Tasty Mushrooms From Dirty Diapers

June 15th, 2011. By Tim Wall

Changing a dirty diaper isn’t a fun job. Eating a diaper is even less fun, but luckily there is a fungi that can do just that.

Oyster mushrooms, Pleurotus ostreatus, can devour 90% of a disposable diaper within two months, observed Alethia Vázquez-Morillas of the Autonomous Metropolitan University in Mexico City in the journal Waste Management.

What’s more, the mushrooms grown on diapers are edible. Vázquez-Morillas has dined upon them herself.

“They are cleaner than most of the vegetables you can find in the market, at least in Mexico,” said Vázquez-Morillas in an interview with the Economist.

Disposable diapers normally take centuries to biodegrade in landfills. They are mostly made of cellulose, the tough material that plants use for structural support. In the airless netherworld of a landfill, cellulose can take 500 years to break down.

BLOG: Mutant Fungus Has a Cellulose Snack Attack

But oyster mushrooms thrive on cellulose. They are already grown on cellulose-rich materials like barley straw, coffee grounds, and even the left-overs from making tequila.

BLOG: Agave: Not Just for Tequila Anymore

Mexico alone throws away 5 billion diapers a year, noted Vázquez-Morillas. When you consider the billions of diapers thrown away around the world, a huge waste management problem could be turned into a cheap supply of mushroom food.

But will people really eat mushrooms grown on Junior’s diapers?

Vázquez-Morillas asserts they are safe, since the diapers are sterilized before use.

The diapers are steam sterilized before being inoculated with mushroom mycelium, the network of white threads that make up much of the fungus’ structure. Steaming kills the bacterias and other fungi that could out-compete the oyster mushrooms for living space on the diapers. It should also knock-out creatures that cause disease in humans.

Unfortunately, the cost of steam cleaning could make the process economically impractical as far as growing mushrooms for market. But the value of breaking down diapers goes beyond the sale price of oyster mushrooms.

BLOG: Engineered Yeast Improves Biofuel Production

Landfills are filling up fast, and getting more expensive to build. Reducing the intake of garbage extends the life of the landfills already in existence. And it looks like mushrooms can help.

http://news.discovery.com/earth/tasty-mushrooms-from-dirty-diapers-110615.htm

All about plants and planters

Removing lead from contaminated soil.

Lead mining existed as long ago as 6000BC. It became commonly used in jewellery as it is more malleable than many metals. Toxicity problems associated with lead became apparent as early as 200BC when colic and gout was blamed on leaden drinking vessels and white lead used in make-up. Most health problems though, came from lead dust caused by mining. The miners’ symptoms of chronic lead poisoning include neurological problems, such as temporary reduced cognitive abilities, gastrointestinal problems, hair loss, insomnia, reproductive difficulties and in extreme cases seizures. Although the Romans used lead pipes for plumbing ( the word plumbing comes from the Roman word for lead: plumbus) this was not a major cause of lead poisoning as the hard water in Rome coated the inside of the pipes with calcium.

Lead poisoning in the last century or more was largely caused by industrial processes and airborne lead particles from car exhaust fumes. Lead accumulation in soil is partly due to the airborne particles and partly due to lead in paint flakes being deposited over time. The control of the use of lead in paint and the removal of lead additives in petrol by the western world reduced soil contamination although some countries continued to use leaded petrol for many years.

Soil contamination is still a major cause for concern. Lead remains in the soil for hundreds if not thousands of years. Children are most affected by contaminated soil as they are most likely to be in contact with it during play and will even ingest it. As with affected adults, intelligence is impaired and this may become permanent if the contamination is high enough or prolonged. There are concerns that the lead from the soil will migrate in to food crops but studies of lead contaminated soil have shown that the fruit of crops contains far less lead than the foliage, although root crops may be contaminated by the presence of soil dust on the surface. Leafy plants such as cabbage and lettuce are of concern. Lead levels remain high in the soil and lead is not taken up by the plant if the the ph level is high and there is organic vegetable matter in the soil.

This may seem unimportant to the homeowner who would think: “why plant crops in contaminated soil anyway?” but the very soil in your garden may be contaminated if there is an older building or shed nearby that will have been painted with lead paint at some stage in its history.

“How will I know if there is lead in my soil?” There are many lead testing kits available on the internet. If the soil lead level is too high there are a few ways in which you can reduce the likelihood of plant contamination. Firstly you can add lime to keep the ph levels above 6.5. This reduces the amount of lead taken up by the plants. Add organic matter such as leaf compost, manure and peat substitutes as organic materials combine with lead to make it less available to the plant. If contamination is high it may be necessary to physically remove the top layer of soil and replace it with new uncontaminated soil. Finally, grow food crops away from roads and buildings where lead paint may have been used. In addition to the above suggestions for reducing the uptake of lead, don’t forget to thoroughly wash the fruit and vegetables as the soil and dust on the surface of the fruit or vegetable may be contaminated.

There is another method for lead removal: bioremediation. There are plants that are very successful at removing cadmium, copper and zinc but lead removal has proved to be more challenging. It has been discovered that certain grasses have proved to be promising and the grass that has the highest uptake of lead is Vetiveria zizanioides. The grasses, which have little decorative value, are planted in the polluted area and then harvested and removed. The plain appearance of this unassuming plant hides a multitude of talents and in addition to its lead removing properties, vetiver oil is antiseptic and can be used for cosmetic and medicinal purposes. The roots can be used for basketry and screen making.

Below: faux lead planter

We have discussed removing lead from soil. We have been accidentally adding lead to our gardens over many years by pollution and with the use of lead paint and indeed have actually added lead on purpose in the form of lead planters. Decorative lead planters were associated with grand country houses and period properties. Little did those proponents of container gardening realise that they were actually poisoning the very earth they cherished. Lead planters are still available today and apart from the toxicity problem they are prohibitively expensive. There is a lead free alternative, however. Lead style planters made from faux lead (actually made from GRP or glass fibre) in the style of the classic containers can be purchased from leading landscape contractors. The classical style and beauty is retained without the inherant drawbacks. They can also be used as water tanks or rain butts.

http://allaboutplantsandplanters.blogspot.ca/2009/05/removing-lead-from-contaminated-soil.html

Eco-friendly Removal of Oil from Soil

JUL 1, 2011 02:45 PM ET // BY TIM WALL

A Lithuanian company claims that their three stage process can remove oil from contaminated soil using only environmentally friendly chemicals, bacteria, and plants.

Oil contaminated soil comes from both accidents and industrial processes. The refining of oil often results in large amounts of highly contaminated sludge. But oil soaked into soil requires different cleaning techniques than oil spills on water.

BLOG: Oil Spill Impacts Louisiana Shores

The company Biocentras first uses a surfactant, a chemical which breaks down the chemically repellent barriers between substances. The surfactant, mixed with water, is used to wash the soil and can be used up to ten times, Biocentras reports. Afterward, the chemical breaks down into a “natural” compound, according to a press release by Eureka, a European business technology advocacy group.

The second stage uses microorganisms to break down the oil remaining in the soil.

“The bacteria used in the process lie dormant in negative temperatures, but then come to life as the temperature rises. However, some organisms can start to degrade oil at temperatures that are only a little more than is required to melt ice,” said Monika Kavaliauske, manager at Biocentras, in a press release by the company. But, she added “it is much more effective in warmer climates.”

Microorganisms break the oil down to a point where hardy plants can be used to further break down the oil. Using plants to clean up the environment is called “phytoremediation.”

Don’t try this at home, only certain plants can take that kind of abuse. Moviegoers might remember the scene in Fight Club where members of Project Mayhem put up a billboard that says, “Did you know used motor oil can be used as fertilizer?”

It can’t.

The whole process takes about one year, and leaves soil that can be used by other, less hardy plants. Biocentras has cleaned soils with up to .67 pounds (300 grams) of oil per kilogram (2.2 pounds) of soil.

BLOG: 4 Feasible Oil-Spill Ideas from the Public

So far more than 22,000 tons of soil have been cleaned using this process, mostly in Lithuania. But Biocentras hopes to expand into the Middle East, where warmer temperatures will make the process even more effective.

“We have no clients in the Middle East and are actively looking for them. There are potential applications for most of the world and we are keen to develop it further,” said Kavaliauske.

IMAGE: Drilling operations to verify the status of the Bruin Lagoon hazardous waste cleanup. This site was contaminated with heavy metals, sulfuric acid and crude oil waste. It was stabilized under Superfund; this picture is of engineers drilling out a soil sample to check its condition (U.S. Army Corps of Engineers).

http://news.discovery.com/earth/plants/eco-friendly-removal-of-oil-from-soil-110701.htm

Fungi Digest Plastic Trash

FEB 11, 2013 03:00 AM ET

 

Chemicals like BPA that leach from plastic waste have been linked to reproductive, developmental and other health issues.

THE GIST

With help from a little ultraviolet light, fungi can break down worrisome plastics.

The technique might help scientists develop environmentally friendly ways of disposing of "bad" plastics.

Ordinary fungi can safely break down polycarbonate plastic -- an omnipresent material that contains the worry-inducing chemical bisphenol A, or BPA.

BPA, which has been linked to a growing number of reproductive, developmental and other health issues, appears in a huge variety of plastic products, including CDs, screwdriver handles, eyeglasses frames, water bottles and toys. Worldwide, some 2.7 million tons of polycarbonate plastic is produced each year.

In experiments, three types of fungi were able to break down about 5 percent of the plastic in their lab dishes over the course a year, as long as the plastic was first zapped with ultraviolet light.

It's a small amount, said lead researcher Mukesh Doble, a chemical engineer at the Indian Institute of Technology in Madras. But the results are encouraging, he said, because no BPA leached into the solution in the process. Down the line, fungi and UV light might be part of an environmentally friendly solution for degrading BPA-containing plastic waste.

"The ultimate goal is to have a sustainable way of disposing of these polymers after they've completed their life that doesn't harm the environment," Doble said. "I think this is a good start in that direction."

As plastic waste piles up, a major fear is that sun, rain and other elements are degrading the material, causing BPA and other chemicals to leach into the environment. These chemicals eventually contaminate our water and food, and threaten our health.

To find a way to break the material down in a safer way, Doble and a colleague started experimenting with three types of fungi, which had been shown in previous work to be capable of degrading some environmental pollutants. Two of the fungal types were extracted from soil. The third is a commercial organism called white-rot fungus. It is commonly used for bioremediation.

In their laboratory, the researchers placed thin sheets of polycarbonate plastic in a liquid solution, which was fortified with some nutrients for the first 10 days to help the fungi grow. When the scientists added fungi to the mix, not much happened.

But when the researchers pre-treated the polycarbonate films by exposing them to ultraviolet light, the fungi started digesting the plastic. A year later, they reported in the journal Biomacromolecules, the fungi had broken down more than 5 percent of the plastic by weight.

"The numbers are small," Doble said. "But the most important part is that BPA is not seen in the solution at the end of one year. That means that the fungi are making use of it."

The fungi use enzymes to cut the plastic into pieces, and Doble suspects that these proteins selectively bite into regions between BPA molecules. That would prevent the chemical from leaching out into the solution. The UV light probably weakens the material enough to let the fungi in.

Someday, a system of bioreactors might use fungi to eat up UV-treated plastics, envisioned Kartik Chandran, a chemical engineer at Columbia University in New York. Further research combined with engineering, he added, could lead to synthetic versions of the fungal proteins that are doing the work.

Polycarbonates aren't the only plastics that contain BPA. And BPA isn't the only chemical of concern in the environment. Studies like this one offer hope that nature might provide answers to some of our stickiest chemical problems.

"Anywhere you look -- shaving cream, toothpaste -- you're bound to find something harmful," said Chandran, who encouraged people to seek out alternative materials, like stainless steel instead of plastic water bottles. "As we find more and more chemicals, we absolutely need to come up with biological solutions for treatment of these compounds."

http://news.discovery.com/earth/fungi-plastic-chemicals-bpa.htm

Bacteria Naturally 'Eat Up' Oil Spill Contamination by Supplementing Diet with Nitrogen

By Tamarra Kemsley

Aug 30, 2013 04:35 PM EDT

Fire boat response crews battle the blazing remnants of the offshore oil rig Deepwater Horizon, off Louisiana, in this April 21, 2010 file handout image. (Photo : Reuters)

The discovery that bacteria living in the Gulf of Mexico beaches "ate up"' the contamination leaked from the Deep Water Horizon oil spill by supplementing their diet with nitrogen could lead to far more sophisticated cleanup techniques, researchers say.

Led by Joel Kostka, a microbiologist from Georgia Institute of Technology, a new study presented to delegates at the Goldschmidt conference explains that because oil is a natural product comprised of decayed plants and animals, it's similar to what bacteria are already accustomed to consuming.

"But because oil is low in nutrients such as nitrogen, this can limit how fast the bacteria grow and how quickly they are able to break down the oil," Kostka said in a statement. "Our analysis showed that some bacteria are able to solve this problem themselves -- by getting their own nitrogen from the air."

Kostka worked with Markus Huettel, a biogeochemist from Florida State University, to analyze more than 500 samples taken over a two-year period from Pensacola beach in the Gulf of Mexico, starting when the Deep Water Horizon oil slick first came ashore in June 2010.

By examining every gene belonging to the bacteria found in the different samples, they were able to determine which bacteria were present and how they responded as conditions changed on the beach. Specifically, the scientists studied the prevalence of genes responsible for encoding for different behaviors, including nitrogen fixing, in order to decipher exactly how the bacteria were breaking down the oil.

"By understanding how the oil is degraded by microbes, which microbes do the work, and the impact of the surrounding environmental conditions, we can develop ways to intervene to support the natural clean-up process," Kostka said.

For instance, knowing exactly how the oil-degrading bacteria are working in different areas affected by a spill make it possible to identify those beaches that are least equipped to self-clean and thus where mitigation efforts are needed most.

However, Kostka warns, any kind of human intervention in this natural clean up process must be carried out "in a very measured and targeted way, to avoid long-term, unintended damage to the ecosystem. For example, in the past, nitrogen [fertilzer] has been sprayed onto contaminated beaches to speed up the work of the bacteria. Our analysis shows that, where bacteria can get this nitrogen naturally, such drastic intervention may not be necessary."  

Furthermore, the research showed that not all bacteria thrived on a high-oil diet, with some bacteria that played an important role in the affected beaches' ecosystems sharply declining following the June 2010 contamination.

"There's a tendency to focus on the short-term, visible effects of an oil spill on the beach and assume that once the beach looks 'clean' then all is back to normal," Kostka said. "Our analysis shows some of the invisible impact in the loss of these important microbes. We need to be aware of the long-term chronic damage both a spill -- and in some cases our attempts to deal with it -- can cause."

http://www.natureworldnews.com/articles/3757/20130830/bacteria-naturally-eat-up-oil-spill-contamination-supplementing-diet-nitrogen.htm