Subscribe free to our newsletters via your
. Earth Science News .




FROTH AND BUBBLE
Maize Plus Bacteria: One-Two Punch Knocks Copper Out of Stamp Sand
by Marcia Goodrich for MTU News
Houghton MI (SPX) Mar 06, 2014


Maize plants grown in stamp sand inoculated with bacteria, left, were considerably more robust than those grown in stamp sand alone, right. This research could lead to new remediation techniques for soils contaminated by copper and other heavy metals.

Scientists have known for years that together, bacteria and plants can remediate contaminated sites. Ramakrishna Wusirika, of Michigan Technological University, has determined that how you add bacteria to the mix can make a big difference.

He has also shed light on the biochemical pathways that allow plants and bacteria to clean up some of the worst soils on the planet while increasing their fertility.

Wusirika, an associate professor of biological sciences, first collected stamp sands near the village of Gay, in Michigan's Upper Peninsula. For decades, copper mining companies crushed copper ore and dumped the remnants-an estimated 500 million tons of stamp sand-throughout the region. Almost nothing grows on these manmade deserts, which are laced with high concentrations of copper, arsenic and other plant-unfriendly chemicals.

Then, Wusirika and his team planted maize in the stamp sand, incorporating bacteria in four different ways:

1. mixing it in the stamp sand before planting seed;

2. coating seed with bacteria and planting it;

3. germinating seeds and planting them in soil to which bacteria were added; and

4. the conventional method, immersing the roots of maize seedlings in bacteria and planting them in stamp sand.

After 45 days, the team uprooted the plants and measured their dry weight. All maize grown with bacteria was significantly more vigorous-from two to five times larger-than the maize grown in stamp sand alone. The biggest were those planted as seedlings or as germinated seeds.

However, when the researchers analyzed the dried maize, they made a surprising discovery: the seed-planted maize took up far more copper as a percentage of dry weight. In other words, the smaller plants pulled more copper, ounce per ounce, out of the stamp sands than the bigger ones.

That has implications for land managers trying to remediate contaminated sites, or even for farmers working with marginal soils, Wusirika said. The usual technique-applying bacteria to seedlings' roots before transplanting-works fine in the lab but would be impractical for large-scale projects. This could open the door to simple, practical remediation of copper-contaminated soils.

But the mere fact that all the plants grown with bacteria did so well also piqued his curiosity. "When we saw this, we wondered what the bacteria were doing to the soil," Wusirika said. "Based on our research, it looks like they are improving enzyme activity and increasing soil fertility," in part by freeing up phosphorus that had been locked in the rock.

The bacteria are also changing copper into a form that the plants can take up. "With bacteria, the exchangeable copper is increased three times," he said. "There's still a lot of copper that's not available, but it is moving in the right direction."

By analyzing metabolic compounds, the team was able to show that the bacteria enhance photosynthesis and help the plants make growth hormones. Bacteria also appear to affect the amount phenolics produced by the maize. Phenolics are antioxidants similar to those in grapes and red wine.

Compared to plants grown in normal soil without bacteria, plants grown in stamp sand alone showed a five-fold increase in phenolics. However, phenolics in plants grown in stamp sand with bacteria showed a lesser increase.

"Growing in stamp sand is very stressful for plants, and they respond by increasing their antioxidant production," Wusirika said. "Adding the metal-resistant bacteria enables the plants to cope with stress better, resulting in reduced levels of phenolics."

"There's still a lot to understand here," he added. "We'd like to do a study on stamp sands in the field, and we'd also like to work with plants besides maize. We think this work has applications in organic agriculture as well as remediation."

Wusirika's work is featured on the research crowdfunding site Superior Ideas.

An article on their work, "Integrated Metabolomic and Proteomic Approaches Dissect the Effect of Metal-Resistant Bacteria on Maize Biomass and Copper Uptake," coauthored by PhD graduate student Kefeng Li, now at the University of California at San Diego; graduate students Venkataramana R. Pidatala and Rafi Shaik; Associate Professor Rupali Datta; and Wusirika has been published in the January issue of Environmental Science and Technology.

.


Related Links
Michigan Technological University
Our Polluted World and Cleaning It Up






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





FROTH AND BUBBLE
China's premier 'declares war' on pollution
Beijing (AFP) March 05, 2014
Chinese Premier Li Keqiang on Wednesday said he is "declaring war" on pollution, describing it as a "red-light warning" against inefficiency as he sought to address public concerns on issues from acrid smog to food safety. China's three decades of rapid industrialisation and urbanisation have transformed its economy, and seen incomes soar. But they have also brought severe environmental ... read more


FROTH AND BUBBLE
Australia rescues 13 shipwrecked Iranians off Pakistan

UN report sees $1.45 tn global warming cost: media

Corpses still being found in Philippine typhoon zone

Tunisian navy 'rescues 98 sub-Saharan migrants'

FROTH AND BUBBLE
3-D printer creates transformative device for heart treatment

First step towards programmable materials

Save Money and the Planet: Turn Your Old Milk Jugs into 3D Printer Filament

New formula to calculate hue improves accuracy of color analysis

FROTH AND BUBBLE
Global warming felt to deepest reaches of ocean

Marine algae can sense the rainbow

We want to save water, but do we know how?

The surface of the sea is a sink for nitrogen oxides at night

FROTH AND BUBBLE
Warm Rivers Play Role in Arctic Sea Ice Melt

Ancestors of America's original people lived on long-gone land bridge

Native Americans lived in Bering Strait for millennia: study

Alaska mine could be blocked to save salmon fisheries

FROTH AND BUBBLE
Homogeneity of food has serious implications for farming and nutrition

Bison ready for new pastures?

Cows are smarter when raised in pairs

New invasive species breakthrough sparks interest around the world

FROTH AND BUBBLE
European flood risk could double by 2050

Flood cost in EU may double by 2050: study

Volcanoes, including Mount Hood in the US, can quickly become active

What has happened to the tsunami debris from Japan?

FROTH AND BUBBLE
Fighting breaks out in South Sudan army barracks

UN extends easing of Somalia weapons embargo

Little hope for C.Africa Muslims ahead of French president visit

Kenya boosts airport defence, warning of Islamist threat

FROTH AND BUBBLE
Research reveals first glimpse of brain circuit that helps experience to shape perception

Cambodia's floating villages face uncertain future

Baylor Sheds New Light on the Habitat of Early Apes

Oldest fortified settlement in North America discovered in Georgia




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.