Identification and genetic characterization of phenol-degrading bacterium isolated from oil contaminated

A phenol-degrading novel monosodium glutamate was isolated from oil contaminated soil in India. This strain was found capable to utilize and tolerate up to 9.5 mM of phenol. Based on the results of phylogenetic similarity of 16S recombinant ribonucleic acid (rRNA) gene sequences and fatty acid analysis, strain MSG8 was identified as a novel Acinetobacter sp. The sequence of the partial largest subunit of multicomponent phenol hydroxylase (LmPH) gene of this isolated strain was identified and compared with LmPH gene of Pseudomonas sp.CF600. Reversed phase high performance liquid chromatography showed that the isolate can degrade phenol through catechol ortho fission pathway. In this paper, we reported about the new strain of Acinetobacter sp. capable of degrading phenol (9.5 mM of phenol concentration) under normal conditions. Therefore, strain MSG8 can potentially be used in bioremediation of phenol. The given data demonstrates that the isolated strain exhibits the characteristics of an efficient phenol-degrading microorganism.Keywords: Phenol, degradation, monosodium glutamate, bioremediation, Acinetobacter sp.African Journal of Biotechnology Vol. 12(8), pp. 791-79

Variation in elemental composition as influenced by chlorpyrifos application in mung bean (Vigna radiata L.)

AbstractChlorpyrifos (O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate), is an organophosphate insecticide effective against a broad spectrum of insect pests of economically important crops. The present study investigated the effects of chlorpyrifos application on sulfate assimilation and macro elemental composition in different plant parts at different phenological stages. Field experiments were conducted in the month of April 2008–2009. The individual plot size was 6m2 (4m×1.5m) having 4 rows with a row-to-row distance of 15inches and plant to plant distance of 10inches. The number of plants per m2 was 15. Seedlings were collected at 5 (preflowering), 10 (flowering) and 20 (postflowering) DAT (day after treatment) to analyze the effect of chlorpyrifos on APR activity and elemental composition. At harvest stage, seed from individual treatments were analyzed for sulfur containing amino acids like methionine and cysteine content. Twenty-day-old seedlings of Vigna radiata L. were subjected to chlorpyrifos at different concentrations ranging from 0 to 1.5mM through foliar spray in the field condition. A significant increase (50% in cysteine content and 50–92% in methionine content) in sulfur containing amino acids at a higher dose rate of 1.5mM was recorded in seeds, however the increased activity of adenosine 5-phosphosulfate reductase (APR), the key enzyme in sulfate assimilation was recorded in all the three parts of the plant (leaf, stem, root.). Transiently lower nitrogen, sulfur and carbon content in 0.6 and 1.5mM chlorpyrifos application in V. radiata L. supports the inhibition of metabolic processes. However, reverse trend was exhibited at 0.3mM for same parameters. These results suggest the stimulatory effects on sulfate assimilation in V. radiata L. while as inhibitory effects were prevalent on elemental composition

Chromium stress in Brassica juncea L. cv. 'Pusa Jai Kissan' under hydroponic culture

Chromium (Cr) entering plant tissue inhibits most physiological processes at all levels of metabolism including inhibition of growth, photosynthesis and nitrate assimilation. Since Cr exists in many forms, its toxicity to plants depends on its valence state, with Cr (VI) found to be highly toxic and mobile than Cr (III). Different concentrations of Cr (0, 25, 50 and 100 μM) in the form of K2Cr2O7 was added to 30 days old Brassica juncea plant and harvested on the 3rd and 5th days after treatment for estimation of plant growth, chlorophyll, total soluble protein, free amino acids and nitrate reductase activity. Cr was found to cause deleterious effects on whole plant growth. The potential of plants with the capacity to accumulate or to stabilize Cr compounds for bioremediation of Cr contamination has gained interest in recent years. The biochemical aspects like photosynthetic pigments (Chl a and Chl b), total protein and amino acids content decreased with Cr concentration. A significant increase in nitrate reductase activity was observed corresponding to Cr concentration.Key words: Brassica juncea, chromium, heavy metal, phytoremediation

Establishment of efficient method for callus culture and shoot regeneration of local Indian garlic (var. Yamuna safed)

The experiment was designed to investigate the regeneration potentiality of a garlic variety (Yamuna Safed (G1)), and also to develop an efficient protocol for regeneration of garlic via callus culture. Higher percentage of callus was initiated from the combination of BAP and 2, 4 D at 2.0 mg/l and 0.25 mg/l respectively.  The hormone 2, 4-D, commonly used in tissue culture in garlic was found to be detrimental when used at the levels described in literatures. Rooting of individual shoots was induced after transfer to medium without growth regulator. The plantlets were established in the soil after acclimatization. ÂÂ

Efficient Plant regeneration through leaf, In vitro Flowering and Biochemical studies during morphogenesis of Solanum nigrum L.

In this investigation, Murashige and Skoog (MS) medium when supplemented with 6-benzylamino purine (BAP) or Kinetin produced high frequency of in vitro shoot directly from in vitro raised Solanum nigrum leaves without any callusing stage. Among the plant growth regulators (PGRs) the best response was noted at 2.0 mgl-1 BAP and 1.5 mgl-1 kinetin. Shoot formation and multiplication were more pronounced on dorsal leaf surface (0.5-1.5 cm2) compared to ventral. Biochemical studies including soluble protein, sugar and amino acid were carried out in order to know the differences in reserves of some biochemical entities. Nearly all parameters were high in samples derived from dorsal leaf, which was grown in MS augmented with 2.0 mgl-1 BAP or 1.5 mgl-1kinetin. The present investigation also describes first successful induction of in vitro flowering in S. nigrum, which can augment selective hybridization. Finally, the in vitro raised shoots were treated with various concentrations of auxins for obtaining roots, the rooted plantlets were transplanted with 100% survival in field conditions

Variation in elemental composition as influenced by chlorpyrifos application in mung bean (Vigna radiata L.)

Chlorpyrifos (O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate), is an organophosphate insecticide effective against a broad spectrum of insect pests of economically important crops. The present study investigated the effects of chlorpyrifos application on sulfate assimilation and macro elemental composition in different plant parts at different phenological stages. Field experiments were conducted in the month of April 2008–2009. The individual plot size was 6 m2 (4 m × 1.5 m) having 4 rows with a row-to-row distance of 15 inches and plant to plant distance of 10 inches. The number of plants per m2 was 15. Seedlings were collected at 5 (preflowering), 10 (flowering) and 20 (postflowering) DAT (day after treatment) to analyze the effect of chlorpyrifos on APR activity and elemental composition. At harvest stage, seed from individual treatments were analyzed for sulfur containing amino acids like methionine and cysteine content. Twenty-day-old seedlings of Vigna radiata L. were subjected to chlorpyrifos at different concentrations ranging from 0 to 1.5 mM through foliar spray in the field condition. A significant increase (50% in cysteine content and 50–92% in methionine content) in sulfur containing amino acids at a higher dose rate of 1.5 mM was recorded in seeds, however the increased activity of adenosine 5-phosphosulfate reductase (APR), the key enzyme in sulfate assimilation was recorded in all the three parts of the plant (leaf, stem, root.). Transiently lower nitrogen, sulfur and carbon content in 0.6 and 1.5 mM chlorpyrifos application in V. radiata L. supports the inhibition of metabolic processes. However, reverse trend was exhibited at 0.3 mM for same parameters. These results suggest the stimulatory effects on sulfate assimilation in V. radiata L. while as inhibitory effects were prevalent on elemental composition. Keywords: Green gram, Insecticide, Sulfur, Nitrogen, Carbon, Assimilatio

Evaluation of oxidative stress in Vigna radiata L. in response to chlorpyrifos

This study aims to evaluate the effect of chlorpyrifos on several metabolic and stress related parameters of Vigna radiata L. Twenty-days-old plants were exposed to several concentrations of chlorpyrifos, ranging from 0 – 1.5 mM through foliar spray in the field condition. Analyses were done at pre flowering (Day 5), flowering (Day 10) and post flowering (Day 20) stages after the treatment. Lipid peroxidation rate, proline, dehydroascorbate, oxidized and total glutathione were all ascended. Chlorpyrifos enhanced lipid peroxidation rate and proline content with 1.5 mM at day 20 whereas dehydroascorbate, oxidized and total glutathione were increased in 1.5 mM at day 10. However, dose dependence significantly declined in content of ascorbate and reduced glutathione levels were observed at all growth stages. Among the enzymatic antioxidants, activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase enhanced significantly in all the concentrations at day 10. Maximum catalase activity was observed at day 10 in control and it declined thereafter. The above results clearly depicted the provoked state of oxidative stress under chlorpyrifos exposure in Vigna radiata L. and therefore can be used to evaluate the degree of insecticide contamination to plant which may be serving as biomarker in Vigna radiata L

Establishment of efficient method for callus culture and shoot regeneration of local Indian garlic (var. Yamuna safed)

The experiment was designed to investigate the regeneration potentiality of a garlic variety (Yamuna Safed (G1)), and also to develop an efficient protocol for regeneration of garlic via callus culture. Higher percentage of callus was initiated from the combination of BAP and 2, 4 D at 2.0 mg/l and 0.25 mg/l respectively.  The hormone 2, 4-D, commonly used in tissue culture in garlic was found to be detrimental when used at the levels described in literatures. Rooting of individual shoots was induced after transfer to medium without growth regulator. The plantlets were established in the soil after acclimatization. Â

Effects of presowing gamma irradiation on the photosynthetic pigments, sugar content and carbon gain of Cullen corylifolium (L.) Medik

To determine the effects of gamma radiation on the photosynthetic pigments, sugar content and total carbon gain, seeds of Cullen corylifolium (L.) Medik. were irradiated with variable doses (0, 2.5, 5, 10, 15, and 20 kGy) at the rate of 1.65 kGy h-1 from 60Co gamma source. Cullen corylifolium represents an important Chinese medicine with adequate levels of secondary metabolites, thus we hypothesized that gamma irradiation could modulate primary metabolites which could supplement secondary metabolite levels. The seeds were then transferred to field for biochemical analysis at different developmental stages; pre-flowering, flowering and post-flowering. Gamma dosage at 10 kGy resulted in a significant increase in concentration of chlorophyll a (61.17%), chlorophyll b (93.18%) and total chlorophyll (71.66%), suggesting that low doses of radiation could activate photosynthetic pigment system while at 15 and 20 kGy dose resulted in depletion of such parameters. Sugar and total C analysis of plants irradiated at 10 kGy demonstrated significantly maximum (216.01%) sugar content in leaves at all developmental stages and significantly minimum (46.13%) and (57.81%) in plants raised from seeds irradiated at 15 and 20 kGy respectively. Effective stimulatory dose for C. corylifolium '11062' is 10 kGy. In contrast, the carotenoid content of the plants exposed to 15 and 20 kGy was maximum than control. Significance of such stimulation correlated with increasing C mass of the plant concerned is discussed in the light of newer aspects in research

Effects of presowing gamma irradiation on the photosynthetic pigments, sugar content and carbon gain of Cullen corylifolium (L.) Medik.

To determine the effects of gamma radiation on the photosynthetic pigments, sugar content and total carbon gain, seeds of Cullen corylifolium (L.) Medik. were irradiated with variable doses (0, 2.5, 5, 10, 15, and 20 kGy) at the rate of 1.65 kGy h-1 from 60Co gamma source. Cullen corylifolium represents an important Chinese medicine with adequate levels of secondary metabolites, thus we hypothesized that gamma irradiation could modulate primary metabolites which could supplement secondary metabolite levels. The seeds were then transferred to field for biochemical analysis at different developmental stages; pre-flowering, flowering and post-flowering. Gamma dosage at 10 kGy resulted in a significant increase in concentration of chlorophyll a (61.17%), chlorophyll b (93.18%) and total chlorophyll (71.66%), suggesting that low doses of radiation could activate photosynthetic pigment system while at 15 and 20 kGy dose resulted in depletion of such parameters. Sugar and total C analysis of plants irradiated at 10 kGy demonstrated significantly maximum (216.01%) sugar content in leaves at all developmental stages and significantly minimum (46.13%) and (57.81%) in plants raised from seeds irradiated at 15 and 20 kGy respectively. Effective stimulatory dose for C. corylifolium '11062' is 10 kGy. In contrast, the carotenoid content of the plants exposed to 15 and 20 kGy was maximum than control. Significance of such stimulation correlated with increasing C mass of the plant concerned is discussed in the light of newer aspects in research