Biological pretreatment of sugarcane trash for its conversion to fermentable sugars

Pretreatment of lignocellulosic biomasses, the first step in their conversion to utilizable molecules requires very high energy (steam and electricity), corrosion resistant high-pressure reactors and high temperatures. These severe conditions not only add to the cost component of the entire process but also lead to the loss of sugars to the side reactions. Microbial pretreatments have been reported to be associated with reducing the cost factors as well as the severities of the reactions. Eight bioagents, including fungi and bacteria, were screened for their pretreatment effects on sugarcane trash. They narrowed down the C:N ratio of trash from 108:1 to a varying range of approximately 42:1 to 60:1.The maximum drop in C:N ratio of 61% was observed using Aspergillus terreus followed by Cellulomonas uda (52%) and Trichoderma reesei and Zymomonas mobilis (49%). The bioagents helped in degradation of sugarcane trash by production of cellulases, the maximum being produced by A. terreus, (12 fold) followed by C. uda (10 fold), Cellulomonas cartae (9 fold) and Bacillus macerans (8 fold). The microbial pretreatment of trash rendered the easy accessibility of sugars for enzymatic hydrolysis, which can be directed for production of alcohol.     

Immobilization of Xylan-Degrading Enzymes from Scytalidium thermophilum on Eudragit L-100

Summary Xylanase from Scytalidium thermophilum was immobilized on Eudragit L-100, a pH sensitive copolymer of methacrylic acid and methyl methacrylate. The enzyme was non-covalently immobilized and the system expressed 70% xylanase activity. The immobilized preparation had broader optimum temperature of activity between 55 and 65 °C as compared to 65 °C in case of free enzyme and broader optimum pH between 6.0 and 7.0 as compared to 6.5 in case of free enzyme. Immobilization increased the t_1/2 of enzyme at 60 °C from 15 to 30 min with a stabilization factor of 2. The K_m and V_max values for the immobilized and free xylanase were 0.5% xylan and 0.89 μmol/ml/min and 0.35% xylan and 1.01 μmol/ml/min respectively. An Arrhenius plot showed an increased value of activation energy for immobilized xylanase (227 kcal/mol) as compared to free xylanase (210 kcal/mol) confirming the higher temperature stability of the free enzyme. Enzymatic saccharification of xylan was also improved by xylanase immobilization.     

ERK activation is only one role of PKC in TCR-independent cytotoxic T cell granule exocytosis

Cytotoxic T cells (CTLs) kill target cells by releasing lytic agents via regulated exocytosis. Three signals are known to be required for exocytosis: an increase in intracellular Ca²⁺, activation of protein kinase C (PKC) and activation of extracellular signal regulated signal kinase (ERK). ERK activation required for exocytosis depends on activity of PKC. The simplest possibility is that the sole effect of PKC required for exocytosis is ERK activation. Testing this requires dissociating ERK and PKC activation. We did this using TCR-independent stimulation of TALL-104 human leukemic CTLs. When cells are stimulated with thapsigargin and PMA, agents that increase intracellular Ca²⁺ and activate PKC, respectively, PKC-dependent ERK activation is required for lytic granule exocytosis. Expressing a constitutively active mutant MAP kinase kinase activates ERK independent of PKC. However, activating ERK without PKC does not support lytic granule exocytosis, indicating that there are multiple effects of PKC required for granule exocytosis.     

Development and characterization of novel microsatellite markers in the Asiatic lion (Panthera leo persica)

All cat species, except domestic cats, are either threatened or endangered. The Asiatic lion (Panthera leo persica), a critically endangered species, is driven to a single habitat zone in Gir forests in India for its survival. The present status of this big cat compels us to acquire deeper knowledge of its genetic variability and phylogenetic relationships. Here we report the isolation of highly polymorphic microsatellite loci from a partial genomic library of the Asiatic lion. These loci were characterized and have shown high levels of variation ranging from six to 11 alleles per locus in the population studied.     

Isolation and characterization of a bacteriocin produced by Cicer-Rhizobium

A constitutively expressed bacteriocin from Cicer-Rhizobium was purified to homogeneity. The purified preparation yielded a homogenous protein with a molecular weight of about 29 kDa. This protein was heat stable, unaffected by nucleases and was found to have an iso-electric point (pI) of 4.6. The N-terminal sequence of the protein was found to be M-N-N-N-Y-R-E-L-L-P-I-I-G-P-P-W-A-E-I-E, sharing 78% homology with linocin M18. Bacteriocin bioactivity was correlated with the presence of a 29 kDa protein in the growth diffusates of the culture. A mutant strain unable to produce this bacteriocin was found to have a statistically significant reduction in nodule occupancy and competitiveness against the wild type and indigeneous populations under unsterile conditions. Bacteriocin production by the mutant carrying the complement clone pJNP365 was found to be stable even in an unsterile environment.     

Antagonists of the human A2A receptor. Part 5: Highly bio-available pyrimidine-4-carboxamides

A novel series of antagonists of the human A_2A receptor have been identified and have been shown to display good potency and high degrees of selectivity over other receptor sub-types. Displaying in vivo potency in commonly used disease models and high oral bio-availability, this class of compounds may serve as clinically useful treatments for the relief of the symptoms associated with Parkinson’s disease.     

Modification of flag leaf senescence and yield characters in barley (Hordeum vulgare L.) by gibberellic acid and kinetin

Barley plants (Hordeum vulgare L.) received foliar applications of 10^–4 M gibberellic acid (GA₃) and Kinetin (KN) individually and in combination at one or more of three growth stages: flag leaf appearance (I), ear emergence (II), and the first stage of senescence initiation in the flag leaf (III). Both plant growth regulators (PGR) hastened onset of senescence when sprayed at Stage I and/or Stage II. Treatment at Stage III, either alone or in combination with treatments at the other stages, tended to postpone senescence. Yield components also showed stage-dependent response: Stage I treatment increased the formation of total and bearing tillers, and Stage III treatment improved grain number and weight. However, while GA₃ proved more effective than KN, the two together acted antagonistically.     

Population Dynamics of the Root-Knot Nematode Meloidogyne Triticoryzae under Five Rice-Based Cropping Systems

Population dynamics of M. triticoryzae in five rice-based cropping systems have revealed that rice was the main host. Most of the population growth which contributed to the peak population density in September occurred in the rice crop. The other crops in the Rabi and summer seasons had a profound influence on the height of the peak in the succeeding rice crop. Some level of reproduction occurred in wheat, greengram and berseem in Rabi which contributed to relatively higher equilibrium densities. The potato variety Pusa Bahar increased the population density while Pusa Badshah decreased it. The lower temperature during the Rabi season also limited the rate of population growth. The incorporation of organic matter into the soil, either as crop residues of greengram or berseem, reduced the population growth of M. triticoryzae .     

Chemical reaction- and particle diffusion-based kinetic modeling of metal biosorption by a Phormidium sp.-dominated cyanobacterial mat

The present study explores the suitability of chemical reaction-based and diffusion-based kinetic models for defining the biosorption of Cu(II), Cd(II) and Pb(II) by Phormidium sp.-dominated mat. The time-course data of metal sorption by the test mat significantly (r² = 0.932-0.999) fitted to the chemical reaction-based models namely pseudo-first-order, -second-order, and the general rate law. However, these models fail to accurately describe the kinetics of metal biosorption due either to prefixed order or unjustifiable change in rate constant and reaction order with varying concentrations of metal and biomass in the solution. The diffusion-based models, namely, the intra-particle diffusion model and the external mass transfer model fitted well to the time-course metal sorption data, thus suggesting involvement of both external and intra-particle diffusion processes in sorption of test metals by mat biomass. However, the Boyd kinetic expression clearly showed that the external mass transfer is the dominant process.