Biotechnology and Environmental Sciences

The antibacterial activity of a water-soluble chitosan derivative prepared by chemical modification to quaternary ammonium compound N,N,N-trimethylchitosan (TC) was investigated against four selected waterborne pathogens: Aeromonas hydrophila ATCC 35654, Yersinia enterocolitica ATCC 9610, Listeria monocytogenes ATCC 19111 and Escherichia coli O157:H7 ATCC 32150. An inactivation of 4 log CFU/ml of all waterborne pathogens was noted for the quaternized chitosan as compared with chitosan over a short contact time (30 min) and low dosage (4.5 ppm) at ambient temperature. A marked increase in glucose level, protein content and lactate dehydrogenase (LDH) activity was observed concurrently in the cell supernatant to be a major bactericidal mechanism. The results suggest that the TC derivative may be a promising commercial substitute for acid-soluble chitosan for rapid and effective disinfection of water.

This study evaluated the antibacterial spectrum and safety of a chemically modified biopolymeric flocculant (TMB) against waterborne pathogens. The biopolymer previously characterized as polysaccharide with flocculating activity is produced extracellularly by the bacterium Klebsiella terrigena. The amino sugars on the polymer were chemically modified by quaternization, which resulted in N,N,N trimethyl biopolymer (TMB). Quaternization was effective in imparting biocidal activity to TMB against five selected waterborne pathogens, namely, Aeromonas hydrophila, Yersinia enterocolitica, Salmonella typhimurium, Listeria monocytogenes and Escherichia coli O157:H7. 99.999% inactivation was achieved with S. typhimurium at a dose of 60 μg ml−1 of TMB within 60 min at the ambient temperature, followed by other pathogens. Haemotological, histopathological and general examinations indicated no adverse effects in Swiss albino mice fed with the quaternized biopolymer (120 mg kg−1 body weight−1 da...

Ectomycorrhizal fungi (ECM) are known to protect the host plant from heavy metal stress. But the information on molecular mechanisms involved in this process is still ambiguous. The present study intends on providing insight into the Cu detoxification mechanism in ECM fungus , a new species isolated from north western Himalayas. Two metallothionein genes and , were isolated from the cDNA and characterized for their potential role in Cu-detoxification and homeostasis. The response of these genes to the extracellular concentrations of copper was studied by qPCR analysis. Both genes were actively induced under exogenous Cu stress, thus can be classified as Cu-thioneins. Further, the functional complementation of these genes in the Cu sensitive yeast mutant , successfully restored their wild type phenotype of Cu tolerance.This shows that both and plays an important role in Cu detoxification and homeostasis in ECM fungus .

Fried sourdough bread (bhatura) with an elevated amount of g-aminobutyric acid (GABA) was produced using lactic acid bacteria (LAB). The LAB starter was screened and isolated from pickled yam showing highest GABA content and was identified as Lactococcus lactis subsp. lactis. The maximum GABA production in de Man Rogosa Sharpe (MRS) media supplemented with monosodium glutamate (MSG) was 110 mg/100 ml at pH 5, and 1-3% NaCl did not change the production of GABA significantly ( p . 0.05). When MSG was replaced with Vigna mungo in sourdough, the amount of GABA for bhatura was 226.22 mg/100 g representing about 10-fold increase. A sensory evaluation resulted as the overall general acceptability of bhatura to be 4.91^0.03 on a five-point hedonic scale. Thus, the results indicated the potential of L. lactis as a LAB starter for the production of GABA-enriched bhatura. Although other physiological effects can be expected in the product, animal and clinical studies are mandatory prior to application of this food.

Several factors influencing micropropagation of a selected elite clone of Eucalyptus tereticornis Sm. were investigated. Amongst different cytokinins tested, 6-benzyleadenine proved to be the most effective cytokinin for shoot multiplication and elongation. The initial size of the shoot clump (inoculum) also influenced shoot multiplication and elongation. The number of shoots proliferated per culture vessel were significantly higher (342 shoots per culture vessel) when larger shoot clumps (15-20 shoots) were inoculated, compared to smaller shoot clumps (4-5 shoots), which resulted in a reduced shoot proliferation rates (245 shoots per culture vessel). However, the number of elongated shoots (65 per culture vessel) and shoot length (5.23 cm) were higher in cultures which were inoculated with smaller shoot clumps in comparison to those cultures which were inoculated with larger shoot clumps (54 shoots per culture vessel with shoot length of 4.17 cm). The maximum number of rooted shoots (80.7 %) was obtained on one fourth-strength MS medium supplemented with 5.0 μM indolebutyric acid. The number of shoots proliferated, elongated, rooting frequency, and subsequent survival of plants after acclimatization were higher in cultures incubated under photosynthetically active radiation (PAR) compared to those incubated under cool fluorescent lights (CFL). Osmotic potential of the sap and chlorophyll content of cultures incubated under PAR were also higher than those incubated under CFL. Following transfer of plants to soil, inoculation with a suspension of Bacillus subtilis (plant growth-promoting bacterium) increased the survival rate of plants by 10 %, yielding successful transfer of 84 % of plants. Random amplified polymorphic DNA and inter simple sequence repeat analyses indicated a high level of clonal uniformity amongst regenerated plants and also with that of the mother plant.

Fresh squeezed juices of Kinnow-mandarin and carrots, sold by street vendors in Patiala city were analyzed for their microbiological qualities during the months of October through March. The total viable counts of all samples (150) were approximately Log 6 with loads of total faecal coliform and total Staphylococcal counts. Qualitative analysis showed the presence of coagulase positive S.aureus in forty-five samples of carrot juices (30%) and eighteen samples of kinnowmandarin juices (12%). There was no significant difference between carrot and kinnow-mandarin juice samples in total viable counts, total staphylococcal counts or total coliform counts. However S.enteridis was detected in three samples of carrot juices obtained from two different areas of the city. Our results demonstrate the hygienic quality of two most popular types of street vended fruit juices-(fresh squeezed carrot and kinnow -mandarin)their risk to the consumers and suggest the urgent need for government participation in developing suitable intervention measures to improve microbial quality of juices.

Single nucleotide polymorphisms (SNPs) may be considered the ultimate genetic markers as they represent the finest resolution of a DNA sequence (a single nucleotide), and are generally abundant in populations with a low mutation rate. SNPs are important tools in studying complex genetic traits and genome evolution. SNP mining can be done by experimental and computational methods. Computational strategies for SNP discovery make use of a large number of sequences present in public databases [in most cases as expressed sequence tags (ESTs)] and are considered to be faster and more cost-effective than experimental procedures. A major challenge in computational SNP discovery is distinguishing allelic variation from sequence variation between paralogous sequences, in addition to recognizing sequencing errors. For the majority of the public EST sequences, trace or quality files are lacking which makes detection of reliable SNPs even more difficult because it has to rely on sequence comparisons only. In the present study, online SNP and allele detection tool HaploSNPer (based on QualitySNP pipeline) and Sorghum bicolor genome was used. As a result, 77094 potential SNPs and 40589 reliable SNPs were detected in S. bicolor. In the 77094 potential SNPs detected transitions, transversions and indels were 34398, 35871 and 6825, respectively. In the 40589 reliable SNPs detected transitions, transversions and indels were 17042, 20500 and 3047, respectively.

Single nucleotide polymorphisms (SNPs) may be considered the ultimate genetic markers as they represent the finest resolution of a DNA sequence (a single nucleotide), and are generally abundant in populations with a low mutation rate. SNPs are important tools in studying complex genetic traits and genome evolution. SNP mining can be done by experimental and computational methods. Computational strategies for SNP discovery make use of a large number of sequences present in public databases [in most cases as expressed sequence tags (ESTs)] and are considered to be faster and more cost-effective than experimental procedures. A major challenge in computational SNP discovery is distinguishing allelic variation from sequence variation between paralogous sequences, in addition to recognizing sequencing errors. For the majority of the public EST sequences, trace or quality files are lacking which makes detection of reliable SNPs even more difficult because it has to rely on sequence compari...

Singhal and Saxena: Comparative Screening of Catechin Isomers Fem proteins are the essential structural proteins of various gram-positive bacteria. These are of three different types namely FemX (FmhB), FemA and FemB. Only two Fem protein crystallographic structures are available till date, one for FemA in Staphylococcus aureus and another for FemX in Weissella viridescensis. In this study, computational methods are used to evaluate interaction of FemA protein with catechin and epicatechin analogues. The interaction of FemA protein with catechin and epicatechin analogues are confirmed by binding energy and scores given by Autodock Vina and UCSF Dock docking softwares, which is followed by Lipinski filters and toxicity studies using online Lipinski server of SCFBIO and OSIRIS. Catechin gallate has been found as the best ligand for FemA protein in all aspects and it has outperformed all catechin and epicatechin isomers.

Drug discovery is a cost intensive and time consuming approach therefore contingent alternatives are being explored to combat drug resistant bacteria which cause chronic infections. Resistance modifying agents offer plausible alternatives in reviving the current antimicrobial drugs thereby making them effective to be used in clinical settings. We for the first time report the promising activity of (À)-Catechin gallate selected using in silico studies with FemA protein of Staphylococcus aureus. The MIC of the test isolates of S. aureus viz. NCTC 6571, MTCC737 and MTCC 96 by visual method was 500 mg and 8000 mg for Oxacillin and Penicillin respectively. (À)-Catechin gallate induced an 8-fold reduction in the MIC of Oxacillin in S. aureus NCTC 6571 and MTCC 737 at concentration of 7.8 mg/ml and 31.25 mg/ml respectively. A 4-fold reduction, in MIC of Penicillin and Oxacillin at concentration of 7.8 mg/ml of (À)-Catechin gallate in NCTC 6571 and MTCC 96 respectively. These synergistic combinations in time kill assay exhibited a reduction between 2 and 6 log 10 in the CFU of the test microbes thereby suggesting (À)-Catechin gallate to be a promising candidate for further evaluation as a resistance modifying agent to overcome resistance to first generation of b-lactam antibiotics.

The physical properties of the soil, specifically the soil texture as a result of rock weathering, is an important factor to study since it is one of the determinants of forest soil quality. This study aims to determine the soil physical properties of the Camba Formation (Tmc) and Volcanic Camba Formation (Tmcv) in the Bulusaraung Lower Mountain Forest. Twenty soil sampling points were systematically placed on each formation. Soil samples obtained were subsequently analyzed at the Chemical and

The class of Riemann zeta distribution is one of the classical classes of probability distributions on R. Multidimensional Shintani zeta function is introduced and its definable probability distributions on R d are studied. This class contains some fundamental probability distributions such as binomial and Poisson distributions. The relation with multidimensional polynomial Euler product, which induces multidimensional infinitely divisible distributions on R d , is also studied.

h i g h l i g h t s " Spent substrate from three mushrooms varied in population and diversity of microbes. " Two fungi and three bacteria exhibited appreciable activities of laccase, MnP and LiP. " Presence of glucose and sucrose and 30°C temperature supported higher decolorization. " Wheat straw and paddy straw worked as best immobilizing agents for two fungi. " Consortium of two fungi and three bacteria led complete effluent decolorization.

In this study, we report the development of a phosphate sensor by exploiting phosphate-binding capability of Acinetobacter sp. biopolymer. An engineered strain of Acinetobacter sp. overproducing biopolymer was selected by Tn5 mutagenesis. The mutant showed a five-fold increase in biopolymer production and an increase in expression of intracellular biopolymer synthetic enzymes, phosphoglucomutase and glucosyl transferase. Physical and chemical analysis of biopolymer revealed a porous, compact surface morphology and a polysaccharide structure with predominance of uronic acid residues. Cellulose acetate membranes precoated with purified biopolymer were exposed to phosphate solutions and membrane-bound phosphate was determined by stannous chloride method. The colored membranes were analyzed by a LED (690 nm)/photodiode detection system. The phosphate concentration was estimated by converting the amperometric signal to phosphate concentrations from a standard plot.

Ectomycorrhizal fungi (ECM) are known to protect the host plant from heavy metal stress. But the information on molecular mechanisms involved in this process is still ambiguous. The present study intends on providing insight into the Cu detoxification mechanism in ECM fungus , a new species isolated from north western Himalayas. Two metallothionein genes and , were isolated from the cDNA and characterized for their potential role in Cu-detoxification and homeostasis. The response of these genes to the extracellular concentrations of copper was studied by qPCR analysis. Both genes were actively induced under exogenous Cu stress, thus can be classified as Cu-thioneins. Further, the functional complementation of these genes in the Cu sensitive yeast mutant , successfully restored their wild type phenotype of Cu tolerance.This shows that both and plays an important role in Cu detoxification and homeostasis in ECM fungus .

r e V i e W F o c u s o n M e M b r a n e P r ot e i n s ABC transporters are a family of membrane proteins that mediate diverse ATP-driven transport processes. They contain a pair of conserved cytoplasmic domains termed ATP-binding cassettes (ABC) or nucleotide-binding domains (NBD) . The NBDs hydrolyze ATP and drive conformational changes in the attached transmembrane domains (TMDs), thus allowing substrates to cross the lipid bilayer of the membrane and either be imported into or exported out of the cytoplasm (domain arrangement and conserved sequence motifs are shown in Box 1 and , and representative structures of the different subfamilies of ABC transporters in .