sexta-feira, 8 de novembro de 2019
The secrets of secretion: Isolating eucalyptus genes for oils, biofuel
Date: May 8, 2019 Source: Michigan Technological University Summary: Close genetic analysis of 480 blue mallee eucalyptus plants provides clues to modify cultivars for greater yield, whether for essential oils or jet fuel.
What is the genetic basis for eucalyptus trees to produce that fragrant oil many of us associate with trips to the spa? Carsten Külheim, associate professor in Michigan Technological University's School of Forest Resources and Environmental Science, has spent the past 10 years of his career studying eucalyptus. They are diverse, fast-growing species that includes scrubby bushes and 300-foot-tall flowering trees -- mostly indigenous to Australia, but also New Guinea and Indonesia.
In particular, Külheim studies terpenes, organic compounds found in the plant's leaves. Terpenes enable certain species (mostly plants, but also some insects) that produce them to give off strong odors that deter pests or attract pollinators. For example, hops, a primary ingredient in beer, contain terpenes, which gives the hops their piney smell. Certain varieties of eucalyptus and tea tree produce great quantities of just the right terpenes, which can be used for essential oils or biofuel distillation.
It is said that Australia's Blue Mountains take their name from the smog-like mist eucalyptus trees emit, particularly on hot days; this mist is composed of terpenes vaporizing in the heat. Külheim and his fellow researchers want to know what, at the genetic level, causes production of about 50 different terpenes so they can crank it up to use the oil as a renewable fuel.
In the article "High marker density GWAS provides novel insights into the genomic architecture of terpene oil yield in Eucalyptus" in the journal New Phytologist, Külheim and his coauthors investigate the genetic basis of variation in oil yield in blue mallee, a eucalyptus native to Australia. This will allow for a faster and more efficient domestication, making the production of renewable fuels from eucalypt plantations more feasible.
One reason for the interest in eucalyptus oil is because bioethanol (typically made from corn) and biodiesel (typically made with vegetable and soybean oils) do not have sufficient energy density to be useful for the aviation industry. Eucalyptus oil, however, can be converted into high-energy biofuel that can be used for jet fuel and even tactical missile fuel (JP-10).
However, many eucalypts currently have not been domesticated and vary greatly in their oil yield. Using genome-wide association studies (GWAS), Külheim has identified the genes that produce the components of eucalyptus oil that may be used for jet fuel, and the aspects that may be used for the production of biodiesel.
"This enables us to select for trees that mostly produce useful oil components for our purposes; we can use biotechnology to remove the genes for unwanted components or enhance the desired ones," Külheim said. "We hope to provide eucalyptus farmers with genetic marker information to select trees at an earlier stage in their growth for higher terpene production. By choosing to cultivate new trees from power terpene producers, farmers are able to create new generations of the plants that naturally produce more oils."
But beyond the promise of eucalyptus oil for biofuels and the beauty and wellness industries, the species could also prove an excellent cash crop for farmers in arid regions. The trees grow well in hot, dry regions, don't need to be irrigated, and thus do not compete with food production on arable land.
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Materials provided by Michigan Technological University. Note: Content may be edited for style and length.
Journal Reference:
David Kainer, Amanda Padovan, Joerg Degenhardt, Sandra Krause, Prodyut Mondal, William J. Foley, Carsten Külheim. High marker density GWAS provides novel insights into the genomic architecture of terpene oil yield in Eucalyptus. New Phytologist, 2019; DOI: 10.1111/nph.15887
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Michigan Technological University. "The secrets of secretion: Isolating eucalyptus genes for oils, biofuel." ScienceDaily. ScienceDaily, 8 May 2019. <www.sciencedaily.com/releases/2019/05/190508134515.htm>.
Medicinal mushroom discovered in Thailand
Date: May 8, 2019 Source: Pensoft Publishers Summary: A species of medicinal mushroom was recorded for the first time in Thailand. Scientists also report the first assessment of the optimum conditions needed for the species to grow its mycelia and spread its colony.
A species of globally recognised medicinal mushroom was recorded for the first time in Thailand. Commonly referred to as lingzhi, the fungus (Ganoderma tropicum) was collected from the base of a living tree in Chiang Rai Province, Northern Thailand. Additionally, the study reports the first assessment of the optimum conditions needed for the species to grow its mycelia (the vegetative part of a fungus consisting of a branching network of fine, thread-like structures) and spread its colony.
The discoveries are published in the open-access journal MycoKeys by a research team from the Chinese Academy of Sciences, University of Chinese Academy of Sciences, World Agroforestry Centre, Kunming Institute of Botany (China) and Center of Excellence in Fungal Research, Mae Fah Luang University (Thailand), led by Thatsanee Luangharn.
Over the last centuries, the studied mushroom and its related species in the genus Ganoderma have been used extensively in traditional Asian medicines due to their natural bioactive compounds, including polysaccharides, triterpenoids, sterols, and secondary metabolites, which are used in the treatment of various diseases. Other compounds derived from lingzhi, such as the studied species, also demonstrate antimicrobial activities. The medicinal use of these mushrooms is recognised by the World Health Organization and they are featured in the Chinese Pharmacopoeia.
The studied mushroom belongs to a group known to be parasitic or pathogenic on a wide range of tree species. The species is characterised with strongly laccate fruiting bodies and a cap with distinctly dark brown base colour and reddish shades. It grows to up to 7-12 cm in length, 4-8 cm in width and is up to 1.5 cm thick. While the mushroom has so far been widely reported from tropical areas, including mainland China, Taiwan and South America, it had never been recorded from Thailand.
During their research, the scientists found that mycelial production for Ganoderma tropicum is most successful on Potato Dextrose Agar, Malt Extract Agar, and Yeast extract Peptose Dextrose Agar, at a temperature of 25-28 °C and 7-8 pH. Unfortunately, mushroom fruiting was not achieved in the experiment.
Story Source:
Materials provided by Pensoft Publishers. The original story is licensed under a Creative Commons License. Note: Content may be edited for style and length.
Journal Reference:
Thatsanee Luangharn, Samantha C. Karunarathna, Peter E. Mortimer, Kevin D. Hyde, Naritsada Thongklang, Jianchu Xu. A new record of Ganoderma tropicum (Basidiomycota, Polyporales) for Thailand and first assessment of optimum conditions for mycelia production. MycoKeys, 2019; 51: 65 DOI: 10.3897/mycokeys.51.33513
Cite This Page:
Pensoft Publishers. "Medicinal mushroom discovered in Thailand." ScienceDaily. ScienceDaily, 8 May 2019. <www.sciencedaily.com/releases/2019/05/190508113343.htm>.
quarta-feira, 6 de novembro de 2019
Visible light and nanoparticle catalysts produce desirable bioactive molecules
Simple photochemical method takes advantage of quantum mechanics
Date: October 30, 2019 Source: Northwestern University
Summary:
Chemists have used visible light and extremely tiny nanoparticles to quickly and simply make molecules that are of the same class as many lead compounds for drug development. Driven by light, the nanoparticle catalysts perform chemical reactions with very specific chemical products -- molecules that don't just have the right chemical formulas but also have specific arrangements of their atoms in space. And the catalyst can be reused for additional chemical reactions.
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Avocados, as a substitution for carbohydrates, can suppress hunger without adding calories
Meals that include fresh avocado can significantly suppress hunger and increase meal satisfaction
Date: May 8, 2019 Source: Illinois Institute of Technology Summary: A new study suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.
A new study released by the Center for Nutrition Research at Illinois Institute of Technology suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.
As rates of obesity in the United States continue to rise, the findings from Illinois Tech suggest that simple dietary changes can have an important impact on managing hunger and aiding metabolic control.
The new research, published in the peer-reviewed journal Nutrients, assessed the underlying physiological effects of including whole and half fresh Hass avocados on hunger, fullness, and how satisfied subjects felt over a six-hour period. Researchers evaluated these effects in 31 overweight and obese adults in a randomized three-arm crossover clinical trial. These dietary changes were also shown to limit insulin and blood glucose excursions, further reducing the risk of diabetes and cardiovascular disease by adding healthy fats and fibers into a regular daily diet.
"For years, fats have been targeted as the main cause of obesity, and now carbohydrates have come under scrutiny for their role in appetite regulation and weight control," said Britt Burton-Freeman, Ph.D., director of the Center for Nutrition Research at Illinois Tech. "There is no 'one size fits all' solution when it comes to optimal meal composition for managing appetite. However, understanding the relationship between food chemistry and its physiological effects in different populations can reveal opportunities for addressing appetite control and reducing rates of obesity, putting us a step closer to personalized dietary recommendations."
The research found that meals including avocado not only resulted in a significant reduction in hunger and an increase in how satisfied participants felt, but also found that an intestinal hormone called PYY was an important messenger of the physiological response.
Story Source:
Materials provided by Illinois Institute of Technology. Note: Content may be edited for style and length.
Journal Reference:
Lanjun Zhu, Yancui Huang, Indika Edirisinghe, Eunyoung Park, Britt Burton-Freeman. Using the Avocado to Test the Satiety Effects of a Fat-Fiber Combination in Place of Carbohydrate Energy in a Breakfast Meal in Overweight and Obese Men and Women: A Randomized Clinical Trial. Nutrients, 2019; 11 (5): 952 DOI: 10.3390/nu11050952
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Illinois Institute of Technology. "Avocados, as a substitution for carbohydrates, can suppress hunger without adding calories: Meals that include fresh avocado can significantly suppress hunger and increase meal satisfaction." ScienceDaily. ScienceDaily, 8 May 2019. <www.sciencedaily.com/releases/2019/05/190508134529.htm>.
terça-feira, 5 de novembro de 2019
Essential oils from garlic and other herbs kill 'persister' Lyme disease bacteria
Date: December 3, 2018 Source: Johns Hopkins University Bloomberg School of Public Health Summary: Oils from garlic and several other common herbs and medicinal plants show strong activity against the bacterium that causes Lyme disease, according to a new study.
Oils from garlic and several other common herbs and medicinal plants show strong activity against the bacterium that causes Lyme disease, according to a study by researchers at Johns Hopkins Bloomberg School of Public Health. These oils may be especially useful in alleviating Lyme symptoms that persist despite standard antibiotic treatment, the study also suggests.
The study, published October 16 in the journal Antibiotics, included lab-dish tests of 35 essential oils -- oils that are pressed from plants or their fruits and contain the plant's main fragrance, or "essence." The Bloomberg School researchers found that 10 of these, including oils from garlic cloves, myrrh trees, thyme leaves, cinnamon bark, allspice berries and cumin seeds, showed strong killing activity against dormant and slow-growing "persister" forms of the Lyme disease bacterium.
"We found that these essential oils were even better at killing the 'persister' forms of Lyme bacteria than standard Lyme antibiotics," says study senior author Ying Zhang, MD, PhD, professor in the Department of Molecular Microbiology and Immunology at the Bloomberg School.
There are an estimated 300,000 new cases of Lyme disease each year in the United States. Standard treatment with doxycycline or an alternative antibiotic for a few weeks usually clears the infection and resolves symptoms. However, about 10 to 20 percent of patients report persistent symptoms including fatigue and joint pain -- often termed "persistent Lyme infection" or "post-treatment Lyme disease syndrome" (PTLDS) that in some cases can last for months or years.
The cause of this lingering syndrome isn't known. But it is known that cultures of Lyme disease bacteria, Borrelia burgdorferi, can enter a so-called stationary phase in which many of the cells divide slowly or not at all. The slow-dividing or dormant cells are "persister" cells, which can form naturally under nutrient starvation or stress conditions, and are more resistant to antibiotics. Some researchers have sought other drugs or medicinal compounds that can kill persister Lyme bacteria in the hope that these compounds can be used to treat people with persistent Lyme symptoms.
Zhang and his laboratory have been at the forefront of these efforts. In 2014, his lab screened FDA-approved drugs for activity against persister Lyme bacteria and found many candidates including daptomycin (used to treat MRSA) that had better activity than the current Lyme antibiotics. In 2015, they reported that a three-antibiotic combination -- doxycycline, cefoperazone and daptomycin -- reliably killed Lyme persister bacteria in lab dish tests. In a 2017 study they found that essential oils from oregano, cinnamon bark, clove buds, citronella and wintergreen killed stationary phase Lyme bacteria even more potently than daptomycin, the champion among tested pharmaceuticals.
In the new study Zhang and his team extended their lab-dish testing to include 35 other essential oils, and found 10 that show significant killing activity against stationary phase Lyme bacteria cultures at concentrations of just one part per thousand. At this concentration, five of these oils, derived respectively from garlic bulbs, allspice berries, myrrh trees, spiked ginger lily blossoms and may change fruit successfully killed all stationary phase Lyme bacteria in their culture dishes in seven days, so no bacteria grew back in 21 days.
Oils from thyme leaves, cumin seeds and amyris wood also performed well, as did cinnamaldehyde, the fragrant main ingredient of cinnamon bark oil.
Lab-dish tests such as these represent an early stage of research, but Zhang and colleagues hope in the near future to continue their investigations of essential oils with tests in live animals, including tests in mouse models of persistent Lyme infection. If those tests go well and the effective doses seem safe, Zhang expects to organize initial tests in humans.
"At this stage these essential oils look very promising as candidate treatments for persistent Lyme infection, but ultimately we need properly designed clinical trials," he says.
Support for the research came from the Global Lyme Alliance, LivLyme Foundation, NatCapLyme, and the Einstein-Sim Family Charitable Fund.
Story Source:
Materials provided by Johns Hopkins University Bloomberg School of Public Health. Note: Content may be edited for style and length.
Journal Reference:
Jie Feng, Wanliang Shi, Judith Miklossy, Genevieve Tauxe, Conor McMeniman, Ying Zhang. Identification of Essential Oils with Strong Activity against Stationary Phase Borrelia burgdorferi. Antibiotics, 2018; 7 (4): 89 DOI: 10.3390/antibiotics7040089
Cite This Page:
Johns Hopkins University Bloomberg School of Public Health. "Essential oils from garlic and other herbs kill 'persister' Lyme disease bacteria." ScienceDaily. ScienceDaily, 3 December 2018. <www.sciencedaily.com/releases/2018/12/181203115443.htm>.
segunda-feira, 4 de novembro de 2019
Urban trees 'live fast, die young' compared to those in rural forests
Unusual features of street-tree life cycles should inform urban greening campaigns
Date: May 8, 2019 Source: PLOS
Summary:
Urban trees grow more quickly but die faster than rural trees, resulting in a net loss of street-tree carbon storage over time, according to a new study. The findings suggest that planting initiatives alone may not be sufficient to maintain or enhance canopy cover and biomass due to the unique demographics of urban ecosystems.
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