Connect with us

Bioengineer

Bacterial cellulose degradation system could give boost to biofuels production

Credit: NINS/IMS Efforts to find ways to break down cellulose, the tough stuff that makes up plant cell walls, faster…

Published

on

Efforts to find ways to break down cellulose, the tough stuff that makes up plant cell walls, faster and more productively has long been a goal of industrial researchers.

When plants are processed into biofuels or other biomass applications, cellulose has to be degraded into simpler sugar molecules first, and this step can represent up to a quarter of the operating and capital costs of biofuel production. If this process can be made faster and more productive, it won’t just save industry money, but such efficiencies could also reduce the environmental impact of production.

Cellulose molecules bind very strongly to each other, making cellulose very hard to break down. Some fungi are able to break it down, however, and their cellulose degradation systems are well known.

Fungi produce many types of cellulases–enzymes that speed up the chemical reaction that degrades cellulose. And such fungi have been widely used in industry for this reason. For example, the fungus Trichoderma reesei–discovered during World War Two in the Pacific as a result of its eating away at tents and clothing–is used in the production of stone-washed jeans. Cellobiohydrolase, a type of cellulase that the fungus produces, breaks down cellulose into cellobiose, a simple sugar more easily useable by organisms. This slightly degrades the denim material in places, which in turn softens it–making it appear as if washed with stones–and makes it more comfortable to wear.

But there is another type of cellulose degradation system used by some bacteria, and which is similar in many ways to that used by this fungus. But this system has not been very well understood until now. In a paper in the Journal of Biological Chemistry on August 18th, researchers from Japan’s Institute for Molecular Science, National Institutes of Natural Sciences (IMS, NINS) have finally described this system in detail at the single-molecule level.

The type of cellobiohydrolase produced by the bacterium Cellulomonas fimi has a similar catalytic domain to the cellobiohydrolase produced by T. reesei. The catalytic domain of an enzyme is its region that interacts with a molecule that it wants to change or break down (in order to cause the enzymatic reaction). Both the fungus and the bacteria’s cellulose degradation system also exhibit similar hydrolytic activity (the way that they use water to break down the cellulose’s chemical bonds).

But the two systems have different carbohydrate-binding modules (the series of proteins in the enzyme that bind to the carbohydrates in the cellulose) and what are termed “linkers”, in essence the part of the enzyme that links the catalytic domain to the carbohydrate-binding modules.

In earlier research, the NINS scientists had already established that the structure of the linker region of the fungal cellobiohydrolase played a crucial role in how fast the enzyme binds to cellulose (and thus how fast the system degrades cellulose).

“So the obvious next questions were: Even though these other parts of the bacterium’s cellobiohydrolase are different to those of the fungus, do they nevertheless do something similar?” said Akihiko Nakamura and Ryota Iino, the researchers on the team. “Do they also speed up cellulose degradation?”

They found that they do. The scientists used single-molecule fluorescence imaging–an advanced method of microscopy that delivers images of living cells with a resolution of just tens of nanometers–to observe the bacterium’s cellobiohydrolase binding to and dissociating from cellulose molecules.

This allowed them to clarify the functions of the different parts of the cellulose degradation system. They found that the carbohydrate-binding modules were indeed important for the initial binding, but the role played by the linker region was fairly minor.

However, they found that the catalytic domain was not so similar after all. Its structure showed longer loops at the entrance and exit of a “tunnel” in the heart of the system compared to that of the fungus. And this difference in the tunnel structure results in higher processivity–the ability of an enzyme to set off multiple consecutive reactions.

###

Source: https://bioengineer.org/bacterial-cellulose-degradation-system-could-give-boost-to-biofuels-production/

[ALT0]

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Bioengineer

Reduced microbial stability linked to soil carbon loss in active layer under alpine permafrost degra

Credit: NIEER Chinese researchers have recently discovered links between reduction in microbial stability and soil carbon loss in the active

Published

on

Chinese researchers have recently discovered links between reduction in microbial stability and soil carbon loss in the active layer of degraded alpine permafrost on the Qinghai-Tibet Plateau (QTP).

The researchers, headed by Prof. CHEN Shengyun from the Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences (CAS), and XUE Kai from University of Chinese Academy of Sciences, conducted a combined in-depth analysis of soil microbial communities and their co-occurrence networks in the active permafrost layer along an extensive gradient of permafrost degradation.

The QTP encompasses the largest extent of high-altitude mountain permafrost in the world. This permafrost is different than high-latitude permafrost and stores massive soil carbon. An often ignored characteristic of permafrost is that the carbon pool in the active layer soil is more active and directly affected by climate change, compared to deeper layers.

Triggered by climate warming, permafrost degradation may decrease soil carbon stability and induce massive carbon loss, thus leading to positive carbon-climate feedback. However, microbial-mediated mechanisms for carbon loss from the active layer soil in degraded permafrost still remain unclear.

In this study, the researchers found that alpine permafrost degradation reduced the stability of active layer microbial communities as evidenced by increased sensitivity of microbial composition to environmental change, promoted destabilizing network properties and reduced resistance to node or edge attacking of the microbial network.

They discovered that soil organic carbon loss in severely degraded permafrost is associated with increased microbial dissimilarity, thereby potentially contributing to a positive carbon feedback in alpine permafrost on the QTP.

###

The results were published in PNAS in an article entitled “Reduced microbial stability in the active layer is associated with carbon loss under alpine permafrost degradation”.

This research was financially supported by the National Natural Science Foundation of China, the Strategic Priority Research Program (A) of CAS and the Second Tibetan Plateau Scientific Expedition and Research Program.

Triggered by climate warming, permafrost degradation may decrease soil carbon stability and induce massive carbon loss, thus leading to positive carbon-climate feedback. However, microbial-mediated mechanisms for carbon loss from the active layer soil in degraded permafrost still remain unclear.

Source: https://bioengineer.org/reduced-microbial-stability-linked-to-soil-carbon-loss-in-active-layer-under-alpine-permafrost-degra/

reduced-microbial-stability-linked-to-soil-carbon-loss-in-active-layer-under-alpine-permafrost-degra

Continue Reading

Bioengineer

SNMMI Image of the Year: PET imaging measures cognitive impairment in COVID-19 patients

Credit: G Blazhenets et al., Department of Nuclear Medicine, Medical Center – University of Freiburg, Faculty of Medicine, University of

Published

on

Credit: G Blazhenets et al., Department of Nuclear Medicine, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg.

Reston, VA–The effects of COVID-19 on the brain can be accurately measured with positron emission tomography (PET), according to research presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2021 Annual Meeting. In the study, newly diagnosed COVID-19 patients, who required inpatient treatment and underwent PET brain scans, were found to have deficits in neuronal function and accompanying cognitive impairment, and in some, this impairment continued six months after their diagnosis. The detailed depiction of areas of cognitive impairment, neurological symptoms and comparison of impairment over a six-month time frame has been selected as SNMMI’s 2021 Image of the Year.

Each year, SNMMI chooses an image that best exemplifies the most promising advances in the field of nuclear medicine and molecular imaging. The state-of-the-art technologies captured in these images demonstrate the capacity to improve patient care by detecting disease, aiding diagnosis, improving clinical confidence, and providing a means of selecting appropriate treatments. This year, the SNMMI Henry N. Wagner, Jr., Image of the Year was chosen from more than 1,280 abstracts submitted to the meeting and voted on by reviewers and the society leadership.

“As the SARS-CoV-2 pandemic proceeds, it has become increasingly clear that neurocognitive long-term consequences occur not only in severe COVID-19 cases, but in mild and moderate cases as well. Neurocognitive deficits like impaired memory, disturbed concentration and cognitive problems may persist well beyond the acute phase of the disease,” said Ganna Blazhenets, PhD, a post-doctoral researcher in Medical Imaging at the University Medical Center Freiburg, in Freiburg, Germany.

To study cognitive impairment associated with COVID-19, researchers carried out a prospective study on recently diagnosed COVID-19 patients who required inpatient treatment for non-neurological complaints. A cognitive assessment was performed, followed by imaging with 18F-FDG PET if at least two new neurological symptoms were present. By comparing COVID-19 patients to controls, the Freiburg group established a COVID-19-related covariance pattern of brain metabolism with most prominent decreases in cortical regions. Across patients, the expression of this pattern showed a very high correlation with the patients’ cognitive performance.

Follow-up PET imaging was performed six months after the initial COVID-19 diagnosis. Imaging results showed a significant improvement in the neurocognitive deficits in most patients, accompanied by an almost complete normalization of the brain metabolism.

“We can clearly state that a significant recovery of regional neuronal function and cognition occurs for most COVID-19 patients based on the results of this study. However, it is important to recognize the evidence of longer-lasting deficits in neuronal function and accompanying cognitive deficits is still measurable in some patients six months after manifestation of disease,” noted Blazhenets. “As a result, post-COVID-19 patients with persistent cognitive complaints should be presented to a neurologist and possibly allocated to cognitive rehabilitation programs.”

“18F-FDG PET is an established biomarker of neuronal function and neuronal injury,” stated SNMMI’s Scientific Program Committee chair, Umar Mahmood, MD, PhD. “As shown the Image of the Year, it can be applied to unravel neuronal correlates of the cognitive decline in patients after COVID-19. Since 18F-FDG PET is widely available, it may therefore aid in the diagnostic work-up and follow-up in patients with persistent cognitive impairment after COVID-19.”

###

Abstract 41. “Altered regional cerebral function and its association with cognitive impairment in COVID 19: A prospective FDG PET study.” Ganna Blazhenets, Johannes Thurow, Lars Frings and Philipp Meyer, Department of Nuclear Medicine, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Nils Schroeter, Tobias Bormann, Cornelius Weiller, Andrea Dressing and Jonas Hosp; Department of Neurology and Clinical Neuroscience, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; and Dirk Wagner, Department of Internal Medicine, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

All 2021 SNMMI Annual Meeting abstracts can be found online at https://jnm.snmjournals.org/content/62/supplement_1.

About the Society of Nuclear Medicine and Molecular Imaging

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and medical organization dedicated to advancing nuclear medicine and molecular imaging, vital elements of precision medicine that allow diagnosis and treatment to be tailored to individual patients in order to achieve the best possible outcomes.

SNMMI’s members set the standard for molecular imaging and nuclear medicine practice by creating guidelines, sharing information through journals and meetings and leading advocacy on key issues that affect molecular imaging and therapy research and practice. For more information, visit http://www.snmmi.org.

“As the SARS-CoV-2 pandemic proceeds, it has become increasingly clear that neurocognitive long-term consequences occur not only in severe COVID-19 cases, but in mild and moderate cases as well. Neurocognitive deficits like impaired memory, disturbed concentration and cognitive problems may persist well beyond the acute phase of the disease,” said Ganna Blazhenets, PhD, a post-doctoral researcher in Medical Imaging at the University Medical Center Freiburg, in Freiburg, Germany.

Source: https://bioengineer.org/snmmi-image-of-the-year-pet-imaging-measures-cognitive-impairment-in-covid-19-patients/

snmmi-image-of-the-year:-pet-imaging-measures-cognitive-impairment-in-covid-19-patients

Continue Reading

Bioengineer

Scientists demonstrate promising new approach for treating cystic fibrosis

Scientists led by UNC School of Medicine researchers Silvia Kreda, Ph.D., and Rudolph Juliano, Ph.D., created an improved oligonucleotide therapy

Published

on

Scientists led by UNC School of Medicine researchers Silvia Kreda, Ph.D., and Rudolph Juliano, Ph.D., created an improved oligonucleotide therapy strategy with the potential for treating other pulmonary diseases, such as COPD and asthma

CHAPEL HILL, NC – UNC School of Medicine scientists led a collaboration of researchers to demonstrate a potentially powerful new strategy for treating cystic fibrosis (CF) and potentially a wide range of other diseases. It involves small, nucleic acid molecules called oligonucleotides that can correct some of the gene defects that underlie CF but are not addressed by existing modulator therapies. The researchers used a new delivery method that overcomes traditional obstacles of getting oligonucleotides into lung cells.

As the scientists reported in the journal Nucleic Acids Research, they demonstrated the striking effectiveness of their approach in cells derived from a CF patient and in mice.

“With our oligonucleotide delivery platform, we were able to restore the activity of the protein that does not work normally in CF, and we saw a prolonged effect with just one modest dose, so we’re really excited about the potential of this strategy,” said study senior author Silvia Kreda, PhD, an associate professor in the UNC Department of Medicine and the UNC Department Biochemistry & Biophysics, and a member of the Marsico Lung Institute at the UNC School of Medicine.

Kreda and her lab collaborated on the study with a team headed by Rudolph Juliano, PhD, Boshamer Distinguished Professor Emeritus in the UNC Department of Pharmacology, and co-founder and Chief Scientific Officer of the biotech startup Initos Pharmaceuticals.

About 30,000 people in the United States have CF, an inherited disorder in which gene mutations cause the functional absence of an important protein called CFTR. Absent CFTR, the mucus lining the lungs and upper airways becomes dehydrated and highly susceptible to bacterial infections, which occur frequently and lead to progressive lung damage.

Treatments for CF now include CFTR modulator drugs, which effectively restore partial CFTR function in many cases. However, CFTR modulators cannot help roughly ten percent of CF patients, often because the underlying gene defect is of the type known as a splicing defect.

CF and splicing defects

Splicing is a process that occurs when genes are copied out – or transcribed – into temporary strands of RNA. A complex of enzymes and other molecules then chops up the RNA strand and re-assembles them, typically after deleting certain unwanted segments. Splicing occurs for most human genes, and cells can re-assemble the RNA segments in different ways so different versions of a protein can be made from a single gene. However, defects in splicing can lead to many diseases – including CF when CFTR’s gene transcript is mis-spliced.

In principle, properly designed oligonucleotides can correct some kinds of splicing defects. In recent years the U.S. Food and Drug Administration has approved two “splice switching oligonucleotide” therapies for inherited muscular diseases.

In practice, though, getting oligonucleotides into cells, and to the locations within cells where they can correct RNA splicing defects, has been extremely challenging for some organs.

“It has been especially difficult to get significant concentrations of oligonucleotides into the lungs to target pulmonary diseases,” Kreda said.

Therapeutic oligonucleotides, when injected into the blood, have to run a long gauntlet of biological systems that are designed to keep the body safe from viruses and other unwanted molecules. Even when oligonucleotides get into cells, the most usually are trapped within vesicles called endosomes, and are sent back outside the cell or degraded by enzymes before they can ever do their work.

A new delivery strategy

The strategy developed by Kreda, Juliano, and their colleagues overcomes these obstacles by adding two new features to splice switching oligonucleotides: Firstly, the oligonucleotides are connected to short, protein-like molecules called peptides that are designed to help them to distribute in the body and get into cells. Secondly, there is a separate treatment with small molecules called OECs, developed by Juliano and Initos, which help the therapeutic oligonucleotides escape their entrapment within endosomes.

The researchers demonstrated this combined approach in cultured airway cells from a human CF patient with a common splicing-defect mutation.

“Adding it just once to these cells, at a relatively low concentration, essentially corrected CFTR to a normal level of functioning, with no evidence of toxicity to the cells,” Kreda said.

The results were much better with than without OECs, and improved with OEC dose.

There is no mouse model for splicing-defect CF, but the researchers successfully tested their general approach using a different oligonucleotide in a mouse model of a splicing defect affecting a reporter gene. In these experiments, the researchers observed that the correction of the splicing defect in the mouse lungs lasted for at least three weeks after a single treatment – hinting that patients taking such therapies might need only sporadic dosing.

The researchers now plan further preclinical studies of their potential CF treatment in preparation for possible clinical trials.

###

Yan Dang, Catharina van Heusden, Veronica Nickerson, Felicity Chung, Yang Wang, Nancy Quinney, Martina Gentzsch, and Scott Randell were other contributors to this study from the Marsico Lung Institute; Ryszard Kole a co-author from the UNC Department of Pharmacology.

The Cystic Fibrosis Foundation and the National Institutes of Health supported this work.

Scientists Demonstrate Promising New Approach for Treating Cystic Fibrosis

Source: https://bioengineer.org/scientists-demonstrate-promising-new-approach-for-treating-cystic-fibrosis/

scientists-demonstrate-promising-new-approach-for-treating-cystic-fibrosis

Continue Reading

Title

Ventureburn5 hours ago

ZwartTech launches Talent Foundation to equip Africans with digital skills

Lagos-based ZwartTech has announced the launch of its new edtech, Zwart Talent Foundation (ZTF) in a statement on 30 July...

CNBC1 day ago

Earnings

Corporate Company Earnings, Find Earnings Per Share and Earnings History Online

Bioengineer3 days ago

Reduced microbial stability linked to soil carbon loss in active layer under alpine permafrost degra

Credit: NIEER Chinese researchers have recently discovered links between reduction in microbial stability and soil carbon loss in the active

Reuters4 days ago

Chipmaker TSMC says too early to say on Germany expansion

Taiwan Semiconductor Manufacturing Co Ltd (TSMC) (2330.TW) said on Monday that it was too early to say whether it will...

Bioengineer5 days ago

SNMMI Image of the Year: PET imaging measures cognitive impairment in COVID-19 patients

Credit: G Blazhenets et al., Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of

Techcrunch6 days ago

The DL on CockroachDB – TechCrunch

As college students at Berkeley, Spencer Kimball and Peter Mattis created a successful open-source graphics program, GIMP, which got the...

CNBC6 days ago

International: Top News And Analysis

CNBC International is the world leader for news on business, technology, China, trade, oil prices, the Middle East and markets.

Blockchain news1 week ago

Ethereum is Expected to Undergo a 90% Daily Emission Reduction Following ETH 2.0 Upgrade

Market analyst Lark Davis believes that Ethereum 2.0 upgrade will prompt a 90% daily emission reduction from 12,800 to 1,280.

Reuters1 week ago

EXCLUSIVE India watchdog accuses Amazon of concealing facts in deal for Future Group unit

India's antitrust regulator has accused Amazon.com Inc (AMZN.O) of concealing facts and making false submissions when it sought approval for...

Bioengineer2 weeks ago

Scientists demonstrate promising new approach for treating cystic fibrosis

Scientists led by UNC School of Medicine researchers Silvia Kreda, Ph.D., and Rudolph Juliano, Ph.D., created an improved oligonucleotide therapy

Review

    Select language

    Trending