Prodigiosin production from Serratia marcescens strain CSK and their antioxidant, antibacterial, cytotoxic effect and in silico study of caspase-3 apoptotic protein.

The present study emphasizes the production and optimization of prodigiosin (PG) pigment from Serratia marcescens strain CSK, which was isolated from Shevaroy Hills, Salem district, Tamil Nadu, India. The response surface methodology analysis was applied for the optimization process of PG production. The maximum production of PG (2950 mg/L) was obtained at pH 7.0 with the addition of tryptophan (4.0 g/L) and sucrose (3.0 g/L) with 60 h of incubation. Further, the PG was characterized using high-performance liquid chromatography, Fourier-transform infrared spectroscopy, and gas chromatography-mass spectrometry. The purified PG exhibited strong antioxidant and antibacterial activities. Also, PG's cytotoxic effects against human breast cancer (MCF-7) cells were observed through acridine orange-ethidium bromide (AO-EB) and Hoechst staining. Molecular dockingstudies revealed that PG could bind positively to the caspase-3 (breast cancer protein 1RE1) binding site with a binding energy score of 17.37 kcal/mol. Overall, the novel PG was found to be an anticancer drug for potential applications in the pharmaceutical industry.

Optimization of low-cost biosurfactant produced by Bacillus subtilis SASCBT01 and their environmental remediation potential.

The present research aims to enhance the biosurfactant (BS) production using agricultural by-products as a low-cost substrate with the statistical approach. BS production from Bacillus subtilis SASCBT01 was carried out with four different variables such as pH, incubation time, cassava peel waste (CPW) and palmira sprout (PS). The model expected the highest emulsification activity of 65 ± 1·2% after 96-h incubation with 3·0 g l-1 of CPW and PS at pH 7·0. The SASCBT01 strain-based BS was successful at retrieving up to 18% and the highest Pb removal rates were found at 65%. These BS have considered high quality in bioremediation applications.

Chlorpyrifos degradation efficiency of Bacillus sp. laccase immobilized on iron magnetic nanoparticles.

The present study explored the immobilization of laccase onto iron magnetic nanoparticles (MNPs) to enhance its enzymatic properties and applications. The immobilization process was optimized using Box-Behnken design (BBD). BBD showed significance towards the quadratic model with experimental data. Maximum laccase activity recovery (99%) of the predicted model was observed at 0.75 mg/mL of laccase concentration, 200 mg/mL of MNPs, 0.3% cross linking with carbodiimide, and 3 h of cross-linking time. The magnetization activity of MNPs (8 emu/g) and the immobilized laccase with MNPs (4 emu/g) was analyzed using vibrating sample magnetometer (VSM). Maximum activity of immobilized laccase was observed at pH 7.0 and 55 °C. The immobilized laccase has greater stability (100 h) and significant chlorpyrifos (pesticide) degradation activity. High-performance liquid chromatography (HPLC) results confirmed the degraded metabolic products of chlorpyrifos. In all, the immobilized laccase was superior to free laccase, showing promising structural and application characteristics.

Significance of allochthonous brackish water Halomonas sp. on biodegradation of low and high molecular weight polycyclic aromatic hydrocarbons.

The present study is aimed to isolate and identify polycyclic aromatic hydrocarbons (PAHs) degrading bacteria from brackish water and to assess the biodegradation efficiency against low and high molecular weight PAHs. Among 15 isolates, the isolate designated as RM effectively degraded 100 mg/L of phenanthrene (Phe) (67.0%), pyrene (Pyr) (63.0%), naphthalene (NaP) (60.0%), and benzo [a]pyrene (BaP) (58.0%) after 7 days of incubation. Carbon sources, pH, and salinity of the culture medium were optimized to enhance the growth and PAHs biodegradation of the isolate RM. Sucrose was found to be an excellent carbon source to enhance PAHs biodegradation (Phe, 75.0; Pyr, 68.5; NaP, 62.5; and BaP, 59.5%). Furthermore, the isolate showed enhanced degradation at pH 7.0 and 4% salinity. The isolate RM was identified as Halomonas sp. based on partial 16S rDNA gene sequence analysis. The results indicated that the isolate RM (i.e., Halomonas sp.) has the potential to be used in remediation of oil spills in the marine ecosystem.

Production and purification of laccase by Bacillus sp. using millet husks and its pesticide degradation application.

Lignocellulosic agricultural bi-products, pearl millet (PM) and finger millet (FM) husks, were used for the production of laccase using Bacillus sp. PS under solid-state fermentation (SSF). Abiotic variables such as substrate (PM, FM) concentration (1-5%), incubation time (24-96 h) and pH (5-10) were optimized using Response surface methodology (RSM) to maximize the laccase production. The predicted model showed maximum laccase activity of 402 U/mL appearing after 96 h of incubation with PM 2.0 g/L and FM 1.5 g/L at pH 7.0. Single protein band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) confirmed homogeneity of the laccase with a molecular weight of 63-75 kDa. The partially purified laccase effectively degraded the pesticides (Tricel, 71.8 ± 3.5 and Phoskill 77.3 ± 3.4%) within 5 days of incubation (40 °C) in pH 7.0. The pesticide degradation was further confirmed by high-performance liquid chromatography (HPLC) and the chromatograms showed the single dominant peaks at retention time 2.482 (tricel) and 2.608 (phoskill) min, respectively. Pesticide-degrading laccase was produced by Bacillus sp. PS under SSF reveals the utilization of low-cost bi-substrates for enhanced laccase production.

High Tensile Ductility and Strength in Dual-phase Bimodal Steel through Stationary Friction Stir Processing.

The combination of high strength and good ductility are very desirable for advanced structural and functional applications. However, measures to enhance strength typically lead to ductility reduction due to their inverse correlation, nano-grained structures for an instance. Bi-modal grain structure is promising in this regard, but its realization is limited by multiple complex processing steps. Here, we demonstrate a facile single-step processing route for the development of bimodal grain structure in austenitic stainless steel, SS316L. The bimodal structure comprised of fine martensite grains (<500 nm) sandwiched between coarse austenite grains (~10 µm). The dual-phase bimodal structure demonstrated higher yield strength (~620 MPa) compared to ultra-fine grain structure (~450 MPa) concurrent with high uniform tensile ductility (~35%). These exceptional properties are attributed to unique dual-phase, bimodal grain structure which delayed the onset of plastic instability resulting in higher strength as well as larger uniform elongation and work-hardening rate. Our approach may be easily extended to a wide range of material systems to engineer superior performance.

Process optimization of biogas energy production from cow dung with alkali pre-treated coffee pulp.

Biogas production from cow dung with co-substrate agricultural waste is one of the most demanding technologies for generating energy in a sustainable approach considering eco-friendly. In the present study, coffee pulp (CP) was pre-treated with 1% NaOH and combined with various proportions of cow dung (CD) to explore its biogas producing potentiality. The optimization of the process was studied using Response surface methodology. Statistics based on 3-D plots were generated to evaluate the changes in the response surface and to understand the relationship between the biogas yield and other parameters. The highest methane production (144 mL/kg) was achieved after 90 h of incubation with 1:3 of CP and CD at 40 °C. Gas chromatography analyzes the chemical compositions of the generated biogas and its post combustion emissions. The chemical composition of the substrates before digestion and after fermentation (biogas spent sludge) were measured in terms of fiber content and the values were noted as, total solids (0.53%), ash content (9.2%), volatile fatty acid (100 mg/L), organic carbon (46%) and a total carbohydrate (179 mg/g). The results of the optimization of biogas production presented in this work found to have significance with the process parameters. The outcome of the study has supported the fact of conventional combustion technology that has to be upgraded to prevent these hazardous emissions into the atmosphere.

Isolation and Typing of Streptococcus mutans and Streptococcus sobrinus from Caries-active Subjects.

BACKGROUND: Streptococcus mutans and Streptococcus sobrinus are main etiological agents of dental caries. AIM: The aim of the study was to isolate, identify, characterize, and determine the minimum inhibitory concentration (MIC) of S. mutans and S. sobrinus from caries-active subjects. MATERIALS AND METHODS: Sixty-five plaque samples were collected from caries-active subjects aged between 35 and 44 years, processed and cultured on mitis salivarius bacitracin agar. All the bacterial isolates were subjected to morphotyping and the suspected colonies were identified by 16S rDNA sequencing. The S. mutans and S. sobrinus strains were characterized by biotyping and phylogenetic analysis. The MIC of ampicillin and erythromycin was determined by microtiter plate method. RESULTS: Of the study population, 41 isolates displayed typical colony morphologies of S. mutans and S. sobrinus. The 16S rDNA sequencing results revealed that 36 isolates were S. mutans and 5 isolates were S. sobrinus. The biotyping of these isolates demonstrated three biotypes, namely, biotype I (n = 35), biotype III (n = 1), and biotype IV (n = 2). However, 3 isolates exhibited variant biotypes. The phylogenetic analysis revealed that the clinical strains of S. mutans and S. sobrinus clustered independently along with respective reference strains. The average MIC of ampicillin and erythromycin against S. mutans and S. sobrinus was 0.047 µg/ml and 0.39 µg/ml, respectively. CONCLUSION: The 16S rDNA sequencing was an impeccable method for S. mutans and S. sobrinus identification when compared with morphotyping and biotyping methods. The study also suggested that nonspecific bacteria might be involved in caries formation.

Photocatalytic activity of surface fluorinated TiO2-P25 in the degradation of Reactive Orange 4.

Photocatalytic activity of surface fluorinated TiO(2)-P25 (F-TiO(2)-P25) in the degradation of a chlorotriazine azo dye Reactive Orange 4 (RO 4) under ambient conditions was investigated in this study. Characterization of F-TiO(2)-P25 reveals that the catalyst has a strong absorption in the UV range and the presence of F atom in the catalyst. The degradation rate of RO 4 with surface fluorinated TiO(2)-P25 is three times faster than bare TiO(2)-P25. The quantum yield of UV/TiO(2)-P25 process is largely decreased by the increase of initial dye concentration, whereas in UV/F-TiO(2)-P25 process, the influence of initial dye concentration is less. Surface fluorination of TiO(2)-P25 enhanced the adsorption of RO 4 dye, while improving overall degradation rate. The optimum operating conditions of UV/F-TiO(2)-P25 process for efficient degradation are reported.

Photovalorisation of pentafluorobenzoic acid with platinum doped TiO2.

Pt-doped TiO(2) has been prepared and characterized by various surface analytical methods such as BET surface area, scanning electron micrographs (SEM), X-ray diffraction (XRD), energy dispersive X-ray micro analysis (EDX) and diffuse reflectance spectroscopy (DRS). Photodefluoridation of pentafluorobenzoic acid (PFBA) to fluoride ions has been carried out using TiO(2) and Platinum doped TiO(2) with UV-C (200-300 nm) light. The defluoridation was monitored by the ionometer with fluoride ion selective electrode. Photodeposition of 1.5% Platinum on the surface of TiO(2) enhances its photoactivity in pentafluorobenzoic acid defluoridation. In order to optimize the working conditions, effects of pH and initial PFBA concentration were analyzed. Addition of inorganic oxidizing species KIO(4,) H(2)O(2), (NH(4))S(2)O(8) and KBrO(3) strongly influenced the photocatalytic defluoridation of PFBA. The significant enhancement in the Pt-TiO(2) photoactivity under UV irradiation can be ascribed to the platinum deposits, acting as electron traps on the Pt-TiO(2) surface. The fluoride ions formed during photodefluoridation can be used for the production of CaF(2).

Assessment of heavy metal contents in the ambient air of the Coimbatore city, Tamilnadu, India.

Industrialization and urbanization are the two major causes of deteriorating air quality. To evaluate the ambient air quality of the Coimbatore city, suspended particulate matter (SPM) was collected at ten stations and analysed for the heavy metals content. The concentrations of seven heavy metals (Zn, Fe, Cu, Pb, Ni, Cr and Cd) were estimated. The level of SPM was found to be either at permissible or non-permissible limit depending upon the category of the sampling station. At majority of sampling stations, concentrations of Zn were found to be maximum than other heavy metals. The order of average concentrations of heavy metals in Coimbatore atmospheric air was Zn>Fe>Cu>Pb>Cr>Ni>Cd. The usage of Zn for protective coating on iron, steel etc. by the industries in Coimbatore city could be the major reason for the higher concentration of this heavy metal in this region.

A comparative study of quantum yield and electrical energy per order (E(Eo)) for advanced oxidative decolourisation of reactive azo dyes by UV light.

This paper evaluates the quantum yield and electrical energy per order (E(Eo)) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe(2+)/H(2)O(2)/UV>UV/TiO(2)>UV/H(2)O(2). The low efficiency of UV/H(2)O(2) process is mainly due to low UV absorption by hydrogen peroxide at the 365nm. The figure of merit E(Eo) values showed that UV/H(2)O(2) process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H(2)O(2)>UV/TiO(2)>Fe(2+)/H(2)O(2)/UV. At low initial dye concentration higher quantum yield was observed in UV/TiO(2) process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E(Eo) value.

Decolourization of azo dyes and a dye industry effluent by a white rot fungus Thelephora sp.

A white rot fungus Thelephora sp. was used for decolourization of azo dyes such as orange G (50 microM), congo red (50 microM), and amido black 10B (25 microM). Decolourization using the fungus was 33.3%, 97.1% and 98.8% for orange G, congo red and amido black 10B, respectively. An enzymatic dye decolourization study showed that a maximum of 19% orange G was removed by laccase at 15 U/ml whereas lignin peroxidase (LiP) and manganese dependent peroxidase (MnP) at the same concentration decolourized 13.5% and 10.8%, orange G, respectively. A maximum decolourization of 12.0% and 15.0% for congo red and amido black 10B, respectively, was recorded by laccase. A dye industry effluent was treated by the fungus in batch and continuous modes. A maximum decolourization of 61% was achieved on the third day in the batch mode and a maximum decolourization of 50% was obtained by the seventh day in the continuous mode. These results suggest that the batch mode of treatment using Thelephora sp. may be more effective than the continuous mode for colour removal from dye industry effluents.

The Saddle prosthesis in periacetabular tumours.

The Saddle endoprosthesis provides a means of establishing a stable and mobile articulation between the femur and a partially resected pelvis. Six patients with malignant or aggressive benign bone tumours underwent resection and replacement with custom-made Saddle endoprosthesis. Wide margin was achieved in four cases and marginal margin in two. Follow-up ranged from 24 to 41 months. All the six patients were then alive, five being disease-free. One patient developed deep infection and local recurrence necessitating removal of the prosthesis. The functional results were either excellent or good in five patients.

Isolated congenital left ventricular diverticulum in adults.

Isolated congenital ventricular diverticulum or aneurysm is rare and usually arises from the left ventricle. The presentation of this condition is diverse. We report three cases of isolated congenital left ventricular diverticula. The age range was 17-30 years. Chest X-ray provided the earliest clinical suspicion in these three cases of a cardiac anomaly which was diagnosed by echocardiography and confirmed by angiocardiography. The location of the congenital left ventricular diverticulum was the left ventricular apex in two cases and basal in the other. We conclude that congenital left ventricular diverticulum is a disease of protean presentations. A high index of suspicion is necessary while interpreting chest X-rays and echocardiographs to diagnose congenital left ventricular diverticulum. A contractile accessory chamber of the left ventricle with a narrow neck with or without midline defects and an electrocardiogram without Q waves is consistent with the diagnosis of congenital left ventricular diverticulum.