Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Maize Plus Bacteria: One-Two Punch Knocks Copper Out of Stamp Sand

06.03.2014

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.


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.

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.

Michigan Technological University (www.mtu.edu) is a leading public research university developing new technologies and preparing students to create the future for a prosperous and sustainable world. Michigan Tech offers more than 130 undergraduate and graduate degree programs in engineering; forest resources; computing; technology; business; economics; natural, physical and environmental sciences; arts; humanities; and social sciences.

Marcia Goodrich | EurekAlert!

Further reports about: activity bacteria conventional copper developing fertility levels maize planting seeds soils technologies

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>