Effect of Glyphosate and Mancozeb on the Rhizobia Isolated from Nodules of Vicia faba L. and on Their N2-Fixation, North Showa, Amhara Regional State, Ethiopia

This study was designed to assess the effect of glyphosate and mancozeb on growth of Vicia faba rhizobia isolates in vitro and on their N2-fixation performance. Hence, ten isolates were isolated using plant-soil trap method from soil samples collected from farm lands. Those isolates were morphologically characterized using YEMA medium and authenticated as nodulating rhizobia using sand culture. These isolates were treated with 100, 150, and 200 μg a.e. L−1 glyphosate, 100, 150, and 200 mg L−1 mancozeb, and their combinations. The result showed that almost all isolates were affected (only 4–10% survival) at lower (100 mg L−1) concentration of mancozeb. However, 80% of isolates treated with higher concentration (200 μg a.e. L−1) of glyphosate for 72 h formed colonies on YEMA medium. Moderate (40%) isolates also showed better (31–50% and 17–45%) survival within 100 : 100 and 150 : 150 combinations of glyphosate and mancozeb, respectively. For in vivo experiment, faba bean seedlings in sand culture were inoculated with four relatively in vitro test resistant and one sensitive isolates. The inoculated isolates were treated with field recommended concentration of glyphosate, mancozeb, and combinations. Thus, experimental plants almost all showed normal (61–124 nodule plant−1) nodulation and N2-fixation (90–109%) performance as compared to the control.

Effect of Caffeine on Some Selected Biochemical Parameters Using Rat Model

Effect of caffeine on some selected biochemical parameters using rat model was investigated. Standard methods of analysis were used for the study. A total of sixty (60) rats divided equally into five groups of which one group served as the control, and the rest as test groups were used. The test rats were placed on different concentrations of caffeine for twenty-eight (28) days. Results obtained for the selected biochemical parameters revealed that AST and ALT levels of the liver increased significantly (p<0.05) in test rats against the control. Creatinine and electrolyte ions of the kidney increased significantly (p<0.05) in test groups when compared to the control. Haematological indices such as WBC, monocytes, lymphocytes, MCV, MCHC, and MCV levels were significantly altered (p<0.05) in test rats against those of the control. It therefore becomes imperative for those that consume caffeine with believe that it does more good work than harm to take note of these findings. This study has revealed the effect of caffeine on some selected biochemical parameters using rat model.

Antiproliferative Efficacy of Kaempferol on Cultured Daudi Cells: An In Silico and In Vitro Study

There is always a constant need to develop alternative or synergistic anticancer drugs with minimal side effects. One important strategy to develop effective anticancer agents is to investigate potent derived compounds from natural sources. The present study was designed to determine antiproliferative activity of Kaempferol using in silico as well as in vitro study. Docking was performed using human GCN5 (hGCN5) protein involved with cell cycle, apoptosis, and glucose metabolism. Cell viability and cytotoxicity on Daudi cells were evaluated by trypan blue and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in a dose and time dependent manner, respectively. The compound inhibited the proliferation and growth of the Daudi cells, through induced cell death. The pure compound proved lead inhibitors of cell proliferation, thus manifesting significant antiproliferative activity. The docking results revealed that Kaempferol exhibited binding interaction to hGCN5 protein. Further, molecular dynamics using the dock pose of hGCN5-Kaempferol complex were performed to understand the basic structural unit which lead to inefficiency in binding and, therefore, pronounced instability and its possible consequences of reduced binding affinity. The data obtained in this study indicates that Kaempferol is a promising compound leading to inhibition of Daudi cell growth and proliferation.

Evaluation of the Phytotoxic and Genotoxic Potential of Pulp and Paper Mill Effluent Using Vigna radiata and Allium cepa

Pulp and paper mill effluent induced phytotoxicity and genotoxicity in mung bean (Vigna radiata L.) and root tip cells of onion (Allium cepa L.) were investigated. Physicochemical characteristics such as electrical conductivity (EC), biological oxygen demand (BOD5), chemical oxygen demand (COD), and total phenols of the pulp and paper mill effluent were beyond the permissible limit specified for the discharge of effluent in inland water bodies. Compared to control plants, seedling exposed to 100% effluent concentration showed a reduction in root and shoot length and biomass by 65%, 67%, and 84%, respectively, after 5 days of treatment. A. cepa root tip cells exposed to effluent concentrations ranging from 25 to 100% v/v showed a significant decrease in mitotic index (MI) from 32 to 11% with respect to control root tip cells (69%) indicating effluent induced cytotoxicity. Further, the effluent induced DNA damage as evidenced by the presence of various chromosomal aberrations like stickiness, chromosome loss, anaphase bridge, c-mitosis, tripolar anaphase, vagrant chromosome, and telophase bridge and micronucleated and binucleated cell in A. cepa. Findings of the present study indicate that pulp and paper mill effluents may act as genotoxic and phytotoxic agents in plant model system.

Amino Acid Starvation Enhances Programmed Ribosomal Frameshift in Metavirus Ty3 of Saccharomyces cerevisiae

Ty3 is a retroviral-like element and propagates with a retroviral-like mechanism within the yeast cells. Ty3 mRNA contains two coding regions, which are GAG3 and POL3. The coding region POL3 is translated as a GAG3-POL3 fusion protein by a +1 programmed frameshift. In this study, it was shown that the Ty3 frameshift frequency is significantly increased by amino acid starvation in a Gcn2p complex dependent manner. When the yeast cells were subjected to amino acid starvation, the frameshift frequency of Ty3 increased more than 2-fold in the wild-type yeast cells, mostly independent of Gcn4p. However, Ty3 frameshift frequency remained at basal level in the gcn1, gcn20, or gcn2 mutant yeast cells in amino acid starved yeasts. Gcn1p forms a complex with Gcn2p and Gcn20p and is involved in the sensing of uncharged tRNAs on the ribosomal A-site during translation. Increases in uncharged tRNA levels due to amino acid depletion lead to ribosomal pauses. These ribosomal pauses are significant actors in the regulation of Ty3 frameshift frequency. Results of this research revealed that frameshift frequency in Ty3 is regulated by the Gcn2p complex in response to amino acid starvation in yeast.

Bacteriological Contaminants of Some Fresh Vegetables Irrigated with Awetu River in Jimma Town, Southwestern Ethiopia

The main purposes of this study were to determine the bacteriological load and safety of some fresh vegetables irrigated with Awetu River in Jimma town, southwestern Ethiopia. Water and vegetable samples were collected from three different irrigation sites and analyzed for their bacteriological contaminants following standard procedures. The maximum overall means of aerobic mesophilic bacteria, Enterobacteriaceae, aerobic spore formers, staphylococci, and total and fecal coliform counts were 8.06, 7.10, 6.54, and 2.97 log CFU g−1 and 1036 and 716 MPN 100 mL−1, respectively. The microflora of vegetable samples was dominated by Bacillus species (32.7%) followed by Enterobacteriaceae (25%) and Micrococcus (16%). Staphylococcus aureus and Salmonella spp. were detected in 24.0% and 20.7% of the samples, respectively. All the Staphylococcus aureus isolates were resistant to ampicillin, cefuroxime sodium, and penicillin G (100.0% each). All the Salmonella isolates were also resistant to tetracycline, erythromycin, cefuroxime sodium, and penicillin G (100.0% each). The findings reveal that the river water used for irrigation in this study is a possible preharvest source of contamination to fresh vegetables which potentially constitutes a health risk to consumers.

Carbofuran Modulating Functions of Acetylcholinesterase from Rat Brain In Vitro

Carbofuran, a potential environmental xenobiotic, has the ability to cross blood brain barrier and to adversely influence brain functions. In the present study, the impact of carbofuran on the biophysical and biochemical properties of rat brain AChE has been evaluated in vitro. This enzyme was membrane-bound which could be solubilised using Triton-X100 (0.2%, v/v), a nonionic detergent, in the extraction buffer (50 mM phosphate, pH 7.4). The enzyme was highly stable up to one month when stored at -20°C and exhibited optimum activity at pH 7.4 and 37°C. AChE displayed a direct relationship between activity and varying substrate concentrations (acetylthiocholine iodide (ATI)) by following Michaelis-Menten curve. The Km and Vmax values as computed from the Lineweaver-Burk double reciprocal plot of the data were found to be 0.07 mM and 0.066 µmole/mL/min, respectively. The enzyme exhibited IC50 value for carbofuran equal to 6.0 nM. The steady-state kinetic studies to determine mode of action of carbofuran on rat brain AChE displayed it to be noncompetitive in nature with Ki value equal to 5 nm. These experiments suggested that rat brain AChE was very sensitive to carbofuran and this enzyme might serve as a significant biomarker of carbofuran induced neurotoxicity.

Genotoxic Effects of Chlorpyrifos in Freshwater Fish Cirrhinus mrigala Using Micronucleus Assay

The genotoxicity of pesticides is an issue of worldwide concern and chlorpyrifos is one of the largest selling organophosphate agrochemicals that has been widely detected in surface waters of India. The studies on long term genotoxic biomarkers are limited; therefore, present study was carried out to analyze the incidence of nuclear anomalies in the blood cells of fresh water fish Cirrhinus mrigala using micronucleus (MN) assay as a potential tool for assessment of genotoxicity. Acute toxicity of chlorpyrifos was evaluated by exposing fingerlings to different doses of chlorpyrifos (1/20, 1/10, and 1/5 of LC50) and LC50 was calculated as 0.44 mg L−1 using probit analysis. Blood samples were taken on days 2, 4, 8, 12, 21, 28, and 35. In general, significant effects for both concentration and duration of exposure were observed in treated fish. It was found that MN induction was highest on day 14 at 0.08 mg L−1 concentration of chlorpyrifos. It was concluded that chlorpyrifos is genotoxic pesticide causing nuclear anomalies in Cirrhinus mrigala.

Efficacy of EDTA and Phosphorous on Biomass Yield and Total Lipid Accumulation in Two Green Microalgae with Special Emphasis on Neutral Lipid Detection by Flow Cytometry

Chlorella ellipsoidea and Chlorococcum infusionum, promising microalgae for biodiesel feedstock production, were treated with ethylenediaminetetraacetate (EDTA) and phosphorous to induce stress which was then followed by flow cytometry to study the enhanced intracellular neutral lipid content. Treatment resulted in up to a threefold increase in total lipid content of Chlorella (41.8±1.9% at 16 days of incubation period) and more than twofold increases in Chlorococcum (31.3±1.0% at 18 days of incubation period) under phosphorous starvation in the culture. It was observed that maximum biomass yields in Chlorella and Chlorococcum were 1.56±0.06 and 2.17±0.12 g/L at 1.5 g/L of phosphorous after 20 and 18 days of incubation periods, respectively. The qualitative analyses of neutral lipid bodies under stress conditions were performed by confocal microscopy and revealed bright golden-yellow lipid droplets in stress exposed cells. Significant increase of monounsaturated fatty acids under the nutrient limited conditions was suitable to produce biodiesel. The maximum biomass (g/L) and lipid content (% dry cell weight) at different stresses showed significant results (p<0.05) by single-factor Analysis of Variance (ANOVA) followed by Duncan’s Multiple Range Test (DMRT).

Direct Organogenesis from Rhizome Explants in Marsilea quadrifolia L.: A Threatened Fern Species

An efficient micropropagation protocol has been developed for Marsilea quadrifolia L. through direct organogenesis. The mature rhizomes were used as explants and successfully sterilized using 0.1% HgCl2 for the establishment of cultures. The multiple shoots were differentiated from the explants on Murashige and Skoog (MS) medium augmented with 6-benzylaminopurin (BAP). Full strength MS medium was reported to be effective for the induction of sporophytes from the rhizomes after four weeks of inoculation. Maximum response (96%) with average of 6.2 shoots (2.72 cm length) was achieved on full strength of MS medium augmented with 0.5 mg/L BAP in culture initiation experiments. The cultures were further proliferated in clusters (79.0±0.37 shoots per explant) with stunted growth on half strength MS medium supplemented with 0.25 mg/L BAP after four weeks. These stunted shoots were elongated (5.30 cm long) on half MS medium devoid of growth hormones. Root induction and proliferation (3.0–4.0 cm long) were observed after 4th subculture of sporophytes on hormone-free half strength MS medium. The rooted plantlets were hardened in the fern house for 4-5 weeks and transferred to the field with 92% survival rate. There were no observable differences in between in vivo grown and in vitro propagated plantlets in the field.