Ca2(+)-dependent glucose transport in chicken intestine

Transport of glucose was measured in the intestine of white leghorn layers in vivo using ligated upper small intestinal segment in the presence of Ca2+ and other ions either singly or in combination. Transport of glucose across the intestine was very significantly increased with Ca2+ than Na+, K+ and Po4(3-) individually, but when Ca2+ was combined with Na+, K+ and PO4(3-), the glucose absorption increased significantly over that achieved by Na+ ions alone. These data revealed that Ca2+ ions might be exerting the major influence on glucose transport processes of the chicken intestine.     

Effect of mode of operation of bioreactors on the biosynthesis of penicillin amidase in Escherichia coli

Different operational mode of bioreactors influence the biosynthesis of the enzyme and related products as well as the growth of industrial microorganisms. This communication deals with the effect of mode of operation of various bioreactors with different geometric configurations, viz., batch (includes commercially available batch stirred tank, and custom-designed cylindrical and tapered reactors), batch-fed, continuous flow stirred tank reactors on the biosynthesis of penicillin amidase in Escherichia coli. Experimental findings show that the biosynthesis of penicillin amidase in E. coli show a little variation among batch reactor modes and significant variation on the continuous mode of operation. Further analysis show that the different reactor modes also influence periplasmic localization of the enzyme in the cell.     

Identification of a new group-specific determinant on hepatitis B surface antigen with a synthetic peptide.

In a recent study we demonstrated that a synthetic peptide representing residues 124-147 of the major protein of hepatitis B surface Ag (HBsAg) undergoes spontaneous oligomerization to reconstruct one or more conformational group-specific determinants on HBsAg. The present study was undertaken to identify and characterize the HBsAg-related antigenic determinants on this oligomeric peptide (peptide OS[124-147]). A panel of nine analogs of this peptide was generated by either deleting, substituting, or chemical side chain modification of specific amino acid residues. With HBsAg subtype-specific antisera a single "a" epitope was identified as one that includes Met133 and Lys141. In addition a "d" epitope toward the amino-terminal end of the sequence was also observed. Perturbation of certain amino acid residues was found to enhance a antigenicity and subsequent experiments indicated that maximal expression of this a antigenicity is dependent in part on accessibility of the Lys141 side chain and in part on the primary sequence. With a total of 50 human anti-HBsAg serum samples obtained from individuals vaccinated against hepatitis B, it was demonstrated that these sera recognize the Met133-Lys141-dependent a epitope as the dominant, and in many cases the only, determinant on peptide OS[124-147]. Finally, on immunization, peptide OS[124-147] elicits an anti-HBsAg response that is predominantly anti-a though a lesser contribution from an anti-d response was also obtained.     

Morphological and molecular divergence of Indian hill trout,Barilius bendelisis (Hamilton, 1822) stocks from different Rivers in Indo‐Burma biodiversity hotspot: Does river altitude and Dam play a role?

The present study explains the intraspecific variation in Indian Hill trout (Barilius bendelisis) on the basis of image based truss network system and D‐loop region of mtDNA. A total of 210 samples were collected from three different rivers (Teesta, Kameng and Myntudu River) of North East India in Indo‐Burma Biodiversity Hotspot. By using the software applications (tpsDig version 2.1 and PAST), a total of 25 morphometric measurements were generated from 10 landmarks. The Analysis of Variance (ANOVA), Factor Analysis (FA) and Discriminate Function Analysis (DFA) showed, out of the total variations, factor 1 explained 46.74% while factor 2 and factor 3 explained 27.14% and 11.92%, respectively. Using these variables 83.33% of the cross‐validated specimens were classified into distinct groups. Analysis of Molecular Variance (AMOVA) and pairwise Fst value for D‐loop region of mtDNA also showed high to medium level of genetic variation among the stocks and within the stocks. We conclude that the observed discrete stocks might be the result of changing environmental conditions in different rivers of the hotspot as the rivers are present at different altitudinal labels. It is also believed that the variation might be due to the construction of barrages across the river which hinder the mixing among the stocks.     

Optimization of carbon and nitrogen sources in the medium and environmental factors for enhanced production of chitinase by Trichoderma harzianum

Statistical design was used to determine the optimal levels of medium components, the optimal initial pH of the enzyme production medium, the temperature of fermentation, age of the organism in the slant growth and the age of the inoculum for the production of chitinase in shake flask fermentations. The use of high concentrations of chitin and ammonium sulphate and exclusion of peptone and urea from the medium resulted in the production of higher level of the enzyme. The optimal concentrations of the medium components were 12.5 kg/m³ and 4.2 kg/m³ for the chitin and ammonium sulphate respectively. The effect of the addition of peptone and urea to the optimized medium was studied. The optimal values of initial pH and temperature were 5.6 and 28 °C respectively. The optimal age of the slant and the inoculum were found to be 105 h and 43 h respectively. The highest level of chitinase before optimization of the above variables was 0.054 U which was maximized to the level of 0.197 U.     

Recent trends in fungal laccase for various industrial applications: An eco-friendly approach - A review

The aim of this review is to determine the trends of state-of-art of laccase sources, properties, structure and recent application of fungal laccase in various fields. Laccases are biotechnologically important multi copper proteins that have broad substrate specificity towards aromatic and non-aromatic compounds. Fungi are the major laccase producers especially ascomycetes, deuteromycetes and basidiomycetes, and laccases have an average molecular weight between 50 and 130 kDa. Fungal laccases are used in biotechnological applications for preparation of anticancerous and anti-oxidant hormonal drugs, stabilization of food products, and laccase application is also extended to preparation of biosensors, DNA labeling, immunochemical assay, bioorganic compound synthesis etc. The environmental application of laccase is for biodegradation of dyes, phenols and pesticides, and the mechanism of degradation has been briefly explained. Analysis of the biodegraded dye sample by FT-IR and Mass (ESI)-spectrum has been discussed in a detailed manner. Modeling kinetics has been discussed with respect to degradation of wastes in order to understand the factors involved in the degradation process.     

Endoglucanase from the mixed culture of Trichoderma reesei and Aspergillus wentii

The level of α-mannanase in mixed fungal culture of Trichoderma reesei, D1-6, and Aspergillus wentii, Pt 2804, affects the extracellular activities of cellulase. The endoglucanase component of the cellulase system is a glycoprotein having mannose and other sugars and sugaramines in its glycan moiety. Its activity is inhibited by α-mannanase. The inactivation of endoglucanase by α-mannanase can be prevented by galactose.