Development of nature-based sustainable passive technologies for treating and disinfecting municipal wastewater: Experiences from constructed wetlands and slow sand filter.

There is an urgent need to develop low-cost technology for effective wastewater treatment and its further disinfection to the level that makes it economically useful. This work has designed and evaluated the various types of constructed wetlands (CWs) followed by a slow sand filter (SSF) for wastewater treatment and disinfection. The studied CWs were, CWs with gravels (CW-G), free water surface-CW (FWS-CWs), and CWs integrated microbial fuel cell (MFC) with granular graphite (CW-MFC-GG) planted with Canna indica plant species. These CWs were operated as secondary wastewater treatment technologies followed by SSF for disinfection purposes. The highest total coliform removal was observed in the combination of CW-MFC-GG-SSF which achieved a final concentration of 172 CFU/100 mL, whereas faecal coliform removal was 100 % with the combinations of CW-G-SSF and CW-MFC-GG-SSF, achieving 0 CFU/100 mL in the effluent. In contrast, FWS-SSF achieved the lowest total and faecal coliform removal attaining a final concentration of 542 CFU/100 mL and 240 CFU/100 mL, respectively. Furthermore, E. coli were detected as negative/absent in CW-G-SSF and CW-MFC-GG-SSF, while it was positive for FWS-SSF. In addition, the highest turbidity removal was achieved in CW-MFC-GG and SSF combination of 92.75 % from the municipal wastewater influent turbidity of 82.8 NTU. Furthermore, in terms of overall treatment performance of CW-G-SSF and CW-MFC-GG-SSF, these systems were able to treat 72.7 ± 5.5 % and 67.0 ± 2.4 % of COD and 92.3 % and 87.6 % of phosphate, respectively. Additionally, CW-MFC-GG also exhibited a power density of 85.71 mA/m3 and a current density of 25.71 mW/m3 with 700 Ω of internal resistance. Thus, CW-G and CW-MFC-GG followed by SSF could be a promising solution for enhanced disinfection and wastewater treatment.

Feasibility of implementing public-private mix approach for tuberculosis case management in Pokhara Metropolitan City of western Nepal: a qualitative study.

Background: The Public-Private Mix (PPM) approach is a strategic initiative that involves engaging all private and public health care providers in the fight against tuberculosis using international health care standards. For tuberculosis control in Nepal, the PPM approach could be a milestone. This study aimed to explore the barriers to a public-private mix approach in the management of tuberculosis cases in Nepal. Methods: We conducted key informant interviews with 20 participants, 14 of whom were from private clinics, polyclinics, and hospitals where the PPM approach was used, two from government hospitals, and four from policymakers. All data were audio-recorded, transcribed, and translated into English. The transcripts of the interviews were manually organized, and themes were generated and categorized into 1. TB case detection, 2. patient-related barriers, and 3. health-system-related barriers. Results: A total of 20 respondents participated in the study. Barriers to PPM were identified into following three themes: (1) Obstacles related to TB case detection, (2) Obstacles related to patients, and (3) Obstacles related to health-care system. PPM implementation was challenged by following sub-themes that included staff turnover, low private sector participation in workshops, a lack of trainings, poor recording and reporting, insufficient joint monitoring and supervision, poor financial benefit, lack of coordination and collaboration, and non-supportive TB-related policies and strategies. Conclusion: Government stakeholders can significantly benefit by applying a proactive role working with the private in monitoring and supervision. The joint efforts with private sector can then enable all stakeholders to follow the government policy, practice and protocols in case finding, holding and other preventive approaches. Future research are essential in exploring how PPM could be optimized.

Anxiety and Depression Among Health Sciences Students in Home Quarantine During the COVID-19 Pandemic in Selected Provinces of Nepal.

Aim: This study aimed to assess anxiety and depression among health sciences students at home quarantine during the COVID-19 pandemic in selected provinces of Nepal. Methods: A web-based cross-sectional study was conducted among 409 health science students enrolled at graduate and post-graduate levels in selected universities and their affiliated colleges. Students from selected colleges were asked to fill out a survey, that was made available through email and social media outlets such as Facebook and Viber. The data were downloaded in Excel and imported to SPSS version 16 for analysis. Results : The prevalence of anxiety and depression was 15.7 and 10.7%, respectively. The study showed significant associations between (i) place of province and anxiety; (ii) sleep per day and depression; (iii) hours spent on the internet per day for education and depression; (iv) postponement of final exams and depression. There were no significant associations with the socio-demographic variables. Conclusion: Anxiety and depression in health science students showed correlation with the province, internet use for education, and postponement of exams. These correlations could be common among students in other fields as well. A large-scale study covering a wider geographical area and various fields of education is necessary to further evaluate the impact of COVID-19 on (health sciences) students. The integration of mental health programs both as an intervention and a curriculum level among students is critical to ensure the health of the students.

Pharmacokinetic characterization of fluorocoxib D, a cyclooxygenase-2-targeted optical imaging agent for detection of cancer.

SIGNIFICANCE: Fluorocoxib D, N-[(rhodamin-X-yl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetamide, is a water-soluble optical imaging agent to detect cyclooxygenase-2 (COX-2)-expressing cancer cells. AIM: We evaluated the pharmacokinetic and safety properties of fluorocoxib D and its ability to detect cancer cells in vitro and in vivo. APPROACH: Pharmacokinetic parameters of fluorocoxib D were assessed from plasma collected at designated time points after intravenous administration of 1 mg / kg fluorocoxib D in six research dogs using a high-performance liquid chromatography analysis. Safety of fluorocoxib D was assessed for 3 days after its administration using physical assessment, complete blood count, serum chemistry profile, and complete urinalysis in six research dogs. The ability of fluorocoxib D to detect COX-2-expressing cancer cells was performed using human 5637 cells in vitro and during rhinoscopy evaluation of specific fluorocoxib D uptake by canine cancer cells in vivo. RESULTS: No evidence of toxicity and no clinically relevant adverse events were noted in dogs. Peak concentration of fluorocoxib D (114.8 ± 50.5 ng / ml) was detected in plasma collected at 0.5 h after its administration. Pretreatment of celecoxib blocked specific uptake of fluorocoxib D in COX-2-expressing human 5637 cancer cells. Fluorocoxib D uptake was detected in histology-confirmed COX-2-expressing head and neck cancer during rhinoscopy in a client-owned dog in vivo. Specific tumor-to-normal tissue ratio of detected fluorocoxib D signal was in an average of 3.7 ± 0.9 using Image J analysis. CONCLUSIONS: Our results suggest that fluorocoxib D is a safe optical imaging agent used for detection of COX-2-expressing cancers and their margins during image-guided minimally invasive biopsy and surgical procedures.

Communications via the Small Leucine-rich Proteoglycans: Molecular Specificity in Inflammation and Autoimmune Diseases.

Inflammation is a highly regulated biological response of the immune system that is triggered by assaulting pathogens or endogenous alarmins. It is now well established that some soluble extracellular matrix constituents, such as small leucine-rich proteoglycans (SLRPs), can act as danger signals and trigger aseptic inflammation by interacting with innate immune receptors. SLRP inflammatory signaling cascade goes far beyond its canonical function. By choosing specific innate immune receptors, coreceptors, and adaptor molecules, SLRPs promote a switch between pro- and anti-inflammatory signaling, thereby determining disease resolution or chronification. Moreover, by orchestrating signaling through various receptors, SLRPs fine-tune inflammation and, despite their structural homology, regulate inflammatory processes in a molecule-specific manner. Hence, the overarching theme of this review is to highlight the molecular and functional specificity of biglycan-, decorin-, lumican-, and fibromodulin-mediated signaling in inflammatory and autoimmune diseases.

Detection of tyrosine kinase inhibitors-induced COX-2 expression in bladder cancer by fluorocoxib A.

Among challenges of targeted therapies is the activation of alternative pro-survival signaling pathways in cancer cells, resulting in an acquired drug resistance. Cyclooxygenase-2 (COX-2) is overexpressed in bladder cancer cells, making it an attractive molecular target for the detection and treatment of cancer. Fluorocoxib A is an optical imaging agent that selectively targets COX-2. In this study, we evaluated the ability of fluorocoxib A to monitor the responses of bladder cancer to targeted therapies in vivo. The effects of several tyrosine kinase inhibitors (TKIs: axitinib, AB1010, toceranib, imatinib, erlotinib, gefitinib, imatinib, sorafenib, vandetanib, SP600125, UO126, and AZD 5438) on COX-2 expression were validated in ten human and canine bladder cancer cell lines (J82, RT4, T24, UM-UC-3, 5637, SW780, TCCSUP, K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#5Lilly) in vitro. The effects of TKIs on bladder cancer in vivo were evaluated using the COX-2-expressing K9TCC#5Lilly xenograft mouse model and detected by fluorocoxib A. The increased COX-2 expression was detected by all tested TKIs in at least one of the tested COX-2-expressing bladder cancer cell lines (5637, SW780, TCCSUP, K9TCC#1Lillie, K9TCC#2Dakota, and K9TCC#5Lilly) in vitro. In addition, fluorocoxib A uptake correlated with the AB1010- and imatinib-induced COX-2 expression in the K9TCC#5Lilly xenografts in vivo. In conclusion, these results indicate that fluorocoxib A could be used for the monitoring the early responses to targeted therapies in COX-2-expressing bladder cancer.

WT1 regulates cyclin A1 expression in K562 cells.

The restricted expression of Wilms tumor 1 (WT1) and cyclin A1 (CCNA1) in normal tissues, as opposed to their abnormal expression in leukemia demonstrates the applicability of WT1 and CCNA1 as cancer antigens for immunotherapy, and as markers for prognosis and relapse. In this study, the WT1 and CCNA1 mRNA levels were found to be elevated in bone marrow samples from pediatric acute promyelocytic leukemia (APL or AML­M3) patients, and to be quite varied in pediatric acute lymphocytic leukemia (ALL) patients, compared to non­leukemic bone marrow controls. Consistent with the observed upregulation of both WT1 and CCNA1 in APL, WT1 overexpression elevated the CCNA1 mRNA levels in K562 leukemia cells. Treatment with curcumin decreased the WT1 levels in K562 cells, and also decreased CCNA1 protein expression. The examination of the CCNA1 promoter identified potential canonical WT1 binding sites within the 3­kb region upstream of the transcription start site. Chromatin immunoprecipitation and luciferase reporter assays confirmed WT1 binding and the activation of the CCNA1 promoter. Furthermore, the GC­rich core CCNA1 promoter region provided additional non­canonical WT1 activation sites, as revealed by promoter assays. The importance of the GC­rich core region of the CCNA1 promoter was confirmed by treating the K562 cells with mithramycin A, which blocks the binding of zinc finger transcription factors to GC­rich sequences. Mithramycin A subsequently suppressed both CCNA1 promoter activity and protein expression in the K562 cells. Taken together, the data from the WT1 overexpression, and curcumin and mithramycin A treatment experiments, as well as those from chromatin binding assays, along with inferences from patient RNA analyses, establish a plausible link between WT1 and CCNA1, and support the functional significance of an elevated WT1 expression in leukemia, which may also affect CCNA1 expression.

Platelet-rich plasma affects the proliferation of canine bone marrow-derived mesenchymal stromal cells in vitro.

BACKGROUND: Reported efficacy of platelet-rich plasma (PRP) in regenerative medicine is contradictory. We validated the effects of PRP on proliferation of canine bone marrow-derived multipotent mesenchymal stromal cells (K9BMMSCs) in vitro. PRP was extracted from blood of six dogs with osteoarthritis. K9BMMSCs were established from bone marrow and characterized for CD90 and CD19 expression by immunocytochemistry. Effects of PRP concentrations on viability of matching autologous K9BMMSCs were validated using MTS assay. RESULTS: Positive CD90 and negative CD19 expression confirmed MSC origin. PRP at 40% volume/volume concentration increased, while PRP at 80 and 100% v/v concentrations suppressed viability of tested K9BMMSCs. CONCLUSION: PRP concentration plays an important role in K9BMMSCs viability, which could affect tissue repairs in vivo.

Active and passive biosorption of Pb(II)using live and dead biomass of marine bacterium Bacillus xiamenensis PbRPSD202: Kinetics and isotherm studies.

A highly lead(II) resistant (up to 2200 mg/l) bacterium PbRPSD202 was selected among 210 lead resistant bacteria isolated from marine environment of Paradeep Port, Odisha for possible biosoption of toxic Pb (II) ions from metals polluted environments. The bacterium was identified as Bacillus xiamenensis following the phenotypic as well as 16S rRNA gene sequence analysis. In addition to Pb(II), it also showed resistance towards other heavy metals like Cd(II), Cr(VI), As(III), Cu(II), Ni(II) and Zn(II). Batch biosorption of Pb(II) using both live and dead biomass of this strain was investigated under different operational parametric conditions such as pH, temperature, NaCl concentration, shaking speed, treatment time, biomass concentration and initial Pb(II) concentration. The maximum Pb(II) uptake of 216.75 and 207.4 mg/g biomass was obtained with live and dead biomass, respectively, at the optimum condition (4% w/v NaCl, pH 6.0, 35 °C, 140 rpm and 1 g/l biosorbent dose). Both active as well as passive Pb(II) bio-sorption process showed best fit with the pseudo-second-order kinetic model. The sorption mechanism was favoured with Langmuir isotherm model indicating monolayer type adsorption. FTIR and FESEM-EDX analysis further ensured the possible interactions of Pb(II) with bacterial cell surface ligands like hydroxyl, carbonyl, carboxyl and amine groups during surface adsorption. TEM analysis revealed the intracellular accumulation of lead ions. This investigation highlights the potential application of this bacterium for bioremediation of lead(II) from the multiple metals contaminated saline environment through biosorption.

Mutations of p53 decrease sensitivity to the anthracycline treatments in bladder cancer cells.

Due to doxorubicin (Dox) cardiotoxicity, the next generation of novel non-cardiotoxic anthracyclines, including AD 312 and AD 198, were synthesized and validated. In this study, we assessed the efficacy and mechanisms of anthracyclines-induced apoptosis and inhibition of cell viability in human bladder cancer cells expressing wild-type (wt) p53 (RT4 and SW780) and mutated (mt) p53 (UM-UC-3, 5637, T-24, J82, and TCCSUP) protein. Anthracyclines inhibited cell viability in tested TCC cells, but were less effective in mt-p53 TCC cells, especially in the drug-resistant J82 and TCCSUP cells. Anthracyclines upregulated the expression of wt p53 protein in RT4 and SW780 cells, but had no effect on expression of mt p53 protein in UM-UC-3, 5637, T-24, J82, and TCCSUP cells. The anthracyclines activated caspase 3/7 and cleavage of PARP in wt-p53 RT4 and SW780 cells, and mt-p53 5637, UM-UC-3, and T-24, but not in mt-p53 J82 and TCCSUP cells. The anthracyclines-induced cleavage of PARP was blocked by p53 siRNA in wt-p53 RT4 cells. Co-treatment of AD 198 with PRIMA-1 significantly inhibited cell viability of mt-p53 J82 cells, but had no effect in wt-p53 RT4 cells. AD 198 blocked c-myc expression in mt-p53 UM-UC-3, 5637, T-24, and J82 cells, however no expression of c-myc was detected in wt-p53 RT4 and SW780 cells. In conclusion, our results demonstrated that the anthracycline-induced resistance in bladder cancer cells positively correlated with TP53 mutations in the tetramerization domain in J82 and TCCSUP cells. Further, AD 312 and AD 198 are promising chemotherapeutic drugs for bladder cancer, especially in combination with PRIMA-1.

Aligned nanofiber material supports cell growth and increases osteogenesis in canine adipose-derived mesenchymal stem cells in vitro.

Tissue engineering shows great promise for the treatment of degenerative diseases, including bone repair. Polymer nanofibers provide a three-dimensional (3-D) scaffold for attachment and growth of mesenchymal stem cells. Increasing evidence supports that fiber alignment on scaffolds plays a major role in the viability and differentiation of stem cells. We compared the cell viability of canine adipose tissue-derived mesenchymal stem cells (cADMSCs) cultured in the aligned- (NanoAligned™) and random- (NanoECM™) oriented polycaprolactone (PCL) nanofiber-coated plates to control polystyrene tissue culture plates using a proliferation assay. Ability of the plates to induce differentiation of cADMSCs into osteocytes, adipocytes, and neurons was evaluated based on expression of the osteocyte markers, COL1A1 and osterix; adipocyte markers PPARγ2 and LPL; and neuronal marker nestin using RT-PCR. Proliferation results demonstrated that aligned-oriented PCL nanofiber-coated plates were more suitable substrate for cADMSCs after 7 days in culture compared to random-oriented PCL nanofiber-coated or control plates. Additionally, we demonstrated that both 3-D PCL nanofiber-coated plates were a better scaffold for cADMSCs differentiation into osteocytes compared to control plates. In conclusion, our results confirm that PCL nanofiber is a suitable tissue engineering material for use in regenerative medicine for canine patients in vivo. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1780-1788, 2018.

Photocatalytic destruction of Escherichia coli in water by V2O5 /TiO2.

Vanadia modified titania (V2O5/TiO2) photo-catalysts are prepared by incipient wet impregnation method using aqueous ammonium metavanadate and anatase (Aldrich) titania. Titania with various loading concentrations of vanadia from 0 to 10 wt.% have been prepared and characterized by X-ray diffraction (XRD), Thermogravimetry (TGA), Laser Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), UV-Visible Spectrophotometry and Transmission Electron Microscopy (TEM). XRD study reveals that vanadia loading on titania does not bring any phase change of titania, however, diffuse (UV-Vis) reflectance spectra show that absorption edge of titania shifted from UV to visible region. TEM confirms that titania and vanadia modified titania have the particle size below 50 nm. XPS shows alteration of 2p3/2 peak of V(V) in the V2O5/TiO2 samples whereas no such change is noticed in pure V2O5 indicating the interaction between vanadia and titania support. Antibacterial activity of each sample has been investigated against Escherichia coli present in the water under both UV-Visible irradiation and UV alone. V2O5/TiO2 catalysts exhibit better photocatalytic effect than the unmodified titania and pure V2O5. It is observed that with increasing loading concentrations of V2O5 from 0 to 10 wt.% on titania support, the photocatalytic annihilation of E.coli is also increased and found to be little higher under UV alone than the UV-Visible irradiation.

Evaluation of simultaneous nutrient and COD removal with polyhydroxybutyrate (PHB) accumulation using mixed microbial consortia under anoxic condition and their bioinformatics analysis.

Simultaneous nitrate-N, phosphate and COD removal was evaluated from synthetic waste water using mixed microbial consortia in an anoxic environment under various initial carbon load (ICL) in a batch scale reactor system. Within 6 hours of incubation, enriched DNPAOs (Denitrifying Polyphosphate Accumulating Microorganisms) were able to remove maximum COD (87%) at 2 g/L of ICL whereas maximum nitrate-N (97%) and phosphate (87%) removal along with PHB accumulation (49 mg/L) was achieved at 8 g/L of ICL. Exhaustion of nitrate-N, beyond 6 hours of incubation, had a detrimental effect on COD and phosphate removal rate. Fresh supply of nitrate-N to the reaction medium, beyond 6 hours, helped revive the removal rates of both COD and phosphate. Therefore, it was apparent that in spite of a high carbon load, maximum COD and nutrient removal can be maintained, with adequate nitrate-N availability. Denitrifying condition in the medium was evident from an increasing pH trend. PHB accumulation by the mixed culture was directly proportional to ICL; however the time taken for accumulation at higher ICL was more. Unlike conventional EBPR, PHB depletion did not support phosphate accumulation in this case. The unique aspect of all the batch studies were PHB accumulation was observed along with phosphate uptake and nitrate reduction under anoxic conditions. Bioinformatics analysis followed by pyrosequencing of the mixed culture DNA from the seed sludge revealed the dominance of denitrifying population, such as Corynebacterium, Rhodocyclus and Paraccocus (Alphaproteobacteria and Betaproteobacteria). Rarefaction curve indicated complete bacterial population and corresponding number of OTUs through sequence analysis. Chao1 and Shannon index (H') was used to study the diversity of sampling. "UCI95" and "LCI95" indicated 95% confidence level of upper and lower values of Chao1 for each distance. Values of Chao1 index supported the results of rarefaction curve.

Synthesis and characterization of titania nanorods from ilmenite for photocatalytic annihilation of E. coli.

Titania nanorod structures have been obtained by thermal plasma reduction of ilmenite (FeTiO3) followed by chemical treatments. Inherently present iron in the titania nanorods acts as a dopant which results in shifting the absorption edge of titania from ultraviolet to visible region. X-ray diffraction (XRD) study confirms the existence of rutile phase of titania. X-ray Photoelectron Spectroscopy (XPS) reveals the presence of Ti(4+), O(2-), Fe(3+) and surface hydroxyl group. Transmission Electron Microscopy (TEM) confirms the formation of nanorod structure having width of 6 nm and length of 32 nm. Photocatalytic annihilation property of titania nanorods derived from ilmenite (titania-I), rutile titania obtained from titanium(IV) butoxide (titania-A) and Degussa P25 titania was studied under UV and UV-Visible irradiation conditions separately and compared. The time required for complete photocatalytic annihilation of Escherichiacoli cells are 10, 15 and 45 min under UV irradiation whereas it has taken 15, 10-15, 30 min under UV-Visible irradiation for titania-A, Degussa P25 titania and titania-I respectively. It is observed that titania-I shows significantly stronger antibacterial property under UV-Visible irradiation compared to UV alone.

A marine sponge associated strain of Bacillus subtilis and other marine bacteria can produce anticholinesterase compounds.

BACKGROUND: Acetylcholinesterase (AChE) inhibitors or anticholinesterases reduce the activity of enzyme acetylcholinesterase that degrades the neurotransmitter acetylcholine in the brain. The inhibitors have a significant pharmacological role in neurodegenerative diseases like Alzheimer's and Parkinson's etc. Although plants have been a significant source of these compounds, there are very few sporadic reports of microorganisms producing such inhibitors. Anticholinesterase activity in bacterial associates of marine soft corals and sponges were not previously reported. RESULTS: We screened 887 marine bacteria for the presence of acetylcholinesterase inhibitors, in a microplate based assay, and found that 140 (15.8%) of them inhibit the electric eel enzyme, acetylcholinesterase. Majority of the active isolates were bacterial associates of soft corals followed by sediment isolates while most of the potent inhibitors belonged to the bacterial associates of marine sponges. Maximum inhibition (54%) was exhibited by a bacterial strain M18SP4P (ii), isolated from the marine sponge Fasciospongia cavernosa. Based on phenotypic characterization and 16S rDNA sequencing, the strain was identified as Bacillus subtilis - revealing yet another activity in a strain of the model organism that is considered to be a cell factory. TLC bioautography of the methanol extract of this culture, showed the presence of two major components having this activity, when compared to Galanthamine, the positive control. CONCLUSION: From the results of our study, we conclude that acetylcholinesterase inhibitors are quite prevalent in marine bacteria, particularly the bacterial associates of marine invertebrates. Several potential AChE inhibitors in marine bacteria are waiting to be discovered to provide easily manipulable natural sources for the mass production of these therapeutic compounds.

Water disinfection through photoactive modified titania.

TiO(2), N-TiO(2) and S-TiO(2) samples have been prepared by various chemical methods. These samples were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Laser Raman spectrometer, UV-Visible spectrophotometer, field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). X-ray powder diffraction study reveals that all three samples are single anatase phase of titania and the crystallinity of titania decreases with sulphur doping whereas nitrogen doping does not affect it. UV-Visible (diffuse) reflectance spectra shows that doping of titania with nitrogen and sulphur shift the absorption edge of titania from ultraviolet to visible region. XPS study confirms that both nitrogen and sulphur are well doped in the titania lattice. It is observed that nitrogen occupies at both substitutional and interstitial position in the lattice of titania. FE-SEM and TEM studies demonstrate that the particles are below 50nm range. It is found that S and N doping of titania increased its water disinfection property in the order TiO(2)

Investigation on mechanism of Cr(VI) reduction and removal by Bacillus amyloliquefaciens, a novel chromate tolerant bacterium isolated from chromite mine soil.

A strain CSB 9 isolated from chromite mine soil of Sukinda, India was identified as Bacillus amyloliquefaciens based on biochemical and 16S rRNA gene sequencing. The strain exhibited relatively high tolerance to Cr(VI) (⩽900mgL(-1)) and fast reduction rate of 2.22mg Cr(VI) L(-1)h(-1), under optimized conditions of 100mgL(-1) Cr(VI), pH 7 and temperature 35°C within 45h. Mechanism of Cr(VI) reduction as well as nature and fate of the reduced product were studied to determine the scope of removal of reduced Cr(III) end product. AAS analyses of the culture products treated with Cr(VI) for 45h showed the distribution of Cr(III) in pellet and culture supernatant to be 37.4±1.7 and 62.6±3.4mgL(-1), respectively. In SEM images, the bacterial pellets with Cr(VI) treatment appeared coagulated, rough and porous whereas the pellets without Cr(VI) treatment appeared regular, smooth and non-porous in structure. SEM-EDX of the bacterial precipitates under Cr(VI) treatment revealed immobilization of Cr(III) species on the bacterial cell surface. Further Raman spectroscopy analysis confirmed the presence of Cr(III) species, with characteristic peak at around 600cm(-1). TEM-EDX study of the bacterial precipitates under Cr(VI) treatment showed intracellular deposition of Cr(III) which are in nanometric range. Further characterization of reduced product by XRD, FT-IR and SAED analyses suggested the formation of poorly crystalline end products. A Cr(VI) removal mechanism considering both the surface immobilization and intracellular accumulation of Cr(III) along with the formation of coagulated cell precipitate by living B. amyloliquefaciens was suggested.

Diversity of marine bacteria producing beta-glucosidase inhibitors.

BACKGROUND: Beta-glucosidase inhibitors are being extensively studied for use as anti-diabetics, anti-obesity and anti-tumour compounds. So far, these compounds have been reported in large numbers from plants, mushrooms, algae and fungi. There are very few reports of such inhibitors from bacteria in the open literature, particularly marine bacteria; although the best known inhibitor deoxynojirimycin was isolated from bacilli and actinomycete. Through this study, we tried to discover the diversity of microbial associates of marine sponge and sediment producing ß-glucosidase inhibitors. RESULTS: We found 41 (22.7%) out of 181 bacteria, produced such inhibitors. The inhibitors are abundant in bacterial associates of marine sponge Aka coralliphaga. When these bacteria were phylogenetically analyzed, it was found that marine bacteria producing glucosidase inhibitors belong to the phylum Firmicutes (23), Actinobacteria (9), Proteobacteria (7) and Bacteroidetes (1). CONCLUSION: A significant number of marine bacteria belonging to a wide range of bacterial taxa were found to produce ß-glucosidase inhibitors. These compounds are abundantly present in bacteria of the phylum Firmicutes followed by the phylum Actinobacteria. The results nurture a hope of finding new compounds, which can inhibit glucosidases, in the bacterial domain of marine organisms. Thus, marine microbial cells can be utilized as producers of pharmacologically essential enzyme inhibitors.

A novel method for screening beta-glucosidase inhibitors.

BACKGROUND: Few beta-glucosidase inhibitors have so far been reported from microorganisms due to the practical difficulties in performing the inhibition tests and subsequent interpretation of results. In an effort to investigate marine microbial extracts for ß-glucosidase inhibitors, we developed a new protocol, using esculin as substrate in an agar plate based assay, to screen a large number of microbial extracts in a short span of time. RESULTS: With the new method, pale yellowish zones against the blackish brown background could be visually observed with more clarity in sample extracts where ß-glucosidase inhibitor was present. The new method was compared with the closest existing method and established beyond doubt. This agar plate based procedure required about one hour for minimum 12 samples and the throughput increases with the size of the agar gel plate used. CONCLUSIONS: The new protocol was simple, rapid and effective in detecting beta-glucosidase inhibitors in microbial extracts.

The Wilms' tumor gene (WT1) regulates E-cadherin expression and migration of prostate cancer cells.

BACKGROUND: One key step in the development of prostate cancer (PCa) metastasis is the loss of E-cadherin expression associated with increased cellular motility and tumor invasion. This loss of E-cadherin expression is also required during normal embryogenesis and similar transcriptional repressors have been identified in both processes. We have previously reported the presence of one such transcription factor, WT1 in high Gleason grade prostate tumor tissues, and its absence in non-neoplastic or benign prostatic hyperplasia tissues. RESULTS: To better understand the effect of WT1 on E-cadherin expression and migration of PCa cells we quantified WT1 and E-cadherin mRNA levels in normal prostate epithelial and PCa cell lines with varying migratory potential. In WT1 transfected cells E-cadherin transcript levels were decreased, while they were increased in siWT1-RNA transfected PCa cells, suggesting that elevated WT1 expression was sufficient to dampen E-cadherin levels and potentially enhance migratory ability. To delineate the mechanism of WT1-mediated repression of E-cadherin, potential WT1 binding sites were tested in vitro and in vivo binding of WT1 to the E-cadherin promoter in the chromatin of LNCaP and PC3 cells was assessed by Chromatin Immunoprecipitation. The effect of WT1 binding was measured in reporter assays; in PC3 and DU145 cells WT1 decreased the activity of the proximal E-cadherin promoter. Using site-directed mutagenesis, a newly identified WT1 binding site located 146 bp from the transcription start site was shown to be required for this repression by WT1. Transwell migration and wound healing assays revealed that in LNCaP cells with low migratory potential, over-expression of WT1 was sufficient to enhance migration, conversely, in the highly migratory PC3 cells silencing of WT1 decreased migration. CONCLUSIONS: These findings suggested that WT1 expression in high grade prostate cancer may contribute to migration and metastasis. Thus, in prostate cancer WT1 may function as a novel oncogene facilitating development of the lethal metastatic phenotype.