scholarly journals Design and Operation of Empirical Manganese-Removing Bioreactors and Integration into a Composite Modular System for Remediating and Recovering Metals from Acidic Mine Waters

2021 ◽  
Vol 11 (9) ◽  
pp. 4287
Author(s):  
Ana Laura Santos ◽  
D. Barrie Johnson

Packed bed bioreactors were used to remove soluble manganese from a synthetic mine water as the final stage of an integrated bioremediation process. The synthetic mine water had undergone initial processing using a sulfidogenic bioreactor (pH 4.0–5.5) which removed all transition metals present in elevated concentrations (Cu, Ni, Zn and Co) apart from manganese. The aerobic bioreactors were packed with pebbles collected from a freshwater stream that were coated with black-colored, Mn(IV)-containing biofilms, and their capacity to remove soluble Mn (II) from the synthetic mine water was tested at varying hydraulic retention times (11–45 h) and influent liquor pH values (5.0 or 6.5). Over 99% of manganese was removed from the partly processed mine water when operated at pH 6.5 and a HRT of 45 h. Molecular techniques (clone libraries and T-RFLP analysis) were used to characterize the biofilms and identified two heterotrophic Mn-oxidizing microorganisms: the bacterium Leptothrix discophora and what appears to be a novel fungal species. The latter was isolated and characterized in vitro.

2003 ◽  
Vol 69 (5) ◽  
pp. 2548-2554 ◽  
Author(s):  
Liliya G. Nikolcheva ◽  
Amanda M. Cockshutt ◽  
Felix Bärlocher

ABSTRACT Traditional microscope-based estimates of species richness of aquatic hyphomycetes depend upon the ability of the species in the community to sporulate. Molecular techniques which detect DNA from all stages of the life cycle could potentially circumvent the problems associated with traditional methods. Leaf disks from red maple, alder, linden, beech, and oak as well as birch wood sticks were submerged in a stream in southeastern Canada for 7, 14, and 28 days. Fungal biomass, estimated by the amount of ergosterol present, increased with time on all substrates. Alder, linden, and maple leaves were colonized earlier and accumulated the highest fungal biomass. Counts and identifications of released conidia suggested that fungal species richness increased, while community evenness decreased, with time (up to 11 species on day 28). Conidia of Articulospora tetracladia dominated. Modifications of two molecular methods—denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis—suggested that both species richness and community evenness decreased with time. The dominant ribotype matched that of A. tetracladia. Species richness estimates based on DGGE were consistently higher than those based on T-RFLP analysis and exceeded those based on spore identification on days 7 and 14. Since traditional and molecular techniques assess different aspects of the fungal organism, both are essential for a balanced view of fungal succession on leaves decaying in streams.


2013 ◽  
Vol 80 (2) ◽  
pp. 672-680 ◽  
Author(s):  
D. Barrie Johnson ◽  
Kevin B. Hallberg ◽  
Sabrina Hedrich

ABSTRACTA betaproteobacterium, shown by molecular techniques to have widespread global distribution in extremely acidic (pH 2 to 4) ferruginous mine waters and also to be a major component of “acid streamer” growths in mine-impacted water bodies, has proven to be recalcitrant to enrichment and isolation. A modified “overlay” solid medium was devised and used to isolate this bacterium from a number of mine water samples. The physiological and phylogenetic characteristics of a pure culture of an isolate from an abandoned copper mine (“Ferrovum myxofaciens” strain P3G) have been elucidated. “F. myxofaciens” is an extremely acidophilic, psychrotolerant obligate autotroph that appears to use only ferrous iron as an electron donor and oxygen as an electron acceptor. It appears to use the Calvin-Benson-Bassham pathway to fix CO2and is diazotrophic. It also produces copious amounts of extracellular polymeric materials that cause cells to attach to each other (and to form small streamer-like growthin vitro) and to different solid surfaces. “F. myxofaciens” can catalyze the oxidative dissolution of pyrite and, like many other acidophiles, is tolerant of many (cationic) transition metals. “F. myxofaciens” and related clone sequences form a monophyletic group within theBetaproteobacteriadistantly related to classified orders, with genera of the familyNitrosomonadaceae(lithoautotrophic, ammonium-oxidizing neutrophiles) as the closest relatives. On the basis of the phylogenetic and phenotypic differences of “F. myxofaciens” and otherBetaproteobacteria, a new family, “Ferrovaceae,” and order, “Ferrovales,” within the classBetaproteobacteriaare proposed. “F. myxofaciens” is the first extreme acidophile to be described in the classBetaproteobacteria.


2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 701
Author(s):  
Ovidiu Bîcă ◽  
Ioan Sârbu ◽  
Carmen Iulia Ciongradi

This article reviews the latest information about preserving reproductive potential that can offer enhanced prospects for future conception in the pediatric male population with cancer, whose fertility is threatened because of the gonadotoxic effects of chemotherapy and radiation. An estimated 400,000 children and adolescents aged 0–19 years will be diagnosed with cancer each year. Fertility is compromised in one-third of adult male survivors of childhood cancer. We present the latest approaches and techniques for fertility preservation, starting with fertility preservation counselling, a clinical practice guideline used around the world and finishing with recent advances in basic science and translational research. Improving strategies for the maturation of germ cells in vitro combined with new molecular techniques for gene editing could be the next scientific keystone to eradicate genetic diseases such as cancer related mutations in the offspring of cancer survivors.


2006 ◽  
Vol 396 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Chrysoula Panethymitaki ◽  
Paul W. Bowyer ◽  
Helen P. Price ◽  
Robin J. Leatherbarrow ◽  
Katherine A. Brown ◽  
...  

The eukaryotic enzyme NMT (myristoyl-CoA:protein N-myristoyltransferase) has been characterized in a range of species from Saccharomyces cerevisiae to Homo sapiens. NMT is essential for viability in a number of human pathogens, including the fungi Candida albicans and Cryptococcus neoformans, and the parasitic protozoa Leishmania major and Trypanosoma brucei. We have purified the Leishmania and T. brucei NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and specific peptide substrates. A number of inhibitory compounds that target NMT in fungal species have been tested against the parasite enzymes in vitro and against live parasites in vivo. Two of these compounds inhibit TbNMT with IC50 values of <1 μM and are also active against mammalian parasite stages, with ED50 (the effective dose that allows 50% cell growth) values of 16–66 μM and low toxicity to murine macrophages. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against infectious diseases including African sleeping sickness and Nagana.


2016 ◽  
Vol 2 ◽  
Author(s):  
PANTELIS NTAIS ◽  
VASILIKI CHRISTODOULOU ◽  
EMMANOUIL DOKIANAKIS ◽  
MARIA ANTONIOU

SUMMARYLeishmaniasis and dirofilariasis are parasitic diseases of humans and dogs, worldwide, and they are often found as coinfections in endemic areas. Cases of human and canine dirofilariasis have being reported in Greece and leishmaniasis is endemic in most prefectures in humans and dogs. In most cases, dirofilariasis is established by parasitological (the modified Knott's test) and/or immunological methods, whilst for leishmaniasis molecular techniques and culture are also used. During an epidemiological study in Greece, 22·1% of the 5772 dogs studied were found positive by serology forLeishmania.Blood cultures of 165 (12·94%) of these animals producedLeishmaniapromastigotes and 26 (2·03%)Dirofilariamicrofilariae (L1), whilst only in two (0·16%) bothLeishmaniaandDirofilariaL1 appeared. The aim was to assess coinfections by the two parasites in dogs in Greece, the isolation and survival ofDirofilariamicrofilariae andLeishmaniapromastigotes using clotted blood (a fast, simple and low-cost method) and the survival potential of the two parasites in coexistence,in vitro.


2020 ◽  
Vol 8 (1) ◽  
pp. 69 ◽  
Author(s):  
Marco Camardo Leggieri ◽  
Amedeo Pietri ◽  
Paola Battilani

No information is available in the literature about the influence of temperature (T) on Penicillium and Aspergillus spp. growth and mycotoxin production on cheese rinds. The aim of this work was to: (i) study fungal ecology on cheese in terms of T requirements, focusing on the partitioning of mycotoxins between the rind and mycelium; and (ii) validate predictive models previously developed by in vitro trials. Grana cheese rind blocks were inoculated with A. versicolor, P. crustosum, P. nordicum, P. roqueforti, and P. verrucosum, incubated at different T regimes (10–30 °C, step 5 °C) and after 14 days the production of mycotoxins (ochratoxin A (OTA); sterigmatocystin (STC); roquefortine C (ROQ-C), mycophenolic acid (MPA), Pr toxin (PR-Tox), citrinin (CIT), cyclopiazonic acid (CPA)) was quantified. All the fungi grew optimally around 15–25 °C and produced the expected mycotoxins (except MPA, Pr-Tox, and CIT). The majority of the mycotoxins produced remained in the mycelium (~90%) in three out of five fungal species (P. crustosum, P. nordicum, and P. roqueforti); the opposite occurred for A. versicolor and P. verrucosum with 71% and 58% of STC and OTA detected in cheese rind, respectively. Available predictive models fitted fungal growth on the cheese rind well, but validation was not possible for mycotoxins because they were produced in a very narrow T range.


Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Angela Brunetti ◽  
Antonio Matere ◽  
Valentina Lumia ◽  
Vittorio Pasciuta ◽  
Valeria Fusco ◽  
...  

Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by wood discoloration, bark canker, and canopy blight. During surveys of olive groves in Apulia (southern Italy), we noticed that—in some areas—trees were heavily affected by severe branch and twig dieback. In addition, chlorosis and the appearance of red-bronze patches on the leaf preceded the wilting of the foliage, with necrotic leaves persisting on the twigs. Given the severity of the manifestation in zones also subject to olive quick decline syndrome (OQDS) caused by Xylella fastidiosa subsp. pauca, we investigated the etiology and provide indications for differentiating the symptoms from OQDS. Isolation from diseased wood samples revealed a mycete, which was morphologically and molecularly identified as N. mediterraneum. The pathogenicity tests clearly showed that this fungus is able to cause the natural symptoms. Therefore, also considering the low number of tested samples, N. mediterraneum is a potential causal agent of the observed disease. Specifically, inoculation of the twigs caused complete wilting in two to three weeks, while inoculation at the base of the stem caused severe girdling wedge-shaped cankers. The growth rate of the fungus in in vitro tests was progressively higher from 10 to 30 °C, failing to grow at higher temperatures, but keeping its viability even after prolonged exposure at 50 °C. The capacity of the isolate to produce catenulate chlamydospores, which is novel for the species, highlights the possibility of a new morphological strain within N. mediterraneum. Further investigations are ongoing to verify whether additional fungal species are involved in this symptomatology.


2018 ◽  
Vol 3 (01) ◽  
pp. 62-69
Author(s):  
Eka Corneliyawati ◽  
Massora Massora ◽  
Khikmah Khikmah ◽  
As’ad Syamsul Arifin

The rhizosphere is the zone of soil surrounding a plant root where plant roots, soil and the soil biota interact with each other. Chitinolytic fungi has been effectively used in biological control agens. The chitinase activity causes lysis of the fungi cell wall pathogen. The aim of the research was to find optimization of activity chitinase enzyme from rhizosphere soil was conducted in vitro. Optimal growth chitinase production for TKR3 fungi isolate were concentration of chitin 0,2% (b/v), pH 5,5, temperature 30ºC, agitation 150 rpm and incubation time at four days. The optimum yield of chitinase production is influenced by fungal species and environmental conditions.


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