The organisms thriving under extreme conditions better than any other organism living on Earth, fascinate by their hostile growing parameters, physiological features, and their production of valuable ...bioactive metabolites. This is the case of microorganisms (bacteria, archaea, and fungi) that grow optimally at high salinities and are able to produce biomolecules of pharmaceutical interest for therapeutic applications. As along as the microbiota is being approached by massive sequencing, novel insights are revealing the environmental conditions on which the compounds are produced in the microbial community without more stress than sharing the same substratum with their peers, the salt. In this review are reported the molecules described and produced by halophilic microorganisms with a spectrum of action in vitro: antimicrobial and anticancer. The action mechanisms of these molecules, the urgent need to introduce alternative lead compounds and the current aspects on the exploitation and its limitations are discussed.
To gain a better understanding of how divergence occurs, and how taxonomy can benefit from studying natural populations, we isolated and examined 25 closely related
strains obtained from different ...hypersaline communities and compared them to validly named species and other reference strains using five taxonomic study approaches: phylogenetic analysis using the 16S rRNA gene and multilocus sequencing analysis (MLSA), polar lipid profiles (PLP), average nucleotide identity (ANI) and DNA-DNA hybridization (DDH). 16S rRNA gene sequence could not differentiate the newly isolated strains from described species, while MLSA grouped strains into three major clusters. Two of those MLSA clusters distinguished candidates for new species. The third cluster with concatenated sequence identity equal to or greater than 97.5% was comprised of strains from Aran-Bidgol Lake (Iran) and solar salterns in Namibia and Spain, and two previously described species isolated from Mexico and Algeria. PLP and DDH analyses showed that Aran-Bidgol strains formed uniform populations, and that strains isolated from other geographic locations were heterogeneous and divergent, indicating that they may constitute different species. Therefore, applying only sequencing approaches and similarity cutoffs for circumscribing species may be too conservative, lumping concealed diversity into a single taxon. Further, our data support the interpretation that local populations experience unique evolutionary homogenization pressures, and once relieved of insular constraints (e.g., through migration) are free to diverge.
This is a continuity of a series of taxonomic papers where materials are examined, described and novel combinations are proposed where necessary to improve our traditional species concepts and ...provide updates on their classification. In addition to extensive morphological descriptions and appropriate asexual and sexual connections, DNA sequence data are also analysed from concatenated datasets (rDNA, TEF-α, RBP2 and β-Tubulin) to infer phylogenetic relationships and substantiate systematic position of taxa within appropriate ranks. Wherever new species or combinations are being proposed, we apply an integrative approach (morphological and molecular data as well as ecological features wherever applicable). Notes on 125 fungal taxa are compiled in this paper, including eight new genera, 101 new species, two new combinations, one neotype, four reference specimens, new host or distribution records for eight species and one alternative morphs. The new genera introduced in this paper are
Alloarthopyrenia
,
Arundellina
,
Camarosporioides
,
Neomassaria
,
Neomassarina
,
Neotruncatella
,
Paracapsulospora
and
Pseudophaeosphaeria
. The new species are
Alfaria spartii
,
Alloarthopyrenia italica
,
Anthostomella ravenna
,
An
.
thailandica
,
Arthrinium paraphaeospermum
,
Arundellina typhae
,
Aspergillus koreanus
,
Asterina cynometrae
,
Bertiella ellipsoidea
,
Blastophorum aquaticum
,
Cainia globosa
,
Camarosporioides phragmitis
,
Ceramothyrium menglunense
,
Chaetosphaeronema achilleae
,
Chlamydotubeufia helicospora
,
Ciliochorella phanericola
,
Clavulinopsis aurantiaca
,
Colletotrichum insertae
,
Comoclathris italica
,
Coronophora myricoides
,
Cortinarius fulvescentoideus
,
Co
.
nymphatus
,
Co
.
pseudobulliardioides
,
Co
.
tenuifulvescens
,
Cunninghamella gigacellularis
,
Cyathus pyristriatus
,
Cytospora cotini
,
Dematiopleospora alliariae
,
De
.
cirsii
,
Diaporthe aseana
,
Di
.
garethjonesii
,
Distoseptispora multiseptata
,
Dis
.
tectonae
,
Dis
.
tectonigena
,
Dothiora buxi
,
Emericellopsis persica
,
Gloniopsis calami
,
Helicoma guttulatum
,
Helvella floriforma
,
H
.
oblongispora
,
Hermatomyces subiculosa
,
Juncaceicola italica
,
Lactarius dirkii
,
Lentithecium unicellulare
,
Le
.
voraginesporum
,
Leptosphaeria cirsii
,
Leptosphaeria irregularis
,
Leptospora galii
,
Le
.
thailandica
,
Lindgomyces pseudomadisonensis
,
Lophiotrema bambusae
,
Lo
.
fallopiae
,
Meliola citri-maximae
,
Minimelanolocus submersus
,
Montagnula cirsii
,
Mortierella fluviae
,
Muriphaeosphaeria ambrosiae
,
Neodidymelliopsis ranunculi
,
Neomassaria fabacearum
,
Neomassarina thailandica
,
Neomicrosphaeropsis cytisi
,
Neo
.
cytisinus
,
Neo
.
minima
,
Neopestalotiopsis cocoës
,
Neopestalotiopsis musae
,
Neoroussoella lenispora
,
Neotorula submersa
,
Neotruncatella endophytica
,
Nodulosphaeria italica
,
Occultibambusa aquatica
,
Oc
.
chiangraiensis
,
Ophiocordyceps hemisphaerica
,
Op
.
lacrimoidis
,
Paracapsulospora metroxyli
,
Pestalotiopsis sequoiae
,
Peziza fruticosa
,
Pleurotrema thailandica
,
Poaceicola arundinis
,
Polyporus mangshanensis
,
Pseudocoleophoma typhicola
,
Pseudodictyosporium thailandica
,
Pseudophaeosphaeria rubi
,
Purpureocillium sodanum
,
Ramariopsis atlantica
,
Rhodocybe griseoaurantia
,
Rh
.
indica
,
Rh
.
luteobrunnea
,
Russula indoalba
,
Ru
.
pseudoamoenicolor
,
Sporidesmium aquaticivaginatum
,
Sp
.
olivaceoconidium
,
Sp
.
pyriformatum
,
Stagonospora forlicesenensis
,
Stagonosporopsis centaureae
,
Terriera thailandica
,
Tremateia arundicola
,
Tr
.
guiyangensis
,
Trichomerium bambusae
,
Tubeufia hyalospora
,
Tu
.
roseohelicospora
and
Wojnowicia italica
. New combinations are given for
Hermatomyces mirum
and
Pallidocercospora thailandica
. A neotype is proposed for
Cortinarius fulvescens
. Reference specimens are given for
Aquaphila albicans
,
Leptospora rubella
,
Platychora ulmi
and
Meliola pseudosasae
, while new host or distribution records are provided for
Diaporthe eres
,
Di. siamensis
,
Di
.
foeniculina
,
Dothiorella iranica
,
Do. sarmentorum
,
Do. vidmadera
,
Helvella tinta
and
Vaginatispora fuckelii
, with full taxonomic details. An asexual state is also reported for the first time in
Neoacanthostigma septoconstrictum
. This paper contributes to a more comprehensive update and improved identification of many ascomycetes and basiodiomycetes.
One of the challenges in the petroleum hydrocarbon contaminated groundwater remediation by oxygen releasing compounds (ORCs) is to identify the remediation mechanism and determine the impact of ORCs ...on the environment and the intrinsic groundwater microorganisms. In this research, the application of encapsulated magnesium peroxide (MgO2) nanoparticles in the permeable reactive barrier (PRB) for bioremediation of the groundwater contaminated by toluene and naphthalene was studied in the continuous flow sand-packed plexiglass columns within 50 d experiments. For the biodiversity studies, next generation sequencing (NGS) of the 16S rRNA gene was applied. The results showed that naphthalene was metabolized (within 20 days) faster than toluene (after 30 days) by microorganisms of the aqueous phase. By comparing the contaminant removal in the biotic (which resulted in the complete contaminant removal) and abiotic (around 32% removal for naphthalene and 36% for toluene after 50 d) conditions, the significant role of microorganisms on the decontamination process was proved. Furthermore, the attached microbial communities on the porous media were visualized by scanning electron microscopy (SEM). Microbial community structure analysis by NGS technique revealed that the microbial species which were able to degrade toluene and naphthalene such as P. putida and P. mendocina respectively were stimulated by addition of MgO2 nanoparticles. The presented study resulted in a momentous insight into the application of MgO2 nanoparticles in the hydrocarbon compounds removal from groundwater.
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•Magnesium peroxide is able to remove BTEX and PAH from groundwater.•Encapsulation of MgO2 improves the groundwater remediation.•The intrinsic groundwater flora plays a key role in the bioremediation process.•Groundwater microbial structure is changed within the remediation according to NGS.
The halophilic microorganisms living in extreme environments contain high concentrations of carotenoids with notable medical abilities. The purpose of this study was to evaluate the anticancer effect ...of carotenoids extracted from native Iranian halophilic microorganisms with the ability to inhibit breast cancer cell line. To begin the study, 40 halophilic strains were cultured, and 8 strains capable of producing pigmented colonies were chosen from those cultured strains. In the next step, from among 8 strains using MTT assay, 1 capable of reducing cell viability of the breast cancer MCF‐7 cell line was chosen as a selective strain. The principal carotenoid was characterized using UV‐visible, FT‐IR spectroscopic, and LC‐MASS analyses. Using real time PCR technique, the expression of genes specific for apoptosis, in the presence or absence of carotenoid, was examined. Among all strains, carotenoid extracted from strain A15 had the most potent cytotoxic effect on breast cancer cell line (IC50 = 0.0645 mg/mL). 16S rRNA gene analysis showed that strain A15 had similarity with Haloarcula hispanica for about 99.5%. According to the analysis results, it could be estimated that the principal carotenoid extracted form Haloarcula sp. A15 was similar to bacterioruberin. Both early and late apoptosis were increased significantly about 10% and 39%, respectively, due to upregulation of CASP3, CASP8, BAX genes expression in MCF‐7 cell line. In contrast, the expression of genes MKI67, SOX2 were significantly downregulated in treated MCF‐7 cell line. The results of this study showed that Halophilic archaeon strain could be a good candidate for the production of high added‐value bacterioruberin due to its possible anticancer properties.
Significance statement
The results of the present study showed that the pigment obtained from A Haloarcula sp. A15 present in native saline environments of Iran increases the expression of apoptotic genes in the MCF‐7 cell model of breast cancer. The results of this research may provide a target for elucidating the possible activity of the cytotoxic, antiproliferative, and apoptosis‐inducing pigment extracted from archaea halophile in MCF‐7 cell line in breast cancer treatment. Therefore, it is assumed that it is possible to introduce this compound (pigment), after further research, as a new anticancer raw material with natural origin in medicine. The proposed study design divulges the importance of investigating of apoptotic genes expressions to find better therapeutic options to combat breast cancer.
The Persian Gulf, hosting ca. 48% of the world's oil reserves, has been chronically exposed to natural oil seepage. Oil spill studies show a shift in microbial community composition in response to ...oil pollution; however, the influence of chronic oil exposure on the microbial community remains unknown. We performed genome-resolved comparative analyses of the water and sediment samples along Persian Gulf's pollution continuum (Strait of Hormuz, Asalouyeh, and Khark Island). Continuous exposure to trace amounts of pollution primed the intrinsic and rare marine oil-degrading microbes such as Oceanospirillales, Flavobacteriales, Alteromonadales, and Rhodobacterales to bloom in response to oil pollution in Asalouyeh and Khark samples. Comparative analysis of the Persian Gulf samples with 106 oil-polluted marine samples reveals that the hydrocarbon type, exposure time, and sediment depth are the main determinants of microbial response to pollution. High aliphatic content of the pollution enriched for Oceanospirillales, Alteromonadales, and Pseudomonadales whereas, Alteromonadales, Cellvibrionales, Flavobacteriales, and Rhodobacterales dominate polyaromatic polluted samples. In chronic exposure and oil spill events, the community composition converges towards higher dominance of oil-degrading constituents while promoting the division of labor for successful bioremediation.
Hydrocarbons (HCs) are organic compounds composed solely of carbon and hydrogen that are mainly accumulated in oil reservoirs. As the introduction of all classes of hydrocarbons including crude oil ...and oil products into the environment has increased significantly, oil pollution has become a global ecological problem. However, our perception of pathways for biotic degradation of major HCs and key enzymes in these bioconversion processes has mainly been based on cultured microbes and is biased by uneven taxonomic representation. Here we used Annotree to provide a gene-centric view of the aerobic degradation ability of aliphatic and aromatic HCs in 23,446 genomes from 123 bacterial and 14 archaeal phyla. Apart from the widespread genetic potential for HC degradation in Proteobacteria, Actinobacteriota, Bacteroidota, and Firmicutes, genomes from an additional 18 bacterial and 3 archaeal phyla also hosted key HC degrading enzymes. Among these, such degradation potential has not been previously reported for representatives in the phyla UBA8248, Tectomicrobia, SAR324, and Eremiobacterota. Genomes containing whole pathways for complete degradation of HCs were only detected in Proteobacteria and Actinobacteriota. Except for several members of Crenarchaeota, Halobacterota, and Nanoarchaeota that have tmoA, ladA, and alkB/M key genes, respectively, representatives of archaeal genomes made a small contribution to HC degradation. None of the screened archaeal genomes coded for complete HC degradation pathways studied here; however, they contribute significantly to peripheral routes of HC degradation with bacteria. Phylogeny reconstruction showed that the reservoir of key aerobic hydrocarbon-degrading enzymes in Bacteria and Archaea undergoes extensive diversification via gene duplication and horizontal gene transfer. This diversification could potentially enable microbes to rapidly adapt to novel and manufactured HCs that reach the environment.
Global warming and the limitations of using fossil fuels are a main concern of all societies, and thus, the development of alternative fuel sources is crucial to improving the current global energy ...situation. Biofuels are known as the best alternatives of unrenewable fuels and justify increasing extensive research to develop new and less expensive methods for their production. The most frequent biofuels are bioethanol, biobutanol, biodiesel, and biogas. The production of these biofuels is the result of microbial activity on organic substrates like sugars, starch, oil crops, non-food biomasses, and agricultural and animal wastes. Several industrial production processes are carried out in the presence of high concentrations of NaCl and therefore, researchers have focused on halophiles for biofuel production. In this review, we focus on the role of halophilic microorganisms and their current utilization in the production of all types of biofuels. Also, the outstanding potential of them and their hydrolytic enzymes in the hydrolysis of different kind of biomasses and the production of biofuels are discussed.
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