scholarly journals Potential absorption of mercury-contaminated substrate by Trichoderma sp isolated from Brazil Nuts and Amazon Soil

2021 ◽  
Vol 43 ◽  
pp. e29
Author(s):  
Antonio Ferreira Oliveira ◽  
Alexandro Cezar Florentino ◽  
Adriana Maciel Ferreira ◽  
Irlon Maciel Ferreira ◽  
Ivana Fonseca Costa ◽  
...  

Mercury is an inorganic contaminant with serious harmful consequences to the environment. There has been a continuous rise in its level due to industrialization and other anthropogenic activities, such as the burning of coal and petroleum products, use of mercurial fungicides in agriculture and mercury catalyst in industries, and production of waste by paper industries. Five strains of Trichoderma sp., a filamentous fungi, were used in this study to evaluate their resistance to high concentrations of mercury for the purpose of using them for bioremediation. The solid culture medium used was prepared with malt agar 2% with pH 7.0 in which the strains of Trichoderma sp. were inoculated. The minimum inhibitory concentration (MIC) of the selected Trichoderma sp. isolates was calculated considering the time for growth and concentration of the mercury salt (Hg(NO3)2). At a mercury concentration of 50 mg/mL, maximum growth was first observed in TCH 1 (89.42 ± 0.63 mm) followed by TCH 2 isolate (87.33 ± 0.58 mm). At this concentration, all isolates reached the maximum mycelia growth. When the concentration of 200 mg/L Hg(NO3)2 was used, complete growth inhibition of the isolates was observed. Scanning electron microscopy suggested that differences in sporulation between the control and mercury treatment groups. In conclusion, it can be stated that Trichoderma isolates have great potential for bioremediation of sources contaminated with mercury.

2012 ◽  
Vol 56 (7) ◽  
pp. 3610-3614 ◽  
Author(s):  
Ekaterina Gelman ◽  
John D. McKinney ◽  
Neeraj Dhar

ABSTRACTThe genusMycobacteriumcomprises slow-growing species with generation times ranging from hours to weeks. The protracted incubation time before colonies appear on solid culture medium can result in overgrowth by faster-growing microorganisms. To prevent contamination, the solid media used in laboratories and clinics for cultivation of mycobacteria contain the arylmethane compound malachite green, which has broad-spectrum antimicrobial activity. Malachite green has no impact on the plating efficiency of mycobacteria when cells are grown under normal conditions. However, we found that malachite green interfered with colony formation when bacteria were preexposed to antibiotics targeting cell wall biogenesis (isoniazid, ethionamide, ethambutol). This inhibitory effect of malachite green was not observed when bacteria were preexposed to antibiotics targeting cellular processes other than cell wall biogenesis (rifampin, moxifloxacin, streptomycin). Sputum specimens from tuberculosis patients are routinely evaluated on solid culture medium containing high concentrations of malachite green. This practice could lead to underestimation of bacterial loads and overestimation of chemotherapeutic efficacy.


2021 ◽  
Author(s):  
Patricia M. Glibert ◽  
Cynthia A. Heil ◽  
Christopher J. Madden ◽  
Stephen P. Kelly

AbstractThe availability of dissolved inorganic and organic nutrients and their transformations along the fresh to marine continuum are being modified by various natural and anthropogenic activities and climate-related changes. Subtropical central and eastern Florida Bay, located at the southern end of the Florida peninsula, is classically considered to have inorganic nutrient conditions that are in higher-than-Redfield ratio proportions, and high levels of organic and chemically-reduced forms of nitrogen. However, salinity, pH and nutrients, both organic and inorganic, change with changes in freshwater flows to the bay. Here, using a time series of water quality and physico-chemical conditions from 2009 to 2019, the impacts of distinct changes in managed flow, drought, El Niño-related increases in precipitation, and intensive storms and hurricanes are explored with respect to changes in water quality and resulting ecosystem effects, with a focus on understanding why picocyanobacterial blooms formed when they did. Drought produced hyper-salinity conditions that were associated with a seagrass die-off. Years later, increases in precipitation resulting from intensive storms and a hurricane were associated with high loads of organic nutrients, and declines in pH, likely due to high organic acid input and decaying organic matter, collectively leading to physiologically favorable conditions for growth of the picocyanobacterium, Synechococcus spp. These conditions, including very high concentrations of NH4+, were likely inhibiting for seagrass recovery and for growth of competing phytoplankton or their grazers. Given projected future climate conditions, and anticipated cycles of drought and intensive storms, the likelihood of future seagrass die-offs and picocyanobacterial blooms is high.


1940 ◽  
Vol 72 (6) ◽  
pp. 729-745 ◽  
Author(s):  
Jonas E. Salk ◽  
G. I. Lavin ◽  
Thomas Francis

A study of the antigenic potency of influenza virus inactivated by ultraviolet radiation has been made. Virus so inactivated is still capable of functioning as an immunizing agent when given to mice by the intraperitoneal route. In high concentrations inactivated virus appears to be nearly as effective as active virus but when quantitative comparisons of the immunity induced by different dilutions are made, it is seen that a hundredfold loss in immunizing capacity occurs during inactivation. Virus in suspensions prepared from the lungs of infected mice is inactivated more rapidly than virus in tissue culture medium. A standard for the comparison of vaccines of epidemic influenza virus is proposed.


1984 ◽  
Vol 4 (11) ◽  
pp. 2449-2454 ◽  
Author(s):  
E R Kaufman

A new protocol for inducing mutations in mammalian cells in culture by exposure to the thymidine analog 5-bromodeoxyuridine (BrdUrd) was established. This protocol, called "DNA-dependent" mutagenesis, involved the incorporation of BrdUrd into DNA under nonmutagenic conditions and the subsequent replication of the 5-bromouracil (BrUra)-containing DNA under mutagenic conditions but with no BrdUrd present in the culture medium. The mutagenic conditions were induced by allowing BrUra-containing DNA to replicate in the presence of high concentrations of thymidine. This generated high intracellular levels of dTTP and dGTP, causing nucleotide pool imbalance. The mutagenesis induced by this protocol was found to correlate with the level of BrUra substituted for thymine in DNA.


2021 ◽  
Author(s):  
Bruno G.N. Andrade ◽  
Haithem Afli ◽  
Flavia A. Bressani ◽  
Rafael R. C. Cuadrat ◽  
Priscila S. N. de Oliveira ◽  
...  

Abstract Background: The impact of extreme changes in weather patterns in the economy and human welfare are some of the biggest challenges that our civilization is facing. From the anthropogenic activities that contribute to climate change, reducing the impact of farming activities is a priority, since it is responsible for up to 18% of greenhouse gases linked to such activities. To this end, we tested if the ruminal and fecal microbiome components of 52 Brazilian Nelore bulls, belonging to two treatment groups based on the feed intervention, conventional and by-products based diet, could be used in the future as biomarkers for methane emission and feed efficiency in bovine.Results: We identified a total of 5,693 Amplicon Sequence Variants (ASVs) in the Nelore bulls microbiomes. Differential abundance (DA) analysis with the ANCOM approach identified 30 bacterial and 15 archaea ASVs as DA among treatment groups. Association analysis using Maaslin2 and Mixed Linear Models indicated that bacterial ASVs are linked to the residual methane emission (RCH4) and Residual Feed Intake (RFI) phenotypes, contributing to the host’s phenotypic variation, suggesting their potential as targets for interventions and/or biomarkers.Conclusion: Feed composition induced significant differences in abundance and richness of ruminal and fecal microbial populations. The diet based on industrial byproducts applied to our treatment groups influenced the microbiome diversity of bacteria and archaea, but not of protozoa. Different ASVs were associated with RCH4 emission and RFI in both ruminal and fecal microbiomes. While ruminal ASVs are expected to directly influence RCH4 emission and RFI, the relation of fecal taxa, such as Alistipes and Rikenellaceae (gut group RC9), with these traits might also be associated with host health due to their link to anti-inflammatory compounds, and these have the potential to be used as accessible biomarkers for these complex phenotypes.


Author(s):  
I. V. Mitrofanova ◽  
N. N. Ivanova ◽  
A. E. Paliy ◽  
I. N. Paliy ◽  
O. V. Mitrofanova

The results of temperature influence on the regeneration of microshoots and the level of phenolic compounds in microshoots of two rare plant species under in vitro conditions are presented. It is shown that the maximum growth of the main and the formation of adventitious shoots, leaves occurred at a temperature of 21- 23°C. Reconnaissance experiments on the biochemical study of organs and tissues of the studied species were conducted. It was found that the leaves contain high concentrations of phenolic substances and are characterized by a wide variety of components. It is shown that as the temperature increased, the content of the sum of phenolic substances increased, which negatively affected the morphogenetic potential of the studied species.


1994 ◽  
Vol 29 (9) ◽  
pp. 321-329 ◽  
Author(s):  
Evangelos Terzis

Industrial water usage results in large volumes of liquid wastes rich in organic pollutants. Waste waters from certain industrial chemical operations (e.g. organic synthesis, perfume industry) will sometimes contain organic solvents at relatively high concentrations. The presence of organic solvents is undesirable in the sewerage system and so must be removed from the industrial effluent. Anaerobic treatment of many of these organic solvents is possible, in which the organic material is converted ~90% to volatile substances -carbon dioxide and methane gas- and ~10% to new bacterial cells (solids). Industry will be using less water in the future. Increased water charges will lead to more precise control and integrated processes will reduce wastage. The smaller volumes of more concentrated waste will be ideal for anaerobic digestion. In order to evaluate the optimum conditions for the anaerobic digestion of propan-2-ol (iso-propanol) the kinetic parameters of the Monod rate model, namely, maximum growth rate (µm), yield (Y), half velocity constant (Ks) and endogenous decay coefficient (Kd), were determined at the temperature range 25°-40°C, inclusively. The regulatory role of molecular hydrogen was investigated and discussed, and also its possible use as a monitor feature in the anaerobic digestion.


Picoplankton consists of those organisms found in the open waters of seas and lakes which are capable of passing through a filter with 2 μm pores but not through one with 0.2 μm pores. Cells in this size range are well adapted to planktonic life in that they sink extremely slowly and are more efficient than larger forms in taking up nutrients and absorbing radiant energy. Picophytoplankton includes coccoid cyanobacteria and a variety of eukaryotic algal forms. Strains studied in the laboratory have all been found to show maximum growth at relatively low irradiances, the eukaryotic forms being more efficient than the cyanobacteria in utilizing the blue light which predominates at the bottom of the photic zone in clear oceanic waters. Oceanic strains of coccoid cyanobacteria, however, are characterized by high concentrations of phycoerythrin, which appears to function as a nitrogenous reserve as well as an accessory pigment in photosynthesis. The seasonal and spatial distribution of picophytoplankton seems explicable in terms of these physiological characteristics. Numbers of coccoid cyanobacteria have shown a striking correlation with temperature in a number of different situations. Heterotrophic bacteria are also included in the picoplankton, and a review of the information concerning them suggests that they form a highly dynamic population subsisting on dissolved organic matter liberated by living phytoplankton and zooplankton and by decomposition of dead matter. The productivity of this population in the euphotic zone approaches that of the phytoplankton. Both the picophytoplankton and the bacterioplankton are preyed on by phagotrophic flagellates. Both bacteria and flagellates are active in regeneration of mineral nutrients. Regardless of the salinity, temperature or nutrient status of the water, the numbers of heterotrophic bacteria, picophytoplankton and flagellates tend to be around 10 6 , 10 4 and 10 3 organisms per millilitre respectively. It is suggested that these populations form a basic, self-sustaining and self-regulating community in all natural waters. From present information, it seems that little of the energy which passes through this community finds its way into the larger planktonic organisms, but the role of picoplankton in recycling nutrient elements is of great importance in the marine ecosystem.


2000 ◽  
Vol 27 (7) ◽  
pp. 709 ◽  
Author(s):  
Robert J. Reid ◽  
F. Andrew Smith

The amelioration of Na toxicity by supplementation of Ca in the growth medium was investigated in wheat with the aims of (1) identifying the Ca-dependent processes that determine the growth responses and (2) defining the limits to Ca effects on these processes. Growth of wheat seedlings was strongly inhibited by 150 mM NaCl but improved as the Ca concentration in the nutrient medium was increased up to 2.34 mM. Further increasing Ca to 10 mM did not increase growth, nor did foliar application of Ca. Even at high concentrations of Ca, the maximum growth was only approximately 50% of the growth at low salinity. We conclude that the main component of improved growth caused by Ca was via its apoplastic effects on the transport of Na and K across the root plasma membrane, rather than by increasing root or shoot Ca concentrations. There was no evidence that high salinity inhibited Ca uptake to the shoot. The limits to improvement of growth by Ca appear to relate to the fact that, although Ca is able to ameliorate the toxicity caused by high intracellular Na, it is not able to overcome the osmotic deficits associated with high salinity.


2019 ◽  
Vol 41 (1) ◽  
Author(s):  
Samila Silva Camargo ◽  
Leo Rufato ◽  
Maicon Magro ◽  
André Luiz Kulkamp de Souza

Abstract The in vitro propagation technique via temporary immersion bioreactors is a tool that, through the culture in a liquid medium, allows an increase in the efficiency of seedling production. Several researches with the strawberry crop have shown greater efficiency of the system compared to the conventional process of micropropagation in solid medium. In this sense, the objective herein was to establish a protocol of multiplication and rooting of the ‘Pircinque’ strawberry, in temporary immersion bioreactors. Two distinct and independent studies were carried out, characterized by the multiplication and rooting stages of strawberry explants, newly introduced and registered in Brazil. Two culture media (MS and KNOP) were studied and, as a control treatment, the growth of the explants in solid culture medium was evaluated with the addition of 5 g L-1 of agar. Different immersion times of the culture medium were explored: five or eight times a day, for 15 minutes. The study was composed of the culture medium and immersion time factors, as well as the control (solid) treatment. It was verified that the use of temporary immersion bioreactors system is an efficient technique for the multiplication and rooting of explants of strawberry cv. Pircinque, when compared to the conventional method of micropropagation with the use of solid culture medium, making it possible to optimize the production of seedlings in biofactories. The MS liquid medium, in contact with explants of ‘Pircinque’ strawberry five times a day, increased the growth of the aerial part and the root system.


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