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1.
Syst Appl Microbiol ; 44(6): 126249, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34547593

RESUMO

Nine pure cultures of neutrophilic haloaloarchaea capable of anaerobic growth by carbohydrate-dependent sulfur respiration were isolated from hypersaline lakes in southwestern Siberia and southern Russia. According to phylogenomic analysis the isolates were closely related to each other and formed a new species within the genus Halapricum (family Haloarculaceae). They have three types of catabolism: fermentative, resulting in H2 formation; anaerobic respiration using sulfur compounds as e-acceptors and aerobic respiration. Apart from elemental sulfur, all isolates can also use three different sulfoxides as acceptors and the type strain also grows with thiosulfate, reducing it partially to sulfide and sulfite. All strains utilized sugars and glycerol as the e-donors and C source for anaerobic growth and some can also grow with alpha-glucans, such as starch and dextrins. The major respiratory menaquinones are MK-8:8 and MK-8:7, but 5-19% consists of "thermoplasmata" quinones (MMK-8:8 and MMK-8:7), whose occurrence in haloarchaea is unprecedented. On the basis of their unique physiological properties and results of phylogenomic analysis, the isolates are suggested to be classified into a novel species Halapricum desulfuricans sp. nov. (type strain HSR12-2T = JCM 34032T = UNIQEM U1001T).


Assuntos
Halobacteriales , Lagos , Carboidratos , DNA Bacteriano , Halobacteriales/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre
2.
Int J Mol Sci ; 22(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807153

RESUMO

Soil salinity is an increasing problem facing agriculture in many parts of the world. Climate change and irrigation practices have led to decreased yields of some farmland due to increased salt levels in the soil. Plants that have tolerance to salt are thus needed to feed the world's population. One approach addressing this problem is genetic engineering to introduce genes encoding salinity, but this approach has limitations. Another fairly new approach is the isolation and development of salt-tolerant (halophilic) plant-associated bacteria. These bacteria are used as inoculants to stimulate plant growth. Several reports are now available, demonstrating how the use of halophilic inoculants enhance plant growth in salty soil. However, the mechanisms for this growth stimulation are as yet not clear. Enhanced growth in response to bacterial inoculation is expected to be associated with changes in plant gene expression. In this review, we discuss the current literature and approaches for analyzing altered plant gene expression in response to inoculation with halophilic bacteria. Additionally, challenges and limitations to current approaches are analyzed. A further understanding of the molecular mechanisms involved in enhanced plant growth when inoculated with salt-tolerant bacteria will significantly improve agriculture in areas affected by saline soils.


Assuntos
Halobacteriales/metabolismo , Desenvolvimento Vegetal/genética , Plantas/genética , Plantas/microbiologia , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Bactérias/metabolismo , Expressão Gênica , Genes de Plantas , Raízes de Plantas/metabolismo , Salinidade , Solo/química , Microbiologia do Solo
3.
Genes (Basel) ; 12(1)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33478024

RESUMO

Halotolerant lipolytic enzymes have gained growing interest, due to potential applications under harsh conditions, such as hypersalinity and presence of organic solvents. In this study, a lipolytic gene, est56, encoding 287 amino acids was identified by functional screening of a compost metagenome. Subsequently, the gene was heterologously expressed, and the recombinant protein (Est56) was purified and characterized. Est56 is a mesophilic (Topt 50 °C) and moderate alkaliphilic (pHopt 8) enzyme, showing high thermostability at 30 and 40 °C. Strikingly, Est56 is halotolerant as it exhibited high activity and stability in the presence of up to 4 M NaCl or KCl. Est56 also displayed enhanced stability against high temperatures (50 and 60 °C) and urea (2, 4, and 6 M) in the presence of NaCl. In addition, the recently reported halotolerant lipolytic enzymes were summarized. Phylogenetic analysis grouped these enzymes into 13 lipolytic protein families. The majority (45%) including Est56 belonged to family IV. To explore the haloadaptation of halotolerant enzymes, the amino acid composition between halotolerant and halophilic enzymes was statistically compared. The most distinctive feature of halophilic from non-halophilic enzymes are the higher content of acidic residues (Asp and Glu), and a lower content of lysine, aliphatic hydrophobic (Leu, Met and Ile) and polar (Asn) residues. The amino acid composition and 3-D structure analysis suggested that the high content of acidic residues (Asp and Glu, 12.2%) and low content of lysine residues (0.7%), as well as the excess of surface-exposed acidic residues might be responsible for the haloadaptation of Est56.


Assuntos
Proteínas de Bactérias/metabolismo , Carboxilesterase/metabolismo , Halobacteriales/enzimologia , Metagenoma , Salinidade , Sequência de Aminoácidos/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Carboxilesterase/química , Carboxilesterase/genética , Carboxilesterase/isolamento & purificação , Clonagem Molecular , Compostagem , Ensaios Enzimáticos , Estabilidade Enzimática/genética , Halobacteriales/genética , Interações Hidrofóbicas e Hidrofílicas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
4.
RNA ; 27(2): 133-150, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33184227

RESUMO

The large ribosomal RNAs of eukaryotes frequently contain expansion sequences that add to the size of the rRNAs but do not affect their overall structural layout and are compatible with major ribosomal function as an mRNA translation machine. The expansion of prokaryotic ribosomal RNAs is much less explored. In order to obtain more insight into the structural variability of these conserved molecules, we herein report the results of a comprehensive search for the expansion sequences in prokaryotic 5S rRNAs. Overall, 89 expanded 5S rRNAs of 15 structural types were identified in 15 archaeal and 36 bacterial genomes. Expansion segments ranging in length from 13 to 109 residues were found to be distributed among 17 insertion sites. The strains harboring the expanded 5S rRNAs belong to the bacterial orders Clostridiales, Halanaerobiales, Thermoanaerobacterales, and Alteromonadales as well as the archael order Halobacterales When several copies of a 5S rRNA gene are present in a genome, the expanded versions may coexist with normal 5S rRNA genes. The insertion sequences are typically capable of forming extended helices, which do not seemingly interfere with folding of the conserved core. The expanded 5S rRNAs have largely been overlooked in 5S rRNA databases.


Assuntos
Genoma Arqueal , Genoma Bacteriano , RNA Arqueal/genética , RNA Bacteriano/genética , RNA Ribossômico 5S/genética , Alteromonadaceae/classificação , Alteromonadaceae/genética , Alteromonadaceae/metabolismo , Pareamento de Bases , Sequência de Bases , Clostridiales/classificação , Clostridiales/genética , Clostridiales/metabolismo , Firmicutes/classificação , Firmicutes/genética , Firmicutes/metabolismo , Halobacteriales/classificação , Halobacteriales/genética , Halobacteriales/metabolismo , Conformação de Ácido Nucleico , Filogenia , RNA Arqueal/química , RNA Arqueal/metabolismo , RNA Bacteriano/química , RNA Bacteriano/metabolismo , RNA Ribossômico 5S/química , RNA Ribossômico 5S/metabolismo , Thermoanaerobacterium/classificação , Thermoanaerobacterium/genética , Thermoanaerobacterium/metabolismo
5.
Int J Mol Sci ; 21(21)2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33171852

RESUMO

Growing interest in hypertension-one of the main factors characterizing the cardiometabolic syndrome (CMS)-and anti-hypertensive drugs raised from the emergence of a new coronavirus, SARS-CoV-2, responsible for the COVID19 pandemic. The virus SARS-CoV-2 employs the Angiotensin-converting enzyme 2 (ACE2), a component of the RAAS (Renin-Angiotensin-Aldosterone System) system, as a receptor for entry into the cells. Several classes of synthetic drugs are available for hypertension, rarely associated with severe or mild adverse effects. New natural compounds, such as peptides, might be useful to treat some hypertensive patients. The main feature of ACE inhibitory peptides is the location of the hydrophobic residue, usually Proline, at the C-terminus. Some already known bioactive peptides derived from marine resources have potential ACE inhibitory activity and can be considered therapeutic agents to treat hypertension. Peptides isolated from marine vertebrates, invertebrates, seaweeds, or sea microorganisms displayed important biological activities to treat hypertensive patients. Here, we reviewed the anti-hypertensive activities of bioactive molecules isolated/extracted from marine organisms and discussed the associated molecular mechanisms involved. We also examined ACE2 modulation in sight of SARS2-Cov infection prevention.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Hipertensivos/farmacologia , Antivirais/química , Hipertensão/tratamento farmacológico , Glicoproteína da Espícula de Coronavírus/química , Enzima de Conversão de Angiotensina 2/química , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Anti-Hipertensivos/uso terapêutico , Antivirais/farmacologia , COVID-19/prevenção & controle , Peixes/metabolismo , Halobacteriales/química , Humanos , Simulação de Acoplamento Molecular , Oncorhynchus keta/metabolismo , Peptídeos/química , Peptídeos/farmacologia , SARS-CoV-2/efeitos dos fármacos , Pepinos-do-Mar/química , Undaria/química
6.
Extremophiles ; 24(5): 787-796, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32743715

RESUMO

Salted and ripened fish foods are susceptible to cause histamine poisoning. The present study focuses on microbial histamine degradation from high salted fermented fishery products to deepen our understanding about this new and growing field of research. As a result of this first study related to salted-ripened anchovies (Engraulis anchoita), fifty seven moderate and extreme halophilic microbial isolates from salt and salted-ripened anchovy processes were characterized in terms of their phenotype and histamine-degrading capacity. Only 7%-4 isolates-were able to degrade histamine. None of the histamine-degrading isolates presented proteolytic and/or lipolytic activity. One of them designated A18 was chemotactic toward histamine, an interesting property not previously reported for that chemoattractant. However, the S18 and A18 isolates, genotypically identified as Halobacterium sp. and Halomonas sp. respectively, produced indole and/or H2S, both undesirable characteristics associated to off-flavors occurrence. On the other hand, A28 and S20, identified as Halovibrio sp. and Halobacterium sp. respectively, presented desirable properties, such as cytochrome oxidase and catalase activity, and non-production of H2S and indole. These strains also showed characteristics previously reported as dominant in the ripened stage. The results are promising, and A28 and S20 may have the desirable features to improve the anchovy salting-ripening process.


Assuntos
Halobacteriales , Halomonas , Histamina , Animais , Aquicultura , Peixes , Histamina/metabolismo , RNA Ribossômico 16S , Cloreto de Sódio
7.
Int J Syst Evol Microbiol ; 70(9): 4978-4985, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32783801

RESUMO

A halophilic archaeon named strain LR21T was isolated from a salt mine in Yunnan Province, PR China. Cells were spherical, Gram-stain-negative and motile. Strain LR21T grew at 20-50 °C (optimum, 42 °C), with 8-30 % (w/v) NaCl (optimum, 23 %) and at pH 5.5-9.5 (optimum, pH 7.5-8.5). Mg2+ was not required for growth. The major polar lipid profile comprised phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol sulfate. Strain LR21T had two dissimilar 16S rRNA genes (rrnA and rrnB) and they were closely related to Halomicroarcula limicola YGHS32T, Hma. pellucida BNERC31T and Hma. salina YGHS18T with sequence similarities of 95.3-99.0, 93.0-96.2 and 93.2-95.9 %, respectively, and much lower values to other members. The rpoB' gene sequence similarities between strain LR21T and Hma. limicola YGHS32T, Hma. pellucida BNERC31T and Hma. salina YGHS18T were 95.2, 91.2 and 91.2 % respectively. The values of average nucleotide identity (ANI) and average amino-acid identity (AAI) between strain LR21T and Hma. limicola YGHS32T, were 89.0 and 90.1 %, respectively. DNA relatedness between strains LR21T and Hma. limicola YGHS32T determined by in silico DNA-DNA hybridization was 36.8 %. Values of ANI and AAI between strain LR21T and other members in the genus Halomicroarcula were far below 95 % and the DNA-DNA relatedness values between strain LR21T and its close relatives were much lower than 70 %, which is far below the boundary for delineation of a new species prokaryote. The DNA G+C content of strain LR21T was 62.0 mol% (genome). The results suggested that strain LR21T represents a novel species of the genus Halomicroarcula, for which the name Halomicroarcula amylolytica sp. nov. is proposed. The type strain is LR21T (=CGMCC 1.13611T=NBRC 113588T).


Assuntos
Halobacteriales/classificação , Filogenia , Composição de Bases , China , DNA Arqueal/genética , Ácidos Graxos/química , Genes Arqueais , Halobacteriales/isolamento & purificação , Mineração , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio
8.
Int J Syst Evol Microbiol ; 70(5): 3399-3405, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32374250

RESUMO

The genus Natronolimnobius, currently including four species, is a member of the order Natrialbales, class Halobacteria, and consists of obligately alkaliphilic and extremely halophilic members found exclusively in highly alkaline hypersaline soda lakes. The species were classified into this genus mostly based on phylogenetic analysis of the 16S rRNA gene. However, a more advanced phylogenomic reconstruction based on 122 conserved single-copy archaeal protein markers clearly indicates a polyphyletic origin of the species included into this genus, thus warranting its reclassification into three separate genera. We therefore propose to transfer Nlb. innermongolicus (type strain N-1311) to a new genus Natronolimnohabitans as Nlh. innermongolicus comb. nov. and to transfer Nlb. aegyptiacus (type strain JW/NM-HA 15) and Nlb. sulfurireducens (type strain AArc1) to a new genus Natrarchaeobaculum as Nbl. aegyptiacum comb. nov. and Nbl. sulfurireducens comb. nov. The phylogenomic differentiation of these four species is also supported by the ANI/AAI distances and unique phenotypes. The most important physiological differences includes a previously unreported ability for cellulose and xylan utilization in Nlb. baerhuensis, thermophily in Nbl. aegyptiacus and anaerobic sulfur respiration in Nbl. sulfurireducens. We further present an emended description of Natronolimnobius baerhuensis.


Assuntos
Halobacteriaceae/classificação , Halobacteriales/classificação , Filogenia , Composição de Bases , DNA Arqueal/genética , Lagos/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
9.
Biosci. j. (Online) ; 36(3): 1024-1031, 01-05-2020. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1147195

RESUMO

Halophilic bacteria are microorganisms that grow optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents. Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively. Two bacterial isolates i.e. Bacillus glycinifermentans S3 and Enterobacter cloacae W1were found to possess significant amylase and protease activity.


Bactérias halofílicas são microrganismos que crescem de maneira ideal na presença de uma concentração muito alta de cloreto de sódio. Halófilos são fontes vitais de várias enzimas, incluindo hidrolases, que são muito estáveis e cataliticamente altamente eficientes em alta concentração de sal e outras condições extremas, como alta temperatura, pH e presença de solventes orgânicos. Várias hidrolases como amilases, proteases e lipases foram obtidas a partir de bactérias halofílicas e são comumente usadas para várias aplicações industriais. Iniciamos uma triagem para isolar e caracterizar as bactérias halofílicas do Mar Vermelho, que é um dos corpos de água mais salgados do mundo. Amostras de água e solo, coletadas na costa do Mar Vermelho, Jeddah, na Arábia Saudita, foram examinadas quanto ao isolamento de bactérias halofílicas. Foram obtidos dez isolados bacterianos, caracterizados por testes bioquímicos e seqüenciamento do gene 16S rRNA. As bactérias produtoras de hidrolase entre os isolados foram triadas por ensaio em placa em placas de amido e ágar de gelatina para amilase e protease, respectivamente. Verificou-se que dois isolados bacterianos, isto é, Bacillus glycinifermentans S3 e Enterobacter cloacae W1, possuíam significativa atividade de amilase e protease.


Assuntos
Peptídeo Hidrolases , Halobacteriales , Salinidade , Amilases , Hidrolases
10.
Genes (Basel) ; 11(4)2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32252451

RESUMO

Halophilic microorganisms are found in all domains of life and thrive in hypersaline (high salt content) environments. These unusual microbes have been a subject of study for many years due to their interesting properties and physiology. Study of the genetics of halophilic microorganisms (from gene expression and regulation to genomics) has provided understanding into mechanisms of how life can occur at high salinity levels. Here we highlight recent studies that advance knowledge of biological function through study of the genetics of halophilic microorganisms and their viruses.


Assuntos
Archaea/genética , Halobacteriales/genética , Tolerância ao Sal/genética , Archaea/metabolismo , Cloreto de Sódio/metabolismo
11.
Int J Syst Evol Microbiol ; 70(4): 2879-2887, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32213254

RESUMO

A novel Gram-stain-negative, aerobic and rod-shaped halophilic archaeon, designated HD8-45T, was isolated from the red brine of salted brown alga Laminaria produced at Dalian, PR China. According to the results of 16S rRNA gene and rpoB' gene sequence comparisons, strain HD8-45T showed the highest sequence similarity to the corresponding genes of Salinirussus salinus YGH44T (95.1 and 85.2 % similarities, respectively), Halovenus aranensis EB27T (91.2 and 86.0 % similarities, respectively). The low sequence similarity and the phylogeny implied the novel generic status of strain HD8-45T. Genomic relatedness analyses showed that strain HD8-45T were clearly distinguished from other species in the order Halobacteriales, with average nucleotide identity, amino acid identity and in silico DNA-DNA hybridization values not more than 75.1, 65.6 and 21.5 %. The polar lipid pattern contained phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, two major glycolipids and two minor glycolipids. The two major glycolipids and a minor glycolipid were chromatographically identical to disulfated mannosyl glucosyl diether, sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. The major respiratory quinones were menaquinone MK-8 and MK-8(H2). The DNA G+C content was 62.0 mol% (Tm) and 61.9 mol% (genome). All these results showed that strain HD8-45T represents a novel species of a new genus in the order Halobacteriales, for which the name Salinibaculum litoreum gen. nov., sp. nov. is proposed. The type strain of Salinibaculum litoreum is HD8-45T (=CGMCC 1.15328T=JCM 31107T).


Assuntos
Halobacteriales/classificação , Laminaria/microbiologia , Filogenia , Composição de Bases , China , DNA Arqueal/genética , Genes Arqueais , Glicolipídeos/química , Halobacteriales/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Sais , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
12.
FEMS Microbiol Lett ; 366(18)2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31742601

RESUMO

Adaptive strategies responsible for heavy metal tolerance were explored in the extremely halophilic archaeon Halomicrobium mukohataei DSM 12286. The tested strain was seemingly able to overcome silver-induced oxidative stress (assessed by malondialdehyde quantification, catalase assay and total antioxidant capacity measurement) mainly through non-enzymatic antioxidants. Energy dispersive spectrometry analysis illustrated the presence of colloidal silver in Hmc. mukohataei cultures exposed to AgNO3. Bright-field and transmission electron microscopy images, as well as dynamic light scattering analysis, demonstrated the presence of intracellular nanoparticles, mostly spherical, within a size range of 20-100 nm. As determined by the zeta potential measurement, the biosynthesized nanoparticles were highly stable, with a negative surface charge. Our research is a first attempt in the systematic study of the oxidative stress and intracellular silver nanoparticle accumulation, generated by exposure to silver ions, in members of Halobacteria class, thus broadening our knowledge on mechanisms supporting heavy metal tolerance of microbial cells living under saline conditions.


Assuntos
Adaptação Fisiológica , Halobacteriaceae/efeitos dos fármacos , Halobacteriales/efeitos dos fármacos , Nitrato de Prata/toxicidade , Catalase/metabolismo , Halobacteriaceae/metabolismo , Halobacteriaceae/ultraestrutura , Halobacteriales/metabolismo , Halobacteriales/ultraestrutura , Malondialdeído/metabolismo , Testes de Sensibilidade Microbiana , Nanopartículas/química , Nanopartículas/ultraestrutura , Estresse Oxidativo , Tamanho da Partícula , Prata/química , Prata/metabolismo , Eletricidade Estática
13.
FEMS Microbiol Ecol ; 95(12)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31730173

RESUMO

Archaea have been the most overlooked and enigmatic of the three domains of life for decades. Knowledge of key ecological interactions, such as trophic links between this domain and higher level organisms, remains extremely limited. The co-occurrence of halophilic Archaea (haloarchaea) and the non-selective filter feeder, brine shrimp Artemia under the unique ecological characteristics of hypersaline aquatic environments, constitutes an excellent opportunity to further unravel the ecological role of the Archaea domain as a source of food to zooplankton metazoans. In the present study, we combine the use of haloarchaea biomass assimilation experiments using 13C isotope as tracer, with gnotobiotic Artemia culture tests using haloarchaea mono-diets, to investigate potential trophic links between the organisms. Our results demonstrated the ability of Artemia to assimilate nutrients from mono-diets of haloarchaea biomass in order to survive and grow, providing clear indications that archivory may occur in hypersaline aquatic environments. Additionally, our study highlights the use of stable isotopes labelling as a potential tool to further disentangle the specific pathways by which archaeal cellular constituents are digested by consumers.


Assuntos
Artemia/microbiologia , Dieta , Halobacteriales/fisiologia , Animais , Biomassa , Isótopos de Carbono , Salinidade , Zooplâncton/metabolismo
14.
J Microbiol ; 57(11): 997-1002, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31659686

RESUMO

A Gram-stain-positive, rod-shaped, alkalitolerant, and halophilic bacterium-designated as strain NKC3-5T-was isolated from kimchi that was collected from the Geumsan area in the Republic of Korea. Cells of isolated strain NKC3-5T were 0.5-0.7 µm wide and 1.4-2.8 µm long. The strain NKC3-5T could grow at up to 20.0% (w/v) NaCl (optimum 10%), pH 6.5-10.0 (optimum pH 9.0), and 25-40°C (optimum 35°C). The cells were able to reduce nitrate under aerobic conditions, which is the first report in the genus Salicibibacter. The genome size and genomic G + C content of strain NKC3-5T were 3,754,174 bp and 45.9 mol%, respectively; it contained 3,630 coding sequences, 16S rRNA genes (six 16S, five 5S, and five 23S), and 59 tRNA genes. Phylogenetic analysis based on 16S rRNA showed that strain NKC3-5T clustered with bacterium Salicibibacter kimchii NKC1-1T, with a similarity of 96.2-97.6%, but formed a distinct branch with other published species of the family Bacillaceae. In addition, OrthoANI value between strain NKC3-5T and Salicibibacter kimchii NKC1-1T was far lower than the species demarcation threshold. Using functional genome annotation, the result found that carbohydrate, amino acid, and vitamin metabolism related genes were highly distributed in the genome of strain NKC3-5T. Comparative genomic analysis revealed that strain NKC3-5T had 716 pan-genome orthologous groups (POGs), dominated with carbohydrate metabolism. Phylogenomic analysis based on the concatenated core POGs revealed that strain NKC3-5T was closely related to Salicibibacter kimchii. The predominant polar lipids were phosphatidylglycerol and two unidentified lipids. Anteiso-C15:0, iso-C17:0, anteiso-C17:0, and iso-C15:0 were the major cellular fatty acids, and menaquinone-7 was the major isoprenoid quinone present in strain NKC3-5T. Cell wall peptidoglycan analysis of strain NKC3-5T showed that meso-diaminopimelic acid was the diagnostic diamino acid. The phephenotypic, genomic, phylogenetic, and chemotaxonomic properties reveal that the strain represents a novel species of the genus Salicibibacter, for which the name Salicibibacter halophilus sp. nov. is proposed, with the type strain NKC3-5T (= KACC 21230T = JCM 33437T).


Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Filogenia , Bacillaceae/genética , Bacillaceae/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/metabolismo , Ácidos Graxos/química , Genes Bacterianos/genética , Genômica , Halobacteriales , Concentração de Íons de Hidrogênio , Peptidoglicano/química , RNA Ribossômico 16S/genética , República da Coreia , Tolerância ao Sal , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo , Vitamina K 2/análogos & derivados , Vitamina K 2/química , Sequenciamento Completo do Genoma
15.
J Microbiol Methods ; 166: 105704, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31494180

RESUMO

Industrial biotechnology aims to compete as a stronger alternative ensuring environmental friendly microbial-based production that seeks to curb the predicament of pollution. However, the high cost of bioprocessing is a severe drawback, and therefore, new approaches must be developed to overcome this challenge. Halophiles have shown potentials of overcoming this challenge and are of much preference for unsterile and continuous contamination-free bioprocess due to their unique ability to grow under harsh environmental conditions. Recent advances in genetic manipulations have been established to better the performance of halophiles for industrial applications. Many researchers produced various products such as polyhydroxyalkanoates (PHA), ectoines, biosurfactants, and antioxidants using halophiles, and further efforts have been established to develop halophiles as the foundation for low-cost bioprocess. This paper provides a useful reference for researchers on the merits, drawbacks, achievements, and application of halophiles for bioproduction.


Assuntos
Halobacteriales/metabolismo , Microbiologia Industrial/métodos , Poli-Hidroxialcanoatos/biossíntese
16.
Int J Syst Evol Microbiol ; 69(9): 2662-2673, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31166158

RESUMO

Eight pure cultures of alkaliphilic haloaloarchaea capable of growth by dissimilatory sulfur reduction (previously only shown for neutrophilic haloarchaea) were isolated from hypersaline alkaline lakes in different geographic locations. These anaerobic enrichments, inoculated with sediments and brines, used formate, butyrate and peptone as electron donors and elemental sulfur as an electron acceptor 4 M total Na+ and at pH 9-10. According to 16S rRNA gene sequencing, the isolates fell into two distinct groups. A major group, comprising seven obligate alkaliphilic isolates from highly alkaline soda lakes, represents a new species-level branch within the genus Natronolimnobius (order Natrialbales), while a single moderately alkaliphilic isolate from the less alkaline Searles Lake forms a novel genus-level lineage within the order Haloferacales. The cells of the isolates are either flat rods or coccoid. They are facultative anaerobes using formate or H2 (in the presence of acetate or yeast extract as carbon source), C4-C9 fatty acids or peptone (the major group) as electron donors and either sulfur or DMSO (the major group) as electron acceptors. Aerobic growth is only possible with organic acids and peptone-yeast extract. All isolates are extreme halophiles, growing optimally at 4 M total Na+. On the basis of their unique physiological properties and distinct phylogeny, we propose that the seven isolates from the soda lakes are placed into a novel species, Natronolimnobiussulfurireducens sp. nov. (type strain AArc1T=JCM 30663T=UNIQEM U932T), and the Searles Lake isolate, AArc-SlT, into a new genus and species Halalkaliarchaeum desulfuricum (=JCM 30664T=UNIQEM U999T).


Assuntos
Halobacteriaceae/classificação , Halobacteriales/classificação , Lagos/microbiologia , Filogenia , Salinidade , Composição de Bases , California , Ácidos Graxos/química , Halobacteriaceae/isolamento & purificação , Halobacteriales/isolamento & purificação , Pigmentação , RNA Ribossômico 16S/genética , Federação Russa , Sais , Análise de Sequência de DNA , Enxofre/metabolismo
17.
Genes (Basel) ; 10(5)2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31137536

RESUMO

Salt mines are among the most extreme environments as they combine darkness, low nutrient availability, and hypersaline conditions. Based on comparative genomics and transcriptomics, we describe in this work the adaptive strategies of the true halophilic fungus Aspergillus salisburgensis, found in a salt mine in Austria, and compare this strain to the ex-type halotolerant fungal strain Aspergillus sclerotialis. On a genomic level, A. salisburgensis exhibits a reduced genome size compared to A. sclerotialis, as well as a contraction of genes involved in transport processes. The proteome of A. sclerotialis exhibits an increased proportion of alanine, glycine, and proline compared to the proteome of non-halophilic species. Transcriptome analyses of both strains growing at 5% and 20% NaCl show that A. salisburgensis regulates three-times fewer genes than A. sclerotialis in order to adapt to the higher salt concentration. In A. sclerotialis, the increased osmotic stress impacted processes related to translation, transcription, transport, and energy. In contrast, membrane-related and lignolytic proteins were significantly affected in A. salisburgensis.


Assuntos
Aspergillus/genética , Tolerância ao Sal/genética , Aspergillus/metabolismo , Áustria , Biologia Computacional/métodos , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica , Genoma , Genômica/métodos , Halobacteriales/genética , Pressão Osmótica/fisiologia , Filogenia , Proteoma/genética , Cloreto de Sódio/metabolismo , Transcriptoma
18.
J Microbiol Biotechnol ; 29(5): 765-775, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-30982319

RESUMO

A new α-amylase-encoding gene (amySL3) of glycoside hydrolase (GH) family 13 was identified in soda lake isolate Alkalibacterium sp. SL3. The deduced AmySL3 shares high identities (82-98%) with putative α-amylases from the genus Alkalibacterium, but has low identities (<53%) with functionally characterized counterparts. amySL3 was successfully expressed in Escherichia coli, and the recombinant enzyme (rAmySL3) was purified to electrophoretic homogeneity. The optimal temperature and pH of the activity of the purified rAmySL3 were determined to be 45°C and pH 7.5, respectively. rAmySL3 was found to be extremely halophilic, showing maximal enzyme activity at a nearly saturated concentration of NaCl. Its thermostability was greatly enhanced in the presence of 4 M NaCl, and it was highly stable in 5 M NaCl. Moreover, the enzyme did not require calcium ions for activity, and was strongly resistant to a range of surfactants and hydrophobic organic solvents. The major hydrolysis products of rAmySL3 from soluble starch were maltobiose and maltotriose. The high ratio of acidic amino acids and highly negative electrostatic potential surface might account for the halophilic nature of AmySL3. The extremely halophilic, calcium-independent, and surfactant-resistant properties make AmySL3 a promising candidate enzyme for both basic research and industrial applications.


Assuntos
Cálcio/efeitos adversos , Carnobacteriaceae/enzimologia , Halobacteriales , Tensoativos/efeitos adversos , alfa-Amilases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carnobacteriaceae/genética , Clonagem Molecular , DNA Bacteriano , Ensaios Enzimáticos , Estabilidade Enzimática , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Concentração de Íons de Hidrogênio , Lagos/microbiologia , Estrutura Terciária de Proteína , Proteínas Recombinantes/genética , Alinhamento de Sequência , Análise de Sequência de Proteína , Cloreto de Sódio , Solventes/efeitos adversos , Amido/metabolismo , Especificidade por Substrato , Temperatura , alfa-Amilases/efeitos dos fármacos , alfa-Amilases/genética
19.
Mol Biol Rep ; 46(3): 3275-3286, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30993582

RESUMO

It was confirmed that several enzymes have anti-cancer activity. The enzymes L-asparaginase, L-glutaminase, and L-arginase were chosen according to amino acids starvation in cancer cells and screened in halophilic and halotolerant bacteria, given probably less immunological reactions of halophilic or halotolerant enzymes in patients. Out of 110 halophilic and halotolerant strains, isolated from different saline environments in Iran and screened, some could produce a variety of anticancer enzymes. A total of 29, 4, and 2 strains produced L-asparaginase, L-glutaminase, and L-arginase, respectively. According to the phenotypic characteristics and partial 16S rRNA gene sequence analysis, the positive strains-strains with the ability to produce these anticancer enzymes-were identified as the members of the genera: Bacillus, Dietzia, Halobacillus, Rhodococcus, Paenibacillus and Planococcus as Gram-positive bacteria and Pseudomonas, Marinobacter, Halomonas, Idiomarina, Vibrio and Stappia as Gram-negative bacteria. The production of anticancer enzymes was mostly observed in the rod-shaped Gram-negative isolates, particularly in the members of the genera Halomonas and Marinobacter. Most of the enzymes were produced in the stationary phase of growth and the maximum enzyme activity was experienced in strain GBPx3 (Vibrio sp.) for L-asparaginase at 1.0 IU/ml, strain R2S25 (Rhodococcus sp.) for L-glutaminase at 0.6 IU/ml and strain GAAy3 (Planococcus sp.) for L-arginase at 3.1 IU/ml. The optimum temperature and pH for L-asparaginase and L-glutaminase activities in selected strains were similar to the physiological conditions of human body and the enzymes could tolerate NaCl up to 7.5% concentration.


Assuntos
Bactérias/genética , Tolerância ao Sal/genética , Antineoplásicos , Asparaginase/metabolismo , DNA Bacteriano/genética , Halobacteriales/genética , Irã (Geográfico) , Filogenia , RNA Ribossômico 16S/genética , Solução Salina , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo
20.
Extremophiles ; 23(3): 359-365, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30810807

RESUMO

The use of stable isotope (SI) labelling and tracing of live diets is currently considered one of the most comprehensive tools to detect their uptake and assimilation by aquatic organisms. These techniques are indeed widely used in nutritional studies to follow the fate of specific microbial dietary components, unraveling trophic interactions. Nevertheless, to the current date our understanding of aquatic trophic relationships has yet to include a whole domain of life, the Archaea. The aim of the present research was, therefore, to describe a halophilic Archaea (haloarchaea) labelling procedure, using the SI 13C and 15N, to enable the application of SI tracing in future studies of haloarchaea consumption by aquatic metazoans. To this end, three 13C enriched carbon sources and two 15N enriched nitrogen sources were tested as potential labels to enrich cells of three haloarchaea strains when supplemented to the culture medium. Our overall results indicate 13C-glycerol as the most effective carbon source to achieve an efficient 13C enrichment in haloarchaea cells, with Δδ13C values above 5000‰ in all tested haloarchaea strains. As for 15N enriched nitrogen sources, both (15NH4)2SO4 and 15NH4Cl seem to be readily assimilated, also resulting in efficient 15N enrichment in haloarchaea cells, with Δδ15N values higher than 20,000‰. We believe that the proposed methodology will allow for the use of SI labelled haloarchaea biomass in feeding tests, potentially providing unambiguous confirmation of the assimilation of haloarchaea biomass by aquatic metazoans.


Assuntos
Biomassa , Isótopos de Carbono/química , Cadeia Alimentar , Halobacteriales/crescimento & desenvolvimento , Marcação por Isótopo/métodos , Isótopos de Nitrogênio/química , Animais
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