RESUMO
In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH.
Assuntos
Biodiversidade , Halobacteriaceae/classificação , Halobacteriaceae/isolamento & purificação , Salinidade , Microbiologia do Solo , Solo/química , Análise por Conglomerados , DNA Arqueal/química , DNA Arqueal/genética , Concentração de Íons de Hidrogênio , México , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de SequênciaRESUMO
Three halophilic archaeal strains, MH2-243-1(T), MH2-93-1 and MH2-91-1 were isolated from commercial salt samples from Japan, Australia, and Bolivia. Strain MH2-243-1(T) was able to grow in the presence of 12-30% (w/v) NaCl (optimum, 18% NaCl), at pH 4.5-7.0 (optimum, pH 6.0) and at 20-60 °C (optimum, 40 °C). Strains MH2-91-1 and MH2-93-1 grew in slightly different ranges. The orthologous 16S rRNA gene sequences of the three strains were almost identical (99.8-99.9% similarities), and the closest relative was Salarchaeum japonicum JCM 16327(T) with 94.2-94.3% 16S rRNA gene sequence similarities, followed by strains of members of the closely related genera Halobacterium and Halarchaeum . The RNA polymerase subunit B' gene (rpoB') sequence also showed the highest similarity (86.6%) to that of Salarchaeum japonicum JCM 16327(T). The DNA G+C contents of strains MH2-243-1(T), MH2-93-1 and MH2-91-1 were 68.5, 68.8 and 68.3 mol%, respectively. DNA-DNA relatedness values amongst the three strains were 97-99%. The polar lipids of the three strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and at least seven unidentified glycolipids. The polar lipid composition differed from those of Salarchaeum japonicum and species of the genera Halobacterium and Halarchaeum . Based on the phenotypic and phylogenetic analyses, it is proposed that the isolates represent a novel species of a new genus, for which the name Halocalculus aciditolerans gen. nov., sp. nov. is proposed. The type strain of the type species is MH2-243-1(T) (â=âJCM 19596(T)â=KCTC 4149(T)) isolated from solar salt produced in Japan. MH2-93-1 (â=âJCM 19595) and MH2-91-1 (â=âJCM 19594) are additional strains of the type species.
Assuntos
Halobacteriaceae/classificação , Filogenia , Cloreto de Sódio , Austrália , Bolívia , DNA Arqueal/genética , Genes Arqueais , Glicolipídeos/química , Halobacteriaceae/genética , Halobacteriaceae/isolamento & purificação , Japão , Lipídeos/química , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A new haloalkaliphilic archaeon, strain B4(T), was isolated from the former lake Texcoco in Mexico. The cells were Gram-negative, pleomorphic-shaped, pink to red pigmented and aerobic. Strain B4(T) required at least 2.5 M NaCl for growth, with optimum growth at 3.4 M NaCl. It was able to grow over a pH range of 7.5-10.0 and temperature of 25-50 °C, with optimal growth at pH 9 and 37 °C. Cells are lysed in hypotonic treatment with less than 1.3 M NaCl. The major polar lipids of strain B4(T) were phosphatidylglycerol and methyl-phosphatidylglycerophosphate. Phospholipids were detected, but not glycolipids. The nucleotide sequence of the 16S rRNA gene revealed that the strain B4(T) was phylogenetically related to members of the genus Natronorubrum. Sequence similarity with Natronorubrum tibetense was 96.28 %, with Natronorubrum sulfidifaciens 95.06 % and Natronorubrum sediminis 94.98 %. The G+C content of the DNA was 63.3 mol%. The name of Natronorubrum texcoconense sp. nov. is proposed. The type strain is B4(T) (=CECT 8067(T) = JCM 17497(T)).
Assuntos
Halobacteriaceae/classificação , Lagos/microbiologia , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Sequência de Bases , DNA Arqueal/genética , Genes de RNAr , Halobacteriaceae/genética , Halobacteriaceae/isolamento & purificação , Concentração de Íons de Hidrogênio , México , Dados de Sequência Molecular , Fosfolipídeos/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio , TemperaturaRESUMO
Two extremely halophilic archaea, strains MGY-184(T) and MGY-205, were isolated from sea salt produced in Japan and rock salt imported from Bolivia, respectively. Both strains were pleomorphic, non-motile, Gram-negative and required more than 5â% (w/v) NaCl for growth, with optimum at 9-12â%, in the presence of 2â% (w/v) MgCl2â.â6H2O. In the presence of 18â% (w/v) MgCl2â.â6H2O, however, both strains showed growth even at 1.0â% (w/v) NaCl. Both strains possessed two 16S rRNA genes (rrnA and rrnB), and they revealed closest similarity to Halobaculum gomorrense JCM 9908(T), the single species with a validly published name of the genus Halobaculum, with similarity of 97.8â%. The rrnA and rrnB genes of both strains were 100â% similar. The rrnA genes were 97.6â% similar to the rrnB genes in both strains. DNA G+C contents of strains MGY-184(T) and MGY-205 were 67.0 and 67.4 mol%, respectively. Polar lipid analysis revealed that the two strains contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester derived from C20C20 archaeol. The DNA-DNA hybridization value between the two strains was 70â% and both strains showed low levels of DNA-DNA relatedness (48-50â%) with Halobaculum gomorrense JCM 9908(T). Physiological and biochemical characteristics allowed differentiation of strains MGY-184(T) and MGY-205 from Halobaculum gomorrense JCM 9908(T). Therefore, strains MGY-184(T) and MGY-205 represent a novel species of the genus Halobaculum, for which the name Halobaculum magnesiiphilum sp. nov. is proposed; the type strain is MGY-184(T) (â=âJCM 17821(T)â=âKCTC 4100(T)).
Assuntos
Halobacteriaceae/classificação , Filogenia , Cloreto de Sódio , Composição de Bases , Bolívia , DNA Arqueal/genética , Halobacteriaceae/genética , Halobacteriaceae/isolamento & purificação , Japão , Magnésio/metabolismo , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fosfatidilgliceróis/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Two extremely halophilic archaea, strains Al-5(T) and K-1, were isolated from Lake Tebenquiche (Atacama Saltern, Chile) and Ezzemoul sabkha (Algeria), respectively. Cells of the two strains were short-rod-shaped and Gram-negative; colonies were orange-pigmented. They grew optimally at 37-40 degrees C and pH 7.0-7.5 in the presence of 25 % (w/v) NaCl. Magnesium was not required. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerophosphate methyl ester, the absence of phosphatidylglycerosulfate, and the presence of sulfated diglycosyl diether and diether diglycosyl as the sole glycolipids. DNA G+C contents of strains Al-5(T) and K-1 were 52.4 and 52.9 mol% (T(m) method), respectively. 16S rRNA gene sequence comparison with database sequences showed that strains Al-5(T) and K-1 were most closely related to Halomicrobium mukohataei DSM 12286(T) (similarities of 97.5 and 96.9 %, respectively). DNA-DNA hybridization indicated that strains Al-5(T) and K-1 were members of a single species. However, DNA-DNA relatedness to Halomicrobium mukohataei was 55.7+/-2.5 %. A comparative analysis of phenotypic characteristics and DNA-DNA hybridization between the isolates and Halomicrobium mukohataei DSM 12286(T) supported the conclusion that Al-5(T) and K-1 represent a novel species within the genus Halomicrobium, for which the name Halomicrobium katesii sp. nov. is proposed. The type strain is Al-5(T) (=CECT 7257(T)=DSM 19301(T)).
Assuntos
Água Doce/microbiologia , Halobacteriaceae/classificação , Halobacteriaceae/genética , Argélia , Técnicas de Tipagem Bacteriana , Composição de Bases , Chile , DNA Arqueal/genética , Genes Arqueais , Genes de RNAr , Glicolipídeos/química , Halobacteriaceae/química , Halobacteriaceae/isolamento & purificação , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio , Microbiologia da ÁguaRESUMO
Molecular techniques were used to compare the compositions of the bacterial communities of the 2 following lagoons from the former soda Texcoco Lake, Mexico: the restored Facultativa lagoon and the Nabor Carrillo lagoon. Ribosomal intergenic spacer analysis (RISA) revealed that bacterial communities of the 2 lagoons were different and presented a relatively low diversity. Clone libraries of 16S rDNA genes were constructed, and significant phylotypes were distinguished by restriction fragment length polymorphism (RFLP). A representative clone from each phylotype was partially sequenced. Molecular identification and phylogenetic analyses based on ribosomal sequences revealed that the Facultativa lagoon harbored mainly gamma- and beta-Proteobacteria, low G+C Gram-positive bacteria, and several members of the Halobacteriaceae family of archaea. The Nabor Carrillo lagoon mainly included typical halophilic and alkaliphilic low G+C Gram-positive bacteria, gamma-Proteobacteria, and beta-Proteobacteria similar to those found in other soda lakes. Several probably noncultured new bacterial species were detected. Three strains were isolated from the Nabor Carrillo lagoon, their partial 16S rDNA sequences were obtained. On this basis, they were identified as Halomonas magadiensis (H1), Halomonas eurihalina (H2), and Staphylococcus sciuri (H3). This is the first study that uses molecular techniques to investigate potential genetic diversity in the Texcoco lakes. In this preliminary evaluation, we infer the presence of alkalophilic, halophilic, or haloalkaliphilic bacteria potentially useful for biotechnology.
Assuntos
Archaea/classificação , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/isolamento & purificação , Microbiologia da Água , Archaea/genética , Bactérias/genética , Betaproteobacteria/classificação , Betaproteobacteria/isolamento & purificação , Biodiversidade , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , DNA Espaçador Ribossômico/isolamento & purificação , Ecossistema , Gammaproteobacteria/classificação , Gammaproteobacteria/isolamento & purificação , Genes de RNAr , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Halobacteriaceae/classificação , Halobacteriaceae/isolamento & purificação , Halomonas/classificação , Halomonas/isolamento & purificação , México , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Staphylococcus/classificação , Staphylococcus/isolamento & purificaçãoRESUMO
A novel extremely halophilic archaeon was isolated from Lake Tebenquiche, situated in the northern part of the Atacama Saltern, Chile. The cells of these micro-organisms were mostly irregularly disc-shaped. They grew in medium containing saturated concentrations of NaCl and did not require magnesium for optimal growth. The polar lipid composition revealed the presence of mannosyl-2-sulfate-(1-4)-glycosyl-archaeol, the main glycolipid of the genus Halorubrum, and two new glycolipids. The G+C content of the DNA was 63.2 mol%. Phylogenetic analysis of the 16S rRNA gene placed strain ALT6-92T within the Halorubrum cluster. The low DNA-DNA hybridization value justified classification in a new species for which the name Halorubrum tebenquichense sp. nov. is proposed. The type strain is ALT6-92T (= CECT 5317T = DSM 14210T).
Assuntos
Água Doce/microbiologia , Halobacteriaceae/classificação , Halobacteriaceae/crescimento & desenvolvimento , Cloreto de Sódio , Composição de Bases , Chile , DNA Ribossômico/análise , Halobacteriaceae/genética , Halobacteriaceae/isolamento & purificação , Lipídeos/análise , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A novel extremely halophilic archaeon was isolated from the solar salterns of Cabo Rojo, Puerto Rico. The organism is very pleomorphic, motile and requires at least 8% (w/v) NaCl to grow. Polar lipid composition revealed the presence of a novel non-sulfate-containing glycolipid and the absence of the glycerol diether analogue of phosphatidylglycerosulfate. The G + C content of the DNA is 59 mol%. On the basis of 16S rRNA sequence data, the new isolate cannot be classified in one of the recognized genera, but occupies a position that is distantly related to the genus Haloferax. All these features justify the creation of a new genus and a new species for the family Halobacteriaceae, order Halobacteriales. The name Halogeometricum borinquense gen. nov., sp. nov. is proposed. The type strain is ATCC 700274T.
Assuntos
Halobacteriaceae/classificação , Halobacteriaceae/isolamento & purificação , Composição de Bases , DNA Arqueal/química , DNA Ribossômico/química , Halobacteriaceae/fisiologia , Halobacteriaceae/ultraestrutura , Lipídeos/análise , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Porto Rico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Terminologia como Assunto , Microbiologia da ÁguaRESUMO
Strains arg-1T (T = type strain) and arg-2T, two new strains of extremely halophilic archaea, were isolated from the soils of the Argentine salt flats. The taxonomic features of arg-1T were similar to, but distinct from, those of the type strain of Haloarcula vallismortis and other Haloarcula species. On the 16S rRNA phylogenetic tree, strain arg-1T formed a cluster together with Haloarcula species. Strain arg-2T differed in its glycolipid composition but still was more closely related to the genus Haloarcula than to other established genera. We propose that strain arg-1T be classified as a member of a new species, Haloarcula argentinensis, and that strain arg-2T be classified as a member of Haloarcula mukohataei sp. nov., although arg-2T may belong to a new genus or a subgenus of the genus Haloarcula. The type strain of H. argentinensis is strain arg-1 (= JCM 9737), and the type strain of H. mukohataei is strain arg-2 (= JCM 9738).