Monday, May 26, 2008

Vivan los Hongos!

On May 28th, community representatives from Ecuador and Nigeria are traveling to San Ramon, California along with Bay Area activists to demonstrate at the gates of Chevron corporate headquarters during their annual shareholder meeting. Supportive shareholders inside will confront Chevron executives about the toxic legacy of oil extraction in the Ecuadorian Amazon. The Nigerian delta has also faced similarly serious health and ecological consequences as a result of oil development.

As for news on the fungal front, I am quite happy to write that our second attempt at mycoremediation in the Amazon has quite literally born fruit. Three weeks after we set up our experiment, a number of the boxes have begun to fruit mushrooms—directly out of the petroleum-saturated layer. We put yellow plastic screens directly on top of the contamination layer for easy monitoring. When we need to take a sample, we can simply lift the screen and get down to the area of interest. The screens also have the benefit of providing a clear visual marker for locating the oil layer.

Multiple clusters of little mushroom primordia (baby mushrooms!) were poking out everywhere from fuzzy-white mycelium. In many boxes, the overall effect was a graying of the black, oil-soaked sections as a result of dense mycelial growth. Every single box currently has healthy mycelium growing inside the contaminated layers, even in our most concentrated treatments, such as the one pictured.

There are no mushrooms fruiting in the large pits we dug and filled with spawn, sawdust and other mushroom substrates. However, the lack of fruit bodies is really not important, since the vegetative state of the mushrooms, the mycelium, is what does the majority of the heavy-lifting in remediation. By use of the yellow screens we were able to peer under several feet of piled spawn and substrate and confirm the presence of mycelium in our pits as well. These fine threads of fungi branch and grow densely through soil and substrate, excreting oil-digesting enzymes along the way.

Visualizing the growth processes in action here is an exercise in pretending to be very small. If I was roughly the size of a cell, the span of a centimeter or two is quite daunting. This is the scale that mycelium operates on. Our mycelium responded to a similar distance created by the plastic screens by sending down ropey rhizoids, root-like fungal structures used for entering a substrate. We can assume that the fungus produced rhizoids because it recognizes petroleum as a tasty meal and is willing to expend metabolic energy to reach (pictured).

In some of our pits, we encountered some weedy fungi that rapidly fruited and died. Despite this, directly under these mushrooms was healthy, almond-scented oyster mushroom mycelium. As such, it seems that our oyster mushrooms are able to hold their own against the first round of competition.

In the following weeks we will be taking samples for laboratory analysis to get a quantitative picture of exactly how much hydrocarbon pollution has actually been digested. Qualitatively speaking, our progress thus far has met and exceeded all of our highest expectations.

Monday, May 12, 2008

photo dump

Oil-acclimated sawdust spawn

Redefining volunteerism in the Amazon

Three different contamination concentrations

Here we have some low-tech pastuerization of mushroom substrate

The hair mats, in all their glory

Four deep, plastic-lined pits, ready for action

In situ remediation site

Thursday, May 1, 2008

Cooking with Crude

The big news around Lago Agrio is that Ecuadorian lawyers Pablo Fajardo Mendoza and Luis Yanza each won the coveted Goldman Environmental Prize for their work building a class-action environmental lawsuit against Texaco/Chevron for what is now an estimated $16 billion in damages. It was an important time for us as well, since we were busy setting up our second mycoremediation experiment on Donald's land. Drawn by the news of the Goldman Award, two journalists dropped by to snap photos of our work throughout our stay. It also seems that folks in Fort Bragg, CA are also looking to take the mycoremediation out of the lab and into the field to work on dioxin pollution.

I have to take this opportunity to say that if it were not for the outstanding effort of our six volunteers, two competent hired hands, Donald, Jess and Ricardo, I'd still be in Lago. Thanks, guys. Working with crude oil is just about the messiest job I can think of, and we all spent 7 long, hard days getting to know a barrel of the stuff.

We collected the crude from a 30 year-old waste pit because we wanted to test our method with the nastiest petroleum contamination we could find. The waste pit we collected from was smack in the middle of jungle land. Despite the dense thicket of Ecuadorian Amazon that closed around all sides, the contamination had effectively created a clearing in the canopy where trees and underbrush were unable to grow. Only a few sickly, scrubby plants clung to life on top of the litter that had built up over the decades on top of the aging crude. We built a bamboo bridge of sorts to stand above the pool and formed a chain of goop-filled buckets back to the truck that held an empty 55 gallon barrel.

On the way back to our site, we stopped at a sugarcane farm and drank some of the sweet, green juice being produced for raw sugar. Below the horse-powered sugarcane mill was a large field of sugarcane husk. We collected a small load of the sugarcane husk, thanked our hosts and moved on. The husks represented an abundant potential mushroom substrate and we intended to include it in this round of investigations. During this trip, we also collected coconut shells to use the discarded fiber and local grass-straw for more substrate trials. And of course, who could forget the human hair. As it turns out, some of our friends thought our cause was worthy enough to donate their dreadlocks and one of our volunteers, Eric, was even inspired to lend his beard to the project.

The barrel of crude had to be processed a bit before we could begin our experiment. Old oil off-gases toxic volatile compounds for years and some of it eventually hardens into an asphalt-like substance. Those asphalt stones represent a problem for our analytical purposes because they are 100% petroleum and cause the lab to report much higher levels of petroleum than are biologically significant. In a real-world remediation project, we would not have to worry about them since they have essentially become part of the local geology at that point and are biological-nonparticipants, inaccessible by hyphae and otherwise not really going anywhere. This is a long way of saying we had to push a barrel of gloppy oil through a metal sieve by hand. It only took a day and a half of three people in safety gear working nonstop.

Next came the preparation of our contamination mixture. By carefully measuring how much petroleum we had at the beginning of our test, we are able to determine the total amount and rate of hydrocarbons being metabolized by our mycelium throughout our experiment. While also mostly unnecessary in an applied mycoremediation scenario, this meant mushing buckets of earth with oil and sawdust in various proportions by hand. It was kind of like making really disgusting bread. Knowing these ratios also provides us with information important for assessing how much earth and/or organic material must be added to a given site to create a comfy environment for our mushrooms to do their work. Always thinking low-tech, we heat-pasteurized our substrate in 55 gallon drums over both gas-fueled and wood burning fires. The acclimated mycelium had already colonized bags full of sawdust and by adding them to pasteurized bulk substrate, we allowed them to expand their mycelial mass quickly in a new environment rife with potential competitors.

Since the last thing any of us wanted to do was create more pollution by spreading the existing stuff around, we took every precaution in the protection of Donald's land. While a large number of our experimental treatments are being conducted in small microcosm boxes, we tested larger areas more similar to actual waste sites in very large, deep pits. Somehow, the exciting world of mycoremediation required me to dig holes in the dead Amazonian heat for three days. The pits were lined with two layers of the thickest plastic available and staked into place. Inside, we heaped contaminated soil, substrate and acclimated mycelium for remediation. In two weeks we will be checking our progress, but Donald is there monitoring the site daily.