scholarly journals Isolation, characterization and optimization of chrysene degradation using bacteria isolated from oil-contaminated water

Author(s):  
Smeera Thomas ◽  
Nitha Thalakkale Veettil ◽  
Kavitha Subbiah

Abstract Polyaromatic hydrocarbons (PAHs) are uncharged, non-polar molecules generated from natural and anthropogenic activities, where the emissions from anthropogenic activities predominate. Chrysene is a high molecular weight PAH, which is found to be highly recalcitrant and mutagenic in nature. The aim of this study was to isolate chrysene-degrading microorganisms from oil-contaminated water and to enhance their degradative conditions using design expert. From the various samples collected, 19 bacterial strains were obtained through enrichment culture and the one which showed highest activity was identified by 16S rRNA sequencing as Bacillus halotolerans. Under optimum conditions of 100 mg/l chrysene concentration, 1,000 mg/l nitrogen source, pH 6, B. halotolerans exhibited 90% chrysene degradation on sixth day. Positive results for the enzymes laccase and catechol 1,2 dioxygenase confirmed the ability for chrysene degradation by the isolated strain. Major metabolic intermediate determined in GCMS analysis was diisooctyl phthalate. Hence it can be concluded that Bacillus halotolerans can be a promising candidate for the removal of HMW hydrocarbons from contaminated environments.

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 783-799
Author(s):  
Maryam Ariannezhad ◽  
Davood Habibi ◽  
Somayyeh Heydari ◽  
Vahideh Khorramabadi

A new magnetic supported manganese-based coordination complex (Fe3O4@SiO2@CPTMS@MBOL@ Mn) was prepared in consecutive stages and characterized via various techniques (VSM, SEM, TEM, XRD, FT-IR, EDX, TG-DTA, and ICP). To evaluate its application, it was used for synthesis of divers Indazolophthalazinetriones in a simple procedure via the one-pot three-component condensation reaction of aldehydes, dimedone, and phthalhydrazide in ethanol under reflux conditions. The Mn catalyst can be recycled without any noticeable loss in catalytic activity. Additionally, the antibacterial properties of the nano-catalyst were studied against some bacterial strains.


2018 ◽  
Vol 81 (10) ◽  
pp. 1723-1728 ◽  
Author(s):  
STEVE L. TAYLOR ◽  
JULIE A. NORDLEE ◽  
SHYAMALI JAYASENA ◽  
JOSEPH L. BAUMERT

ABSTRACT A portable, handheld gluten detection device, the Nima sensor, is now available for consumers wishing to determine if gluten is present in food. By U.S. regulation, gluten-free foods should contain <20 ppm of gluten. Thirteen gluten-free foods (muffins, three different types of bread, three different types of pasta, puffed corn snack, ice cream, meatballs, vinegar and oil salad dressing, oatmeal, and dark chocolate) were prepared; each food was spiked on a weight to weight basis with gluten levels of 0, 5, 10, 20, 30, 40, and 100 ppm before processing or preparation. Unprocessed and processed foods were tested with the handheld gluten sensor and by two gluten-specific enzyme-linked immunosorbent assays (ELISAs) on the basis of the R5 and G12 monoclonal antibodies, respectively. The portable gluten detection device detected gluten in all food types at the 30-ppm addition level, failing to detect gluten in only 5 (6.4%) of 78 subsamples. At the 20-ppm addition level, the portable gluten detection device failed to detect gluten in one type of pasta but detected gluten residues in 63 (87.5%) of 72 other subsamples. The device was able to detect gluten at the 10-ppm addition level in 9 of the 13 food matrices (41 of 54 subsamples, 75.9%) but not in the three types of pasta and the puffed corn snack. The gluten-sensing device did not perform reliably at the 5-ppm addition level in 11 of 13 food matrices (exceptions: ice cream and muffins). In contrast, the ELISA methods were highly reliable at gluten addition levels of ≥10 ppm in all food matrices. The portable gluten detection device yielded a low percentage of false-positive results (4 of 111, 3.6%) in these food matrices. Thus, this handheld portable gluten sensor performed reliably in the detection of gluten in foods having ≥20 ppm of added gluten with only 18 (5.9%) of 306 failures, if results of the one type of pasta are excluded. The device worked with greater reliability as the gluten levels in the foods increased.


2021 ◽  
Vol 5 (1) ◽  
pp. 1-9
Author(s):  
Antonio Carlos Pereira de Menezes Filho ◽  
Matheus Vinícius Abadia Ventura ◽  
Carlos Frederico de Souza Castro

Tibouchina granulosa is a species that blooms annually in several regions of Brazil. This species is still little explored in terms of phytocompounds in all organs of this plant, especially the floral organ. Flowers of T. granulosa were collected in the municipality of Rio Verde, Goiás, Brazil, in 2021. The hydroethanolic floral extract was prepared by maceration and qualitative phytochemical (colorimetric reactions and salt formation) and antibacterial analyzes performed and the results expressed in millimeters of inhibition at different concentrations in mg mL-1. Several phytochemical classes were observed with positive results, especially for alkaloids, phenolics, oxylates, saponins, carbohydrates and tannins. As for the bacterial assay, potential antibacterial activity was observed for all bacterial strains tested, except for Salmonella serovar Thyphymurium and serovar Enteritidis. Expressive inhibitions were observed for Enterococcus faecalis > Pseudomonas aeruginosa > Staphylococcus aureus and Escherichia coli at the highest concentrations between 100-50 mg mL-1. The floral extract of Tibouchina granulosa showed phytotherapeutic potential with the presence of several phytochemical groups and expressive antibacterial activity.


2020 ◽  
Vol 32 ◽  
Author(s):  
Juliana Alves Resende ◽  
Vânia Lúcia da Silva ◽  
Claudio Galuppo Diniz

Abstract: From an anthropocentric perspective, aquatic environments are important to maintain health and survival, however, as they are sometimes managed based on misconception, they are considered a convergent pathway for anthropogenic residues and sanitation. Thus, it is observed that these ecosystems have been threatened by chemical pollution due to xenobiotics, especially from a more contemporary approach, by the selective pressure associated with antimicrobials. There are several studies that report the enrichment of antimicrobial resistant bacteria and mobilizable antimicrobial resistance genes in aquatic and adjacent ecosystems. From the perspective of the emerging and reemerging number of diseases related to the interplay of human, animal, and environmental factors, a new conception arose to address these issues holistically, which is known as the One Health approach. Scientific and political discourse on this conception should lead to effective action plans for preventing and controlling the spread of infectious diseases in open environment, including those impacted by anthropogenic activities. Therefore, nowadays, discussions on antimicrobial resistance are becoming broader and are requiring a multi-disciplinary view to address health and environmental challenges, which includes aquatic environment management. Water may represent one of the most important ecosystems for the in antimicrobial resistance phenomenon that arises when a dynamic and singular microbial community may be influenced by several characteristics. As antimicrobial substances do not all degrade at the same time under the same treatment, strategies concerning their removal from the environment should consider their individualized chemical characteristics.


2021 ◽  
Author(s):  
Dibakar Roy ◽  
Dasari Sreekanth ◽  
Deepak Pawar ◽  
Himanshu Mahawar ◽  
Kamal K. Barman

Arsenic (As) is the one the most toxic element present in earth which poses a serious threat to the environment and human health. Arsenic contamination of drinking water in South and Southeast Asia reported one of the most threatening problems that causes serious health hazard of millions of people of India and Bangladesh. Further, use of arsenic contaminated ground water for irrigation purpose causes entry of arsenic in food crops, especially in Rice and other vegetable crops. Currently various chemical technologies utilized for As removal from contaminated water like adsorption and co-precipitation using salts, activated charcoal, ion exchange, membrane filtration etc. are very costly and cannot be used for large scale for drinking and agriculture use. In contrast, phytoremediation utilizes green plats to remove pollutants from contaminated water using various mechanisms such as rhizofiltration, phytoextraction, phytostabilization, phytodegrartion and phytovolatilization. A large numbers of terrestrial and aquatic weed flora have been identified so far having hyper metal, metalloid and organic pollutant removal capacity. Among the terrestrial weed flora Arundo donax, Typha latifolia, Typha angustifolia, Vetivaria zizinoids etc. are the hyper As accumulator. Similarly Eicchornea crassipes (Water hyacinth), Pistia stratiotes (water lettuce), Lemna minor (duck weed), Hyrdilla verticillata, Ceratophyllum demersum, Spirodella polyrhiza, Azola, Wolfia spp., etc. are also capable to extract higher amount of arsenic from contaminated water. These weed flora having As tolerance mechanism in their system and thus remediate As contaminated water vis-à-vis continue their life cycle. In this chapter we will discuss about As extraction potential of various aquatic and semi aquatic weeds from contaminated water, their tolerance mechanism, future scope and their application in future world mitigating As contamination in water resources.


Author(s):  
João Antônio Salvador de Souza ◽  
José Alonso Borba

ABSTRACT The aim of this article was to evaluate the effect of company earnings and of harmonization with IFRS on the readability of Management Reports in the Brazilian stock market. There is a gap to be filled both in the elaboration and adaptation of readability measures to the context studied, as the studies tend to replicate the original formulas, and in identifying the determinants of the readability of Brazilian company reports, as the research in this field remains in its infancy and the results are inconclusive. The results provide indications for investors to identify complex textual information and may help public policymakers to establish a simple writing manual, along the lines of the SEC’s 1998 Plain English Handbook. The modified metrics and the one developed overcome the criticisms regarding the use of readability formulas in accounting research and could be used in substitution of the original metrics in future studies. An econometric model was used that presents the determinants of readability. Readability was calculated for the Results Analysis section of the Management Report. The resulting construct is understood via three attributes: persistence, current performance, and the reference benchmark. Harmonization with IFRS is a dummy variable, which delimits the pre- and post-IFRS periods. The hypotheses were tested in a sample of Brazilian companies made up of 714 company-year observations covering the period from 2006 to 2019. The descriptive results show that there is an apparent improvement in the readability of the reports in the pre- and post-IFRS period comparison. The econometric evidence shows that, in general, companies with persistent and positive earnings present less complex reports and are more likely to have highly readable reports, because managers publish reports with better readability to signal positive results to the market.


2020 ◽  
Vol 8 (4) ◽  
pp. 507 ◽  
Author(s):  
Tiziana Nardi

In agriculture, the wine sector is one of the industries most affected by the sustainability issue. It is responsible for about 0.3% of annual global greenhouse gas emissions from anthropogenic activities. Sustainability in vitiviniculture was firstly linked to vineyard management, where the use of fertilizers, pesticides and heavy metals is a major concern. More recently, the contribution of winemaking, from grape harvest to bottling, has also been considered. Several cellar processes could be improved for reducing the environmental impact of the whole chain, including microbe-driven transformations. This paper reviews the potential of microorganisms and interactions thereof as a natural, environmentally friendly tool to improve the sustainability aspects of winemaking, all along the production chain. The main phases identified as potentially interesting for exploiting microbial activities to lower inputs are: (i) pre-fermentative stages, (ii) alcoholic fermentation, (iii) stage between alcoholic and malolactic fermentation, (iv) malolactic fermentation, (v) stabilization and spoilage risk management, and (vi) by-products and wastewater treatment. The presence of proper yeast or bacterial strains, the management and timing of inoculation of starter cultures, and some appropriate technological modifications that favor selected microbial activities can lead to several positive effects, including (among other) energy savings, reduction of chemical additives such as sulfites, and reuse of certain residues.


2020 ◽  
Vol 81 (10) ◽  
pp. 2244-2249
Author(s):  
U. Utami ◽  
L. Harianie ◽  
N. R. Dunyana ◽  
Romaidi

Abstract Anthropogenic activities such as oil exploration have resulted in an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous bacterial communities have enhanced tolerance to heavy metals, we isolated and characterized culturable lead-resistant bacteria from an oil wastewater sample and determined whether they could reduce lead ions from the medium. The wastewater sample containing indigenous bacteria were taken out from a traditional oil field, Bojonegoro District, East Java, Indonesia, and bacteria were cultured Halomonas complex (HMC) medium containing lead (II) chloride (PbCl2) with different concentrations. Bioaccumulation of lead by heavy-metals resistant bacteria was determined by using atomic absorption spectrophotometry (AAS). Our result found 21 bacterial strains that resist lead ions, of which one strain (RPb5-3) highly resisted to 10 mM. This bacterial strain also exhibited the highest accumulation of Pb, and it could grow at various temperatures, or more than their original environment. The bacterial strains could be used for bioremediation of lead toxicity, especially in oil pollutants.


1999 ◽  
Vol 65 (7) ◽  
pp. 2871-2876 ◽  
Author(s):  
Sandra Iurescia ◽  
Andrea M. Marconi ◽  
Daniela Tofani ◽  
Augusto Gambacorta ◽  
Annalisa Paternò ◽  
...  

ABSTRACT The M1 strain, able to grow on β-myrcene as the sole carbon and energy source, was isolated by an enrichment culture and identified as a Pseudomonas sp. One β-myrcene-negative mutant, called N22, obtained by transposon mutagenesis, accumulated (E)-2-methyl-6-methylen-2,7-octadien-1-ol (or myrcen-8-ol) as a unique β-myrcene biotransformation product. This compound was identified by gas chromatography-mass spectrometry. We cloned and sequenced the DNA regions flanking the transposon and used these fragments to identify the M1 genomic library clones containing the wild-type copy of the interrupted gene. One of the selected cosmids, containing a 22-kb genomic insert, was able to complement the N22 mutant for growth on β-myrcene. A 5,370-bp-long sequence spanning the region interrupted by the transposon in the mutant was determined. We identified four open reading frames, named myrA,myrB, myrC, and myrD, which can potentially code for an aldehyde dehydrogenase, an alcohol dehydrogenase, an acyl-coenzyme A (CoA) synthetase, and an enoyl-CoA hydratase, respectively. myrA, myrB, andmyrC are likely organized in an operon, since they are separated by only 19 and 36 nucleotides (nt), respectively, and no promoter-like sequences have been found in these regions. ThemyrD gene starts 224 nt upstream of myrA and is divergently transcribed. The myrB sequence was found to be completely identical to the one flanking the transposon in the mutant. Therefore, we could ascertain that the transposon had been inserted inside the myrB gene, in complete agreement with the accumulation of (E)-2-methyl-6-methylen-2,7-octadien-1-ol by the mutant. Based on sequence and biotransformation data, we propose a pathway for β-myrcene catabolism in Pseudomonas sp. strain M1.


Author(s):  
Priyanka Chaudhary ◽  
Harmesh Sahay ◽  
Richa Sharma ◽  
Alok Kumar Pandey ◽  
Shashi Bala Singh ◽  
...  

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