Joan McLean - Academia.edu (original) (raw)

Papers by Joan McLean

ABSTRACT Chickpea (Cicer arietinum L.) is an annual winter legume and is a good source of seed pr... more ABSTRACT Chickpea (Cicer arietinum L.) is an annual winter legume and is a good source of seed proteins and carbohydrates. Chickpea crop plays a significant role in agronomy by maintaining soil fertility due to its nitrogen fixing ability. Rhizobia are the root nodule bacterial symbionts of legumes, which fix atmospheric N in a process known as biological nitrogen fixation. All described rhizobial species belong to ten genera of α-proteobacteria and three genera of β-proteobacteria. Mesorhizobia nodulate a wide variety of legumes, such as chickpea (Sprent 2009). Non-nodulating endosymbiotic bacteria are also present in nodules (Li et al. 2008). For example Paenibacillus has been localized by In situ hybridization in the nodules as endosymbiont and has been shown to increase the plant yield (Annapurna et al. 2013). The main objective of this study was to compare diversity of bacteria in the nodules of chickpea growing in different regions of Pakistan.

Field Analytical Chemistry & Technology, 1998

A novel colorimetric-based field test kit, the Quick Testா, has been developed by Envirol Inc. (N... more A novel colorimetric-based field test kit, the Quick Testா, has been developed by Envirol Inc. (North Logan, UT), for the quantitation of pentachlorophenol (PCP) in soil. The Quick Test differs from commercially available immunoassay field tests for PCP in that it is based on a photochemically induced oxidation-reduction reaction between PCP and a reagent that produces coloration proportional to concentration. Standard quality-control procedures were used to characterize the performance of the Quick Test and to test the suitability of this new method for field investigations of PCP-contaminated sites. A method detection limit of was 1.5 mg/kg achieved with a dynamic range up to making 100 mg/kg, this procedure of practical use at many PCP-contaminated sites. Accuracy and precision for the analysis of PCP in soils were comparable to laboratory standard methods that involve Soxhlet extractions and chromatographic quantitation. Because this is an oxidation-reduction reaction between halogenated molecules and the reagent, many, but not all, halogenated organic compounds will cause a response. An acid-base cleanup stop eliminates all but acidic halogenated compounds. The performance of the Quick Test in the field was compared with laboratory results. The statistical analyses performed to determine intermethod accuracy were linear regression analysis and the Wilcoxon Signed Ranks test. All data sets had r 2 values greater than 0.915 and y-intercept values and the slope of the line that were not statistically different from 0 and 1, respectively, at a 90% confidence level. Data sets were not statistically different by the Wilcoxon test (95% confidence level), confirming the results from the regression analysis-that the Quick Test provided data equivalent (1 : 1) to the confirmatory methods.

Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine, Jan 25, 2016

Cost-effective "green" methods of producing Ag nanoparticles (NPs) are being examined b... more Cost-effective "green" methods of producing Ag nanoparticles (NPs) are being examined because of the potential of these NPs as antimicrobials. Ag NPs were generated from Ag ions using extracellular metabolites from a soil-borne Pythium species. The NPs were variable in size, but had one dimension less than 50 nm and were biocoated; aggregation and coating changed with acetone precipitation. They had dose-dependent lethal effects on a soil pseudomonad, Pseudomonas chlororaphis O6, and were about 30-fold more effective than Ag(+) ions. A role of reactive oxygen species in cell death was demonstrated by use of fluorescent dyes responsive to superoxide anion and peroxide accumulation. Also mutants of the pseudomonad, defective in enzymes that protect against oxidative stress, were more sensitive than the wild type strain; mutant sensitivity differed between exposure to Ag NPs and Ag(+) ions demonstrating a nano-effect. Imaging of bacterial cells treated with the biocoated Ag N...

The Regional Superfund Ground-Water Forum is a group of scientists, representing EPA's Region... more The Regional Superfund Ground-Water Forum is a group of scientists, representing EPA's Regional Superfund Offices, organized to exchange up-to-date information related to ground-water remediation at Superfund sites. One of the major issues of concern to the Forum is the mobility of metals in soils as related to subsurface remediation. For the purposes of this Issue Paper, those metals most commonly

Journal of Medical Imaging and Radiation Sciences, 2014

Soil Science Society of America Journal, 1992

... of Agronomy, Kansas State Univ., Manhattan, KS 66506-3801; and JE McLean, Utah Water Research... more ... of Agronomy, Kansas State Univ., Manhattan, KS 66506-3801; and JE McLean, Utah Water Research Lab., Utah State Univ., Lo-gan, UT 84322 ... The Br concentra-tion was measured using an Orion 94-35A specific-ion elec-trode and an Orion 94-35A specific-ion electrode and ...

Soil Science, 1991

The authors previous findings suggested different Cu and Cd retention mechanisms for each of two ... more The authors previous findings suggested different Cu and Cd retention mechanisms for each of two calcareous soils. Solubility data indicated that the Skumpah soil (30% CaCOâ) reacted with the water extract of an acid mine waste to form tenorite (CuO). Batch desorption of the waste-extract equilibrated Kidman soil (0.2% CaCOâ) with CaClâ indicated that cation exchange was the metal retention

Applied microbiology and biotechnology, 2016

Trichloroethene (TCE) in groundwater is a major health concern and biostimulation/bioaugmentation... more Trichloroethene (TCE) in groundwater is a major health concern and biostimulation/bioaugmentation-based strategies have been evaluated to achieve complete reductive dechlorination with varying success. Different carbon sources were hypothesized to stimulate different extents of TCE reductive dechlorination. Ecological conditions that developed different dechlorination stages were investigated by quantitating Dehalococcoides 16S rRNA (Dhc) and reductive dehalogenase gene abundance, and by describing biogeochemical properties of laboratory columns in response to this biostimulation. Eight large columns (183 cm × 15.2 cm), packed with aquifer material from Hill AFB, Utah, that were continuously fed TCE for 7.5 years. Duplicate columns were biostimulated with whey or one of two different Newman Zone® emulsified oil formulations containing either nonionic surfactant (EOLN) or standard surfactant (EOL). Two columns were non-stimulated controls. Complete (whey amended), partial (EOLN amend...

Research in microbiology, Jan 23, 2016

Serratia species-affiliated DNA sequences have recently been discovered in the root nodules of tw... more Serratia species-affiliated DNA sequences have recently been discovered in the root nodules of two chickpea cultivars; however, little is known about their potential influence on chickpea plant growth. All Serratia-affiliated sequences (1136) could be grouped into two clusters at 98% DNA similarity. The major cluster, represented by 96% of sequences, was closely associated with Serratia marcescens sequences from GenBank. In the current study, we isolated two Serratia strains, 5D and RTL100, from root nodules of a field-grown Desi cultivar from Faisalabad and Thal areas, respectively. In vitro, strain 5D showed significantly higher phosphate (P) solubilization and lactic acid production than RTL100, whereas a comparable concentration of phytohormone was produced by both isolates. The application of Serratia strain 5D as an inoculum resulted in 25.55% and 30.85% increases in the grain yield of crops grown on fertile soil in irrigated areas and nutrient-deficient soil in rainfed areas,...

Arch Environ Contam Toxicol, 2005

Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT... more Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT, was amended with 14 C pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. Humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. Biologic activity promoted 14 C association with the fulvic acid fraction, but humic acid-associated 14 C did not increase with biologic activity. The Aboatox flash toxicity assay was used to assess the toxicity of humic and fulvic acid fractions. The fulvic acid gave no toxic response, but the humic acid showed significant toxicity. The observed toxicity was likely associated with pentachlorophenol, a known contaminant of the soil that was removed by solvent extraction of the humic acid and that correlated well with toxicity reduction.

Journal of Environmental Engineering, Jun 1, 1988

Evaluation of Mobility of Pesticides in Soil Using US EPA Methodology. [Journal of Environmental ... more Evaluation of Mobility of Pesticides in Soil Using US EPA Methodology. [Journal of Environmental Engineering 114, 689 (1988)]. Joan E. McLean, Ronald C. Sims, William J. Doucctte, Craig R. Caupp, William J. Grenney Member, ASCE. Abstract. ...

Applied Geochemistry, 2015

Background: Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into con... more Background: Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature.

Soils from four different geographic locations with different compositions all reduced mineraliza... more Soils from four different geographic locations with different compositions all reduced mineralization of pyrene by P. chrysosporium when compared to a non-soil system. Two clays, bentonite and kaolinite, differentially decreased the mineralization of pyrene. Bentonite sorbed pyrene to a greater extent and was more inhibitory to mineralization than kaolinite. Sand had little effect on mineralization. Four artificial soils, made with different proportions of sand, silt and clay, free of organic matter and microbes, inhibited mineralization by P. chrysosporium. Inhibition increased with greater proportions of silts. These findings suggest that soil type may influence the bioremediation potential of P. chrysosporium.