scholarly journals Enhanced Cypermethrin Degradation Kinetics and Metabolic Pathway in Bacillus thuringiensis Strain SG4

2020 ◽  
Vol 8 (2) ◽  
pp. 223 ◽  
Author(s):  
Pankaj Bhatt ◽  
Yaohua Huang ◽  
Wenping Zhang ◽  
Anita Sharma ◽  
Shaohua Chen
Keyword(s):  
Bacillus Thuringiensis ◽  
Metabolic Pathway ◽  
Large Scale ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Active Role ◽  
Minimal Salt Medium ◽  
Bacterial Strains ◽  
Soil Slurry ◽  
Thuringiensis Strain

Cypermethrin is popularly used as an insecticide in households and agricultural fields, resulting in serious environmental contamination. Rapid and effective techniques that minimize or remove insecticidal residues from the environment are urgently required. However, the currently available cypermethrin-degrading bacterial strains are suboptimal. We aimed to characterize the kinetics and metabolic pathway of highly efficient cypermethrin-degrading Bacillus thuringiensis strain SG4. Strain SG4 effectively degraded cypermethrin under different conditions. The maximum degradation was observed at 32 °C, pH 7.0, and a shaking speed of 110 rpm, and about 80% of the initial dose of cypermethrin (50 mg·L−1) was degraded in minimal salt medium within 15 days. SG4 cells immobilized with sodium alginate provided a higher degradation rate (85.0%) and lower half-life (t1/2) of 5.3 days compared to the 52.9 days of the control. Bioaugmentation of cypermethrin-contaminated soil slurry with strain SG4 significantly enhanced its biodegradation (83.3%). Analysis of the degradation products led to identification of nine metabolites of cypermethrin, which revealed that cypermethrin could be degraded first by cleavage of its ester bond, followed by degradation of the benzene ring, and subsequent metabolism. A new degradation pathway for cypermethrin was proposed based on analysis of the metabolites. We investigated the active role of B. thuringiensis strain SG4 in cypermethrin degradation under various conditions that could be applied in large-scale pollutant treatment.

Phyto-fabrication of Iron Nanoparticles: Characterization and Antibacterial Capacity

2020 ◽  
Vol 16 ◽  
Author(s):  
Asma S. Algebaly ◽  
Afrah E. Mohammed ◽  
Mudawi M. Elobeid
Keyword(s):  
Electron Microscopy ◽  
Plant Extracts ◽  
Large Scale ◽  
Iron Nanoparticles ◽  
Ethanolic Extract ◽  
Green Technology ◽  
Resistant Bacteria ◽  
Scale Production ◽  
Bacterial Strains ◽  
Plant Sources

Introduction: Fabrication of iron nanoparticles (FeNPs) has recently gained a great concern for their varied applications in remediation technologies of the environment. Objective: The current study aimed to fabricate iron nanoparticles by green technology approach using different plant sources, Azadirachta indica leaf and Calligonum comosum root following two extraction methods. Methods: Currently, a mixture of FeCl2 and FeCl3 was used to react with the plant extracts which are considered as reducing and stabilizing agents for the generation of FeNPs in one step. Different techniques were used for FeNPs identification. Results: Immediately after mixing of the two reaction components, the color changed to dark brown as an indication of safe conversion of Fe ions to FeNPs, that later confirmed by zeta sizer, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). FeNPs fabricated by C. comosum showed smaller size when compared by those fabricated by A. indica. Using both plant sources, FeNPs fabricated by the aqueous extract had smaller size in relation to those fabricated by ethanolic extract. Furthermore, antibacterial ability against two bacterial strains was approved. Conclusion: The current results indicated that, at room temperature plant extracts fabricated Fe ion to Fe nanoparticles, suggesting its probable usage for large scale production as well as its suitability against bacteria. It could also be recommended for antibiotic resistant bacteria.

Multi-chain action of exo-D-galacturonanase from carrot

1983 ◽  
Vol 48 (12) ◽  
pp. 3579-3588
Author(s):  
Kveta Heinrichová ◽  
Jana Perečková
Keyword(s):  
Optimal Condition ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Hydrolytic Cleavage ◽  
Chain Mechanism ◽  
Modes Of Action ◽  
Enzyme Degradation ◽  
Good Agreement

Two possible modes of action of exo-D-galacturonanase from carrot (E.C. 3.2.1.67) were investigated; this enzyme catalyses the sequential hydrolytic cleavage of pectants and oligogalacturonans by a terminal action from the nonreducing end of the molecule. The experiments indicate that the investigated exo-D-galacturonanase degrades these substrates by a predominantly multi-chain mechanism. Distribution of degradation products of oligomeric substrates (hexa- and pentagalacturonide) under an optimal condition for the action of the enzyme (pH and temperature) indicates that a multi-chain enzyme attack with a prevalent simple collision is involved. Results of the enzyme degradation kinetics are in a good agreement with the above-mentioned presumption.

scholarly journals The in vitro assessment of the toxicity of volatile, oxidisable, redox-cycling compounds: phenols as an example

2021 ◽  
Author(s):  
Laia Tolosa ◽  
Teresa Martínez-Sena ◽  
Johannes P. Schimming ◽  
Erika Moro ◽  
Sylvia E. Escher ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Redox Cycling ◽  
In Vitro Toxicity ◽  
Cross Contamination ◽  
Physicochemical Changes ◽  
In Vitro Assessment ◽  
Biological Performance

AbstractPhenols are regarded as highly toxic chemicals. Their effects are difficult to study in in vitro systems because of their ambiguous fate (degradation, auto-oxidation and volatility). In the course of in vitro studies of a series of redox-cycling phenols, we found evidences of cross-contamination in several in vitro high-throughput test systems, in particular by trimethylbenzene-1, 4-diol/trimethylhydroquinone (TMHQ) and 2,6-di-tertbutyl-4-ethylphenol (DTBEP), and investigated in detail the physicochemical basis for such phenomenon and how to prevent it. TMHQ has fast degradation kinetics followed by significant diffusion rates of the resulting quinone to adjacent wells, other degradation products being able to air-diffuse as well. DTBEP showed lower degradation kinetics, but a higher diffusion rate. In both cases the in vitro toxicity was underestimated because of a decrease in concentration, in addition to cross-contamination to neighbouring wells. We identified four degradation products for TMHQ and five for DTBEP indicating that the current effects measured on cells are not only attributable to the parent phenolic compound. To overcome these drawbacks, we investigated in detail the physicochemical changes occurring in the course of the incubation and made use of gas-permeable and non-permeable plastic seals to prevent it. Diffusion was greatly prevented by the use of both plastic seals, as revealed by GC–MS analysis. Gas non-permeable plastic seals, reduced to a minimum compounds diffusion as well oxidation and did not affect the biological performance of cultured cells. Hence, no toxicological cross-contamination was observed in neighbouring wells, thus allowing a more reliable in vitro assessment of phenol-induced toxicity.

scholarly journals Biodegradation of 5-(Hydroxymethyl)-furfural and Furan Derivatives

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1283 ◽  
Author(s):  
María Isabel Igeño ◽  
Rubén Sánchez-Clemente ◽  
Ana G. Población ◽  
M. Isabel Guijo ◽  
Faustino Merchán ◽  
...  
Keyword(s):  
Furan Ring ◽  
Degradation Products ◽  
Chemical Compounds ◽  
Aldehyde Group ◽  
Bacterial Strains ◽  
Fermentation Inhibitors ◽  
Furan Derivatives ◽  
Hydroxymethyl Furfural ◽  
Common Thread ◽  
Lignocellulose Hydrolysates

Furfural and 5-hydroxymethylfurfural (HMF) are degradation products of lignocellulose during pretreatment operations. Furfural compounds are a group of chemical compounds whose common thread is an aldehyde group attached to a furan ring, and they constitute a problem for the development of second-generation biofuels because they act as fermentation inhibitors of the lignocellulose hydrolysates. Up to date, very few bacteria have been described to be able to eliminate them. The objective of this work was to isolate and characterize bacterial strains able to use, as the sole carbon source, 5-(hydroxymethyl)-furfural (HMF) and furan derivatives.

Dual Insecticidal Activity of Spodoptera-Toxic Bacillus thuringiensis Strain Transformed with Lepidopteran-Specific Cry Toxin

2007 ◽  
Vol 10 (2) ◽  
pp. 137-143
Author(s):  
Joong Nam Kang ◽  
Jong Yul Roh ◽  
Sang Chul Shin ◽  
Sang-Hyun Koh ◽  
Yeong Jin Chung ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insecticidal Activity ◽  
Cry Toxin ◽  
Thuringiensis Strain

scholarly journals Potential of Flocculant-Aided Soil Slurry Dewatering in Land Reclamation: Laboratory Investigations

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yang Jiao ◽  
Jia He ◽  
Peiyuan Zhou ◽  
Ziqian Cao
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Land Reclamation ◽  
Drainage Water ◽  
Tube Model ◽  
Soil Slurry ◽  
Vacuum Preloading ◽  
Geotextile Tube ◽  
Laboratory Investigations ◽  
Flocculation Effect

When soil slurry is used as a fill material in land reclamation projects, vacuum preloading or geotextile tube systems are often adopted for the dewatering treatment in a large scale. However, these two methods often suffer from clogging problems and impede further dewatering treatment. In this study, we test the potential of using flocculants to enhance the dewatering efficiency in a vacuum preloading model test and a geotextile tube model test. Experimental results show that, by adding a flocculant into soil slurry, the dewatering efficiency in terms of drainage volumes and rates is significantly improved as compared to that in pure soil slurry. The amounts of drainage water in the tests with flocculant addition are about 20% and 100% more than those in pure slurry tests in the vacuum preloading and geotextile tube model tests, respectively. The underlying reason could be the flocculation effect that prevents the movement of small soil grains and the formation of impermeable layers on the filters.

Control of chironomid midge larvae in wastewater stabilisation ponds: comparison of five compounds

2005 ◽  
Vol 51 (12) ◽  
pp. 191-199 ◽  
Author(s):  
R. Craggs ◽  
L. Golding ◽  
S. Clearwater ◽  
L. Susarla ◽  
W. Donovan
Keyword(s):  
New Zealand ◽  
Bacillus Thuringiensis ◽  
Urban Areas ◽  
Large Scale ◽  
Adult Emergence ◽  
Small Scale ◽  
Slight Reduction ◽  
Organic Loading ◽  
Valuable Component ◽  
Pre Treatment

Chironomid midge larvae are a valuable component of wastewater stabilisation pond (WSP) ecology. However, in high numbers, adult midge swarms can be a nuisance to near-by urban areas. Improving WSP treatment by incorporating aerobic or maturation ponds or by the addition of pre-treatment to reduce organic loading also increases the availability of aerobic sediment (midge larva habitat) in the pond system and the potential for midge nuisance problems. The efficacy of Maldison, an organophosphate traditionally used to control midge larvae in New Zealand WSPs, was compared to Bacillus thuringiensis var. israelensis (Bti), Methoprene, Pyriproxyfen and Diflubenzuron which are all more specific to insects and have fewer adverse environmental effects. Initial laboratory trials established the concentration of each compound required to achieve 95% control of the midge population. During 21-day small-scale trials within the WSP, Bti, Diflubenzuron and Maldison reduced live larvae numbers substantially (80–89%) compared to controls and adult midge emergence was markedly reduced by all compounds (72–96%). Large-scale trials with Bti (Vectobac® WG) powder (1000 μg/L) only caused a slight reduction in midge larvae numbers compared to controls and had little effect on adult emergence, however, Methoprene (Prolink XRG granules) (50 μgAI/L) reduced midge adult emergence by ∼80% over 25 days and has been used successfully to control several midge nuisance outbreaks.

scholarly journals Biodegradation of two organic UV-Filters by single bacteria strains

2021 ◽  
Author(s):  
Florentina Laura Chiriac ◽  
Catalina Stoica ◽  
Iuiana Paun ◽  
Florinela Pirvu ◽  
Toma Galaon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Emerging Contaminants ◽  
Degradation Products ◽  
Aquatic Organisms ◽  
Uv Filters ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Biodegradation Process ◽  
Salmonella Thyphimurium ◽  
Organic Uv Filters

Abstract Organic UV-filters, including 4-hydroxybenzophenone (4-HBP) and 2,4-dihydroxybenzophenone (BP-1), are persistent emerging contaminants whose presence in the environment poses a threat to aquatic organisms due to their endocrine disruptor’s properties. For this reason, finding suitable technological processes for their safety and efficient removal from the environment represent a priority for the scientific community. To the author’s knowledge, until now, there are no studies reporting the biodegradation of 4-HBP and BP-1 by a single bacteria strain. In this paper, there were tested the 4-HBP and BP-1 biodegradation potential of two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Salmonella typhimurium and Serratia rubidae). The 4-HPB biodegradation process was observed only in the presence of Gram-negative bacterial strains. Thus, the biodegradation rates of 4-HBP reached up to 12.7% after 24h of incubation in presence of Salmonella thyphimurium and up to 24.0% after 24h of incubation with Serratia rubidae. Staphylococcus aureus was able to biodegrade 26.7% of BP-1, while Salmonella thiphymurium was able to biodegrade 14.7% of BP-1 after 24h of incubation. Their biodegradation products generated during the 4-HBP biodegradation process by Serratia rubidae were analyzed through LC-MS/MS analysis. The (bio)degradation products were benzophenone and a multi-hydroxylated derivative of 4-HBP and the degradation pathways were proposed. The data obtained in this study gave important information regarding the 4-HBP and BP-1 potential biodegradation by single bacterial strains.

Sign in / Sign up

Export Citation Format

Share Document