Microbial Diversity and Genetic Response to Stress Conditions of Extremophilic Bacteria Isolated from the Escondida Copper Mine

2009 ◽  
Vol 71-73 ◽  
pp. 55-58 ◽  
Author(s):  
Pedro Antonio Galleguillos ◽  
Kevin B. Hallberg ◽  
D. Barrie Johnson

The Escondida mine, located in northern Chile, is the largest copper producing mine in the world. It has an abundant low-grade (ca. 0.5% Cu) sulfide copper ore reservoir, which is processed in large heap bioreactors at the mine. To understand better how microorganisms adapt to heap leaching environments, we have isolated and identified acidophiles from pregnant leach solution (PLS) from the heaps. Six bacteria and one archaeon were isolated directly on solid overlay media, and identified by phylogenetic analyses of their 16S rRNA genes as strains of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, Acidiphilium cryptum and Ferroplasma acidiphilum. The sequences of the 16S rRNA genes from isolated strains showed high similarity with those detected previously by culture-independent analyses performed on samples from a pilot plant for this process. Of the three known species of Leptospirillum, only L. ferriphilum has been detected in Escondida PLS. Tolerance of the Escondida isolate (coded IESL-25) to copper and some other transition metals such as zinc, nickel and silver was compared with several other strains of both L. ferriphilum and Leptospirillum ferrooxidans. It was noted that all L. ferriphilum strains (including IESL-25) displayed far greater tolerance to both copper and silver than strains of L. ferrooxidans, though tolerance to zinc and nickel was similar among isolates of both species. Micro-representational-difference analysis (MRDA) was used to study the genetic response of L. ferriphilum IESL-25 to high copper concentration. Gene sequences obtained by MRDA were analyzed using available genomic information for L. ferriphilum and one copper-induced gene identified appears to be involved in lipopolysaccharide biosynthesis.

2015 ◽  
Vol 65 (Pt_7) ◽  
pp. 2320-2325 ◽  
Author(s):  
Shih-Yao Lin ◽  
Asif Hameed ◽  
Cheng-Zhe Wen ◽  
You-Cheng Liu ◽  
Yi-Han Hsu ◽  
...  

A Gram-stain-negative, aerobic, rod-shaped, yellow-pigment-producing bacterium (designated strain CC-CZW007T) was isolated from seafood samples (sea urchins) at Penghu Island in Taiwan. Strain CC-CZW007T grew optimally at pH 7.0 and 30 °C in the presence of 3 % (w/v) NaCl. The novel strain shared highest 16S rRNA gene sequence similarity to Vitellibacter vladivostokensis JCM 11732T (96.8 %), Vitellibacter soesokkakensis KCTC 32536T (96.4 %), Vitellibacter nionensis KCTC 32420T (95.8 %) and Vitellibacter aestuarii JCM 15496T (95.6 %) and lower sequence similarity to members of other genera. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CZW007T with respect to other species of the genus Vitellibacter. The major fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile was composed of major amounts of phosphatidylethanolamine, unidentified lipids and aminolipids; a moderate amount of aminophospholipid was also detected. The DNA G+C content was 34.7 mol%. The predominant quinone system was menaquinone (MK-6). On the basis of polyphasic taxonomic evidence presented here, strain CC-CZW007T is proposed to represent a novel species within the genus Vitellibacter, for which the name Vitellibacter echinoideorum sp. nov. is proposed. The type strain is CC-CZW007T ( = BCRC 80886T = JCM 30378T).


2007 ◽  
Vol 20-21 ◽  
pp. 539-542 ◽  
Author(s):  
Francisco Remonsellez ◽  
F. Galleguillos ◽  
Sonestie Janse van Rensburg ◽  
G.F. Rautenbach ◽  
Pedro A. Galleguillos ◽  
...  

Microbial heap bioleaching is being used as an industrial process to recover copper from low grade ores. It is known that a consortium of different microorganisms participates in this process. Therefore identification and quantification of communities inhabiting heap bioleaching operations is a key step for understanding the dynamics and role of these microorganisms in the process. A quantitative real-time PCR approach was used to investigate the microbial dynamics in this process. To study the microbial population inhabiting a low-grade copper sulphide ore bioleaching industrial heap process at Escondida Mine in Chile, 16S rRNA genetic libraries were constructed using bacterial and archaeal universal primers. Phylogenetic analyses of sequences retrieved from genetic libraries showed that the community is mainly composed by microoganisms related to Acidithiobacillus ferrooxidans (2 strains), Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans, Leptospirillum ferriphilum and the archaea Ferroplasma. Specific primers for real-time PCR determination were designed and tested to amplify each of the sequences obtained by cloning. Standard curves for real time PCR were performed using plasmid DNA from selected clones. This methodology is actually being used to monitor relevant microorganisms inhabiting this low-grade copper sulphide ore bioleaching industrial heap.


2006 ◽  
Vol 72 (7) ◽  
pp. 5077-5082 ◽  
Author(s):  
Thomas A. Auchtung ◽  
Cristina D. Takacs-Vesbach ◽  
Colleen M. Cavanaugh

ABSTRACT The environmental distribution and phylogeny of “Korarchaeota,” a proposed ancient archaeal division, was investigated by using the 16S rRNA gene framework. Korarchaeota-specific primers were designed based on previously published sequences and used to screen a variety of environments. Korarchaeota 16S rRNA genes were amplified exclusively from high temperature Yellowstone National Park hot springs and a 9°N East Pacific Rise deep-sea hydrothermal vent. Phylogenetic analyses of these and all available sequences suggest that Korarchaeota exhibit a high level of endemicity.


2020 ◽  
Vol 13 (7) ◽  
pp. 1462-1472
Author(s):  
Haitham Elbir ◽  
Faisal Almathen ◽  
Ayman Elnahas

Background and Aim: Hyalomma dromedarii ticks are vectors of disease agents and hosts of Francisella-like endosymbionts (FLEs). Knowledge about intraspecific genetic variation among H. dromedarii and its Francisella species is limited. The aims of this study were to investigate whether certain H. dromedarii genotypes are specialized in carrying specific Francisella species genotypes and scrutinize the population structure of H. dromedarii ticks in Saudi Arabia. Materials and Methods: We collected 151 H. dromedarii ticks from 33 camels from 13 locations in Saudi Arabia. The second internal transcribed spacer (ITS2), cytochrome c oxidase subunit-1(COI), and 16S rRNA genes were used for single-and multi-locus sequence typing and phylogenetic analyses. H. dromedarii-borne Francisella was screened using the tul4 gene and 16S rRNA Francisella-specific primers followed by amplicon Sanger sequencing. Results: Single-locus typing of ticks using ITS2, 16S rRNA, and COI genes yielded 1, 10, and 31 sequence types (ST), respectively, with pairwise sequence similarity of 100% for ITS2, 99.18-99.86% for COI, and 99.50-99.75% for 16S rRNA. COI sequence analysis indicated a lack of strict geographical structuration, as ST15 was found in both Saudi Arabia and Kenya. In contrast, multilocus sequence typing resolved 148 H. dromedarii ticks into 39 genotypes of ticks and three genotypes of FLEs. The ST2-FLE genotype was carried by the tick genotype ST35, while the ST1-FLE genotype and 41.89% of the ST3-FLE genotype were carried by the tick genotype ST32. Accordingly, there appeared to be no specialization of certain tick genotypes to harbor-specific FLE genotypes. Conclusion: For the 1st time, we have provided an overview of the population structure of H. dromedarii ticks and FLE strains. We found a low level of genetic diversity among FLEs and non-specialized circulation of FLEs among H. dromedarii ticks.


2017 ◽  
Vol 66 (1) ◽  
pp. 39-56
Author(s):  
Nilgun Tekin ◽  
Arzu Coleri Cihan ◽  
Basar Karaca ◽  
Cumhur Cokmus

Alkaline proteases have biotechnological importance due to their activity and stability at alkaline pH. 56 bacteria, capable of growing under alkaline conditions were isolated and their alkaline protease activities were carried out at different parameters to determine their optimum alkaline protease production conditions. Seven isolates were showed higher alkaline protease production capacity than the reference strains. The highest alkaline protease producing isolates (103125 U/g), E114 and C265, were identified as Bacillus licheniformis with 99.4% and Bacillus mojavensis 99.8% based on 16S rRNA gene sequence similarities, respectively. Interestingly, the isolates identified as Bacillus safensis were also found to be high alkaline protease producing strains. Genotypic characterizations of the isolates were also determined by using a wide range of molecular techniques (ARDRA, ITS-PCR, (GTG)5-PCR, BOX-PCR). These different techniques allowed us to differentiate the alkaliphilic isolates and the results were in concurrence with phylogenetic analyses of the 16S rRNA genes. While ITS-PCR provided the highest correlation with 16S rRNA groups, (GTG)5-PCR showed the highest differentiation at species and intra-species level. In this study, each of the biotechnologically valuable alkaline protease producing isolates was grouped into their taxonomic positions with multi-genotypic analyses.


Author(s):  
Mohamad Syazwan Ngalimat ◽  
Suriana Sabri

Many of the publically available Bacillus 16S rRNA genes and genomes in the NCBI database are inconsistently assigned as B. amyloliquefaciens. The highly conserved nature of the 16S rRNA gene makes it fail to differentiate species within the operational group B. amyloliquefaciens. Here, comparative phylogenies of the complete 16S rRNA, gyrB, rpoB, trpB, recA, and cheA nucleotide sequences of bacterial strains within the operational group were analyzed. As the result, the gyrB, rpoB, and trpB phylogenetic analyses showed stable topology that comprised three monophyletic clades: (i) B. amyloliquefaciens; (ii) B. siamensis; and (iii) B. velezensis. Phylogenies derived by comparison of the gyrB, rpoB, trpB, recA, and cheA with the 16S rRNA gene-derived phylogeny was significant as evaluated by the likelihood ratio test. The trpB, rpoB, and trpB gene-derived phylogenies provide a tool for speciation within the operational group B. amyloliquefaciens.


Author(s):  
Shih-Yao Lin ◽  
Chia-Fang Tsai ◽  
Asif Hameed ◽  
Chiu-Chung Young

A polyphasic taxonomic approach was used to characterize a Gram-stain-positive bacterium, designated strain CC-CFT486T, isolated from soil sampled in a maize field in Taiwan. Cells of strain CC-CFT486T were short rods, motile with polar flagella, catalase-positive and oxidase-positive. Optimal growth occurred at 30 °С, pH 8 and 1 % NaCl. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CFT486T associated with Aeromicrobium panacisoli (97.0 % sequence identity), Aeromicrobium lacus (97.0 %), Aeromicrobium erythreum (96.8 %) and Aeromicrobium alkaliterrae (96.8 %), and lower sequence similarity values to other species. Average nucleotide identity (ANI) values were 70.6–77.8 % (n=11) compared within the type strains of the genus Aeromicrobium . Strain CC-CFT486T contained C16 : 0, C17 : 0, C17 : 1  ω8c and C18 : 1  ω9c as the predominant fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, two unidentified aminophospholipids and three unknown phospholipids. The cell wall peptidoglycan of strains CC-CFT486T contained ll-diaminopimelic acid (ll-DAP) and the major polyamine was spermidine. The DNA G+C content was 70.6 mol% and the predominant quinone was menaquinone 9 (MK-9). Based on its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence and ANI analyses, strain CC-CFT486T is proposed to represent a novel Aeromicrobium species, for which the name Aeromicrobium terrae sp. nov. (type strain CC-CFT486T=BCRC 81217T=JCM 33499T).


1998 ◽  
Vol 64 (7) ◽  
pp. 2545-2553 ◽  
Author(s):  
Franco Widmer ◽  
Ramon J. Seidler ◽  
Patrick M. Gillevet ◽  
Lidia S. Watrud ◽  
George D. Di Giovanni

ABSTRACT Pseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection ofPseudomonas species in the environment may help us gain a more complete understanding of the ecological significance of these microorganisms. The objective of this study was to develop a PCR protocol for selective detection ofPseudomonas (sensu stricto) in environmental samples. Extensive database searches identified a highly selective PCR primer pair for amplification of Pseudomonas16S rRNA genes. A protocol that included PCR amplification and restriction analysis, a general cloning and sequencing strategy, and phylogenetic analyses was developed. The PCR protocol was validated by testing 50 target and 14 nontarget pure cultures, which confirmed the selectivity to 100%. Further validation used amplification of target sequences from purified bulk soil DNA followed by cloning of PCR products. Restriction analysis with HaeIII revealed eight different fragmentation patterns among 36 clones. Sequencing and phylogenetic analysis of 8 representative clones indicated that 91.7% of the products were derived from target organisms of the PCR protocol. Three patterns, representing only 8.3% of the 36 clones, were derived from non-Pseudomonas or chimeric PCR artifacts. Three patterns, representing 61.1% of the clones, clustered with sequences of confirmed Pseudomonas species, whereas two patterns, representing 30.6% of the clones, formed a novel phylogenetic cluster closely associated with Pseudomonas species. The results indicated that the Pseudomonas-selective PCR primers were highly specific and may represent a powerful tool forPseudomonas population structure analyses and taxonomic confirmations.


2020 ◽  
Vol 70 (11) ◽  
pp. 5725-5733 ◽  
Author(s):  
Shih-Yao Lin ◽  
Chia-Fang Tsai ◽  
Asif Hameed ◽  
Chiu-Chung Young

A polyphasic taxonomic approach was used to characterize a Gram-stain-positive bacterium, designated strain CC-CFT480T, isolated from soil sampled in a maize field in Taiwan, ROC. Cells of strain CC-CFT480T were rod-shaped, motile with polar flagella, catalase-positive and oxidase-positive. Optimal growth occurred at 30 °С, pH 8 and 3 % NaCl. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CFT480T associated with Cerasibacillus quisquiliarum (97.2 % sequence identity), Virgibacillus soli (95.7 %), Virgibacillus carmonensis (95.4 %) and Virgibacillus byunsanensis (95.2 %), and lower sequence similarity values to other species. Average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain CC-CFT480T and C. quisquiliarum were 74.2 and 20.1 %, respectively. Strain CC-CFT480T contained iso-C15:0, C16:1 ω7c alcohol and iso-C17:1 ω10c as the predominant fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unknown aminophospholipids, one uncharacterized aminophospholipid and two unknown phospholipids. The major polyamine was spermidine. The DNA G+C content was 34.8 mol% and the predominant quinone was menaquinone 7 (MK-7). Based on its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence, ANI and dDDH analyses, strain CC-CFT480T is proposed to represent a novel Cerasibacillus species, for which the name Cerasibacillus terrae sp. nov. (type strain CC-CFT480T=BCRC 81216T=JCM 33498T).


2020 ◽  
Vol 70 (12) ◽  
pp. 6257-6265 ◽  
Author(s):  
Soon Dong Lee ◽  
In Seop Kim

A marine alphaproteobacterium, designated as strain GH3-10T, was isolated from the rhizosphere mud of a halophyte (Suaeda japonica) collected at the seashore of Gangwha Island, Republic of Korea. The isolate was found to be Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive, non-motile, short rods and produced orange-coloured colonies. The 16S rRNA gene- and whole genome-based phylogenetic analyses exhibited that strain GH3-10T belonged to the genus Aurantiacibacter and was most closely related to Aurantiacibacter atlanticus s21-N3T (98.7 % 16S rRNA gene sequence similarity) and Aurantiacibacter marinus KCTC 23554T (98.4 %). The major respiratory quinone was ubiquinone-10. The polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid and an unidentified lipid. The major fatty acids were C18 : 1  ω7c, summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and C18 : 1  ω7c 10-methyl. The DNA G+C content was 61.3 mol% (by genome). Average nucleotide identity and DNA–DNA relatedness values between the isolate and its phylogenetically closest relatives, together with phenotypic distinctness warranted the taxonomic description of a new species. On the basis of data obtained by a polyphasic approach, strain GH3-10T (=KCTC 62379T=JCM 32444T) represents a novel species of the genus Aurantiacibacter , for which the name Aurantiacibacter rhizosphaerae sp. nov. is proposed. According to phylogenetic coherence based on 16S rRNA genes and core genomes, it is also proposed that Erythrobacter suaedae Lee et al. 2019. and Erythrobacter flavus Yoon et al. 2003 be transferred to Aurantiacibacter suaedae comb. nov. and Qipengyuania flava comb. nov., respectively.


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