microorganisms

Biosurfactants And Oil Spills | Earth Wise

August 22, 2023 By EarthWise Leave a Comment

About 400 million gallons of oil leaks into the ocean every year. This is a major source of environmental pollution. Oil contains many hazardous compounds that are toxic or mutagenic for marine organisms.

When oil spill incidents occur, large quantities of chemical dispersants, sometimes as much as millions of gallons, are applied to dissolve oil slicks, prevent oil from reaching coastlines, and enhance the dispersion of the oil in the water. The hope for doing this is that microbial oil degradation will be enhanced as a result. Certain microorganisms present in the water can feed on crude oil components and break them down into harmless substances.

A study at the University of Stuttgart in Germany in 2015 showed that chemical dispersants in fact can slow down microbial oil degradation and therefore inhibit water purification. The oil components need to be broken down sufficiently for them to be bioavailable to microorganisms. The study found that dispersants were not accomplishing this.

A new study by the same group along with researchers from the University of Tubingen in Germany and the University of Georgia has found that using biosurfactants rather than chemical dispersants stimulates different microbial oil degraders with respect to their growth and activity and can enhance our ability to deal with oil spills. Treating the water with the biosurfactant rhamnolipid rather than any of the generally-used dispersants provided much higher rates of microbial breakdown of oil components.

The hope is that this work can lead to the development of effective and environmentally friendly approaches to combatting oil spills.

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Biosurfactants might offer an environmentally friendly solution for tackling oil spills

Photo, posted June 11, 2010, courtesy of Deepwater Horizon Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Environmental DNA | Earth Wise

August 5, 2022 By EarthWise Leave a Comment

Marine protected areas are sections of the ocean where governments place limits on human activity. They are intended to provide long-term protection to important marine and coastal ecosystems. MPAs are important because they can protect depleted, threatened, rare, and endangered species and populations.

In January 2020, the Republic of Palau in the western Pacific Ocean created one of the world’s largest marine protected areas. The Palau National Marine Sanctuary covers 80% of the country’s economic zone and prohibits all extractive activity like fishing and mining over a 183,000 square mile area in order for the island nation to ensure its food security and grow its economy in the face of climate change.

The Marine Sanctuary is an ambitious enterprise. The question is how Palau can evaluate whether and how well it is working?

A team of scientists from Stanford University and Palau-based colleagues are making use of Environmental DNA – or eDNA – technology to monitor the large-scale marine protected area. eDNA is the cells, waste, viruses, and microorganisms that plants and animals leave behind. Samples of marine eDNA effectively provide a fingerprint of the organisms that have recently passed through the water in a given area. This gives scientists a way to assess an ecosystem’s biodiversity and keep track of the types of species inhabiting a specific area. Using eDNA, it is possible to keep track of all the organisms that live below the surface and learn about things we can’t even see.

The team has embarked on a program of periodic sampling of the waters off Palau and hope to be able to monitor the results of establishing the Marine Sanctuary.

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eDNA: Bringing biodiversity to the surface

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tourism And Invasive Species | Earth Wise

March 7, 2022 By EarthWise Leave a Comment

Tourism has experienced exponential growth during the past 70 years. In 1950, there were 25 million international tourist arrivals. By 1990, it had ballooned to 435 million. Between 1990 and 2018, the numbers more than tripled reaching more than 1.4 billion. And by 2030, the number of international tourist arrivals is expected to reach 1.8 billion.

Tourism is vital to the success of many economies around the world. Tourism can boost revenue, provide jobs, develop infrastructure, protect wildlife, and help preserve heritage sites and cultures. But there can also be many downsides to tourism, one of which is that it can contribute to the introduction and spread of invasive species. Non-native organisms can cause all sorts of social, environmental, and economic damage.

Tourists help spread invasive organisms far and wide. These organisms hitch rides in their luggage and on their shoes and clothing. A 2011 study in New Zealand found that for every gram of soil on the shoes of in-bound international passengers, there were 2.5 plant seeds, 41 roundworms, 0.004 insects and mites, and many microorganisms.

A new study by researchers from the University of Melbourne in Australia and AgResearch New Zealand examined to what degree tourism plays a role in the spread of invasive species. According to the study, which was recently published in the journal NeoBiota, the research team found that the number of nights spent in hotels significantly correlated to the incursion of invasive species during that period.

Creating effective mechanisms to prevent the introduction of invasive species in the first place is the best way to prevent this problem.

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Unwelcome guests: International tourism and travel can be a pathway for introducing invasive species

Number of tourist arrivals

Photo, posted March 27, 2005, courtesy of John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Pesticide From Beer | Earth Wise

July 23, 2021 By EarthWise Leave a Comment

Researchers from the Neiker Basque Institute for Agricultural Research and Development in Spain have demonstrated that a combination of rapeseed cake and beer bagasse can be used to reduce populations of soil parasites and increase crop yields.

Beer bagasse is spent brewers’ grain – the stuff that is left over after the beer is made. Beer brewing generates substantial amounts of by-products, including large amounts of spent grain. It already has some practical uses, including as a feedstock for biofuel, as a food additive, and it even has some medical uses. But the new research has shown that the bagasse can be the basis for a biodisinfestation treatment to be used in agriculture. The aim is to disinfect soils, protect soil microorganisms, and increase crop yields.

The actual material studied was a mixture of beer bagasse, rapeseed cake, and a generous amount of fresh cow manure. The high nitrogen content of the mixture promotes the activity of beneficial microorganisms in the soil, which helps to break down organic matter and kill off nematodes and other parasites that damage crops.

Nematodes are common parasites that can penetrate plant roots to lay their eggs, which damages the root and prevents the plants from absorbing nutrients effectively. Application of the bagasse-based mixture over 12 months increased crop yields by 15% and boosted healthy soil microbes.

The study demonstrated that agricultural byproducts can be an effective treatment for root-knot nematodes and other soil parasites, increase crop yields, and help promote sustainable food systems to reduce waste from the agricultural industry. The researchers hope to identify other potential organic treatments for tackling soil parasite problems.

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Beer byproduct mixed with manure proves an excellent organic pesticide

Photo, posted July 1, 2011, courtesy of Quinn Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Helping Corals With Beneficial Bacteria | Earth Wise

March 31, 2021 By EarthWise Leave a Comment

A group of researchers at the King Abdullah University of Science and Technology in Saudi Arabia is exploring a novel technology to improve the health of corals. Around the globe, corals are being stressed by pathogens, toxins, and warming waters leading to widespread bleaching events.

The new idea is to introduce beneficial bacteria to the corals, thereby boosting the strength and resilience of their symbiotic partners. The concept is akin to the use of probiotics in plant science. Corals rely on bacterial and algal symbionts to provide nutrients, energy (through photosynthesis), toxin regulation, and protection against pathogens.

The researchers selected bacteria that are naturally symbiotic to specific coral species on reefs in the Red Sea, ensuring that no alien bacteria are accidentally introduced. A probiotic cocktail comprising six bacteria strains was used in a laboratory setting. Results in the lab have been promising so far, as they have observed dynamic and metabolic alterations to the corals that boosted their chances of survival under heat stress.

Success in the lab will need to be translated to success in the open oceans, which is challenging. Scaling up and seeding whole reefs might involve robots and artificial intelligence in order to deliver probiotics either into sediments or directly onto corals.

The use of beneficial microorganisms is not the solution to the global destruction of coral reefs. Only worldwide CO₂ mitigation can ultimately accomplish that. But the probiotic approach might buy corals some time as they deal with shifting environmental pressures and try to adapt to a changing world.

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Microbiome boost may help corals resist bleaching

Photo, posted March 18, 2018, courtesy of Steven dos Remedios via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Animals And Social Distancing | Earth Wise

June 16, 2020 By EarthWise Leave a Comment

As the spread of COVID-19 continues throughout the U.S. and around the world, health officials continue to ask people to keep physical space between themselves and others outside their homes. It’s an important and effective way to slow down and prevent the spread of disease.

But it’s not just humans who can benefit from social distancing. It turns out that animals can, too.

Microorganisms living on or inside our bodies are important for both our health and for the development of disease. Researchers from the University of Texas at San Antonio have found evidence for the importance of social distancing to minimize the spread of microbes among individuals. The researchers studied wild monkeys to find out what role diet, genetics, social groupings, and distance in a social network play when it comes to the microbes found inside the gut. The gut microbiome refers to all the microorganisms living in the digestive tract.

The research team studied the fecal matter of 45 female colobus monkeys that congregated in eight different social groups in a small forest in Ghana. The researchers observed major differences in gut microbiomes between the eight social groups. But individual monkeys from different groups that were more closely connected to the population’s social network had more similar gut microbiomes. The findings, recently published in the journal Animal Behaviour, indicate that microbes may be transmitted between monkeys during occasional encounters with other monkeys from different social groups.

Learning how microorganisms pass among monkeys can help researchers understand how diseases spread. Understanding how diseases spread can help guide decision making during this pandemic and any future disease outbreaks.

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Even animals benefit from social distance to prevent disease, research shows

Photo, posted January 10, 2007, courtesy of Silke Baron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Fresh Produce | Earth Wise

May 26, 2020 By EarthWise Leave a Comment

Fresh fruits and vegetables can sometimes become contaminated by microorganisms during their long journey from fields to restaurants and grocery stores. Contaminated produce can spoil other produce, which increases the number of fruits and vegetables in the supply chain that can cause illnesses.

In order to prevent this cross-contamination between produce, researchers from Texas A&M University have designed a coating that can be applied to food-contact surfaces, like buckets, rollers, and conveyor belts. The newly-created dual-function coating is both water-repellent and germicidal. In other words, it can both repel and kill. Without water, the researchers say bacteria can’t stick or multiply on surfaces, drastically reducing contamination.

To make this dual-function coating, the researchers chemically-attached a thin layer of silica to an aluminum sheet. They then added a mixture of silica and lysozyme, a naturally-occurring germicidal protein found in egg whites and tears. Together, the silica-aluminum and the silica-lysozyme formed microscopic bumps and crevices. According to the research team, this rough texture, albeit microscopic, is the key to the coating’s superhydrophobic properties.

The researchers tested the coating’s effectiveness at curbing the growth of two strains of disease-causing bacteria: Salmonella and Listeria. Upon review, the number of bacteria found on the dual-coating surfaces was 99.99% less than what was found on the uncoated surfaces.

Despite the success in preventing bacterial spread, the research team said more research needs to be done to see how well the coating works for mitigating viral cross-contamination. Since the coating would need to be reapplied after a certain amount of use, the researchers also plan to develop more permanent, dual-function coatings.

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New dual-action coating keeps bacteria from cross-contaminating fresh produce

Photo, posted April 14, 2012, courtesy of U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mealworms And Plastic | Earth Wise

January 21, 2020 By EarthWise Leave a Comment

Mealworms are widely cultivated beetle larvae that people feed to pets and to wild birds. But it turns out, they may have an even more valuable purpose: they can eat plastic and even plastic containing dangerous chemical additives.

Four years ago, researchers at Stanford discovered that mealworms can actually subsist on a diet of various types of plastic. They found that microorganisms in the worms’ guts actually biodegrade the plastic. It might be possible to cultivate the worms using unrecyclable plastic, rather than feeding them grains and fruits. However, there is the issue of whether it would be safe to feed the plastic-eating worms to other animals, given the possibility that harmful chemicals in plastic additives might accumulate in the worms over time.

Recently, the Stanford researchers studied what happens when the worms ingested Styrofoam or polystyrene. The plastic commonly used for packaging and insulation typically contains a flame retardant called hexabromocyclododecane, or HBCD. Studies have shown that HBCD can have significant health and environmental impacts, ranging from endocrine disruption to neurotoxicity.

According to the study, mealworms in the experiment excreted about half of the polystyrene they consumed as tiny, partially degraded fragments and the other half as carbon dioxide. With it, they excreted the HBCD. Mealworms fed a steady diet of HBCD-laden polystyrene were as healthy as those eating a normal diet. And shrimp fed a steady diet of the HBCD-ingesting mealworms also had no ill effects.

It is true that the HBCD excreted by the worms still poses a hazard and must be dealt with in some manner, but mealworms may have a role to play in dealing with unrecyclable plastics like Styrofoam.

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Stanford researchers show that mealworms can safely consume toxic additive-containing plastic

Photo, posted May 11, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Biofuel Waste Into Valuable Chemicals

December 20, 2017 By EarthWise Leave a Comment

When biofuels are made, tough plant material is left over as waste. The material is lignin, which is a main component of plant cell walls that gives plants their structural integrity. Lignin is made up of many valuable compounds, but taking it apart to extract them is very difficult.