Enhancement Effects of Biosurfactant Produced by Pseudomonas aeruginosa MTCC 2297 and Pseudomonas fluorescens on Sugar Cane Bagasse Composting

Biosurfactant produced by Pseudomonas aeruginosa MTCC2297 and Pseudomonas fluorescens (a Mangrove forest isolate) was added to the Sugar cane bagasse decomposing process to initiate and enhance the production of reducing sugars. Both isolates produced a glycolipid biosurfactant, namely a rhamnolipid that was confirmed by biochemical and analytical studies. The surface tension of fermentation broth reduced from 73 to 34.2 mN/m by P. aeruginosa MTCC 2297 and from 76 to 29 mN/m by P. fluorescens. Sugar cane bagasse decomposing process was attempted by two different methods, adding pure rhamnolipid and on-site production of it were compared. The study revealed that rhamnolipid concentration of 0.75gl-1 was  optimum for composting process and the optimum temperature for compost pile production was 32°Cfor the first 48h subsequently 35°C for the next 48h. At the optimum temperature for this two-stage fermentation, the production of reducing sugar could be increased to 15.73 gl-1 for P. aeruginosa MTCC 2297 and for the P. fluorescens  reducing sugar increased to 15.88 gl-1,  both experiments resulted  in higher values than  that of the treatment without rhamnolipid sample. The results indicate that application biosurfactant could possibly reduce the composting period. As the compost pile production of rhamnolipid does not require the purification process, the production cost reduced significantly.--------------------------------------------------------------------------------------------------------Department of Microbiology, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Chidambaram, Tamil Nadu, India-608002. *Corresponding author, Email: [email protected], Mob: +91-9842059688                Cite This Article As: Parthasarathi, R. and   P. K. Sivakumaar. 2010. Enhancement Effects of Biosurfactant Produced by Pseudomonas aeruginosa MTCC 2297 and Pseudomonas fluorescens on Sugar Cane Bagasse Composting. J. Ecobiotechnol. 2(3): 33-39

Electric field driven destabilization of the insulating state in nominally pure LaMnO3

We report an electric field driven destabilization of the insulating state in nominally pure LaMnO3 single crystal with a moderate field which leads to a resistive state transition below 300 K. The transition is between the insulating state in LaMnO3 and a high resistance bad metallic state that has a temperature independent resistivity. The transition occurs at a threshold field (Eth) which shows a steep enhancement on cooling. While at lower temperatures the transition is sharp and involves large change in resistance but it softens on heating and eventually absent above 280K. When the Mn4+ content is increased by Sr substitution up to x=0.1, the observed transition though observable in certain temperature range, softens considerably. The observation has been explained as bias driven percolation type transition between two coexisting phases, where the majority phase is a charge and orbitally ordered polaronic insulating phase and the minority phase is a bad metallic phase. The mobile fraction f of the bad metallic phase deduced from the experimental data follows an activated kinetics with the activation energy nearly equal to 200 meV and the prefactor fo is a strong function of the field that leads to a rapid enhancement of f on application of field leading to the resistive state transition. We suggest likely scenarios for such co-existing phases in nominally pure LaMnO3 that can lead to the bias driven percolation type transition.Comment: Accepted in JPC

Cosmic optical activity from an inhomogeneous Kalb-Ramond field

The effects of introducing a harmonic spatial inhomogeneity into the Kalb-Ramond field, interacting with the Maxwell field according to a `string-inspired' proposal made in earlier work are investigated. We examine in particular the effects on the polarization of synchrotron radiation from cosmologically distant (i.e. of redshift greater than 2) galaxies, as well as the relation between the electric and magnetic components of the radiation field. The rotation of the polarization plane of linearly polarized radiation is seen to acquire an additional contribution proportional to the square of the frequency of the dual Kalb-Ramond axion wave, assuming that it is far smaller compared to the frequency of the radiation field.Comment: 9 pages, Revtex, no figure

Universal canonical black hole entropy

Non-rotating black holes in three and four dimensions are shown to possess a canonical entropy obeying the Bekenstein-Hawking area law together with a leading correction (for large horizon areas) given by the logarithm of the area with a {\it universal} finite negative coefficient, provided one assumes that the quantum black hole mass spectrum has a power law relation with the quantum area spectrum found in Non-perturbative Canonical Quantum General Relativity. The thermal instability associated with asymptotically flat black holes appears in the appropriate domain for the index characterising this power law relation, where the canonical entropy (free energy) is seen to turn complex.Comment: Revtex, 5 pages, no figures. Typos corrected and a footnote and some references adde

Current-driven orbital order-disorder transition in LaMnO3

We report significant influence of electric current on the orbital order-disorder transition in LaMnO3. The transition temperature T_OO, thermal hysteresis in the resistivity (rho) versus temperature (T) plot around T_OO, and latent heat L associated with the transition decrease with the increase in current density. Eventually, at a critical current density, L reaches zero. The transition zone, on the other hand, broadens with the increase in current density. The states at ordered, disordered, and transition zone are all found to be stable within the time window from ~10^-3 to ~10^4 seconds.Comment: 7 pages including 5 figures; resolution of Fig.1 is better here than the published versio

Generalized Hawking-Page Phase Transition

The issue of radiant spherical black holes being in stable thermal equilibrium with their radiation bath is reconsidered. Using a simple equilibrium statistical mechanical analysis incorporating Gaussian thermal fluctuations in a canonical ensemble of isolated horizons, the heat capacity is shown to diverge at a critical value of the classical mass of the isolated horizon, given (in Planckian units) by the {\it microcanonical} entropy calculated using Loop Quantum Gravity. The analysis reproduces the Hawking-Page phase transition discerned for anti-de Sitter black holes and generalizes it in the sense that nowhere is any classical metric made use of.Comment: 9 Pages, Latex with 2 eps figure

Dynamic DGT speciation analysis and applicability to natural heterogeneous complexes

Owing to their inherent heterogeneity, the thermodynamic stability of metal ion complexes with natural ligands is characterised by a distribution, and thus is a function of metal-to-ligand ratio. The kinetic features of such metal complexes are also distributed and can be probed by dynamic speciation techniques. The kinetic regime of the metal complex sample can be manipulated via the metal-to-ligand ratio, and the timescale over which kinetic parameters are actually in effect is defined by the window of the chosen technique. Here we detail the kinetic features of diffusive gradients in thin film (DGT), and show that the range of attainable measurement timescales (t) is rather limited: variation of the gel layer thickness practically allows only one order of magnitude in t to be scanned. The more effective use of DGT to probe the distribution of dynamic metal species in heterogeneous systems is via variation of the metal-to-ligand ratio in the sample solution. Compilation of the literature DGT data for natural waters shows that by assuming a Freundlich isotherm relationship, the degree of heterogeneity is reflected in the measured DGT concentration as a function of metal ion loadin

A Cross Sectional Study of Intern’s Willingness to Serve in Rural Primary Health Centres of Andhra Pradesh, India.

The shortage of health professionals in rural areas is a global problem. The urban and rural maldistribution of doctors results in severe problems regarding access to and performance of health care services. Retaining doctors in rural areas is a challenging task for a number of reasons, ranging from personal preferences to difficult work conditions and low remuneration. The objective of the study was to understand the factors influencing medical and dental intern’s choice to work in rural PHC’s as a basis for designing policies to redress geographic imbalances in health professional’s distribution. A total of 385 dental and medical interns in Andhra Pradesh provided a unique contingent valuation data in a cross sectional survey conducted in 4 medical and 4 dental colleges in Andhra Pradesh, using a questionnaire concerning their preferences, related incentives to work in various rural and remote primary health centres of Andhra Pradesh state, India. The response rate of the study was 89 %, (n= 344), with only 24% of interns expressing their willingness to serve in rural/remote primary health centres.Most of the interns stressed for increase in salary, better accommodation and infrastructure of the hospitals as the factors for increasing their retention in remote rural areas. Although most Indian students are motivated to study medicine and dentistry by the desire to help others, this does not translate into willingness to work in rural areas. Efforts from the government to build intrinsic motivation during medical and dental training to serve in these deprived areas should be in focus with addition to improved working and living conditions and better remuneration

Studies on sandal spike. Part II. Physiological significance of the disturbed iron balance in the spike disease of sandal (Santalum album Linn.)

Chlorosis in spiked sandal leaves, as in the chlorotic eaves of other plants, is caused by a deficiency of iron. However, the deficiency appears to be not on account of reduced availability of this element in the soil, but a direct effect of the spike disease, since the soil iron content is normal and the pH of the soil is on the acid side (Table III). Like other chlorotic leaves, the spiked sandal leaves show an increase of amino nitrogen, oxalic and malic acids, and a decrease in calcium content. Thus chlorosis in sandal leaves, caused by spike-induced iron deficiency, bears resemblance to the chlorosis in other leaves which is caused by the reduced iron availability in soils. In spike-diseased plants there is a comparatively higher accumulation of iron in the roots than in the leaves, which suggests that probably the mechanism of translocation of iron in the plant is affected. The preponderance of iron over calcium in the spiked sandal roots, as evidenced by the much lower Ca/Fe ratio in them, seems to be responsible at least in part for the death of root ends and cessation of haustorial connections in the spiked sandal

Mycobacterium tuberculosis ClpC1: characterization and role of the N-terminal domain in its function

Caseinolytic protein, ClpC is a general stress protein which belongs to the heat shock protein HSP100 family of molecular chaperones. Some of the Clp group proteins have been identified as having a role in the pathogenesis of many bacteria. The Mycobacterium tuberculosis genome demonstrates the presence of a ClpC homolog, ClpC1. M. tuberculosis ClpC1 is an 848-amino acid protein, has two repeat sequences at its N-terminus and contains all the determinants to be classified as a member of the HSP100 family. In this study, we overexpressed, purified and functionally characterized M. tuberculosis ClpC1. Recombinant M. tuberculosis ClpC1 showed an inherent ATPase activity, and prevented protein aggregation. Furthermore, to investigate the contribution made by the N-terminal repeats of ClpC1 to its functional activity, two deletion variants, ClpC1Δ1 and ClpC1Δ2, lacking N-terminal repeat I and N-terminal repeat I along with the linker between N-terminal repeats I and II, respectively were generated. Neither deletion affected the ATPase activity. However, ClpC1Δ1 was structurally altered, less stable and was unable to prevent protein aggregation. Compared with wild-type protein, ClpC1Δ2 was more active in preventing protein aggregation and displayed higher ATPase activity at high pH values and temperatures. The study demonstrates that M. tuberculosis ClpC1 manifests chaperone activity in the absence of any adaptor protein and only one of the two N-terminal repeats is sufficient for the chaperone activity. Also, an exposed repeat II makes the protein more stable and functionally more active