scholarly journals Biotransformation Studies on Organochlorine Insecticide, Endosulfan by Indigenous Bacterial Isolate

2017 ◽  
Vol 12 (2) ◽  
pp. 366-376
Author(s):  
M. Supreeth ◽  
N. S. Raju

Aerial application of persistent, bioaccumulative organochlorine pesticide endosulfan on cashew plantations to protect it from mosquito bug has led to contamination of soil and water environments in several parts of South Canara region, India. Endosulfan and its toxic residues like endosulfan sulfate are posing several threats to non-target organisms including humans. Biotransformation of toxic compounds using indigenous microbial strains is considered as safe and cost effective technique in bioremediation. In the present work, the bacterial strain designated as ES-1, has been isolated from the soil by enrichment method. The bacterial strain was found to mineralize endosulfan ˃99% of 100 mg/l completely biotically after 14 days of incubation by forming unknown polar metabolites.Whereas, abiotic degradation resulted in formation of a toxic compound, endosulfan sulfate. Based on 16s rDNA sequence analysis, the strain ES-1 showed 99% similarity to Bacillus sp. The results from the work suggest that, this bacterial strain could be employed for remediation of endosulfan contaminated environments.

2016 ◽  
Vol 73 (12) ◽  
pp. 2896-2903 ◽  
Author(s):  
Lin Wang ◽  
Xiaolin Zhang ◽  
Yongmei Li

Abstract A novel bacterial strain Klebsiella sp. Y1 was isolated from the soil of a constructed wetland, and it was identified based on the 16S rDNA sequence analysis. The co-metabolic degradation of nicosulfuron with glucose by Klebsiella sp. Y1 was investigated. The response surface methodology analysis indicated that the optimal pH and temperature were 7.0 and 35 °C, respectively, for the degradation of nicosulfuron. Under the optimal conditions, the degradation of nicosulfuron fitted Haldane kinetics model well. The removal of nicosulfuron was triggered by the acidification of glucose, which accelerated the hydrolysis of nicosulfuron. Then, the C–N bond of the sulfonylurea bridge was attacked and cleaved. Finally, the detected intermediate 2-amino-4,6-dimethoxypyrimidine was further biodegraded.


2020 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti

Aggregation of amyloid beeta 1-42 (Aβ<sub>42</sub>) peptide causes the formation of clustered deposits knows as amyloid plaques in the brain which leads to neuronal dysfunction and memory loss and associated with many neurological disorders including Alzheimer’s and Parkinson’s. Aβ<sub>42</sub> has core structural motif with phenylalanine at the 19 and 20 positions. The diphenylalanine (FF) residue plays a crucial role in the formation of amyloid fibers and serves as model peptide for studying Aβ<sub>42 </sub>aggregation. FF self-assembles to well-ordered tubular morphology via aromatic pi-pi stackings. Our studies, suggest that the aromatic rings present in the anti-amyloidogenic compounds may interact with the pi-pi stacking interactions present in the FF. Even the compounds which do not have aromatic rings, like cyclodextrin and cucurbituril show anti-amyloid property due to the binding of aromatic ring inside the guest cavity. Hence, our studies also suggest that compounds which may have a functional moiety capable of interacting with the aromatic stacking interactions might be tested for their anti-amyloidogenic properties. Further, in this manuscript, we have proposed two novel nanoparticle based assays for the rapid screening of amyloid inhibitors. In the first assay, interaction between biotin-tagged FF peptide and the streptavidin labelled gold nanoparticles (s-AuNPs) were used. In another assay, thiol-Au interactions were used to develop an assay for detection of amyloid inhibitors. It is envisaged that the proposed analytical method will provide a simple, facile and cost effective technique for the screening of amyloid inhibitors and may be of immense practical implications to find the therapeutic remedies for the diseases associated with the protein aggregation.


2008 ◽  
Vol 53 (No. 3) ◽  
pp. 97-104 ◽  
Author(s):  
M. Zouhar ◽  
M. Marek ◽  
O. Douda ◽  
J. Mazáková ◽  
P. Ryšánek

<i>Ditylenchus dipsaci</i>, the stem nematode, is a migratory endoparasite of over 500 species of angiosperms. The main method of <i>D. dipsaci</i> control is crop rotation, but the presence of morphologically indistinguishable host races with different host preferences makes rotation generally ineffective. Therefore, a sensitive, rapid, reliable, as well as cost effective technique is needed for identification of <i>D. dipsaci</i> in biological samples. This study describes the development of species-specific pairs of PCR oligonucleotides for detection and identification of the <i>D. dipsaci</i> stem nematode in various plant hosts. Designed DIT-2 primer pair specifically amplified a fragment of 325 bp, while DIT-5 primer pair always produced a fragment of 245 bp in all <i>D. dipsaci</i> isolates. Two developed SCAR primer pairs were further tested using template DNA extracted from a collection of twelve healthy plant hosts; no amplification was however observed. The developed PCR protocol has proved to be quite sensitive and able to specifically detect <i>D. dipsaci</i> in artificially infested plant tissues.


Author(s):  
Allicia Ostoposides Imada ◽  
James J. O’Hara ◽  
Ignacio L. Proumen ◽  
Pablo S. Molinari ◽  
Daniel C. Wascher ◽  
...  

2000 ◽  
Vol 58 (2B) ◽  
pp. 424-427 ◽  
Author(s):  
PAULO R. M. DE BITTENCOURT ◽  
MARCOS C. SANDMANN ◽  
MARLUS S. MORO ◽  
JOÃO C. DE ARAÚJO

We revised 16 patients submitted to epilepsy surgery using a new method of digital, real-time, portable electrocorticography. Patients were operated upon over a period of 28 months. There were no complications. The exam was useful in 13 cases. The low installation and operational costs, the reliability and simplicity of the method, indicate it may be useful for defining the epileptogenic regions in a variety of circumnstances, including surgery for tumors, vascular malformations, and other cortical lesions associated with seizure disorders.


2007 ◽  
Vol 53 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Pious Thomas ◽  
Sima Kumari ◽  
Ganiga K. Swarna ◽  
T.K.S. Gowda

Fourteen distinct bacterial clones were isolated from surface-sterilized shoot tips (~1 cm) of papaya (Carica papaya L. ‘Surya’) planted on Murashige and Skoog (MS)-based papaya culture medium (23/50 nos.) during the 2–4 week period following in vitro culturing. These isolates were ascribed to six Gram-negative genera, namely Pantoea ( P. ananatis ), Enterobacter ( E. cloacae ), Brevundimonas ( B. aurantiaca ), Sphingomonas , Methylobacterium ( M. rhodesianum ), and Agrobacterium ( A. tumefaciens ) or two Gram-positive genera, Microbacterium ( M. esteraromaticum ) and Bacillus ( B. benzoevorans ) based on 16S rDNA sequence analysis. Pantoea ananatis was the most frequently isolated organism (70% of the cultures) followed by B. benzoevorans (13%), while others were isolated from single stocks. Bacteria-harboring in vitro cultures often showed a single organism. Pantoea, Enterobacter, and Agrobacterium spp. grew actively on MS-based normal papaya medium, while Microbacterium, Brevundimonas, Bacillus, Sphingomonas, and Methylobacterium spp. failed to grow in the absence of host tissue. Supplying MS medium with tissue extract enhanced the growth of all the organisms in a dose-dependent manner, indicating reliance of the endophyte on its host. Inoculation of papaya seeds with the endophytes (20 h at OD550 = 0.5) led to delayed germination or slow seedling growth initially. However, the inhibition was overcome by 3 months and the seedlings inoculated with Pantoea, Microbacterium, or Sphingomonas spp. displayed significantly better root and shoot growths.


2010 ◽  
Vol 97-101 ◽  
pp. 3803-3806
Author(s):  
Yong Xiang Hu ◽  
Heng Zhang ◽  
Zheng Qiang Yao

Laser interference micro-structuring is a relatively efficient and cost-effective technique for fabricating periodical micro-nano-structuring surfaces. The direct fabrication of sub-micron sized dot array on silicon was performed by four interfering nanosecond laser beams with a diffractive beam splitter. The mechanism to form the dot array was analyzed and it was found that the obtained conical dot array had a negative shape of the interference pattern of four laser beams. A second-order peak between two first-order peaks also occurred due to the liquid-solid expansion.


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