Properties of electrode-attached biofilms for application to microbial fuel cells

Energy, in any form, plays the most important role in the modern world. We have been dependent on conventional energy sources such as coal and petroleum product for quite a long time. Therefore, there is an alarming need for more environmentally sustainable alternative energy resources. This thesis focuses on studies of microbial fuel cells (MFC). MFC devices use electro active bacteria to oxidize organic substrates degrading wastes and generating electricity. In the present study the effect of bacterial biofilms thickness, charge transport and power generation was studied in single chamber electrochemical cell using acetate as an electron donor. The thicker biofilms display higher charge transport diffusion co-efficient than that in thinner films, as increased film porosity of these films improves ion transport, required to maintain electro-neutrality upon electrolysis. Quartz crystal microbalance (QCM) technique was used to understand the effect of initial electro active bacterial attachment and deposition on gold electrode. It was observed that the viscoelastic properties of the biofilm increased as function of time leading to the better current generation. An attempt has been made to produce low cost MFC from the earthen plate, without involving any costly membrane. The material of the earthen plate used is found to be effective for ion transfer. The earthen plate separator is 99 % cheaper than the Nafion membrane, showing promise as an alternate separator for application to MFC technology. The proteomics analysis of Geobacter sulfurreducens growth on carbon cloth electrodes versus planktonic cells revealed different protein expression depending on the nature the of terminal electron acceptor. The majority of the proteins are localized in the cell membrane and involved in energy metabolism, binding and transport functional categories. In the present study the effect of influent chemical oxygen demand (COD) concentration (2000-4000 mg/L) and feed temperature (15 ºC - 32 ºC) on COD removal efficiency and power generation was studied in dual chambered MFC treating synthetic and real dairy wastewater. The results demonstrate the feasibility of novel MFC configuration for an effective wastewater treatment technology which ensures better reliable effluent quality

Comparison of performance of an earthen plate and nafion as membrane separators in dual chamber microbial fuel cells

The performance of microbial fuel cells (MFC) employing an earthen plate as a membrane separator is compared to that using Nafion 117 in an identical up-flow dual-chambered cylindrical cell configuration. The MFC configuration is of a cylindrical outer cathode chamber separated by the membrane from a concentric rectangular inner anode chamber. The fuel cells, operated under continuous mode at hydraulic retention time of 12 hr, achieved average chemical oxygen demand removal efficiency of 60% and 48%, for the Nafion and earthen plate separators, respectively. The microbial fuel cells based on the earthen plate separator generated slightly lower average (28%) and maximum (48%) power densities than Nafion separator which is likely due to the higher membrane resistance. The earthen plate separator is 99% cheaper than the Nafion membrane, showing promise as an alternate separator for application to MFC technology.Support for this research was provided by a Charles Parsons Energy Research Award through Science Foundation Ireland.peer-reviewe

The effect of the lunar cycle on frequency of births: A retrospective observational study in Indian population

For ancient period moon has been held responsible for many biological activities. That way, lunar cycle, by activity of moon, has been held responsible for increase in number of child birth. In this retrospective, observational study, we examined a total of 9890 full-term spontaneous deliveries as well as non-elective cesarean sections that occurred throughout 12 lunar months (February 7 th , 2008-January 25 th , 2009) in a rural medical college to evaluate the influence of the lunar position on the distribution of deliveries among Indian population. Student′s ′t′ test and ANOVA were used for statistical analysis where each delivery was considered as a single measure. We found no significant differences in the frequency of births during various phase of lunar cycle regardless of route of delivery. Our observations do not support the hypothesis of a relationship between lunar cycle and the frequency of obstetric deliveries

Charge transport in films of Geobacter sulfurreducens on graphite electrodes as a function of film thickness

Charge transport throughGeobacter sulfurreducensbiofilms increases with film thickness, as more porous films improves ion transport upon electrolysis.</p

Detection of emerging antibiotic resistance in bacteria isolated from subclinical mastitis in cattle in West Bengal

Aim: The aim of this work was to detect antibiotic resistance in Gram-negative bacteria isolated from subclinical mastitis in cattle in West Bengal. Materials and Methods: The milk samples were collected from the cattle suffering with subclinical mastitis in West Bengal. The milk samples were inoculated into the nutrient broth and incubated at 37°C. On the next day, the growth was transferred into nutrient agar and MacConkey agar. All the pure cultures obtained from nutrient agar slant were subjected to Gram-staining and standard biochemical tests. All the bacterial isolates were tested in vitro for their sensitivity to different antibiotics commonly used in veterinary practices. All Gram-negative isolates including positive control were subjected to polymerase chain reaction (PCR) for detection of blaCTX-M, blaTEM, blaSHV, blaVIM, tetA, tetB, tetC, and tetM genes considered for extended-spectrum β-lactamase (ESBL), metallo-β-lactamase, and tetracycline resistance. Results: In total, 50 Gram-negative organisms (Escherichia coli, Proteus, Pseudomonas, Klebsiella, and Enterobacter) were isolated from milk samples of subclinical mastitis infected cattle. Among these Gram-negative isolates, 48% (24/50) were found either ESBL producing or tetracycline resistant. Out of total 50 Gram-negative isolates, blaCTX-M was detected in 18 (36%) isolates, and 6 (12%) harbored blaTEM genes in PCR. None of the isolates carried blaSHV genes. Further, in this study, 5 (10%) isolates harbored tet(A) gene, and 8 (16%) isolates carried tet(B) gene. No tet(C) gene was detected from the isolates. Conclusion: This study showed emerging trend of antibiotic-resistant Gram-negative bacteria associated with subclinical mastitis in cattle in West Bengal, India

Development of nested polymerase chain reaction-based diagnosis of duck enteritis virus and detection of DNA polymerase gene from non-descriptive duck breeds of West Bengal, India

Aim: The study was undertaken to detect the clinical signs, postmortem lesions of embryonated duck plague (DP) infected eggs, and histopathological changes of chorioallantoic membrane (CAM) in non-descriptive ducks of West Bengal with special reference to standardize nested polymerase chain reaction (PCR). Materials and Methods: After postmortem of suspected carcasses, samples were collected for virus isolation and identification through specific pathogen free (Khaki Campbell) embryonated duck eggs. PCR was also done as confirmatory test after doing postmortem of duck embryos. DP specific nested PCR was standardized for better confirmation of the disease. Sensitivity of nested primers was also tested for DP virus. Results: Gross, postmortem and histopathological changes were prominent in dead embryos. First set of primer was able to detect 602 bp fragments of DNA polymerase gene of duck enteritis virus from infected CAM. Subsequently, a DP specific nested PCR which was very much sensitive for very small amount of viral genome was successfully standardized. After NCBI blast nucleotide sequence of nested PCR product (Accession No. HG425076) showed homology with the sequences data available in GenBank. Conclusion: The study concludes that PCR assay is very much helpful to diagnose DP disease and developed nested PCR is a double confirmatory diagnostic tool for DP

HAEMATOLOGICAL IMPACT OF NATURALLY OCCURING TICK BORNE HAEMOPARASITIC INFECTIONS IN CATTLE OF WEST BENGAL, INDIA

Haemoparasites reduces productivity and may lead to high mortality among animals. The present study was carried out to evaluate the heamotological change in cattle of different districts in West Bengal, India affected with naturally occurring tick- borne haemoparasitic diseases (TBHD). A total of 310 cattle blood samples were screened for the presence of haemoparasites from July, 2015 to June, 2016. The blood samples were examined for haemoparasites by making thin blood smear and staining with Giemsa’s stain. The result showed that108 (34.84%) cattle were found positive with TBHD, out of which 22.9% were Theileria sp, 5.8% were Babesia sp., 11.93% Anaplasma sp., and 5.8% were having mixed infection, respectively. The positive samples were subjected to estimations of haematological parameters i. e. Haemoglobin concentration (Hb), packed cell volume (PCV), total erythrocyte count (TEC) and Total leucocytes count (TLC) using standard protocol. The haematological analysis showed statistically a significant (p<0.01) decreased levels of Hb, PCV, TEC and TLC in infected groups of cattle compared to infection free group cattle. This is probably the first systematic report in West Bengal, India. The result showed the haemoparasites have a negative impact on haematological parameters. This study may be useful in disease epidemiological map preparation, parasitic control policy preparation of the study areas

Shifting the Reactivity of Bis-propargyl Ethers from Garratt–Braverman Cyclization Mode to 1,5‑H Shift Pathway To Yield 3,4-Disubstituted Furans: A Combined Experimental and Computational Study

Aryl or vinyl substituted bis-propargyl ethers upon base treatment generally form phthalans via the Garratt–Braverman (GB) cyclization pathway. In a major departure from this usual route, several aryl/vinyl bis-propargyl ethers with one of the acetylenic arms ending up with 2-tetrahydropyranyloxy methyl or ethoxy methyl have been shown to follow the alternative intramolecular 1,5-H shift pathway upon base treatment. The reaction has led to the formation of synthetically as well as biologically important 3,4-disubstituted furan derivatives in good yields. The initially formed <i>E</i> isomer in solution (CDCl₃) slowly isomerizes to the <i>Z</i> isomer, indicating greater stability of the latter. The factors affecting the interplay between the 1,5-H shift and GB rearrangement have also been evaluated, and the results are supported by DFT-based computational study