NISCAIR Online Periodicals Repository Collection: IJBT Vol.10(3) [July 2011]

Detection of cardamom mosaic virus-related sequences in plant genomes

Tue, 28 Jun 2011 22:58:59 GMT

Title: Detection of cardamom mosaic virus-related sequences in plant genomes

Authors: Jebasingh, T; Backiyarani, S; Manohari, C; Usha, R

Abstract: Cardamom mosaic virus (CdMV)-related sequences have been found in cardamom plant genome. Integrated DNA was sequenced and was found identical to the 3′ end of NIb, the RNA dependent RNA polymerase gene of CdMV. This is the first report on the integration of potyviral partial NIb sequence into a plant genome. These CdMV-relatedintegrated DNA sequences were also detected in a few other plant genomes.

Page(s): 369-371

In vitro multiplication of Merton I. 793–An apple rootstock suitable for replantation

Tue, 28 Jun 2011 22:58:59 GMT

Title: In vitro multiplication of Merton I. 793–An apple rootstock suitable for replantation

Authors: Soni, Mohit; Thakur, Manisha; Modgil, Manju

Abstract: In vitro shoot multiplication of Merton I. 793, a clonal apple rootstock, was achieved through terminal/axillary bud culture using Murashige and Skoog (MS) basal medium supplemented with 0.5-1.0 mg/L 6-benzyl amino purine (BA) and 0.1 mg/L indole-3-butyric acid (IBA). Time of collection of explants, duration of surface sterilents and growth regulators added in the medium influenced the survival of explants and their bud break. Although, the shoots were multiplied on different concentrations of cytokinins and auxins, improved multiplication was achieved with 0.5 mg/L BA and 0.01 mg/L IBA. Of the three types of explants evaluated for shoot multiplication, shoot tips on elongation were found suitable for rooting whereas, nodal cuttings and cluster of small shoots for further multiplication. Low concentrations of α-naphthyl acetic acid (NAA) was proved to be more effective for rooting as compared to IBA and indole-3-acetic acid (IAA). To overcome profuse callus formation during rooting, activated charcoal was added. In another experiment, auxin was discontinued from the rooting medium after few days, thus, resulting in better rooting frequency (72%). Thirty plantlets of Merton I. 793 were successfully hardened after 7 wks, with around 80% survival rate.

Page(s): 362-368

Effect of organic solvents on solvent-tolerant Aeromonas hydrophila IBB_Po8 and Pseudomonas aeruginosa IBB_Po10

Tue, 28 Jun 2011 22:58:59 GMT

Title: Effect of organic solvents on solvent-tolerant Aeromonas hydrophila IBB_Po8 and Pseudomonas aeruginosa IBB_Po10

Authors: Stancu, Mihaela Marilena

Abstract: Alkanes (n-hexane, n-heptane) with logarithm of partition coefficient between n-octanol and water (log P_OW) 3.86 to 4.39 were less toxic to Aeromonas hydrophila IBB_Po8 and Pseudomonas aeruginosa IBB_Po10 as compared to aromatics (toluene, styrene, xylene isomers, ethylbenzene & propylbenzene) with log P_OW2.64 to 3.69. The toxicity of 0.5% (v/v) second phase of organic solvents to these bacteria could be predictable on the basis of the solvents’ log P_OW. The tolerance, viability, adhesion and β-galactosidase activity of A. hydrophila IBB_Po8 and P. aeruginosa IBB_Po10 cells in the presence of 0.5% (v/v) organic solvents varied significantly. The results indicated that A. hydrophila IBB_Po8 was more susceptible to organic solvents than P. aeruginosa IBB_Po10, whereas both the bacterial strains harbour plasmids. A. hydrophila IBB_Po8 did not posses hydrophobe/amphiphile efflux 1 (HAE1) transporter genes, while P. aeruginosa IBB_Po10 did posses these genes. The adaptation mechanisms (modification of cell hydrophobicity, induction of β-galactosidase activity and changes in the membrane’s lipid and protein content) of bacterial cells, underlying solvent tolerance, in A. hydrophila IBB_Po8 and P. aeruginosa IBB_Po10 showed a complex response to the presence of 0.5% (v/v) organic solvents in the culture medium. Bacterial strains able to survive in the presence of organic solvents could be used in two-phase biotransformation systems with whole cells for adequate bioremediation of heavily contaminated sites and could be a source for new solvent-stable enzymes with different applications.

Page(s): 352-361

Enhancement of dextransucrase activity of Pediococcus pentosaceus mutant SPAm1 by response surface methodology

Tue, 28 Jun 2011 22:58:59 GMT

Title: Enhancement of dextransucrase activity of Pediococcus pentosaceus mutant SPAm1 by response surface methodology

Authors: Patel, Seema; Kothari, Damini; Goyal, Arun

Abstract: In the present investigation, an optimal fermentation medium for the production of dextransucrase from mutant SPAm1 of a natural isolate of Pediococcus pentosaceus (GenBank Acc. No. EU569832) was developed following response surface method. A two-level Plackett-Burman design (PBD) and five-level Central composite design (CCD) was combined to optimize the medium composition for enhancement of the dextransucrase activity of SPAm1. A second-order model equation was suggested and validated experimentally. The model adequacy was very satisfactory as the coefficient of determination was 0.958. The optimum values for the tested variables were; sucrose 55.2 g/L; beef extract 2.3 g/L and Tween 80 8.3 mL/L. The predicted dextransucrase activity after response optimization was 15.9 U/mL, whereas the experimental value was 15.6 U/mL at 16 h of incubation, which showed a 3.2-fold enhancement over the enzyme activity (4.9 U/mL) of mutant SPAm1 given by the unoptimized medium. However, the increase in dextransucrase activity by SPAm1 after optimization of the medium was an outstanding 4.6-fold higher over that of the wild-type P. pentosaceus from the unoptimized medium (3.4 U/mL).

Page(s): 346-351

NISCAIR Online Periodicals Repository Collection: IJBT Vol.10(3) [July 2011]

Detection of cardamom mosaic virus-related sequences in plant genomes

In vitro multiplication of Merton I. 793–An apple rootstock suitable for replantation

Effect of organic solvents on solvent-tolerant Aeromonas hydrophila IBBPo8 and Pseudomonas aeruginosa IBBPo10

Enhancement of dextransucrase activity of Pediococcus pentosaceus mutant SPAm1 by response surface methodology

Effect of organic solvents on solvent-tolerant Aeromonas hydrophila IBB_Po8 and Pseudomonas aeruginosa IBB_Po10