Plant regeneration of Mangifera indica using liquid shaker culture to reduce phenolic exudation

The exudation of phenolics from the cut ends of mango explants greatly hinders their regenerative ability in any in vitro growth medium. However, pretreatment of explants using liquid shaker culture helps in overcoming this problem. Explants kept in liquid MS medium supplemented with 1% polyvinylpyrolidone in 250 ml conical flasks on an automated shaker at 75 rpm were able to produce shoots when inoculated on gelled MS medium supplemented with different concentrations of growth regulators.Abbreviations BA benzyladenine - IAA indoleacetic acid - NAA naphthaleneacetic acid - IBA indolebutyric acid     

Investigation on the frequency of B-chromosomes inImpatiens balsamina and the appearance of single flowers on double varieties

A survey of 17 varieties ofImpatiens balsamina for their chromosomal status and frequency of reversion of double flowering to single type was carried out on a local garden population. All the varieties are diploid with 2n=14. Two supernumerary chromosomes, which invariably form a bivalent that is indistinguishable from bivalents of the normal complement, were present in almost all the 12 double flowering varieties while single varieties had only the normal chromosomal complement. Their frequency in double varieties has been studied. No double flower was noted on any single type while single flowers were present in varying frequency on plants of double varieties. The highest frequency of this reversion as well as of supernumerary chromosomes was noted in var. “Deep pink double”. Possible origin of supernumerary chromosomes and their role in this species is discussed.     

Application of a hybrid biofilter column for the removal of Cr(VI) from aqueous solution using an indigenous bacterial strain Pseudomonas taiwanensis

In the present study, a laboratory-scale biofilter column was designed and fabricated. It was packed with a mixture of coal and compost as a packing medium. The column was enriched with an indigenous bacterial strain Pseudomonas taiwanensis isolated from aerobic mixed culture of Sewage Treatment Plant, BITS-Pilani, Pilani campus. The removal of hexavalent chromium [Cr(VI)] from aqueous solution was investigated in the biofilter column. The entire biofiltration operation was divided into five phases (I to V) for a period of 63 days. Biofilter column was subjected to shock loading conditions for 20 days immediately after 63 days of operation. The maximum removal efficiency of 89.4% was obtained during phase V for Cr(VI) inlet concentration of 40 mg L^?1. During shock loading, maximum removal efficiency was obtained as 90% for 48.5–50 mg L^?1 of initial Cr(VI) concentration. Kinetic parameters of biofiltration process for Cr(VI) removal were also determined by fitting Michaelis-Menten kinetic model with experimental data. The Michaelis-Menten kinetic constants were obtained as 0.258 mg L^?1 min^?1 and 26.83 mg L^?1. It was found that Ottengraf-Van den Oever model with zero-order diffusion limitation fit the experimental data quite well for phases III, IV, and V with coefficient of determination (R²) values .97, .99, and .984, respectively. A possible method for safe disposal of packing medium was also presented in this study.     

Synthesis of 4-nitrophenyl acetate using molecular sieve-immobilized lipase from <Emphasis Type="Italic">Bacillus coagulans</Emphasis>

Extracellular lipase from Bacillus coagulans BTS-3 was immobilized on (3 Å × 1.5 mm) molecular sieve. The molecular sieve showed approximately 68.48% binding efficiency for lipase (specific activity 55 IU mg^?1). The immobilized enzyme achieved approx 90% conversion of acetic acid and 4-nitrophenol (100 mM each) into 4-nitrophenyl acetate in n-heptane at 65°C in 3 h. When alkane of C-chain length other than n-heptane was used as the organic solvent, the conversion of 4-nitrophenol and acetic acid was found to decrease. About 88.6% conversion of the reactants into ester was achieved when reactants were used at molar ratio of 1:1. The immobilized lipase brought about conversion of approximately 58% for esterification of 4-nitrophenol and acetic acid into 4-nitrophenyl acetate at a temperature of 65°C after reuse for 5 cycles.     

Whole genome sequence of the rifamycin B-producing strain Amycolatopsis mediterranei S699

Amycolatopsis mediterranei S699 is an actinomycete that produces an important antibiotic, rifamycin B. Semisynthetic derivatives of rifamycin B are used for the treatment of tuberculosis, leprosy, and AIDS-related mycobacterial infections. Here, we report the complete genome sequence (10.2 Mb) of A. mediterranei S699, with 9,575 predicted coding sequences.     

A Paradichlorobenzene, Saponin, Iron Mordant Sequence in the Staining of Meiotic Chromosomes of Ipomea

For the meiotic study of Ipomea spp., flower buds were stripped of the calyx and corolla and soaked in saturated aqueous paradichlorobenzene at about 28° C for 3 hr, transferred to acetic-alcohol (1:3) for 6 hr, then into 1% saponin solution and left overnight. They were mordanted in 1:3 acetic-alcohol saturated with ferric oxide for 24 hr and stained in a mixture of 1% aceto-carmine and 2% aceto-orcein with 1 N HCl in the proportion of 9:9:1. The preparations were mounted in 1% aceto-carmine for temporary use and made permanent by dehydration through the n-butanol schedule. The pollen mother cells had clear cytoplasm with deeply stained chromosomes.     

Polyploidy and pollen variability inPimpinella monoecia

Treatment of seedlings ofPimpinella monoecia with colchicine-gammexane lead to the production of tetraploids. The tetraploids besides showing the meiotic anomalies like univalents, split spindles, multiple spindles, micro-nuclei, nondisjunction, strays, etc., exhibited pollen grains which were triradiate, triangular and quadriradiate while the controls had only one type of bipolar radiosymmetric grains. They have been classified into different types and their frequency has been determinod. A scheme has been presented representing the development of these variable grains from the control type A, which is based on the observation of grains showing intermediate stages. Explanation of this pollen variability has been presented.     

Buffering effect of B-chromosome system of Trigonella foenum-graecum against different soil types

Summary Accessory (B–) chromosomes have been reported in many plants in various regions of the world. Studies on natural populations of certain plants like Phleum phleoides revealed that B-chromosomes were present in different frequencies in different habitats indicating a correlation between B-frequency and environmental conditions. The present experiment was performed to determine the response of B-chromosome carrier and non-carrier plants of Trigonella to different soil conditions. When the morphological data was subjected to analysis of variance, it was found that the carrier plants exhibited uniformity of characters in the different soil types, while the non-carrier plants exhibited considerable variability. The conclusion that can be drawn from this experiment is that B-chromosomes act as a buffering agent, neutralising the variability effect of different soil types.     

Therapeutic associated with occupational exposure to silica

Occupational exposure to silica dust has been increasing the possible risk of varieties of pathologies. The aim of this study was to evaluate the protective activity of ethanolic extract of Glycyrrhiza glabra roots at doses of 500 and 1000 mg/kg, p.o., given for 7 days against the toxicity of SiO(2) nanoparticles (50mg/kg intraperitoneal for 6 weeks) in rats. Exposure to silica altered various respiratory and biochemical variables, including ALT, AST, albumin, urea, uric acid, creatinine, catalase, LPO and GSH. Treatments with G. glabra extract significantly improved antioxidant status towards control. Stone workers in the Gwalior region exposed to silica dust had higher prevalence of cough, wheezing and shortness of breath. Increased serum ACE level was noted in the silica exposed group. It is of immense need to monitor this problem for betterment of worker's health.