Rational Construction of Bacterial Strains with New/Improved Catabolic Capabilities for the Efficient Breakdown of Environmental Pollutants

AbstractThe present study was conducted to determine the culturable bacterial profile from Kestopur canal (Kolkata, India) and analyze their heavy metal tolerance. In addition to daily sewage including solid and soluble wastes, a considerable load of toxic metals are released into this water body from industries, tanneries and agriculture, household as well as health sectors. Screening out microbes from such an environment was done keeping in mind their multifunctional application especially for bioremediation. Heavy metals are major environmental pollutants when present in high concentration in soil and show potential toxic effects on growth and development in plants and animals. Some edible herbs growing in the canal vicinity, and consumed by people, were found to harbour these heavy metals at sub-toxic levels. The bioconcentration factor of these plants being <1 indicates that they probably only absorb but not accumulate heavy metals. All the thirteen Grampositive bacteria isolated from these plants rhizosphere were found to tolerate high concentration of heavy metals like Co, Ni, Pb, Cr, Fe. Phylogenetic analysis of their 16S rDNA genes revealed that they belonged to one main taxonomic group — the Firmicutes. Seven of them were found to be novel with 92–95% sequence homology with known bacterial strains. Further microbiological analyses show that the alkaliphilic Bacillus weihenstephanensis strain IA1 and Exiguobacterium aestuarii strain CE1, with selective antibiotic sensitivity along with high Ni2+ and Cr6+ removal capabilities, respectively, can be prospective candidates for bioremediation.

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Phytostabilization of Polluted Military Soil Supported by Bioaugmentation with PGP-Trace Element Tolerant Bacteria Isolated from Helianthus petiolaris

Agronomy ◽

10.3390/agronomy10020204 ◽

2020 ◽

Vol 10 (2) ◽

pp. 204 ◽

Cited By ~ 4

Author(s):

Anabel Saran ◽

Valeria Imperato ◽

Lucia Fernandez ◽

Panos Gkorezis ◽

Jan d’Haen ◽

...

Keyword(s):

Plant Growth ◽

Trace Element ◽

Animal Health ◽

Environmental Pollutants ◽

Polluted Soil ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Plant Parts ◽

Trace Element Mobility ◽

Helianthus Petiolaris

Lead (Pb) and cadmium (Cd) are major environmental pollutants, and the accumulation of these elements in soils and plants is of great concern in agricultural production due to their toxic effects on crop growth. Also, these elements can enter into the food chain and severely affect human and animal health. Bioaugmentation with plant growth-promoting bacteria (PGPB) can contribute to an environmentally friendly and effective remediation approach by improving plant survival and promoting element phytostabilization or extraction under such harsh conditions. We isolated and characterised Pb and Cd-tolerant root-associated bacteria from Helianthus petiolaris growing on a Pb/Cd polluted soil in order to compose inoculants that can promote plant growth and also ameliorate the phytostabilization or phytoextraction efficiency. One hundred and five trace element-tolerant rhizospheric and endophytic bacterial strains belonging to eight different genera were isolated from the aromatic plant species Helianthus petiolaris. Most of the strains showed multiple PGP-capabilities, ability to immobilise trace elements on their cell wall, and promotion of seed germination. Bacillus paramycoides ST9, Bacillus wiedmannii ST29, Bacillus proteolyticus ST89, Brevibacterium frigoritolerans ST30, Cellulosimicrobium cellulans ST54 and Methylobacterium sp. ST85 were selected to perform bioaugmentation assays in greenhouse microcosms. After 2 months, seedlings of sunflower (H. annuus) grown on polluted soil and inoculated with B. proteolyticus ST89 produced 40% more biomass compared to the non-inoculated control plants and accumulated 20 % less Pb and 40% less Cd in the aboveground plant parts. In contrast, B. paramycoides ST9 increased the bioaccumulation factor (BAF) of Pb three times and of Cd six times without inhibiting plant growth. Our results indicate that, depending on the strain, bioaugmentation with specific beneficial bacteria can improve plant growth and either reduce trace element mobility or enhance plant trace element uptake.

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The Analysis of Bifenox and Dichlobenil Toxicity in Selected Microorganisms and Human Cancer Cells

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16214137 ◽

2019 ◽

Vol 16 (21) ◽

pp. 4137 ◽

Cited By ~ 1

Author(s):

Agata Jabłońska-Trypuć ◽

Urszula Wydro ◽

Lluis Serra-Majem ◽

Elżbieta Wołejko ◽

Andrzej Butarewicz

Keyword(s):

Oxidative Stress ◽

Mammalian Cells ◽

Human Cancer ◽

Environmental Pollutants ◽

Cellular Level ◽

Human Organism ◽

Bacterial Strains ◽

Human Cancer Cells ◽

Oxidative Stress Parameters ◽

Stress Parameters

Bifenox and Dichlobenil belong to the commonly used in Poland in agriculture group of herbicides and their residues are often detected in the environment. They are poorly known regarding their possible carcinogenic and antibacterial effect at the cellular level. Therefore, we decided to study their activity in bacterial strains Aliivibrio fisheri, E. coli, P. aeruginosa, and C. albicans (yeast) and human cancer ZR-75-1 cells. Compounds under study exhibit stimulatory effect on analyzed bacterial strains. The study performed on mammalian cells better reflects the influence of environmental pollutants on human organism, therefore we evaluated the effect of herbicides on ZR-75-1 cells. Cells viability, apoptosis and selected oxidative stress parameters in ZR-75-1 cells were investigated. Both analyzed substances exhibit stimulatory effects on analyzed parameters, however they do not stimulate apoptosis which correlate positively with the induction of oxidative stress. Bifenox and Dichlobenil enhance oxidative stress parameters by the generation of high levels of ROS, which can lead to their adaptation and resistance to the standard treatment regimen.

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Synthesis of MgAl LDH/Acidified g-C3N4 Heterojunction Photocatalyst for Improved Tetracycline Hydrochloride Degradation Activity

NANO ◽

10.1142/s1793292019500668 ◽

2019 ◽

Vol 14 (06) ◽

pp. 1950066 ◽

Cited By ~ 1

Author(s):

Xinyao Li ◽

Jinjuan Xue ◽

Shuaishuai Ma ◽

Peng Xu ◽

Chengjuan Huang ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Diffuse Reflectance Spectroscopy ◽

Environmental Pollutants ◽

Three Dimensional ◽

Tetracycline Hydrochloride ◽

X Ray ◽

Coating Method ◽

Rational Construction

A novel heterojunction photocatalyst consisting of three-dimensional (3D) flower-like MgAl LDH and acidified g-C3N4 (CN-H) was first developed by a simple facile coating method. The obtained MgAl LDH/CN-H samples were thoroughly characterized by powder X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and Brunauer–Emmett–Teller (BET) analyzer. The detailed results demonstrated that g-C3N4 could transform from a generally two-dimensional layered structure into special cavity-like structure after acid treatment. CN-H increased specific surface to expose more active reaction sites in comparison to pristine g-C3N4. MgAl LDH and CN-H with matched band gaps were tightly bonded to form heterojunction structure by strong electrostatic intercalation. The combination could obviously boost the separation of photogenerated carriers. The as-prepared MgAl LDH/CN-H exhibited high photocatalytic performance in the degrading on typical antibiotic tetracycline hydrochloride (TC[Formula: see text][Formula: see text][Formula: see text]HCl), of which degradation rate was 6.5 and even 22 times higher than that of MgAl LDH and pristine g-C3N4, respectively. The synthesis of MgAl LDH/CN-H heterojunction photocatalyst could have some positive suggestions for the rational construction of new photocatalysts and also has great application prospect in the degradation of environmental pollutants.

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Cultivatable bacterial community at a fresh water nullah contaminated with household sewage and industrial waste is more diverse and populated compared to non-polluted water

Canadian Journal of Soil Science ◽

10.1139/cjss-2021-0019 ◽

2021 ◽

Author(s):

Wishal Khan ◽

Sobia Yaseen ◽

Abdul Waheed ◽

Zuhair Hasnain ◽

Zahra Jabeen ◽

...

Keyword(s):

Heavy Metals ◽

Bacterial Community ◽

Bacterial Community Composition ◽

Environmental Pollutants ◽

Oxygen Demand ◽

Polluted Water ◽

Rrna Gene ◽

Bacterial Strains ◽

Broth Microdilution Method ◽

Acinetobacter Guillouiae

The effect of environmental pollutants on living organisms can be assessed by studying the changes in the indigenous microbial community. Therefore, in the present study, cultivatable bacterial community in non-polluted as well as household sewage and industrially polluted water of Lai Nullah flowing through Islamabad-Rawalpindi, Pakistan was analysed. Bacterial community composition and population present in the polluted water was significantly different from the non-polluted water (P < 0.05). Non-polluted water had much fewer species and population of bacteria compared to polluted water. Sequence analysis of bacterial 16S rRNA gene revealed that Citrobacter freundii, Klebsiella pneumoniae, Escherichia coli, Lactobacillus plantarum, Geobacillus stearothermophilus, Enterococcus faecalis, Acinetobacter guillouiae, Ralstonia sp., Comamonas sp. and Stenotrophomonas maltophilia were specific to the polluted water. On the other hand, Aeromonas veronii, Exiguobacterium sp. and Lysinibacillus macroides were only found in the non-polluted water. Among measured physicochemical parameters, higher colony count in the polluted water was best correlated with higher biological oxygen demand, phosphate, sodium and chloride values (Spearman's rho = 0.85). Concentration of heavy metals such as cadmium, chromium, copper, nickel and lead were below 0.03μg/mL at all the study sites. During plate assay, bacterial strains found at polluted sites showed resistance to selected heavy metals with highest minimum inhibitory concentration for lead (8mM) followed by copper (5mM), nickel (3mM) and cadmium (1mM). All the bacterial isolates also showed various levels of resistance against antibiotics ampicillin, tetracycline, ciprofloxacin and vancomycin using broth microdilution method. Current research provides new insight into the effect of household sewage and industrially polluted water of Lai Nullah on the indigenous bacteria".

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Exploring the Bacterial Communities of Infernaccio Waterfalls: A Phenotypic and Molecular Characterization of Acinetobacter and Pseudomonas Strains Living in a Red Epilithic Biofilm

Diversity ◽

10.3390/d11100175 ◽

2019 ◽

Vol 11 (10) ◽

pp. 175 ◽

Cited By ~ 1

Author(s):

Carolina Chiellini ◽

Sofia Chioccioli ◽

Alberto Vassallo ◽

Stefano Mocali ◽

Elisangela Miceli ◽

...

Keyword(s):

Heavy Metals ◽

Bacterial Communities ◽

High Throughput Sequencing ◽

Rapd Analysis ◽

Environmental Pollutants ◽

Biotechnological Applications ◽

Bacterial Strains ◽

Bacterial Composition ◽

Cultivable Bacteria

Acquarossa river (Viterbo, Italy) was the site of a prospering Etruscan civilization thanks to metallurgical activity around 625–550 B.C. This caused the spread of heavy metals throughout the area. Rocks along the river probably act as a filter for these elements and they are covered by two different biofilms (epilithons). They differ for both color and bacterial composition. One is red and is enriched with Pseudomonas strains, while the other one is black and Acinetobacter is the most represented genus. Along the river lay the Infernaccio waterfalls, whose surrounding rocks are covered only by the red epilithon. The bacterial composition of this biofilm was analyzed through high throughput sequencing and compared to those ones of red and black epilithons of Acquarossa river. Moreover, cultivable bacteria were isolated and their phenotype (i.e., resistance against antibiotics and heavy metals) was studied. As previously observed in the case of Acquarossa river, characterization of bacterial composition of the Infernaccio red epilithon revealed that the two most represented genera were Acinetobacter and Pseudomonas. Nonetheless, these strains differed from those isolated from Acquarossa, as revealed by RAPD analysis. This work, besides increasing knowledge about the ecological properties of this site, allowed to isolate new bacterial strains, which could potentially be exploited for biotechnological applications, because of their resistance against environmental pollutants.

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Potential Enhancement of the In-Situ Bioremediation of Contaminated Sites through the Isolation and Screening of Bacterial Strains in Natural Hydrocarbon Springs

Water ◽

10.3390/w12082090 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2090 ◽

Cited By ~ 1

Author(s):

Pietro Rizzo ◽

Matilde Malerba ◽

Antonio Bucci ◽

Anna M. Sanangelantoni ◽

Sara Remelli ◽

...

Keyword(s):

Environmental Pollutants ◽

Hydrocarbon Contamination ◽

Microbial Consortia ◽

Contaminated Sites ◽

Bacterial Strains ◽

Promoting Effect ◽

Isolation And Identification ◽

Petroleum Hydrocarbon Contamination ◽

Emulsifying Capacity ◽

A Site

Petroleum hydrocarbon contamination (PHC) is an issue of major concern worldwide. These compounds represent the most common environmental pollutants and their cleaning up is mandatory. The main goal of this research was to analyze microbial communities in a site in southern Italy characterized by the presence of hydrocarbons of natural origin by using a multidisciplinary approach based on microbiological, geological and hydrological investigations. Bacterial communities of two springs, the surrounding soils, and groundwater were studied through a combination of molecular and culture-dependent methodologies to explore the biodiversity at the study site, to isolate microorganisms with degradative abilities, and to assess their potential to develop effective strategies to restore the environmental quality. Next-generation sequencing revealed the dominance of species of the Proteobacteria phylum but also the presence of other autochthonous hydrocarbon-oxidizing microorganisms affiliated to other phyla (e.g., species of the genera Flavobacterium and Gordonia). The traditional cultivation-based approach led to the isolation and identification of 11 aerobic hydrocarbon-oxidizing proteobacteria, some of which were able to grow with phenanthrene as the sole carbon source. Seven out of the 11 isolated bacterial strains produced emulsion with diesel fuel (most of them showing emulsifying capacity values greater than 50%) with a high stability after 24 h and, in some cases, after 48 h. These results pave the way for further investigations finalized at (1) exploiting both the degradation ability of the bacterial isolates and/or microbial consortia to remediate hydrocarbon-contaminated sites and (2) the capability to produce molecules with a promoting effect for oil polluted matrices restoration.

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