Exploring the Potential of Bacteria-Assisted Phytoremediation of Arsenic-Contaminated Soils

Shagol, Charlotte C.,Chauhan, Puneet S.,Kim, Ki-Yoon,Lee, Sun-Mi,Chung, Jong-Bae,Park, Kee-Woong,Sa, Tong-Min Korean Society of Soil Science and Fertilizer 2011 한국토양비료학회지 Vol.44 No.1

Arsenic pollution is a serious global concern which affects all life forms. Being a toxic metalloid, the continued search for appropriate technologies for its remediation is needed. Phytoremediation, the use of green plants, is not only a low cost but also an environmentally friendly approach for metal uptake and stabilization. However, its application is limited by slow plant growth which is further aggravated by the phytotoxic effect of the pollutant. Attempts to address these constraints were done by exploiting plant-microbe interactions which offers more advantages for phytoremediation. Several bacterial mechanisms that can increase the efficiency of phytoremediation of As are nitrogen fixation, phosphate solubilization, siderophore production, ACC deaminase activity and growth regulator production. Many have been reported for other metals, but few for arsenic. This mini-review attempts to present what has been done so far in exploring plants and their rhizosphere microbiota and some genetic manipulations to increase the efficiency of arsenic soil phytoremediation.

Exploring the Potential of Bacteria-Assisted Phytoremediation of Arsenic-Contaminated Soils

Charlotte C. Shagol,Puneet S. Chauhan,Kiyoon Kim,Sunmi Lee,Jongbae Chung,Keewoong Park,Tongmin Sa 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.1

Arsenic pollution is a serious global concern which affects all life forms. Being a toxic metalloid, the continued search for appropriate technologies for its remediation is needed. Phytoremediation, the use of green plants, is not only a low cost but also an environmentally friendly approach for metal uptake and stabilization. However, its application is limited by slow plant growth which is further aggravated by the phytotoxic effect of the pollutant. Attempts to address these constraints were done by exploiting plant-microbe interactions which offers more advantages for phytoremediation. Several bacterial mechanisms that can increase the efficiency of phytoremediation of As are nitrogen fixation, phosphate solubilization, siderophore production, ACC deaminase activity and growth regulator production. Many have been reported for other metals, but few for arsenic. This mini-review attempts to present what has been done so far in exploring plants and their rhizosphere microbiota and some genetic manipulations to increase the efficiency of arsenic soil phytoremediation.

Identification and Classification of Indoor Plants According to Light Intensity Requirements for Botanical IoT Application

Charlotte C. Shagol,Kwang-Jin Kim,Seung-Won Han,Na Ra Jeong,Hyeon Ju Kim,정영빈,Hyung-Kwon Yun 인간식물환경학회 2018 인간식물환경학회지 Vol.21 No.5

This study aimed to provide information to urban plant growers on the best light requirement for indoor plants. Chlorophyll fluorescence analysis was used to determine the photosynthetic activity of indoor plants as affected by light intensity. Determination of the light intensity requirement for each plant was done by applying the Bayesian Michaelis-Menten equation which was obtained using the Lineweaver-Burk plot. The Vmax and Km values were determined, where the photosynthetic activity measured as electron transport rate (ETR) was denoted as Vmax and light intensity (photosynthetically active radiation, PAR) of ½ maximum ETR was designated as Km. The ETR of 93 indoor plant species were determined and Vmax/2 and Km values of each plant were calculated which resulted in seven levels of light intensity. The levels are as follows: Level 1 - more than the Km value; Levels 2 to 7 were determined using the formula: maximum Km value of the level = Km(½)n-1 where n refers to the level (i.e. n2 = level 2, …7). The best is level 1 while the most sub-optimal is level 7. The different plants have a wide range of light intensity requirements. Majority of the plants (70) had ½ maximum ETR at 20 up to less than 100 μmol m-2 s-1 PAR, while 13 plants at 100 to 149 μmol m-2 s-1 and only 10 plants at 150 up to 290 μmol m-2 s-1. The indoor plants can be classified according to light intensity requirement: low light intensity, e.g. Dracaena sanderiana ‘Gold’ (20.9); moderate light intensity, e.g. Cyclamen persicum (99.1); and high light intensity, Polyscias fruticosa (290.2 μmol·m-2·s-1). The data generated from this study can be utilized in IoT to make the information on plant cultivation and environmental conditions accessible to urban growers who use smartphones.

ACC Deaminase Producing Arsenic Tolerant Bacterial Effect on Mitigation of Stress Ethylene Emission in Maize Grown in an Arsenic Polluted Soil

Charlotte C. Shagol,Parthiban Subramanian,Ramasamy Krishnamoorthy,Kiyoon Kim,Youngwook Lee,Chaemin Kwak,Suppiah Sundaram,Wansik Shin,Tongmin Sa 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.3

Arsenic is a known hazardous metalloid not only to the animals but also to plants. With high concentrations, it can impede normal plant growth and cause even death of plants at extremely high levels. A known plant response to stress conditions such as toxic levels of metal (loids) is the production of stress ethylene, causing inhibitory effect on root growth in plants. When the effect of various arsenic concentrations was tested to maize plant, the stress ethylene emission proportionately increased with increasing concentration of As(V). The inoculation of two arsenic tolerant bacteria; Pseudomonas grimonti JS126 and Pseudomonas taiwanensis JS238 having respective high and low 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity reduced stress ethylene emission by 59% and 30% in maize grown in arsenic polluted soils. The result suggested the possible use of Pseudomonas grimonti JS126 for phytoremediation of arsenic polluted soils.

Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea.

Shagol, Charlotte C,Krishnamoorthy, Ramasamy,Kim, Kiyoon,Sundaram, Subbiah,Sa, Tongmin Ecomed 2014 Environmental Science and Pollution Research Vol.21 No.15

<P>The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20?mM for NaAsO2 and 140 to 310?mM NaH2AsO4??7H2O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200?μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils.</P>

ACC Deaminase Producing Arsenic Tolerant Bacterial Effect on Mitigation of Stress Ethylene Emission in Maize Grown in an Arsenic Polluted Soil

Shagol, Charlotte C.,Subramanian, Parthiban,Krishnamoorthy, Ramasamy,Kim, Kiyoon,Lee, Youngwook,Kwak, Chaemin,Sundaram, Suppiah,Shin, Wansik,Sa, Tongmin Korean Society of Soil Science and Fertilizer 2014 한국토양비료학회지 Vol.47 No.3

Arsenic is a known hazardous metalloid not only to the animals but also to plants. With high concentrations, it can impede normal plant growth and cause even death of plants at extremely high levels. A known plant response to stress conditions such as toxic levels of metal (loids) is the production of stress ethylene, causing inhibitory effect on root growth in plants. When the effect of various arsenic concentrations was tested to maize plant, the stress ethylene emission proportionately increased with increasing concentration of As(V). The inoculation of two arsenic tolerant bacteria; Pseudomonas grimonti JS126 and Pseudomonas taiwanensis JS238 having respective high and low 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity reduced stress ethylene emission by 59% and 30% in maize grown in arsenic polluted soils. The result suggested the possible use of Pseudomonas grimonti JS126 for phytoremediation of arsenic polluted soils.

Use of Terminal Restriction Length Polymorphism (T-RFLP) Analysis to Evaluate Uncultivable Microbial Community Structure of Soil

Chauhan, Puneet Singh,Shagol, Charlotte C.,Yim, Woo-Jong,Tipayno, Sherlyn C.,Kim, Chang-Gi,Sa, Tong-Min Korean Society of Soil Science and Fertilizer 2011 한국토양비료학회지 Vol.44 No.1

Various environmental ecosystems are valuable sources for microbial ecology studies, and their analyses using recently developed molecular ecological approaches have drawn significant attention within the scientific community. Changes in the microbial community structures due to various anthropogenic activities can be evaluated by various culture-independent methods e.g. ARISA, DGGE, SSCP, T-RFLP, clone library, pyrosequencing, etc. Direct amplification of total community DNA and amplification of most conserved region (16S rRNA) are common initial steps, followed by either fingerprinting or sequencing analysis. Fingerprinting methods are relatively quicker than sequencing analysis in evaluating the changes in the microbial community. Being an efficient, sensitive and time- and cost effective method, T-RFLP is regularly used by many researchers to access the microbial diversity. Among various fingerprinting methods T-RFLP became an important tool in studying the microbial community structure because of its sensitivity and reproducibility. In this present review, we will discuss the important developments in T-RFLP methodology to distinguish the total microbial diversity and community composition in the various ecosystems.

Use of Terminal Restriction Length Polymorphism (T-RFLP) Analysis to Evaluate Uncultivable Microbial Community Structure of Soil

Puneet Singh Chauhan,Charlotte C. Shagol,Woojong Yim,Sherlyn C. Tipayno,Chang-Gi Kim,Tongmin Sa 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.1

Various environmental ecosystems are valuable sources for microbial ecology studies, and their analyses using recently developed molecular ecological approaches have drawn significant attention within the scientific community. Changes in the microbial community structures due to various anthropogenic activities can be evaluated by various culture-independent methods e.g. ARISA, DGGE, SSCP, T-RFLP, clone library, pyrosequencing, etc. Direct amplification of total community DNA and amplification of most conserved region (16S rRNA) are common initial steps, followed by either fingerprinting or sequencing analysis. Fingerprinting methods are relatively quicker than sequencing analysis in evaluating the changes in the microbial community. Being an efficient, sensitive and time- and cost effective method, T-RFLP is regularly used by many researchers to access the microbial diversity. Among various fingerprinting methods T-RFLP became an important tool in studying the microbial community structure because of its sensitivity and reproducibility. In this present review, we will discuss the important developments in T-RFLP methodology to distinguish the total microbial diversity and community composition in the various ecosystems.

The Impact of the Morphological Characteristics of Leaves on Particulate Matter Removal Efficiency of Plants

손덕주,김광진,정나라,윤형권,한승원,김정호,도경란,이선화,Charlotte C. Shagol 인간식물환경학회 2019 인간식물환경학회지 Vol.22 No.6

This study was conducted to find out differences in the removal efficiency of particulate matter (PM) depending on the type of plants and the morphological characteristics of leaves. A total of 12 plants were used, with three plants selected for each type of leaves (big leaf, small leaf, compound leaf, needle leaf). We measured the removed amount of PM10 and PM2.5, the structure of the abaxial leaf surface, and the weight of the wax layer of each plant. Plants with the high removal efficiency of PM included Pachira aquatica Aubl., Ardisia crenata, and Dieffenbachia 'Marianne', and plants with the low removal efficiency included Nandina domestica Thunb, Schefflera arboricola, and Quercus dentata. The abaxial leaf surface having a high removal efficiency of PM had many large wrinkles, and the abaxial leaf surface having a medium removal efficiency was flat and smooth. On the other hand, there were many fine hairs on the abaxial leaf surface with a low removal efficiency. According to the plant leaf type, the PM10 removal efficiency of plants with needle leaves was about three times higher than that of other plants. In particular, the wax layer of conifers weighed 6-24 times higher than those of other plants. The stomata of conifers were evenly distributed on the adaxial and abaxial leaf surfaces; however, the stomata of Sciadopitys verticillata appeared in the form of papillae unlike general stomata. Therefore, the removal efficiency of PM varied depending on the macro-, and micro-morphological characteristics of plant leaves such as the structure of the abaxial leaf surface, and the weight of the wax layer. Based on this research, selecting plants that are effective in reducing PM in consideration of the plant type and leaf characteristics will improve indoor air quality and decrease exposure of PM to human body.

Effects of Long-Term Subcultured Arbuscular Mycorrhizal Fungi on Red Pepper Plant Growth and Soil Glomalin Content

( Gopal Selvakumar ),( Pyoung Ho Yi ),( Seong Eun Lee ),( Charlotte C. Shagol ),( Seung Gab Han ),( Tongmin Sa ),( Bong Nam Chung ) 한국균학회 2018 Mycobiology Vol.46 No.2

Arbuscular mycorrhizal fungi (AMF) are well-known for their ability to improve plant growth and help plants withstand abiotic stress conditions. Unlike other fungi and bacteria, AMF cannot be stored, as they are obligate biotrophs. Long-term preservation of AMF spores is challenging and may lead to the loss of viability and efficiency. This study aimed to understand the effect of prolonged subculture of AMF species on the growth and glomalin-related soil protein (GRSP) from red pepper (Capsicum annuum L.). AMF spores were mass-produced using different techniques and subcultured in pots with sorghum sudangrass as the host plant for 3 years. Experimental soil samples were collected from natural grassland. Five different AMF inocula were used in triplicate as treatments. After 70 days of growth, red pepper plants were harvested and plant dry weight, plant nutrient content, mycorrhizal colonization, AMF spore count, and soil glomalin content were determined. AMF-treated plants displayed higher dry weight than controls, with only fruit dry weight being significantly different. Similarly, significant differences in phosphorous and potassium contents of the above-ground plant parts were observed between mycorrhizal and control treatments. In addition, soil GRSP content was significantly higher in plants inoculated with Rhizophagus sp. and Gigaspora margarita. The increased plant growth and GRSP content suggest that AMF can be maintained for 3 years without losing their efficiency if subcultured regularly with different symbiotic host plants.