22 research outputs found
Microbial Ecology of Anaerobic Digesters: The Key Players of Anaerobiosis
Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane and CO2. The conversions of complex organic compounds to CH4 and CO2 are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate. Methanosarcina are able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescent in situ hybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed
Plants as Useful Vectors to Reduce Environmental Toxic Arsenic Content
Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, application of municipal sludge on land, combustion of fossil fuels, As additives to livestock feed, coal fly ash, and use of arsenical pesticides in agricultural sector. Phytoremediation can be viewed as biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the natural ecosystems for subsequent productive use. The present review presents recent scientific developments regarding phytoremediation of arsenic contaminated environments and its possible detoxification mechanisms in plants
Bioactivity-guided isolation of rosmarinic acid as the principle bioactive compound from the butanol extract of Isodon rugosus against pea aphid, Acyrthosiphon pisum
Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control involving the excessive use of synthetic insecticides over decades has led to multiple forms of aphid resistance to most classes of insecticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. It was however not known as which compound was responsible for such activity. To further explore this finding, current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid as the bioactive compound in I. rugosus. Insecticidal activity of rosmarinic acid was carried out using standard protocols on A. pisum. The data was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application
Bioactivity-guided isolation of rosmarinic acid as the principal bioactive compound from the butanol extract of Isodon rugosus against the pea aphid, Acyrthosiphon pisum
Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application
Bioactivity-guided isolation of rosmarinic acid as the principal bioactive compound from the butanol extract of Isodon rugosus against the pea aphid, Acyrthosiphon pisum (vol 14, e0215048, 2019)
[This corrects the article DOI: 10.1371/journal.pone.0215048.]
Antioxidant, Cytotoxic, and Antimicrobial Potential of Silver Nanoparticles Synthesized using Tradescantia pallida Extract
Silver nanoparticles have received much attention, due to their wide range of biological applications as an alternative therapy for disease conditions utilizing the nanobiotechnology domain for synthesis. The current study was performed to examine the antioxidant, anticancer, antibacterial, and antifungal potential of biosynthesized silver nanoparticles (TpAgNPs) using plant extract. The TpAgNPs were produced by reacting the Tradescantia pallida extract and AgNO3 solution in nine various concentration ratios subjected to bioactivities profiling. According to the current findings, plant extract comprising phenolics, flavonoids, and especially anthocyanins played a critical role in the production of TpAgNPs. UV–visible spectroscopy also validated the TpAgNP formation in the peak range of 401–441 nm. Further, the silver ion stabilization by phytochemicals, face-centered cubic structure, crystal size, and spherical morphology of TpAgNPs were analyzed by FTIR, XRD, and SEM. Among all TpAgNPs, the biosynthesized TpAgNP6 with a medium concentration ratio (5:10) and the plant extract had effective antioxidant potentials of 77.2 ± 1.0% and 45.1 ± 0.5% free radical scavenging activity, respectively. The cytotoxic activity of TpAgNP6 in comparison to plant extract for the rhabdomyosarcoma cell line was significantly the lowest with IC50 values of 81.5 ± 1.9 and 90.59 ± 1.6 μg/ml and cell viability % of 24.3 ± 1.62 and 27.4 ± 1.05, respectively. The antibacterial and antifungal results of TpAgNPs revealed significant improvement in comparison to plant extract, i.e., minimum inhibition concentration (MIC) 64 μg/ml against Gram-negative Pseudomonas aeruginosa while, in the case of antifungal assay, TpAgNP6 was active against Candida parapsilosis. These TpAgNPs play a crucial role in determining the therapeutic potential of T. pallida due to their biological efficacy
Comparative arsenic tolerance and accumulation potential between wild Tagetes patula and Tagetes minuta
Arsenic (As) is a bioactive metalloid that is highly toxic to humans, animals, and plants. Environmental contamination
of As especially in groundwater increases due to natural and anthropogenic activities. The present study was performed to
evaluate the potential of wild Tagetes species for the phytoremediation of As contaminated soil/water. This comparative
research aims to analyze As accumulation and tolerance in two wild species of Tagetes, T. minuta and T. patula. The
20 days old seedlings were grown hydroponically and exposed to the different concentrations of As, 0, 50, 150, and
300 µM As2
O3
for 1-, 4- and 7- days intervals.Effect of As stress was measured on the rate of seed germination, growth
parameters like fresh and dry biomass weight, root/shoot length, chlorophyll contents and As contents in root and
shoot in both Tagetes species. Increasing concentration of As restricts the growth activity of T. minuta with toxicity
symptoms on leaves such as chlorosis. Accumulation of As in the shoot was significantly (p ≤ 0.01) high (634 µg g-1 DW)
in T. patula as compared to T. minuta (397 µg g-1 DW) at 300 µM As2
O3
. Both Tagetes species exhibited high variation
for As tolerance parameters as well as for As accumulation patterns. Comparatively good tolerance and accumulation of
As in T. patula suggests that this species could be used in phytoextraction and re-vegetation in As contaminated sites
The genetic analyses of agronomic traits on chromosome 3A of wheat
One of the difficulties in improving wheat is that no one knows the genetic basis for agronomic traits. Previous studies with chromosome substitution lines between hard red winter wheat cultivars \u27Cheyenne\u27 (CNN) and \u27Wichita\u27 (WI), have identified that chromosome 3A contains gene(s), affecting grain yield, yield components, grain volume weight, plant height and anthesis date. However, chromosome substitution lines can only be used to identify the chromosomal location rather than the number and relationship of the genes carried by the chromosome. Using yield trials, molecular markers, and statistical test, we were able to identify one gene controlling anthesis date, one gene controlling tillering, two genes for plant height, two genes controlling kernel weight, and three genes for kernels/tiller. All of these genes are on chromosome 3A, however some are linked and some segregate independently. This research is important because it allows plant breeders to design their breeding programs on a known number of genes for these important traits that can be manipulated
Acylated flavonol glycosides from Tagetes minuta with antibacterial activity
Wild marigold (Tagetes minuta), a flowering plant of the family Asteraceae contains compounds of pharmaceutical and nutritional importance especially essential oils and flavonols. Identification, characterization of flavonols and determination of their antibacterial activity were major objectives of the current study. The isolation and purification of flavonols was accomplished using chromatographic techniques while structural elucidation was completed by LC-MS and NMR spectroscopy. The extracts and purified compounds were tested against various bacterial strains for antibacterial activity. A total of nineteen flavonols were isolated from this species. Of these, seventeen were of butanol and two of ethyl acetate extracts. Based on the concentration and purity, eight potential flavonols were selected and structurally elucidated. Four flavonols, 6-hydroxyquercetin 7-O-β-(6''-galloylglucopyranoside) (2), 6-hydroxykaempferol 7-O-β-glucopyranoside (5), 6-hydroxykaempferol 7-O-β-(6''-galloylglucopyranoside) (7), 6-hydroxyquercetin 7-O-β-(6''-caffeoylglucopyranoside) (9), were identified for the first time from T. minuta. Butanol and ethyl acetate extracts of flowers and seeds showed significant antibacterial activity against Micrococcus leteus, Staphylococcus aureus, Bacillus subtilis and Pseudomonas piket. Among the isolated flavonols only 1, 2 and 18 were found to possess significant antibacterial activity against M. luteus. The extracts and purified flavonols from T. minuta can be potential candidates for antibacterial drug discovery and support to ethnopharmacological use