This study describes the characterization and optimization of medium components for an extracellular detergent, surfactant, organic solvent and thermostable serine alkaline protease produced by alkaliphilic Bacillus pumilus MCAS8 strain isolated from Pulicat lake sediments, Tamil Nadu, India. The strain yielded maximum protease (2,214 U/ml) under optimized conditions: carbon source, citric acid-1.5 % (w/w); inducer, soyabean meal-2 % (w/w); pH 11.0; shaking condition 37 °C for 48 h. The enzyme had pH and temperature optima of 9.0 and 60 °C, respectively. The enzyme displayed the molecular mass of 36 kDa in sodium dodecyl sulphate-polyacrylamide gel electrophoresis study and exhibited activity at a wide range of pH (6.0-11.0) and thermostability (20-70 °C). More than 70 % residual activity was observed when the enzyme was incubated with dithiothreitol, ethylenediaminetetraacetic acid, ethylene glycol tetraacetic acid and H(2)O(2) for 30 min. The protease activity was also enhanced by divalent cations such as Ba(2+), Ca(2+) and Mg(2+) and was strongly inhibited by Fe(2+), Zn(2+), Sr(2+), Hg(2+) and urea. The enzyme retained more than 50 % of its initial activity after pre-incubation for 1 h in the presence of 5 % (v/v) organic solvents such as dimethyl sulphoxide and acetone. The protease could hydrolyse various native proteinaceous substrates (1 % w/v) such as bovine serum albumin, casein, skim milk, gelatine, azocasein and haemoglobin. Wash performance analysis of enzyme revealed that it could effectively remove blood stains from the cotton fabric, thus making it suitable to use as an effective detergent additive. The protease enzyme also exhibited promising result in the dehairing of goat skin. The potency of the eco-friendly enzyme without using any chemicals against washing and dehairing showed that the enzyme could be used for various industrial applications.

Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km2) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets.

Studies on aggregation of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane at low water content were carried out. The critical micelle concentration (cmc) thermodynamic parameters were determined at various temperatures. The observations suggested that the micellization process was endothermic in nature and that it is mainly an entropic process. The cmc was also determined at various R values (R < 3) and it was found that cmc increases with increasing R. The aggregation number was determined at the R value of 1.6. From the pyrene and ANS binding studies, the microviscosity and micropolarity changes on the onset of micellization are well characterized. Spectral studies with ANS indicate a decrease in microviscosity on increase in R value. ANS fluorescence was monitored in the presence of additives like acrylamide, KI3, and tetrabutylammonium iodide. The iodide-based additives lead to quenching of fluorescence of ANS with concomitant red shift in the λem suggesting decreased microviscosity and micropolarity. Acrylamide was shown to increase the polarity by the ANS spectral features. These findings led to the conclusions that the positive ΔH m° values arise mainly from the dismantling of hydrated ions in the quasi-lattice of AOT interior. With an increase in temperature, immobilized structured states of water get destructured, which ultimately leads to favoring the aggregation process.

The outcome of 109 patients with severe head injury was studied in relation to clinical and computed tomographic (CT) criteria on admission, after resuscitation. Age, Glasgow Coma Score (GCS) and state of pupils strongly correlated with outcome. The presence of hypothalamic disturbances, hypoxia and hypotension were associated with an adverse outcome. The CT indicators associated with poor outcome were perimesencephalic cistern (PMC) obliteration, subarachnoid haemorrhage, diffuse axonal injury and acute subdural haematoma. The prognostic value of midline shift and mass effect were influenced by concomitant presence of diffuse brain injury. For the subset of patients aged < 20 years, with GCS 6-8 and patent PMC (n = 21), 71.4% correct predictions were made for a good outcome. For the subset of patients aged > 20 years, with GCS 3-5 and partial or complete obliteration of PMC (n = 28), 89.3% correct predictions were made for a poor outcome.

The temperature dependence of critical micelle concentration (c.m.c.), aggregation number, standard Gibbs energy change (A,G"), enthalpy change (A,/+") and entropy change ( A m s o ) of micelle formation, and proton chemical shifts of the TFA Tyr-Gly-Phe-Ala-OBz peptide (TFA is trifluoroacetic acid) have been presented in the light of NH. . .O=C< hydrogen-bond formation and forces implicated in micellization. It has been found that the c.m.c. of the tetrapeptide increases with increase in temperature from 20 to 40"C, whereas it decreases at temperatures above 40 "C. Moreover, the temperature dependence of the aggregation number, proton chemical shifts and thermodynamic results suggest that intramolecular H bonds are formed at temperatures in the range 2040°C (secondary level of structure) owing to hindrance of rnicelle formation, whereas above 40 "C the intramolecular H bonds of the peptide are broken as micellization increases which demonstrates a tertiary level of structure. It has also been found that the temperature of 40°C appears very significant in that it is close to the temperature at which both the enthalpy and entropy of micellization change sign, which presumably relates to the opposing temperature dependences of hydrophobic and electrostatic interactions, the inverse temperature dependence of hydrophobic interactions reflecting changes in water structure.

Protecting groups in N- and C-terminal positions play a decisive role in the conformational preference of smaller peptides. Conformational analysis of tetrapeptide derivatives containing Ala, Ile and Gly residues was performed. Peptide 1, Boc-Ala-Ile-Ile-Gly-OMe (Boc: tert-butyloxycarbonyl) has a predominantly helical turn conformation in all the alcoholic solvents studied, whereas in the solid state it has a beta-sheet conformation. In contrast, peptide 2, Ac-Ala-Ile-Ile-Gly-OMe (Ac: acetyl) has a random coil conformation in solution. The FTIR spectrum of peptide 1 shows a lower frequency of urethane carbonyl, indicating involvement of the carbonyl group in hydrogen bonding in the helical turn.

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