Current Research:
Ambient Plant Illumination Could Light The Way For Greener Buildings
Biostimulation of Indigenous Microbial Community for Bioremediation of Petroleum Refinery Sludge
Nutrient deficiency severely impairs the catabolic activity of indigenous microorganisms in hydrocarbon rich environments (HREs) and limits the rate of intrinsic bioremediation. The present study aimed to characterize the microbial community in refinery waste and evaluate the scope for biostimulation based in situ bioremediation. Samples recovered from the wastewater lagoon of Guwahati refinery revealed a hydrocarbon enriched [high total petroleum hydrocarbon (TPH)], oxygen-, moisture-limited, reducing environment. Intrinsic biodegradation ability of the indigenous microorganisms was enhanced significantly (>80% reduction in TPH by 90 days) with nitrate amendment. Preferred utilization of both higher- (>C30) and middle- chain (C20-30) length hydrocarbons were evident from GC-MS analysis. Denaturing gradient gel electrophoresis and community level physiological profiling analyses indicated distinct shift in community’s composition and metabolic abilities following nitrogen (N) amendment. High throughput deep sequencing of 16S rRNA gene showed that the native community was mainly composed of hydrocarbon degrading, syntrophic, methanogenic, nitrate/iron/sulfur reducing facultative anaerobic bacteria and archaebacteria, affiliated to γ- and δ-Proteobacteriaand Euryarchaeota respectively. Genes for aerobic and anaerobic alkane metabolism (alkB and bssA), methanogenesis (mcrA), denitrification (nirS and narG) and N2 fixation (nifH) were detected. Concomitant to hydrocarbon degradation, lowering of dissolve O2and increase in oxidation-reduction potential (ORP) marked with an enrichment of N2fixing, nitrate reducing aerobic/facultative anaerobic members [e.g., Azovibrio, Pseudoxanthomonas and Comamonadaceae members] was evident in N amended microcosm. This study highlighted that indigenous community of refinery sludge was intrinsically diverse, yet appreciable rate of in situ bioremediation could be achieved by supplying adequate N sources.
https://www.frontiersin.org/articles/10.3389/fmicb.2016.01407/full
The light-emitting plants, which debuted in 2017, are not genetically modified to produce light. Instead, they are infused with nanoparticles that turn the plant’s stored energy into light, similar to how fireflies glow. “The transformation makes virtually any plant a sustainable, potentially revolutionary technology,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “It promises lighting independent of an electrical grid, with ‘batteries’ you never need to charge, and power lines that you never need to lay.”
Scientists create world’s smallest data recorder from bacteria...
Researchers from Columbia University Medical Centre (CUMC) in US have converted natural bacterial immune system into the world’s smallest data recorde. The researchers modified an ordinary laboratory strain of ubiquitous human gut microbe (bacteria) Escherichia coli (E Coli) which enabled it to record their interactions with environment and also time-stamp events.
The microscopic data recorder was created by taking advantage of CRISPR-Cas, an immune system in many species of bacteria. CRISPR-Cas copies. snippets of DNA from invading viruses so that subsequent generations of bacteria can repel these pathogens more effectively. To build this microscopic recorder, researchers had modified piece of DNA called plasmid, giving it ability to create more copies of itself in the bacterial cell in response to an external signal.
This research lays groundwork for new class of technologies that use bacterial cells for everything from disease diagnosis to environmental monitoring. It may help to record biological changes taking placing in digestive tract which can yield an unprecedented view of previously inaccessible phenomena. It can be also used in environmental sensing and basic studies in ecology and microbiology, where bacteria could monitor otherwise invisible changes without disrupting their surroundings.
Applications of microalgal biofilms for wastewater treatment and bioenergy production
Microalgae have shown clear advantages for the production of biofuels compared with energy crops. Apart from their high growth rates and substantial lipid/triacylglycerol yields, microalgae can grow in wastewaters (animal, municipal and mining wastewaters) efficiently removing their primary nutrients (C, N, and P), heavy metals and micropollutants, and they do not compete with crops for arable lands. However, fundamental barriers to the industrial application of microalgae for biofuel production still include high costs of removing the algae from the water and the water from the algae which can account for up to 30–40% of the total cost of biodiesel production. Algal biofilms are becoming increasingly popular as a strategy for the concentration of microalgae, making harvesting/dewatering easier and cheaper. Results: We have isolated and characterized a number of natural microalgal biofilms from freshwater, saline lakes and marine habitats. Structurally, these biofilms represent complex consortia of unicellular and multicellular, photosynthetic and heterotrophic inhabitants, such as cyanobacteria, microalgae, diatoms, bacteria, and fungi. Biofilm #52 was used as feedstock for bioenergy production. Dark fermentation of its biomass by Enterobacter cloacae DT-1 led to the production of 2.4 mol of H2/mol of reduced sugar. The levels and compositions of saturated, monosaturated and polyunsaturated fatty acids in Biofilm #52 were target-wise modified through the promotion of the growth of selected individual photosynthetic inhabitants. Photosynthetic components isolated from different biofilms were used for tailoring of novel biofilms designed for (i) treatment of specific types of wastewaters, such as reverse osmosis concentrate, (ii) compositions of total fatty acids with a new degree of unsaturation and (iii) bio-flocculation and concentration of commercial microalgal cells. Treatment of different types of wastewaters with biofilms showed a reduction in the concentrations of key nutrients, such as phosphates, ammonia, nitrates, selenium and heavy metals.
Reference: Miranda1 Ana F, Ramkumar Narasimhan, Andriotis Constandino,Höltkemeier Thorben,Yasmin Aneela, Rochfort Simone, Wlodkowic Donald, Morrison Paul, Roddick Felicity, Spangenberg German,Lal Banwari, Subudhi Sanjukta, Mourado Aidyn , 2017, Biotechnol Biofuels, DOI 10.1186/s13068-017-0798-9
Source: http://www.teriin.org/index.php?option=com_publication&task=details&sid=1883&Itemid=151
Applications of microalgal biofilms for wastewater treatment and bioenergy production
Microalgae have shown clear advantages for the production of biofuels compared with energy crops. Apart from their high growth rates and substantial lipid/triacylglycerol yields, microalgae can grow in wastewaters (animal, municipal and mining wastewaters) efficiently removing their primary nutrients (C, N, and P), heavy metals and micropollutants, and they do not compete with crops for arable lands. However, fundamental barriers to the industrial application of microalgae for biofuel production still include high costs of removing the algae from the water and the water from the algae which can account for up to 30–40% of the total cost of biodiesel production. Algal biofilms are becoming increasingly popular as a strategy for the concentration of microalgae, making harvesting/dewatering easier and cheaper. Results: We have isolated and characterized a number of natural microalgal biofilms from freshwater, saline lakes and marine habitats. Structurally, these biofilms represent complex consortia of unicellular and multicellular, photosynthetic and heterotrophic inhabitants, such as cyanobacteria, microalgae, diatoms, bacteria, and fungi. Biofilm #52 was used as feedstock for bioenergy production. Dark fermentation of its biomass by Enterobacter cloacae DT-1 led to the production of 2.4 mol of H2/mol of reduced sugar. The levels and compositions of saturated, monosaturated and polyunsaturated fatty acids in Biofilm #52 were target-wise modified through the promotion of the growth of selected individual photosynthetic inhabitants. Photosynthetic components isolated from different biofilms were used for tailoring of novel biofilms designed for (i) treatment of specific types of wastewaters, such as reverse osmosis concentrate, (ii) compositions of total fatty acids with a new degree of unsaturation and (iii) bio-flocculation and concentration of commercial microalgal cells. Treatment of different types of wastewaters with biofilms showed a reduction in the concentrations of key nutrients, such as phosphates, ammonia, nitrates, selenium and heavy metals.
Reference: Miranda1 Ana F, Ramkumar Narasimhan, Andriotis Constandino,Höltkemeier Thorben,Yasmin Aneela, Rochfort Simone, Wlodkowic Donald, Morrison Paul, Roddick Felicity, Spangenberg German,Lal Banwari, Subudhi Sanjukta, Mourado Aidyn , 2017, Biotechnol Biofuels, DOI 10.1186/s13068-017-0798-9
Source: http://www.teriin.org/index.php?option=com_publication&task=details&sid=1883&Itemid=151
Application of Genetic Engineering in Bioremediation: Deinococcus Radiodurans
Bioremediation is basically a technique in which micro-organisms are utilized for the management of biological waste. Their metabolism is utilized for the removal of pollutants from the environment. Genetic Engineering has now become integrated with bioremediation since many microbes cab be artificially designed which can consume the toxic waste and pollutants that are not usually taken in by normal microbes. This is done by first genetically altering the sequences of the desired microbe and enhancing its ability to digest the toxic particles of the pollutant or by genetically engineering a new microbe which has extraordinary ability to take in, consume and digest the pollutants. Thus, micro-organisms are designed specifically for bioremediation, A recent advancement in this section is genetically modified bacterium Deinococcus radiodurans can consume high amounts of radio-active ionic mercury and toluene from radioactive waste.
The roles of arbuscular mycorrhizal fungi (AMF) in phytoremediation and tree-herb interactions in Pb contaminated soil
Yurong Yang, Yan Liang, Xiaozhen Han, Tsan-Yu Chiu, Amit Ghosh, Hui Chen & Ming Tang, Scientific Reports 6, Article number: 20469 (2016)
doi:10.1038/srep20469
Understanding the roles of arbuscular mycorrhizal fungi (AMF) in plant interaction is essential for optimizing plant distribution to restore degraded ecosystems. This study investigated the effects of AMF and the presence of legume or grass herbs on phytoremediation with a legume tree, Robinia pseudoacacia, in Pb polluted soil. In monoculture, mycorrhizal dependency of legumes was higher than that of grass, and AMF benefited the plant biomass of legumes but had no effect on grass. Mycorrhizal colonization of plant was enhanced by legume neighbors but inhibited by grass neighbor in co-culture system. N, P, S and Mg concentrations of mycorrhizal legumes were larger than these of non-mycorrhizal legumes. Legume herbs decreased soil pH and thereby increased the Pb concentrations of plants. The neighbor effects of legumes shifted from negative to positive with increasing Pb stress levels, whereas grass provided a negative effect on the growth of legume tree. AMF enhanced the competition but equalized growth of legume-legume under unpolluted and Pb stress conditions, respectively. In conclusion, (1) AMF mediate plant interaction through directly influencing plant biomass, and/or indirectly influencing plant photosynthesis, macronutrient acquisition, (2) legume tree inoculated with AMF and co-planted with legume herbs provides an effective way for Pb phytoremediation.
Phytoremediation technology in a three-dimensional scale can be used for remediating HM polluted soil and groundwater.
Electricity generation and waste water treatment of Oil refinery in Microbial fuel cells using Pseudomonas putida
By Using Pseudomonas putida (BCRC 1059), a wild-type bacterium. The refinery waste water could be treated and also generate electic current in air-cathode chamber over four-batch cycles for 63 cumulative days. The oil refinery waste water containing chemical oxygen demand (COD) could be used as a sustrate for electicity generation in the reactor of the MFC. The removal efficiency of the COD reached 30% as a function of time. This study demonstrated that oil refinery waste water could used as a substrate for electricity generation
(Majumdar et. al., 2014 International journal of Hydrogen Energy)
Bacteria that turn waste to energy in microbial fuel cells studied
Anaerobic microorganisms which can consume waste while generating electricity in a type of microbial electrochemical cell known as a microbial fuel cell, are being studied by researchers at Arizona State University’s Biodesign Institute. Joseph Miceli, a researcher at Arizona State University’s (ASU). Biodesign Institute studies specialised microorganisms known as anode respiring bacteria (ARB). Rather than investigating their role in health and disease however, his research explores the ability of these microbes to clean up waste and produce useful energy in the form of electricity or hydrogen.
(http://www.waste management-world. com/ articles/ 2013/04/ bacteria-turn-waste-to-energy-microbial-fuel-cell.html)
Microbial battery: Team uses 'wired microbes' to generate electricity from sewage
Stanford scientists have developed a “battery” that harnesses a special type of microbe to produce electricity by digesting the plant and animal waste dissolved in sewage. Engineers at Stanford University have devised a new way to generate electricity from sewage using naturally-occurring “wired microbes” as mini power plants, producing electricity as they digest plant and animal waste.
(http://phys.org/news/2013-09-microbial-battery-team-wired-microbes.html#jCp) Sep 16, 2013.
Geobacter Bacteria Breakthrough- Electricity Generated From Hydrogen
May 20, 2013
Researchers at the University of Massachusetts, Amherst, have engineered a breed of electricity producing bacteria- the Geobacter species- who grow simply by using hydrogen gas as their exclusive electron donor, while carbon dioxide suffices all its carbon requirements.
A strain of bacteria were specifically engineered in a microbial fuel cell so that they did not feel the requirement of organic carbon, and the conclusion observed was that when the hydrogen supplied to the microbial cell was intermittently stopped, electrical signals drooped substantially and cells attached to the electrodes did not produce any significant electricity.
(http://www.crazyengineers.com/threads/geobacter-bacteria-breakthrough-electricity-generated-from-hydrogen.68064/) May 20, 2013
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