down of lignin. This is of great interest because lignin and cellulose are found together in nature. They are found together in wood and it would seem logical that the genes responsible for the degradation of one or the other are located close together on the genome, on the same chromosomes.

Irati Kortabitarte | alfa
Further information:
http://www.basqueresearch.com

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>