Bioremediation of pesticides in surface soil treatment unit using microbial consortia

Posted by On Filed under Biodegradation and bioremediation papers, Contaminant biodegradation (round 2) papers No Comments

Abstract:

The manufacturing and use of pesticides has been rising tremendously in India. The waste generated by the pesticide industry has become an environmental problem due to the present insufficient and ineffective waste treatment technology involving physico-chemical and biological treatment. The available data indicates that pesticide residues remain in surface soil, leading to toxicity in the soilwater environment. The recent advances in bioremediation technology using microbial consortium has been found effective for treatment of pesticides in soil. In the present study, a Surface Soil Treatment Unit has been designed wherein bioremediation of commonly used pesticides namely chlorpyrifos, cypermethrin, fenvalerate, and trichlopyr butoxyethyl ester at varying concentration viz. 25, 50 and 100 mg/kg have been carried out using cow-dung microbial consortia under simulated environmental conditions. The bioremediation conditions have been monitored and maintained during the study. The investigation has been extended till the parent compound was converted into intermediates and/or less harmful compounds. These then will further mineralize, from part of the microbial food chain and/or become integrated into the humic fractions. The results presented here highlight the potential of cowdung slurry consortia for bioremediation of soil contaminated with pesticides in surface soil treatment unit.

Citation:

Geetha, M., & Fulekar, M. H. (2008). Bioremediation of pesticides in surface soil treatment unit using microbial consortia. African Journal of Environmental Science and Technology, 2(2), 036-045.

https://www.ajol.info/index.php/ajest/article/viewFile/135415/124907

I chose this article because I thought it was interesting that they took cow dung and used it’s natural microbial community to degrade certain pesticides. This could be very beneficial information for agricultural businesses. It could be a very affordable way to decrease concentrations of certain pesticides.

 

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Wastewater treatment: Bioremediation of Wastewater by Iron Oxide-Biochar Nanocomposites Loaded with Photosynthetic Bacteria

Posted by On Filed under Biogeo & wastewater treatment papers No Comments

Citation:

He, S., Zhong, L., Duan, J., Feng, Y., Yang, B., & Yang, L. (2017). Bioremediation of Wastewater by Iron Oxide-Biochar Nanocomposites Loaded with Photosynthetic Bacteria.  Frontiers in Microbiology,  8, 823. https://doi.org/10.3389/fmicb.2017.00823

Abstract:

It has been reported that bacteria-mediated degradation of contaminants is a practical and innocuous wastewater treatment. In addition, iron oxide nanoparticles (NP) are wastewater remediation agents with great potentials due to their strong adsorption capacity, chemical inertness,  and superparamagnetism. Therefore, a combination of NPs and microbes could produce a very desirable alternative to conventional wastewater treatment. For this purpose, we first prepared Fe3O4/biochar nano-composites, followed by loading photosynthetic bacteria (PSB) onto them. It was found that Fe3O4/biochar nano-composites exhibited a high adsorption capacity for PSB (5.45 × 109  cells/g). The efficiency of wastewater pollutants removal by this PSB/Fe3O4/biochar agent was then analyzed. Our results indicated that when loaded onto Fe3O4/biochar nano-composites, PSB’s nutrient removal capability was significantly enhanced (P  < 0.05). This agent removed 83.1% of chemical oxygen demand, 87.5% of NH4+, and 92.1% of PO43-  from the wastewater in our study. Our experiments also demonstrated that such composites are outstanding recyclable agents. Their nutrient removal capability remained effective even after five cycles. In conclusion, we found the PSB/Fe3O4/biochar composites as a very promising material for bioremediation in the wastewater treatment.

Link:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5440585/

I chose this article because I am very interested in coupling biodegradation  with technology. I feel like the two should work together in order for us to find efficient  and safe ways to treat wastewater. The paper is also written very well and succinctly. They are very thorough in describing the problem and what they want to achieve with this research.

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Microbial Communities: Invasive vs. Native Plants Non-Technical Summary

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According to this article, invasive plant species pose a threat to many ecosystems, including wetlands. Invasive plant species have been known to outcompete and take over native plant communities, reduce the amount of different native plants in an area, and alter nitrogen and carbon cycles within the environment by altering the microorganism community (microbiome). This paper focuses on the chemical and physical compositions as well as the soil microbial communities of the Cheboygan March, a freshwater wetland, in Michigan. The marsh was infested by an invasive hybrid species of plant called Typha×glauca about 30-40 years ago. Because the study area was divided into 3 stages (native plants, transitional, and only Typha×glauca), the researchers were able to establish a gradient of infestation, chemical composition, and microbial community differences. They ran chemical composition tests to determine whether this invasive plant species was altering the sediment nutrient content. To determine whether or not the microbial community composition was being altered, they ran sediment samples through DNA sequencing and Polymerase Chain Reaction (PCR: used to amplify certain sections of DNA). They also ran functional gene analysis on the samples to see if microbes were using genes associated with nitrogen uptake and cycling, an important nutrient in the environment. Overall, they found that the microbial community composition was significantly different between the native plant area and the Typha×glauca area. There were more species of bacteria in the Typha×glauca area than the native plant section. Chemically, they found a significant increase in soluble nutrients within the Typha×glauca section. They also found that the abundance of one important gene used for nitrogen cycling by microbes was higher in the Typha×glauca section than in the native area. This study proved that invasive plant species have a significant impact on sediment chemical and microbial characteristics. Invasive plants may hinder the ability for natural wetlands to rid the environment of excess nutrients, thus altering the nutrient cycles for surrounding ecosystems, but more research must be compiled to support this statement.

Citation: Angeloni, N. L., Jankowski, K. J., Tuchman, N. C., & Kelly, J. J. (2006). Effects of an invasive cattail species (Typha× glauca) on sediment nitrogen and microbial community composition in a freshwater wetland. FEMS microbiology letters, 263(1), 86-92.

Article: https://academic.oup.com/femsle/article/263/1/86/598071

 

Microbial Communities: Invasive vs. Native Plants Technical Summary

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A study completed in 2006 focused on the exotic plant invasion of Cheboygan Marsh, a freshwater wetland in Michigan. Previous studies have shown that the introduction of an invasive plant species can alter the microbial community and carbon or nitrogen cycling systems of that area. In this study, researchers focus on an exotic cattail plant species, which they call Typha. Chemical and physical sediment analyses were done by multiple methods to examine nitrate, ammonium, and phosphate concentrations. They also measured sediment water content and organic matter content. Microbial analysis was performed using DNA sequencing and PCR to amplify 16S rRNA. To analyze the composition of genes for denitrification (nirS and nirK), they used specific primers and 16S rRNA amplicon sequencing. Results from sediment chemical and physical analysis suggested that there was a significant increase in nitrate, ammonium, and phosphate concentrations in the Typha infested area. The microbial analysis suggested that there was a significant difference in microbial community composition between the Typha zone and the native plant zone, with the Typha zone showing more bacterial species richness. This was surprising considering the native zone had higher plant species diversity. The nirK  gene could not be amplified possibly due to inhibitory compounds blocking the PCR from working. The nirS gene was significantly more rich in the Typha zone than the native plant zone. Overall, this study found that the invasive Typha plant species could be affecting the marsh’s ability to remove certain nutrients from the water by increasing the amount of soluble nutrients put into the environment and allowing for a shift microbial community composition and denitrifying microbes.

Citation: Angeloni, N. L., Jankowski, K. J., Tuchman, N. C., & Kelly, J. J. (2006). Effects of an invasive cattail species (Typha× glauca) on sediment nitrogen and microbial community composition in a freshwater wetland. FEMS microbiology letters, 263(1), 86-92.

Article:  https://academic.oup.com/femsle/article/263/1/86/598071

The uniqueness and biogeochemical cycling of plant root microbial communities in a floating treatment wetland

Posted by On Filed under Biogeochemical cycling papers No Comments

Citation:

Urakawa, H., Dettmar, D. L., & Thomas, S. (2017). The uniqueness and biogeochemical cycling of plant root microbial communities in a floating treatment wetland. Ecological Engineering, 108(Part B), 573-580. doi:10.1016/j.ecoleng.2017.06.066

Article: https://www.sciencedirect.com/science/article/pii/S0925857417303944

Abstract:

Floating treatment wetlands (FTWs) are an innovative type of phytoremediation technique being used to reduce the impact of excess nutrient loading. Plants hydroponically grown on FTWs take up nutrients from water through their roots. In general microbial communities in the rhizosphere are important for healthy growth and nutrient uptake by plants. Despite most of previous studies focused on the nutrient removal processes, very little is known about microbial communities associated with FTW plant roots. The purpose of this study was to characterize the microbiomes revolving around the submerged roots of FTW in a manmade stormwater pond and to elucidate the source of FTW plant root microbiomes. The microbial communities collected from the plant roots  Canna flaccida  (golden canna) and  Juncus effusus  (soft rush), biofilms of plant pot (polyethylene) and floating mat foam (closed-cell urethane), and surrounding water were studied using 16S rRNA gene amplicon sequencing. The FTW plant root microbiomes were dominated by Alphaproteobacteria and Cyanobacteria at the class level, and  Anabaena,  Rhizobium  and  Rhodobacter  at the genus level. Microbial communities of the FTW plant roots showed unique compositions resembling most closely the surrounding water samples while being quite different from the biofilm samples, leading the conclusion that the major source of microbial populations was the surrounding water. However, the dominance of  Rhizobium  species was only observed in the two plant roots and not recognized in the surrounding water samples, indicating that the FTW roots may selectively shape root microbiomes. Unexpectedly, quite a few groups of microbes were associated with the sulfur cycle. This finding indicates that the oxic-anoxic gradient is formed in the FTW rhizosphere, and this environmental gradient assists to extend the phylogenetic and functional diversities of microorganisms. We anticipate the presence of intrinsic rhizosphere microbiomes and the importance of complex biogeochemical processes that include carbon, sulfur and nitrogen driven by physical activity and chemical releases of FTW plant roots.

 

I chose this paper because I am interested in the role that microbes have in bioremediation of wastes. I found it interesting that the article focused on which microbes were surrounding the FTWs roots and how they could be contributing to denitrification and sulfur  oxidation or sulfide reduction. I thought it was equally interesting that the condition of the plants’ rhizospheres could determine what microbes were present. This article could have serious implications for further studies and for finding further ways to incorporate plants and microbes into bioremediation.

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A1: Intro Post: Bayli Mohl

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Hello everyone!

My name is Bayli Mohl and this is my senior year studying biology with a concentration in physiology. My future goals include becoming a physical therapist and traveling the world. I love reading, camping, cross-country skiing, and biking. I am looking forward to learning about biodegradation of wastes and how that may be done in a cost-effective  way so that the technique may reach impoverished countries.

This is a picture of me near Denali National Park.

A Haiku:

Immense universe

A tiny being eating

Such great importance