scholarly journals Degradation of polystyrene by tropical bacterial and fungal isolates

2021 ◽  
Vol 25 (9) ◽  
pp. 1721-1727
Author(s):  
O.S. Akerele ◽  
O.M. Buraimoh ◽  
I. Humphrey ◽  
M.O. Ilori
Keyword(s):  
Solid Wastes ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Contributing Factors ◽  
Municipal Solid Wastes ◽  
Mineral Salts ◽  
Spectrometry Analysis ◽  
Fungal Isolates ◽  
Significant Difference ◽  
One Way Anova

Plastic waste is one of the major contributing factors to the growth of municipal solid wastes globally. It is a threat to public health and negatively impact the aquatic and terrestrial animals due to its persistence in the environment. Bacterial and fungal isolates were tested for their ability to degrade polystyrene. The cultures were grown on mineral salts medium supplemented with polystyrene as the sole carbon source in 250 mL conical flasks. The polystyrene reduced from 1 g (week 0) to 0.7g (week 7). Statistical analysis of variance (one-way ANOVA) shows a significant difference between the reduction in weight of polystyrene in the experimental flask compared to the control (P<0.05). Gas chromatography mass spectrometry analysis of biodegradation products shows that some toxic polystyrene constituents such as O-xylene, cis-9-hexadecenal and 3-phenol pentadecyl were removed.

Acaricidal properties of the essential oil from Aristolochia trilobata and its major constituents against the two-spotted spider mite (Tetranychus urticae)

2018 ◽  
Vol 98 (6) ◽  
pp. 1342-1348 ◽  
Author(s):  
João Paulo Ramos de Melo ◽  
Claudio Augusto Gomes da Camara ◽  
Gesiane da Silva Lima ◽  
Marcilio Martins de Moraes ◽  
Pericles Barreto Alves
Keyword(s):  
Essential Oil ◽  
Tetranychus Urticae ◽  
Cost Benefit ◽  
Northeastern Brazil ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Artificial Mixture ◽  
Significant Difference ◽  
Cost Benefit Ratio

Tetranychus urticae Koch is a polyphagous pest that is widely distributed throughout the world and causes considerable damage to crops in northeastern Brazil. The effects of the essential oil from Aristolochia trilobata L., selected constituents, and an artificial mixture (sulcatyl acetate, limonene, linalool, and p-cymene) on T. urticae in terms of fumigant action, residual contact, and fecundity were investigated under laboratory conditions. The results were compared with eugenol, Azamax®, and Ortus® as positive controls. Gas chromatography–mass spectrometry analysis of the oil revealed a predominance of monoterpenes, with sulcatyl acetate (24.57% ± 0.40%) as the major component, followed by linalool (10.80% ± 0.27%). Toxicity varied with the method employed. Through fumigation, the A. trilobata oil was about 2.18-fold more toxic than the artificial mixture, whereas no significant difference between the two products was found with regard to residual contact. Regarding the selected compounds, the mite was most susceptible to linalool and p-cymene by fumigation and residual contact, respectively. The plant-based (Azamax®) and synthetic (Ortus®) acaricidal agents were more toxic than the products tested. Moreover, low concentrations of the products investigated herein had no effect on mite survival, but a significant effect was found on the quantity of eggs laid by females. The A. trilobata oil and artificial mixture are promising natural acaricidal agents that have more than one mode of action (fumigation and residual contact) and exert an effect on fecundity. However, further studies are needed to evaluate the cost–benefit ratio for use on organic crops and protected environments in northeastern Brazil.

Spectrophotometry Measurement of Polynuclear Aromatic Hydrocarbons in Hamilton Harbour Sediments

1991 ◽  
Vol 26 (1) ◽  
pp. 1-16 ◽  
Author(s):  
T.P. Murphy ◽  
H. Brouwer ◽  
M.E. Fox ◽  
E. Nagy
Keyword(s):  
Aromatic Hydrocarbons ◽  
Total Concentration ◽  
Coal Tar ◽  
Sediment Cores ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Near Surface ◽  
Spectrometry Analysis ◽  
Hamilton Harbour

Abstract Eighty-one sediment cores were collected to determine the extent of coal tar contamination in a toxic area of Hamilton Harbour. Over 800 samples were analyzed by a UV spectrophotometric technique that was standardized with gas chromatography/mass spectrometry analysis. The coal tar distribution was variable. The highest concentrations were near the Stelco outfalls and the Hamilton-Wentworth combined sewer outfalls. The total concentration of the 16 polynuclear aromatic hydrocarbons (PAHs) in 48,300 m3 of near-surface sediments exceeded 200 µg/g.

scholarly journals Biodegradation and metabolic pathway of fenvalerate by Citrobacter freundii CD-9

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jie Tang ◽  
Dan Lei ◽  
Min Wu ◽  
Qiong Hu ◽  
Qing Zhang
Keyword(s):  
Environmental Pollution ◽  
Environmental Remediation ◽  
High Efficiency ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Citrobacter Freundii ◽  
16S Rrna Sequence ◽  
Intracellular Enzyme ◽  
Pyrethroid Insecticides ◽  
Spectrometry Analysis

Abstract Fenvalerate is a pyrethroid insecticide with rapid action, strong targeting, broad spectrum, and high efficiency. However, continued use of fenvalerate has resulted in its widespread presence as a pollutant in surface streams and soils, causing serious environmental pollution. Pesticide residues in the soil are closely related to food safety, yet little is known regarding the kinetics and metabolic behaviors of fenvalerate. In this study, a fenvalerate-degrading microbial strain, CD-9, isolated from factory sludge, was identified as Citrobacter freundii based on morphological, physio-biochemical, and 16S rRNA sequence analysis. Response surface methodology analysis showed that the optimum conditions for fenvalerate degradation by CD-9 were pH 6.3, substrate concentration 77 mg/L, and inoculum amount 6% (v/v). Under these conditions, approximately 88% of fenvalerate present was degraded within 72 h of culture. Based on high-performance liquid chromatography and gas chromatography-mass spectrometry analysis, ten metabolites were confirmed after the degradation of fenvalerate by strain CD-9. Among them, o-phthalaldehyde is a new metabolite for fenvalerate degradation. Based on the identified metabolites, a possible degradation pathway of fenvalerate by C. freundii CD-9 was proposed. Furthermore, the enzyme localization method was used to study CD-9 bacteria and determine that its degrading enzyme is an intracellular enzyme. The degradation rate of fenvalerate by a crude enzyme solution for over 30 min was 73.87%. These results showed that strain CD-9 may be a suitable organism to eliminate environmental pollution by pyrethroid insecticides and provide a future reference for the preparation of microbial degradation agents and environmental remediation.

Feline Spongy Encephalopathy With a Mutation in the ASPA Gene

2021 ◽  
pp. 030098582110021
Author(s):  
Yuta Takaichi ◽  
James K. Chambers ◽  
Moeko Shiroma-Kohyama ◽  
Makoto Haritani ◽  
Yumi Une ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Canavan Disease ◽  
Mass Spectrometry Analysis ◽  
Intensity Change ◽  
Gas Chromatography Mass Spectrometry ◽  
Clinical Genetic ◽  
Gene Encoding ◽  
Spongy Degeneration ◽  
Spectrometry Analysis ◽  
Dense Granules

Canavan disease is an autosomal recessive leukodystrophy caused by mutations in the gene encoding aspartoacylase (ASPA), which hydrolyses N-acetylaspartate (NAA) to acetate and aspartate. A similar feline neurodegenerative disease associated with a mutation in the ASPA gene is reported herein. Comprehensive clinical, genetic, and pathological analyses were performed on 4 affected cats. Gait disturbance and head tremors initially appeared at 1 to 19 months of age. These cats eventually exhibited dysstasia and seizures and died at 7 to 53 months of age. Magnetic resonance imaging of the brain revealed diffuse symmetrical intensity change of the cerebral cortex, brainstem, and cerebellum. Gas chromatography–mass spectrometry analysis of urine showed significant excretion of NAA. Genetic analysis of the 4 affected cats identified a missense mutation (c.859G>C) in exon 6 of the ASPA gene, which was not detected in 4 neurologically intact cats examined as controls. Postmortem analysis revealed vacuolar changes predominantly distributed in the gray matter of the cerebrum and brain stem as well as in the cerebellar Purkinje cell layer. Immunohistochemically, these vacuoles were surrounded by neurofilaments and sometimes contained MBP- and Olig2-positive cells. Ultrastructurally, a large number of intracytoplasmic vacuoles containing mitochondria and electron-dense granules were detected in the cerebral cortex. All 4 cats were diagnosed as spongy encephalopathy with a mutation in the ASPA gene, a syndrome analogous to human Canavan disease. The histopathological findings suggest that feline ASPA deficiency induces intracytoplasmic edema in neurons and oligodendrocytes, resulting in spongy degeneration of the central nervous system.

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