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Sample records for moderately halophilic bacteria

  1. Biology of Moderately Halophilic Aerobic Bacteria

    PubMed Central

    Ventosa, Antonio; Nieto, Joaquín J.; Oren, Aharon

    1998-01-01

    The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms. PMID:9618450

  2. Salinity, pressure and heavy-metal stress response of moderately halophilic bacteria isolated from hydrothermal-vent environments

    NASA Astrophysics Data System (ADS)

    Kaye, J. Z.; Baross, J. A.

    2002-12-01

    Moderately halophilic bacteria comprised 0.01-10% of the total microbial community in low-temperature hydrothermal emissions and in the overlying water column. The presence of these microorganisms was initially thought to be linked to brines that are produced by super-critical phase separation beneath deep-sea mid-ocean ridges. While there is conclusive evidence that these brines exist at extremely hot (>400°C) temperatures, it is difficult to construct geochemical and fluid-flow models which would delineate extensive subseafloor brine environments in mesophilic to hyperthermophilic temperature ranges. An alternative hypothesis is that halotolerance is actually induced by an environmental stress other than salt. Pressure and heavy metals are likely candidates. Diffuse flow environments at Axial Seamount and the Endeavour Segment of the Juan de Fuca Ridge and along the Southern East Pacific Rise are both elevated in concentrations of heavy metals and under moderate pressure (150-270 atm; higher beneath the seafloor). From these fluids we isolated numerous strains of moderately halophilic bacteria belonging to the genera Halomonas and Marinobacter. At ambient pressure, isolates grew between -1 and 40°C, with up to 25% NaCl, and with 2.0-3.0 mM cadmium. The isolates displayed widely varying pressure maxima and cell yields as a function of temperature and salinity. High pressure and salt (and heavy metals?) may independently induce a stress response that enables these bacteria to cope with all of these stresses. Also in progress are molecular-phylogenetic analyses of moderately halophilic bacterial populations from diffuse flow sites along the Juan de Fuca Ridge. We expect that many of the organisms detected using our novel primers will have been cultured. With the knowledge of their physiologies and how their diversity changes in relation to fluid chemistry, these data may shed light on the dynamic subseafloor hydrothermal system that supports them.

  3. Isolation and characterization of some moderately halophilic bacteria with lipase activity.

    PubMed

    Ghasemi, Y; Rasoul-Amini, S; Kazemi, A; Zarrinic, G; Morowvat, M H; Kargar, M

    2011-01-01

    Lipases are an important class of enzymes which catalyze the hydrolysis of long chain triglycerides and constitute the most prominent group ofbiocatalysts for biotechnological applications. There are a number of lipases, produced by some halophilic microorganisms. In this study, some lipase producing bacteria from Maharlu salt lake located in south of Iran were isolated. All isolates were screened for true lipase activity on plates containing olive oil. The lipase activity was measured using titrimetric methods. Among thirty three isolates, thirteen strains demonstrating orange zone around colonies under UV light, were selected for identification using the molecular methods and some morphological characteristics. The bacterium Bacillus vallismortis BCCS 007 with 3.41 +/- 0.14 U/mL lipase activity was selected as the highest lipase producing isolate. This is the first report of isolation and molecular identification of lipase producing bacteria from Maharlu lake. PMID:22073547

  4. Denitrification by extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1985-01-01

    Extremely halophilic bacteria were isolated from widely separated sites by anaerobic enrichment in the presence of nitrate. The anaerobic growth of several of these isolates was accompanied by the production of nitrite, nitrous oxide, and dinitrogen. These results are a direct confirmation of the existence of extremely halophilic denitrifying bacteria, and suggest that such bacteria may be common inhabitants of hypersaline environments.

  5. Halophilic Amylase from a Moderately Halophilic Micrococcus

    PubMed Central

    Onishi, Hiroshi

    1972-01-01

    A moderately halophilic Micrococcus sp., isolated from unrefined solar salt, produced a considerable amount of extracellular dextrinogenic amylase when cultivated aerobically in media containing 1 to 3 m NaCl. The Micrococcus amylase had maximal activity at pH 6 to 7 in 1.4 to 2 m NaCl or KCl at 50 C. Calcium ion and a high concentration of NaCl or KCl were essential for activity and stability of the amylase. The salt response of the amylase depended greatly on the pH and temperature of the enzyme assay. PMID:5058445

  6. The effect of moderately halophilic bacteria supernatant on proliferation and apoptosis of cancer cells and mesenchymal stem cells.

    PubMed

    Sarvari, S; Seyedjafari, E; Amoozgar, M A; Bakhshandeh, B

    2015-01-01

    Many drug discoveries and developing of their applications has originated from microbial metabolites. The most efforts in development of new drugs are concerned with anti—cancer agents that cause better treatment results, less side effects, and more economical production. Several anti—tumor drugs have been recently extracted from natural microbial products. Among these various microbial diversity, Marin bacteria and Archaea have been considered as important and efficient organisms to serve as manufacturers of diverse bioactive compounds. Moderately halophilic microorganisms isolated from saline ponds and lakes of Iran show high capability for production of bioactive compounds like enzymes, dyes and anti—cancer agents. In this research, nine moderately halophilic bacteria isolates were screened to evaluate their anti—cancer agent productivity. After five days of culture on suitable mediums, supernatant samples were tested for in vitro anti—proliferative activity against Human Umbilical Vein Endothelial Cells (HUVEC) while same concentrations of supernatants were examined for evaluating of proliferative activity against Adipose—derived Mesenchymal stem cells (MSCs). Both assessments were carried out by MTT assay and double PI and DAPI staining. GASX17, GBWy6 and GBPX3 isolates just induced HUVEC cell deaths and exhibited anti—proliferative activity while R2S12 not only reduced HUVEC cell proliferation but also enhanced proliferation of MSCs. R2S12 , GASX17, GBWy6 and GBPX3 isolates were characterized biochemically and six hydrophilic components were detected. This research established new bioactive compounds that could be used as an effective treatment in chemotherapy. PMID:26068916

  7. Carotenoids' production from halophilic bacteria.

    PubMed

    de Lourdes Moreno, María; Sánchez-Porro, Cristina; García, María Teresa; Mellado, Encarnación

    2012-01-01

    Carotenoids have received considerable attention due to their interesting industrial applications and, more importantly, their potential beneficial effects on human health. Halophiles comprise a heterogeneous group of microorganisms that need salts for optimal growth. The pigments produced by these halophilic organisms comprise phytoene, β-carotene, lycopene, derivatives of bacterioruberin, and salinixanthin. Here, we describe the procedure to obtain salinixanthin from the extremely halophilic bacterium Salinibacter ruber. Additionally, we describe the expression of the β-carotene biosynthetic genes crtE, crtY, crtI, and crtB from Pantoea agglomerans in the moderately halophilic bacterium Halomonas elongata obtaining a strain able to produce practically pure β-carotene. Thus, the use of these halophilic microorganisms as a source of carotenoids constitutes an important commercial alternative in the production of carotenoids from biological sources. PMID:22623305

  8. Moderate halophilic bacteria colonizing the phylloplane of halophytes of the subfamily Salicornioideae (Amaranthaceae).

    PubMed

    Mora-Ruiz, Merit del Rocío; Font-Verdera, Francisca; Díaz-Gil, Carlos; Urdiain, Mercedes; Rodríguez-Valdecantos, Gustavo; González, Bernardo; Orfila, Alejandro; Rosselló-Móra, Ramon

    2015-09-01

    Halophytes accumulate large amounts of salt in their tissues, and thus are susceptible to colonization by halotolerant and halophilic microorganisms that might be relevant for the growth and development of the plant. Here, the study of 814 cultured strains and 14,189 sequences obtained by 454 pyrosequencing were combined in order to evaluate the presence, abundance and diversity of halophilic, endophytic and epiphytic microorganisms in the phytosphere of leaves of members of the subfamily Salicornioideae from five locations in Spain and Chile. Cultures were screened by the tandem approach of MALDI-TOF/MS and 16S rRNA gene sequencing. In addition, differential centrifugation was used to enrich endophytes for further DNA isolation, 16S rRNA gene amplification and 454 pyrosequencing. Culturable and non-culturable data showed strong agreement with a predominance of Proteobacteria, Firmicutes and Actinobacteria. The most abundant isolates corresponded to close relatives of the species Chromohalobacter canadensis and Salinicola halophilus that comprised nearly 60% of all isolates and were present in all plants. Up to 66% of the diversity retrieved by pyrosequencing could be brought into pure cultures and the community structures were highly dependent on the compartment where the microorganisms thrived (plant surface or internal tissues). PMID:26164126

  9. Are extreme halophiles actually 'bacteria'

    NASA Technical Reports Server (NTRS)

    Magrum, L. J.; Luehrsen, K. R.; Woese, C. R.

    1978-01-01

    Comparative cataloging of the 16S rRNA of Halobacterium halobium indicates that the organism did not arise, as a halophilic adaptation, from some typical bacterium. Rather, H. halobium is a member of the Archaebacteria, an ancient group of organisms that are no more related to typical bacteria than they are to eucaryotes.

  10. Sensitivity of some marine bacteria, a moderate halophile, and Escherichia coli to uncouplers at alkaline pH.

    PubMed Central

    MacLeod, R A; Wisse, G A; Stejskal, F L

    1988-01-01

    The inhibitory effects of uncouplers on amino acid transport into three marine bacteria, Vibrio alginolyticus 118, Vibrio parahaemolyticus 113, and Alteromonas haloplanktis 214, into a moderate halophile, Vibrio costicola NRC 37001, and into Escherichia coli K-12 were found to vary depending upon the uncoupler tested, its concentration, and the pH. Higher concentrations of all of the uncouplers were required to inhibit transport at pH 8.5 than at pH 7.0. The protonophore carbonyl cyanide m-chlorophenylhydrazone showed the greatest reduction in inhibitory capacity as the pH was increased, carbonyl cyanide p-trifluoromethoxyphenylhydrazone showed less reduction, and 3,3',4',5-tetrachlorosalicylanilide was almost as effective as an inhibitor of amino acid transport at pH 8.5 as at pH 7.0 for all of the organisms except A. haloplanktis 214. Differences between the protonophores in their relative activities at pHs 7.0 and 8.5 were attributed to differences in their pK values. 3,3',4',5-Tetrachlorosalicylanilide, carbonyl cyanide m-chlorophenylhydrazone, 2-heptyl-4-hydroxyquinoline-N-oxide, and NaCN all inhibited Na+ extrusion from Na+-loaded cells of V. alginolyticus 118 at pH 8.5. The results support the conclusion that Na+ extrusion from this organism at pH 8.5 occurs as a result of Na+/H+ antiport activity. Data are presented indicating the presence in V. alginolyticus 118 of an NADH oxidase which is stimulated by Na+ at pH 8.5. PMID:3045092

  11. Sensitivity of some marine bacteria, a moderate halophile, and Escherichia coli to uncouplers at alkaline pH.

    PubMed

    MacLeod, R A; Wisse, G A; Stejskal, F L

    1988-09-01

    The inhibitory effects of uncouplers on amino acid transport into three marine bacteria, Vibrio alginolyticus 118, Vibrio parahaemolyticus 113, and Alteromonas haloplanktis 214, into a moderate halophile, Vibrio costicola NRC 37001, and into Escherichia coli K-12 were found to vary depending upon the uncoupler tested, its concentration, and the pH. Higher concentrations of all of the uncouplers were required to inhibit transport at pH 8.5 than at pH 7.0. The protonophore carbonyl cyanide m-chlorophenylhydrazone showed the greatest reduction in inhibitory capacity as the pH was increased, carbonyl cyanide p-trifluoromethoxyphenylhydrazone showed less reduction, and 3,3',4',5-tetrachlorosalicylanilide was almost as effective as an inhibitor of amino acid transport at pH 8.5 as at pH 7.0 for all of the organisms except A. haloplanktis 214. Differences between the protonophores in their relative activities at pHs 7.0 and 8.5 were attributed to differences in their pK values. 3,3',4',5-Tetrachlorosalicylanilide, carbonyl cyanide m-chlorophenylhydrazone, 2-heptyl-4-hydroxyquinoline-N-oxide, and NaCN all inhibited Na+ extrusion from Na+-loaded cells of V. alginolyticus 118 at pH 8.5. The results support the conclusion that Na+ extrusion from this organism at pH 8.5 occurs as a result of Na+/H+ antiport activity. Data are presented indicating the presence in V. alginolyticus 118 of an NADH oxidase which is stimulated by Na+ at pH 8.5. PMID:3045092

  12. Halomonas qijiaojingensis sp. nov. and Halomonas flava sp. nov., two moderately halophilic bacteria isolated from a salt lake.

    PubMed

    Chen, Chao; Shi, Rong; Liu, Bing-Bing; Zhang, Yun-Jiao; Sun, Hong-Zhuan; Li, Chang-Tian; Tang, Shu-Kun; Zhang, Li-Li; Li, Wen-Jun

    2011-10-01

    Two moderately halophilic, Gram-negative, rod-shaped bacteria, designated YIM 93003(T) and YIM 94343(T), were isolated from a salt lake in Xinjiang province, north-west China. The two strains YIM 93003(T) and YIM 94343(T) grew at 20-40°C, pH 6-9, 0.5-24% (w/v) NaCl and at 20-40°C, pH 6-9, 0.5-23% (w/v) NaCl, respectively. No growth occurred in absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains YIM 93003(T) and YIM 94343(T) were phylogenetically affiliated to the genus Halomonas and exhibited sequence similarity of 97.5% and 97.4% to the type strain Halomonas anticariensis DSM 16096(T), respectively. The strains possessed chemotaxonomic markers that were consistent with their classification in the genus Halomonas (Q-9 as predominant respiratory quinine; C18:1ω7c, C16:0 and C16:1 ω7c/iso-C15:02-OH as the major fatty acids). The DNA-DNA hybridization values for strains YIM 93003(T) and YIM 94343(T), YIM 93003(T) and DSM 16096(T), YIM 94343(T) and DSM 16096(T) were 38.1 ± 3.0, 18.3 ± 4.7, and 20.8 ± 4.6%, respectively. The G+C contents of the strains YIM 93003(T) and YIM 94343(T) were 63.4 and 64.0 mol%, respectively. Based on comparative analysis of physiological, biochemical and chemotaxonomic data, including low DNA-DNA hybridization results, two novel species, Halomonas qijiaojingensis sp. nov., and Halomonas flava sp. nov., are proposed. The type strains are YIM 93003(T) (=CCTCC AB 208133(T) =KCTC 22228(T)) and YIM 94343(T) (=CCTCC AB 2010382(T) =KCTC 23356(T)), respectively. PMID:21656193

  13. Heavy metal resistance in halophilic Bacteria and Archaea.

    PubMed

    Voica, Doriana Mădălina; Bartha, Laszlo; Banciu, Horia Leonard; Oren, Aharon

    2016-07-01

    Heavy metals are dense chemicals with dual biological role as micronutrients and intoxicants. A few hypersaline environmental systems are naturally enriched with heavy metals, while most metal-contaminated sites are a consequence of human activities. Numerous halotolerant and moderately halophilic Bacteria possess metal tolerance, whereas a few archaeal counterparts share similar features. The main mechanisms underlying heavy metal resistance in halophilic Bacteria and Archaea include extracellular metal sequestration by biopolymers, metal efflux mediated by specific transporters and enzymatic detoxification. Biotransformation of metals by halophiles has implications both for trace metal turnover in natural saline ecosystems and for development of novel bioremediation strategies. PMID:27279625

  14. EFFECTS OF ULTRAVIOLET RADIATION ON THE MODERATE HALOPHILE HALOMONAS ELONGATA AND THE EXTREME HALOPHILE HALOBACTERIUM SALINARUM

    EPA Science Inventory

    Both the moderately halophilic bacterium, Halomonas elongata, and the extremely halophilic archaea, Halobacterium salinarum, can be found in hypersaline environments (e.g., salterns). On complex media, H. elongata grows over a salt range of 0.05-5.2 M, whereas, H. salinarum multi...

  15. Halophilic Bacteria as a Source of Novel Hydrolytic Enzymes

    PubMed Central

    de Lourdes Moreno, María; Pérez, Dolores; García, María Teresa; Mellado, Encarnación

    2013-01-01

    Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. The halotolerance of many enzymes derived from halophilic bacteria can be exploited wherever enzymatic transformations are required to function under physical and chemical conditions, such as in the presence of organic solvents and extremes in temperature and salt content. In recent years, different screening programs have been performed in saline habitats in order to isolate and characterize novel enzymatic activities with different properties to those of conventional enzymes. Several halophilic hydrolases have been described, including amylases, lipases and proteases, and then used for biotechnological applications. Moreover, the discovery of biopolymer-degrading enzymes offers a new solution for the treatment of oilfield waste, where high temperature and salinity are typically found, while providing valuable information about heterotrophic processes in saline environments. In this work, we describe the results obtained in different screening programs specially focused on the diversity of halophiles showing hydrolytic activities in saline and hypersaline habitats, including the description of enzymes with special biochemical properties. The intracellular lipolytic enzyme LipBL, produced by the moderately halophilic bacterium Marinobacter lipolyticus, showed advantages over other lipases, being an enzyme active over a wide range of pH values and temperatures. The immobilized LipBL derivatives obtained and tested in regio- and enantioselective reactions, showed an excellent behavior in the production of free polyunsaturated fatty acids (PUFAs). On the other hand, the extremely halophilic bacterium, Salicola marasensis sp. IC10 showing lipase and protease activities, was studied for its ability to produce promising enzymes in terms of its resistance to temperature and salinity. PMID:25371331

  16. Growth Potential of Halophilic Bacteria Isolated from Solar Salt Environments: Carbon Sources and Salt Requirements

    PubMed Central

    Javor, Barbara J.

    1984-01-01

    Eighteen strains of extremely halophilic bacteria and three strains of moderately halophilic bacteria were isolated from four different solar salt environments. Growth tests on carbohydrates, low-molecular-weight carboxylic acids, and complex medium demonstrated that the moderate halophiles and strains of the extreme halophiles Haloarcula and Halococcus grew on most of the substrates tested. Among the Halobacterium isolates were several metabolic groups: strains that grew on a broad range of substrates and strains that were essentially confined to either amino acid (peptone) or carbohydrate oxidation. One strain (WS-4) only grew well on pyruvate and acetate. Most strains of extreme halophiles grew by anaerobic fermentation and possibly by nitrate reduction. Tests of growth potential in natural saltern brines demonstrated that none of the halobacteria grew well in brines which harbor the densest populations of these bacteria in solar salterns. All grew best in brines which were unsaturated with NaCl. The high concentrations of Na+ and Mg2+ found in saltern crystallizer brines limited bacterial growth, but the concentrations of K+ found in these brines had little effect. MgSO4 was relatively more inhibitory to the extreme halophiles than was MgCl2, but the reverse was true for the moderate halophiles. PMID:16346609

  17. Isolation of carbohydrate-metabolizing, extremely halophilic bacteria.

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Hochstein, L. I.

    1972-01-01

    Four previously unrecognized strains of extremely halophilic bacteria that utilize carbohydrates have been isolated. Gas production proved an unreliable index of carbohydrate metabolism; therefore, carbohydrate utilization was measured by determining acid formation and sugar disappearance during growth. By these procedures, carbohydrate utilization was readily detected. The results suggest that carbohydrate dissimilation by extremely halophilic bacteria may be more common than previously thought and that the apparent rarity of carbohydrate-metabolizing halophiles may be an artifact of the isolation procedures used.

  18. Salt-dependent properties of proteins from extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Lanyi, J. K.

    1974-01-01

    Based on information concerning the interaction of salts and macromolecules the literature of the enzymes of halophilic bacteria and their constituents is examined. Although in halophilic systems the salt requirement of enzyme activity is variable the enzymes investigated show a time-dependent inactivation at lower salt concentrations especially in the absence of salt. The studies described show that in some halophilic systems the effect of salt may be restricted to a small region on the protein molecule. The concept of the hydrophobic bond to consider certain solvent-dependent phenomena is introduced. It is shown that some halophilic enzymes are unable to maintain their structure without the involvement of hydrophobic interactions that are usually not supported by water. A table lists indices of hydrophobicity and polarity for various halophilic and nonhalophilic proteins.

  19. ATP Synthesis in the Extremely Halophilic Bacteria

    NASA Technical Reports Server (NTRS)

    Hochstein, Lawrence I.; Morrison, David (Technical Monitor)

    1994-01-01

    The proton-translocating ATPases are multimeric enzymes that carry out a multitude of essential functions. Their origin and evolution represent a seminal event in the early evolution of life. Amino acid sequences of the two largest subunits from archaeal ATPases (A-ATPases), vacuolar ATPases (V-ATPases), and FOF1-ATP syntheses (FATPases) suggest these ATPases evolved from an ancestral vacuolar-like ATP syntheses. A necessary consequence of this notion is that the A-ATPases are ATP syntheses. With the possible exception of the A-ATPase from Halobacterium salinarium. no A-ATPase has been demonstrated to synthesize ATP. The evidence for this case is dubious since ATP synthesis occurs only when conditions are distinctively unphysiological. We demonstrated that ATP synthesis in H.saccharovorum is inconsistent with the operation of an A-type ATPase. In order to determine if this phenomenon was unique to H. saccharovorum, ATP synthesis was examined in various extremely halophilic bacteria with the goal of ascertaining if it resembled what occurred in a. saccharovorum, or was consistent with the operation of an A-type ATPase. A-, V-, and F-type ATPases respond singularly to certain inhibitors. Therefore, the effect of these inhibitors on ATP synthesis in several extreme halophiles was determined. Inhibitors that either blocked or collapsed proton-gradients inhibited the steady state synthesis of ATP thus verifying that synthesis took place at the expense of a proton gradient. Azide, an inhibitor of F-ATPases inhibited ATP synthesis. Since the arginine-dependent synthesis of ATP, which occurs by way of substrate-level phosphorylation, was unaffected by azide, it was unlikely that azide acted as an "uncoupler." N -ethylmaleimide and nitrate, which inhibit V- and A-ATPases, either did not inhibit ATP synthesis or resulted in higher steady-state levels of ATP. These results suggest there are two types of proton-motive ATPases in the extreme halophiles (and presumably in other

  20. Terribacillus aidingensis sp. nov., a moderately halophilic bacterium.

    PubMed

    Liu, Wenyan; Jiang, Linlin; Guo, Chunjing; Yang, Su Sheng

    2010-12-01

    Three Gram-positive, moderately halophilic bacteria, designated YI7-61(T), IA7 and DB2, were isolated from sediments of Aiding salt lake in the Xinjiang region of China. Cells of the strains were rod-shaped, motile by means of peritrichous flagella and produced ellipsoidal spores. Colonies were pale yellow in colour. The strains grew optimally at 30-37 °C, pH 6-7 and 3-7 % (w/v) NaCl. The diamino acid in the murein was meso-diaminopimelic acid and the major quinone system was MK-7. The major cellular fatty acids were anteiso-C(15 : 0) and anteiso-C(17 : 0). The DNA G+C content was 44.6-45.0 mol%. 16S rRNA gene sequence analysis revealed that strains YI7-61(T), IA7 and DB2 were closely related to members of the genus Terribacillus and showed 96.8-97.6, 96.4-97.2 and 95.4-95.5 % 16S rRNA gene sequence similarity with Terribacillus halophilus 002-051(T), Terribacillus saccharophilus RB589 and Terribacillus goriensis CL-GR16(T), respectively. DNA-DNA relatedness among the isolates was 88-92 % and strain YI7-61(T) shared 24, 18 and 18 % DNA-DNA relatedness with T. halophilus JCM 21760(T), T. saccharophilus JCM 21759(T) and T. goriensis DSM 18252(T), respectively. On the basis of phenotypic and phylogenetic distinctiveness, the three isolates should be placed in the genus Terribacillus as representatives of a novel species, for which the name Terribacillus aidingensis sp. nov. is proposed. The type strain is YI7-61(T) (=CGMCC 1.8913(T) =NBRC 105790(T)). PMID:20118295

  1. How to be moderately halophilic with a broad salt tolerance: Cluesfrom the genome of chromohalobacter salexigens

    SciTech Connect

    Oren, Aharon; Larimer, Frank; Richardson, Paul; Lapidus, Alla; Csonka, Laszlo N.

    2004-07-01

    There are two strategies that enable microorganisms to grow at high salt concentrations. Some groups balance the high osmolality of their environment with high intracellular concentrations of KCl1-4. Adaptation of all intracellular proteins is then necessary, and this is reflected in a large excess of acidic over basic residues and a low content of hydrophobic amino acids 2,5-7. Other halophilic and halotolerant microorganisms keep their intracellular ion concentrations low and synthesize or accumulate organic osmotic solutes 8. While halotolerance enables organisms to colonize highly saline environments,the ecological advantage for a salt-requirement is less obvious. We analyzed the amino acid composition of different categories of proteins of the moderately halophilic bacterium Chromohalobacter salexigens, as deduced from its genome sequence. Comparison with non-halophilic bacteria shows only a slight excess of acidic residues in the cytoplasmic proteins, no significant differences in membrane-bound components, but a distinctive halophilic signature of predicted periplasmic proteins, such as the substrate binding proteins of ABC-type transport systems. The salt requirement of proteins located external to the cytoplasmic membrane may thus determine salt requirement and salt tolerance of prokaryotes.

  2. Platinum Recovery from Synthetic Extreme Environments by Halophilic Bacteria.

    PubMed

    Maes, Synthia; Props, Ruben; Fitts, Jeffrey P; Smet, Rebecca De; Vilchez-Vargas, Ramiro; Vital, Marius; Pieper, Dietmar H; Vanhaecke, Frank; Boon, Nico; Hennebel, Tom

    2016-03-01

    Metal recycling based on urban mining needs to be established to tackle the increasing supply risk of critical metals such as platinum. Presently, efficient strategies are missing for the recovery of platinum from diluted industrial process streams, often characterized by extremely low pHs and high salt concentrations. In this research, halophilic mixed cultures were employed for the biological recovery of platinum (Pt). Halophilic bacteria were enriched from Artemia cysts, living in salt lakes, in different salt matrices (sea salt mixture and NH4Cl; 20-210 g L(-1) salts) and at low to neutral pH (pH 3-7). The main taxonomic families present in the halophilic cultures were Halomonadaceae, Bacillaceae, and Idiomarinaceae. The halophilic cultures were able to recover >98% Pt(II) and >97% Pt(IV) at pH 2 within 3-21 h (4-453 mg Ptrecovered h(-1) g(-1) biomass). X-ray absorption spectroscopy confirmed the reduction to Pt(0) and transmission electron microscopy revealed both intra- and extracellular Pt precipitates, with median diameters of 9-30 nm and 11-13 nm, for Pt(II) and Pt(IV), respectively. Flow cytometric membrane integrity staining demonstrated the preservation of cell viability during platinum recovery. This study demonstrates the Pt recovery potential of halophilic mixed cultures in acidic saline conditions. PMID:26854514

  3. [Diversity and enzyme-producing activity of culturable halophilic bacteria in Daishan Saltern of East China].

    PubMed

    Yang, Dan-Dan; Li, Qian; Huang, Jing-Jing; Chen, Min

    2012-11-01

    Soil and saline water samples were collected from the Daishan Saltern of East China, and the halophilic bacteria were isolated and cultured by using selective media, aimed to investigate the diversity and enzyme-producing activity of culturable halophilic bacteria in saltern environment. A total of 181 strains were isolated by culture-dependent method. Specific primers were used to amplify the 16S rRNA gene of bacteria and archaea. The operation taxonomy units (OTUs) were determined by ARDRA method, and the representative strain of each OTU was sequenced. The phylogenetic position of all the isolated strains was determined by 16S rRNA sequencing. The results showed that the isolated 181 strains displayed 21 operational taxonomic units (OTUs), of which, 12 OTUs belonged to halophilic bacteria, and the others belonged to halophilic archaea. Phylogenetic analysis indicated that there were 7 genera presented among the halophilic bacteria group, and 4 genera presented among the halophilic archaea group. The dominant halophilic strains were of Halomonas and Haloarcula, with 46.8% in halophilic bacteria and 49.1% in halophilic archaea group, respectively. Enzyme-producing analysis indicated that most strains displayed enzyme-producing activity, including the activities of producing amylase, proteinase and lipase, and the dominant strains capable of enzyme-producing were of Haloarcula. Our results showed that in the environment of Daishan Saltern, there existed a higher diversity of halophilic bacteria, being a source sink for screening enzyme-producing bacterial strains. PMID:23431797

  4. Draft Genome Sequence of the Moderately Halophilic Bacterium Marinobacter lipolyticus Strain SM19

    PubMed Central

    Papke, R. Thane; de la Haba, Rafael R.; Infante-Domínguez, Carmen; Pérez, Dolores; Sánchez-Porro, Cristina; Lapierre, Pascal

    2013-01-01

    Marinobacter lipolyticus strain SM19, isolated from saline soil in Spain, is a moderately halophilic bacterium belonging to the class Gammaproteobacteria. Here, we report the draft genome sequence of this strain, which consists of a 4.0-Mb chromosome and which is able to produce the halophilic enzyme lipase LipBL. PMID:23814106

  5. Survival of extremely and moderately halophilic isolates of Tunisian solar salterns after UV-B or oxidative stress.

    PubMed

    Trigui, Hana; Masmoudi, Salma; Brochier-Armanet, Céline; Maalej, Sami; Dukan, Sam

    2011-11-01

    Adaptation to a solar saltern environment requires mechanisms providing tolerance not only to salinity but also to UV radiation (UVR) and to reactive oxygen species (ROS). We cultivated prokaryote halophiles from two different salinity ponds: the concentrator M1 pond (240 g·L(-1) NaCl) and the crystallizer TS pond (380 g·L(-1) NaCl). We then estimated UV-B and hydrogen peroxide resistance according to the optimal salt concentration for growth of the isolates. We observed a higher biodiversity of bacterial isolates in M1 than in TS. All strains isolated from TS appeared to be extremely halophilic Archaea from the genus Halorubrum. Culturable strains isolated from M1 included extremely halophilic Archaea (genera Haloferax, Halobacterium, Haloterrigena, and Halorubrum) and moderately halophilic Bacteria (genera Halovibrio and Salicola). We also found that archaeal strains were more resistant than bacterial strains to exposure to ROS and UV-B. All organisms tested were more resistant to UV-B exposure at the optimum NaCl concentration for their growth, which is not always the case for H(2)O(2). Finally, if these results are extended to other prokaryotes present in a solar saltern, we could speculate that UVR has greater impact than ROS on the control of prokaryote biodiversity in a solar saltern. PMID:22017705

  6. Complete genome of Martelella sp. AD-3, a moderately halophilic polycyclic aromatic hydrocarbons-degrading bacterium.

    PubMed

    Cui, Changzheng; Li, Zhijie; Qian, Jiangchao; Shi, Jie; Huang, Ling; Tang, Hongzhi; Chen, Xin; Lin, Kuangfei; Xu, Ping; Liu, Yongdi

    2016-05-10

    Martelella sp. strain AD-3, a moderate halophilic bacterium, was isolated from a petroleum-contaminated soil with high salinity in China. Here, we report the complete genome of strain AD-3, which contains one circular chromosome and two circular plasmids. An array of genes related to metabolism of polycyclic aromatic hydrocarbons and halophilic mechanism in this bacterium was identified by the whole genome analysis. PMID:26988395

  7. Numerical taxonomy of moderately halophilic gram-positive cocci isolated from the Salar de Atacama (Chile).

    PubMed

    Valderrama, M J; Prado, B; del Moral, A; Ríos, R; Ramos-Cormenzana, A; Campos, V

    1991-06-01

    A taxonomic study has been carried out on 22 strains of moderately halophilic motile cocci isolated from the Salar de Atacama (Chile). The 112 phenotypic tests were analyzed by numerical taxonomy using SSM coefficient and the unweighted pair group method of association (UPGMA). At the 67% similarity level, two phenons were obtained: phenon A included 11 strains and phenon B, 11 strains too, whereas the six reference strains did not cluster within these two phenons. These results suggest that moderately halophilic cocci with different phenotypic characteristics from previously described species can be isolated from the hypersaline habitat Salar de Atacama. PMID:1867776

  8. Tetragenococcus muriaticus sp. nov., a new moderately halophilic lactic acid bacterium isolated from fermented squid liver sauce.

    PubMed

    Satomi, M; Kimura, B; Mizoi, M; Sato, T; Fujii, T

    1997-07-01

    A total of 11 strains of moderately halophilic histamine-producing bacteria isolated from fermented squid liver sauce were studied phenotypically, genotypically, and phylogenetically. These strains are considered members of the genus Tetragenococcus based on their physiological, morphological, and chemotaxonomic characteristics. A 16S rRNA gene sequence analysis showed that these strains clustered with, but were separate from, Tetragenococcus halophilus. The results of DNA-DNA hybridization experiments indicated that the new isolates represent a new Tetragenococcus species, for which we propose the name Tetragenococcus muriaticus; strain X-1 (= JCM 10006) is the type strain of this species. PMID:9226914

  9. Endospores of halophilic bacteria of the family Bacillaceae isolated from non-saline Japanese soil may be transported by Kosa event (Asian dust storm)

    PubMed Central

    Echigo, Akinobu; Hino, Miki; Fukushima, Tadamasa; Mizuki, Toru; Kamekura, Masahiro; Usami, Ron

    2005-01-01

    Background Generally, extremophiles have been deemed to survive in the extreme environments to which they had adapted to grow. Recently many extremophiles have been isolated from places where they are not expected to grow. Alkaliphilic microorganisms have been isolated from acidic soil samples with pH 4.0, and thermophiles have been isolated from samples of low temperature. Numerous moderately halophilic microorganisms, defined as those that grow optimally in media containing 0.5–2.5 Molar (3–15%) NaCl, and halotolerant microorganisms that are able to grow in media without added NaCl and in the presence of high NaCl have been isolated from saline environments such as salterns, salt lakes and sea sands. It has tacitly been believed that habitats of halophiles able to grow in media containing more than 20% (3.4 M) are restricted to saline environments, and no reports have been published on the isolation of halophiles from ordinary garden soil samples. Results We demonstrated that many halophilic bacteria that are able to grow in the presence of 20% NaCl are inhabiting in non-saline environments such as ordinary garden soils, yards, fields and roadways in an area surrounding Tokyo, Japan. Analyses of partial 16S rRNA gene sequences of 176 isolates suggested that they were halophiles belonging to genera of the family Bacillaceae, Bacillus (11 isolates), Filobacillus (19 isolates), Gracilibacillus (6 isolates), Halobacillus (102 isolates), Lentibacillus (1 isolate), Paraliobacillus (5 isolates) and Virgibacillus (17 isolates). Sequences of 15 isolates showed similarities less than 92%, suggesting that they may represent novel taxa within the family Bacillaceae. Conclusion The numbers of total bacteria of inland soil samples were in a range from 1.4 × 107/g to 1.1 × 106/g. One tenth of the total bacteria was occupied by endospore-forming bacteria. Only very few of the endospore-forming bacteria, roughly 1 out of 20,000, are halophilic bacteria. Most of the

  10. Diversity of halophilic bacteria isolated from Rambla Salada, Murcia (Spain).

    PubMed

    Luque, Rocío; Béjar, Victoria; Quesada, Emilia; Llamas, Inmaculada

    2014-12-01

    In this study we analyzed the diversity of the halophilic bacteria community from Rambla Salada during the years 2006 and 2007. We collected a total of 364 strains, which were then identified by means of phenotypic tests and by the hypervariable V1-V3 region of the 16S rRNA sequences (around 500 bp). The ribosomal data showed that the isolates belonged to Proteobacteria (72.5%), Firmicutes (25.8%), Actinobacteria (1.4%), and Bacteroidetes (0.3%) phyla, with Gammaproteobacteria the predominant class. Halomonas was the most abundant genus (41.2% isolates) followed by Marinobacter (12.9% isolates) and Bacillus (12.6% isolates). In addition, 9 strains showed <97% sequence identity with validly described species and may well represent new taxa. The diversity of the bacterial community analyzed with the DOTUR package determined 139 operational taxonomic units at 3% genetic distance level. Rarefaction curves and diversity indexes demonstrated that our collection of isolates adequately represented all the bacterial community at Rambla Salada that can be grown under the conditions used in this work. We found that the sampling season influenced the composition of the bacterial community, and bacterial diversity was higher in 2007; this fact could be related to lower salinity at this sampling time. PMID:25403824

  11. Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

    NASA Astrophysics Data System (ADS)

    Deng, Yuangao; Xu, Gaochao; Sui, Liying

    2015-07-01

    A total of 26 isolates were obtained from solar salt ponds of different salinities (100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that five bacteria genera Halomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera Halorubrum were present. The genus Halomonas was predominant with eight strains distributed in a salinity range of 100-200, followed by Halorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate Salimicrobium species based on the phylogenic analysis of the 16S rRNA gene sequence and its biochemical characteristics when compared with known related species.

  12. Production of an extracellular thermohalophilic lipase from a moderately halophilic bacterium, Salinivibrio sp. strain SA-2.

    PubMed

    Amoozegar, Mohammad Ali; Salehghamari, Ensieh; Khajeh, Khosro; Kabiri, Mahbube; Naddaf, Saied

    2008-06-01

    Fifty strains of moderately halophilic bacteria were isolated from various salty environments in Iran. A strain designated as SA-2 was shown to be the best producer of extracellular lipase and was selected for further studies. Biochemical and physiological characterization along with 16S rDNA sequence analysis placed SA-2 in the genus Salinivibrio. The optimum salt, pH, temperature and aeration for enzyme production were 0.1 M KCl, pH 8, 35 degrees C and 150 rpm, respectively. The enzyme production was synchronized bacterial growth and reached a maximum level during the early-stationary phase in the basal medium containing 1 M NaCl. Triacylglycerols enhanced lipase production, while carbohydrates had inhibitory effects on it. The maximum lipase activity was obtained at pH 7.5, 50 degrees C and CaCl(2) concentration of 0.01 M. The enzyme was stable at pH range of 7.5-8 and retained 90% of its activity at 80 degrees C for 30 min. Different concentrations of NaNO(3), Na(2)SO(4), KCl and NaCl had no affect on lipase stability for 3 h. These results suggest that the lipase secreted by Salinivibrio sp. strain SA-2 is industrially important from the perspective of its tolerance to a broad temperature range, its moderate thermoactivity and its high tolerance to a wide range of salt concentrations (0-3 M NaCl). PMID:18506896

  13. Draft Genome Sequence of the Moderately Halophilic Methanotroph Methylohalobius crimeensis Strain 10Ki

    PubMed Central

    Sharp, Christine E.; Smirnova, Angela V.; Kalyuzhnaya, Marina G.; Bringel, Françoise; Hirayama, Hisako; Jetten, Mike S. M.; Khmelenina, Valentina N.; Klotz, Martin G.; Knief, Claudia; Kyrpides, Nikos; Op den Camp, Huub J. M.; Reshetnikov, Alexander S.; Sakai, Yasuyoshi; Shapiro, Nicole; Trotsenko, Yuri A.; Vuilleumier, Stéphane; Woyke, Tanja

    2015-01-01

    Methylohalobius crimeensis strain 10Ki is a moderately halophilic aerobic methanotroph isolated from a hypersaline lake in the Crimean Peninsula, Ukraine. This organism has the highest salt tolerance of any cultured methanotroph. Here, we present a draft genome sequence of this bacterium. PMID:26067976

  14. Workshop on Viability of Halophilic Bacteria in Salt Deposits

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The significance of finding viable extreme halophiles in halites associated with Permian-aged sedimentary deposits is considered. Issues related to the microbiology and geochemistry of the halite environment are addressed. Recommendations that related the significance of this phenomenon to NASA's interest in planetary exploration and the early evolution of life are provided.

  15. Draft Genome Sequence of Staphylococcus succinus Strain CSM-77, a Moderately Halophilic Bacterium Isolated from a Triassic Salt Mine.

    PubMed

    Megaw, Julianne; Gilmore, Brendan F

    2016-01-01

    Here, we report the draft genome sequence of Staphylococcus succinus strain CSM-77. This moderately halophilic bacterium was isolated from the surface of a halite sample obtained from a Triassic salt mine. PMID:27284152

  16. Draft Genome Sequence of Staphylococcus succinus Strain CSM-77, a Moderately Halophilic Bacterium Isolated from a Triassic Salt Mine

    PubMed Central

    Gilmore, Brendan F.

    2016-01-01

    Here, we report the draft genome sequence of Staphylococcus succinus strain CSM-77. This moderately halophilic bacterium was isolated from the surface of a halite sample obtained from a Triassic salt mine. PMID:27284152

  17. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    SciTech Connect

    Arai, Shigeki; Yonezawa, Yasushi; Ishibashi, Matsujiro; Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro; Tokunaga, Hiroko; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2014-03-01

    In order to clarify the structural basis of the halophilic characteristics of an alkaline phosphatase derived from the moderate halophile Halomonas sp. 593 (HaAP), the tertiary structure of HaAP was determined to 2.1 Å resolution by X-ray crystallography. The structural properties of surface negative charge and core hydrophobicity were shown to be intermediate between those characteristic of halophiles and non-halophiles, and may explain the unique functional adaptation to a wide range of salt concentrations. Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (C{sup α} r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior

  18. Heavy metal tolerant halophilic bacteria from Vembanad Lake as possible source for bioremediation of lead and cadmium.

    PubMed

    Sowmya, M; Rejula, M P; Rejith, P G; Mohan, Mahesh; Karuppiah, Makesh; Hatha, A A Mohamed

    2014-07-01

    Microorganisms which can resist high concentration of toxic heavy metals are often considered as effective tools of bioremediation from such pollutants. In the present study, sediment samples from Vembanad Lake were screened for the presence of halophilic bacteria that are tolerant to heavy metals. A total of 35 bacterial strains belonging to different genera such as Alcaligenes, Vibrio, Kurthia, Staphylococcus and members of the family Enterobacteriaceae were isolated from 21 sediment samples during February to April, 2008. The salt tolerance and optimum salt concentrations of the isolates revealed that most of them were moderate halophiles followed by halotolerant and extremely halotolerant groups. The minimum inhibitory concentrations (MICs) against cadmium and lead for each isolate revealed that the isolates showed higher MIC against lead than cadmium. Based on the resistance limit concentration, most of them were more tolerant to lead than cadmium at all the three salt concentrations tested. Heavy metal removal efficiency of selected isolates showed a maximum reduction of 37 and 99% against cadmium and lead respectively. The study reveals the future prospects of halophilic microorganisms in the field of bioremediation. PMID:25004749

  19. How-to-Do-It: A Simple DNA Isolation Technique Using Halophilic Bacteria.

    ERIC Educational Resources Information Center

    Guilfoile, Patrick

    1989-01-01

    Described is a simple technique for isolating DNA from halophilic bacteria. Materials, procedure, and additional experiments are outlined. It is stated that the DNA obtained will be somewhat contaminated with cellular proteins and RNA. Offers a procedure for greater purification. (RT)

  20. High-throughput screening for a moderately halophilic phenol-degrading strain and its salt tolerance response.

    PubMed

    Lu, Zhi-Yan; Guo, Xiao-Jue; Li, Hui; Huang, Zhong-Zi; Lin, Kuang-Fei; Liu, Yong-Di

    2015-01-01

    A high-throughput screening system for moderately halophilic phenol-degrading bacteria from various habitats was developed to replace the conventional strain screening owing to its high efficiency. Bacterial enrichments were cultivated in 48 deep well microplates instead of shake flasks or tubes. Measurement of phenol concentrations was performed in 96-well microplates instead of using the conventional spectrophotometric method or high-performance liquid chromatography (HPLC). The high-throughput screening system was used to cultivate forty-three bacterial enrichments and gained a halophilic bacterial community E3 with the best phenol-degrading capability. Halomonas sp. strain 4-5 was isolated from the E3 community. Strain 4-5 was able to degrade more than 94% of the phenol (500 mg · L(-1) starting concentration) over a range of 3%-10% NaCl. Additionally, the strain accumulated the compatible solute, ectoine, with increasing salt concentrations. PCR detection of the functional genes suggested that the largest subunit of multicomponent phenol hydroxylase (LmPH) and catechol 1,2-dioxygenase (C12O) were active in the phenol degradation process. PMID:26020478

  1. Bioenergetics of the moderately halophilic bacterium Halobacillus halophilus: composition and regulation of the respiratory chain.

    PubMed

    Pade, Nadin; Köcher, Saskia; Roeßler, Markus; Hänelt, Inga; Müller, Volker

    2013-06-01

    In their natural environments, moderately halophilic bacteria are confronted not only with high salinities but also with low oxygen tensions due to the high salinities. The growth of H. halophilus is strictly aerobic. To analyze the dependence of respiration on the NaCl concentration and oxygen availability of the medium, resting cell experiments were performed. The respiration rates were dependent on the NaCl concentration of the growth medium, as well as on the NaCl concentration of the assay buffer, indicating regulation on the transcriptional and the activity level. Respiration was accompanied by the generation of an electrochemical proton potential (Δμ(H+)) across the cytoplasmic membrane whose magnitude was dependent on the external pH. Genes encoding proteins involved in respiration and Δμ(H+) generation, such as a noncoupled NADH dehydrogenase (NDH-2), complex II, and complex III, were identified in the genome. In addition, genes encoding five different terminal oxidases are present. Inhibitor profiling revealed the presence of NDH-2 and complex III, but the nature of the oxidases could not be resolved using this approach. Expression analysis demonstrated that all the different terminal oxidases were indeed expressed, but by far the most prominent was cta, encoding cytochrome caa3 oxidase. The expression of all of the different oxidase genes increased at high NaCl concentrations, and the transcript levels of cta and qox (encoding cytochrome aa3 oxidase) also increased at low oxygen concentrations. These data culminate in a model of the composition and variation of the respiratory chain of H. halophilus. PMID:23584768

  2. Isolation of moderately halophilic pseudoalteromonas producing extracellular hydrolytic enzymes from persian gulf.

    PubMed

    Ardakani, M Roayaie; Poshtkouhian, A; Amoozegar, M A; Zolgharnein, H

    2012-03-01

    Extracellular hydrolytic enzymes such as amylases, proteases, lipases and DNases have quite diverse potential usages in different areas such as food industry, biomedical sciences and chemical industries, also it would be of great importance to have available enzymes showing optimal activities at different values of salt concentrations and temperature. Halophiles are the most likely source of such enzymes, because not only their enzymes are salt-tolerant, but many are also thermotolerant. The purpose of this study was isolation of hydrolytic extracellular enzyme producing halophilic bacteria from water and sediment of the Persian Gulf. Isolated bacteria from water and sediment were inoculated in media with concentration of 0-20% NaCl to determine the optimum salt concentration for growth, isolates were also inoculated in 4 types of solid medium containing substrates of 3 extracellular hydrolytic enzymes including amylase, Protease and Lipase, to determine the quantitative detection of enzyme production, selected strains after more accurate physiological and biochemical studies were identified regarding phylogeny and molecular characteristics using 16S rRNA technique. Isolated enzyme producing bacteria belong to Pseudoalteromonas genera. PMID:23450116

  3. From metagenomics to pure culture: isolation and characterization of the moderately halophilic bacterium Spiribacter salinus gen. nov., sp. nov.

    PubMed

    León, María José; Fernández, Ana B; Ghai, Rohit; Sánchez-Porro, Cristina; Rodriguez-Valera, Francisco; Ventosa, Antonio

    2014-07-01

    Recent metagenomic studies on saltern ponds with intermediate salinities have determined that their microbial communities are dominated by both Euryarchaeota and halophilic bacteria, with a gammaproteobacterium closely related to the genera Alkalilimnicola and Arhodomonas being one of the most predominant microorganisms, making up to 15% of the total prokaryotic population. Here we used several strategies and culture media in order to isolate this organism in pure culture. We report the isolation and taxonomic characterization of this new, never before cultured microorganism, designated M19-40(T), isolated from a saltern located in Isla Cristina, Spain, using a medium with a mixture of 15% salts, yeast extract, and pyruvic acid as the carbon source. Morphologically small curved cells (young cultures) with a tendency to form long spiral cells in older cultures were observed in pure cultures. The organism is a Gram-negative, nonmotile bacterium that is strictly aerobic, non-endospore forming, heterotrophic, and moderately halophilic, and it is able to grow at 10 to 25% (wt/vol) NaCl, with optimal growth occurring at 15% (wt/vol) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that strain M19-40(T) has a low similarity with other previously described bacteria and shows the closest phylogenetic similarity with species of the genera Alkalilimnicola (94.9 to 94.5%), Alkalispirillum (94.3%), and Arhodomonas (93.9%) within the family Ectothiorhodospiraceae. The phenotypic, genotypic, and chemotaxonomic features of this new bacterium showed that it constitutes a new genus and species, for which the name Spiribacter salinus gen. nov., sp. nov., is proposed, with strain M19-40(T) (= CECT 8282(T) = IBRC-M 10768(T) = LMG 27464(T)) being the type strain. PMID:24747894

  4. From Metagenomics to Pure Culture: Isolation and Characterization of the Moderately Halophilic Bacterium Spiribacter salinus gen. nov., sp. nov.

    PubMed Central

    León, María José; Fernández, Ana B.; Ghai, Rohit; Sánchez-Porro, Cristina; Rodriguez-Valera, Francisco

    2014-01-01

    Recent metagenomic studies on saltern ponds with intermediate salinities have determined that their microbial communities are dominated by both Euryarchaeota and halophilic bacteria, with a gammaproteobacterium closely related to the genera Alkalilimnicola and Arhodomonas being one of the most predominant microorganisms, making up to 15% of the total prokaryotic population. Here we used several strategies and culture media in order to isolate this organism in pure culture. We report the isolation and taxonomic characterization of this new, never before cultured microorganism, designated M19-40T, isolated from a saltern located in Isla Cristina, Spain, using a medium with a mixture of 15% salts, yeast extract, and pyruvic acid as the carbon source. Morphologically small curved cells (young cultures) with a tendency to form long spiral cells in older cultures were observed in pure cultures. The organism is a Gram-negative, nonmotile bacterium that is strictly aerobic, non-endospore forming, heterotrophic, and moderately halophilic, and it is able to grow at 10 to 25% (wt/vol) NaCl, with optimal growth occurring at 15% (wt/vol) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that strain M19-40T has a low similarity with other previously described bacteria and shows the closest phylogenetic similarity with species of the genera Alkalilimnicola (94.9 to 94.5%), Alkalispirillum (94.3%), and Arhodomonas (93.9%) within the family Ectothiorhodospiraceae. The phenotypic, genotypic, and chemotaxonomic features of this new bacterium showed that it constitutes a new genus and species, for which the name Spiribacter salinus gen. nov., sp. nov., is proposed, with strain M19-40T (= CECT 8282T = IBRC-M 10768T = LMG 27464T) being the type strain. PMID:24747894

  5. ACTINIDE BIOCOLLOID FORMATION IN BRINE BY HALOPHILIC BACTERIA

    SciTech Connect

    GILLOW,J.B.; FRANCIS,A.J.; DODGE,C.J.; HARRIS,R.; BEVERIDGE,T.J.; BRADY,P.B.; PAPENGUTH,H.W.

    1998-11-09

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  6. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    SciTech Connect

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-07-28

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  7. Actinide biocolloid formation in brine by halophilic bacteria

    SciTech Connect

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1998-12-31

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  8. Regulation of osmoadaptation in the moderate halophile Halobacillus halophilus: chloride, glutamate and switching osmolyte strategies

    PubMed Central

    Saum, Stephan H; Müller, Volker

    2008-01-01

    The moderate halophile Halobacillus halophilus is the paradigm for chloride dependent growth in prokaryotes. Recent experiments shed light on the molecular basis of the chloride dependence that is reviewed here. In the presence of moderate salinities Halobacillus halophilus mainly accumulates glutamine and glutamate to adjust turgor. The transcription of glnA2 (encoding a glutamine synthetase) as well as the glutamine synthetase activity were identified as chloride dependent steps. Halobacillus halophilus switches its osmolyte strategy and produces proline as the main compatible solute at high salinities. Furthermore, Halobacillus halophilus also shifts its osmolyte strategy at the transition from the exponential to the stationary phase where proline is exchanged by ectoine. Glutamate was found as a “second messenger” essential for proline production. This observation leads to a new model of sensing salinity by sensing the physico-chemical properties of different anions. PMID:18442383

  9. Use of Raman spectroscopy for identification of compatible solutes in halophilic bacteria.

    PubMed

    Jehlička, Jan; Oren, Aharon; Vítek, Petr

    2012-05-01

    We explored the use of Raman spectroscopy to detect organic osmotic solutes as biomarkers in the moderately halophilic heterotrophic bacterium Halomonas elongata grown in complex medium (accumulation of glycine betaine) and in defined medium with glucose as carbon source (biosynthesis of ectoine), and in the anoxygenic phototrophic Ectothiorhodospira marismortui known to synthesize glycine betaine in combination with minor amounts of trehalose and N-α-carbamoyl glutamineamide. We tested different methods of preparation of the material: lyophilization, two-phase extraction of water-soluble molecules, and perchlorate extraction. Raman signals of glycine betaine and ectoine were detected; perchlorate extraction followed by desalting the extract on an ion retardation column gave the best results. Lyophilized cells of E. marismortui showed strong signals of carotenoid pigments, and glycine betaine could be detected only after perchlorate extraction and desalting. The data presented show that Raman spectroscopy is a suitable tool to assess the mode of osmotic adaptation used by halophilic microorganisms. PMID:22527044

  10. Extracellular proteases of Halobacillus blutaparonensis strain M9, a new moderately halophilic bacterium

    PubMed Central

    Santos, Anderson F.; Valle, Roberta S.; Pacheco, Clarissa A.; Alvarez, Vanessa M.; Seldin, Lucy; Santos, André L.S.

    2013-01-01

    Halophilic microorganisms are source of potential hydrolytic enzymes to be used in industrial and/or biotechnological processes. In the present study, we have investigated the ability of the moderately halophilic bacterium Halobacillus blutaparonensis (strain M9), a novel species described by our group, to release proteolytic enzymes. This bacterial strain abundantly proliferated in Luria-Bertani broth supplemented with 2.5% NaCl as well as secreted proteases to the extracellular environment. The production of proteases occurred in bacterial cells grown under different concentration of salt, ranging from 0.5% to 10% NaCl, in a similar way. The proteases secreted by H. blutaparonensis presented the following properties: (i) molecular masses ranging from 30 to 80 kDa, (ii) better hydrolytic activities under neutral-alkaline pH range, (iii) expression modulated according to the culture age, (iv) susceptibility to phenylmethylsulphonyl fluoride, classifying them as serine-type proteases, (v) specific cleavage over the chymotrypsin substrate, and (vi) enzymatic stability in the presence of salt (up to 20% NaCl) and organic solvents (e.g., ether, isooctane and cyclohexane). The proteases described herein are promising for industrial practices due to its haloalkaline properties. PMID:24688526

  11. Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria.

    PubMed

    He, Zhanfei; Geng, Sha; Cai, Chaoyang; Liu, Shuai; Liu, Yan; Pan, Yawei; Lou, Liping; Zheng, Ping; Xu, Xinhua; Hu, Baolan

    2015-08-15

    Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite. PMID:26048927

  12. Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

    PubMed Central

    He, Zhanfei; Geng, Sha; Cai, Chaoyang; Liu, Shuai; Liu, Yan; Pan, Yawei; Lou, Liping; Zheng, Ping; Xu, Xinhua

    2015-01-01

    Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite. PMID:26048927

  13. Molecular Mechanisms of Adaptation of the Moderately Halophilic Bacterium Halobacillis halophilus to Its Environment

    PubMed Central

    Hänelt, Inga; Müller, Volker

    2013-01-01

    The capability of osmoadaptation is a prerequisite of organisms that live in an environment with changing salinities. Halobacillus halophilus is a moderately halophilic bacterium that grows between 0.4 and 3 M NaCl by accumulating both chloride and compatible solutes as osmolytes. Chloride is absolutely essential for growth and, moreover, was shown to modulate gene expression and activity of enzymes involved in osmoadaptation. The synthesis of different compatible solutes is strictly salinity- and growth phase-dependent. This unique hybrid strategy of H. halophilus will be reviewed here taking into account the recently published genome sequence. Based on identified genes we will speculate about possible scenarios of the synthesis of compatible solutes and the uptake of potassium ion which would complete our knowledge of the fine-tuned osmoregulation and intracellular osmolyte balance in H. halophilus. PMID:25371341

  14. Bacillus shacheensis sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

    PubMed

    Lei, Zuchao; Qiu, Peng; Ye, Renyuan; Tian, Jiewei; Liu, Yang; Wang, Lei; Tang, Shu-Kun; Li, Wen-Jun; Tian, Yongqiang

    2014-01-01

    A moderately halophilic bacterium, strain HNA-14(T), was isolated from a saline-alkali soil sample collected in Shache County, Xinjiang Province. On the basis of the polyphasic taxonomic data, the isolate was considered to be a member of the genus Bacillus. The organism grew optimally at 30 °C and pH 8.0. It was moderately halophilic and its optimum growth occurred at 5-10% NaCl. The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid and the predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C15:0 and iso-C15:0 and the polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and two unknown phospholipids. The G+C content of the genomic DNA was 48.6 mol%. Strain HNA-14(T) exhibited a low 16S rRNA gene sequence similarity of 96% with its nearest neighbors [Bacillus clausii KSM-K16 (96.5%), Bacillus xiaoxiensis DSM 21943(T)(96.2%), Bacillus clausii DSM 8716(T) (96.1%), Bacillus patagoniensis PAT05(T) (96.1%), Bacillus lehensis MLB-2(T) (96.0%), Bacillus oshimensis K11(T) (95.9%) and Bacillus hunanensis DSM 23008(T) (95.8%)] and the phenotypic characteristics indicate that strain HNA-14(T) can be distinguished from them. Therefore, a novel species of the genus Bacillus, Bacillus shacheensis sp. nov. (type strain, HNA-14(T) = KCTC 33145 = DSM 26902) is proposed. PMID:25008165

  15. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    PubMed Central

    Arai, Shigeki; Yonezawa, Yasushi; Ishibashi, Matsujiro; Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro; Tokunaga, Hiroko; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2014-01-01

    Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (Cα r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior comprising 329 C atoms from completely buried residues, whereas that of VAP comprised 264 C atoms, which may maintain the stability of HaAP under low-salt conditions. These characteristics of HaAP may be responsible for its unique functional adaptation permitting activity over a wide range of salt concentrations. PMID:24598750

  16. Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier

    PubMed Central

    Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

    2013-01-01

    The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. PMID:23929527

  17. Membrane fluidity of halophilic ectoine-secreting bacteria related to osmotic and thermal treatment.

    PubMed

    Bergmann, Sven; David, Florian; Clark, Wiebke; Wittmann, Christoph; Krull, Rainer

    2013-12-01

    In response to sudden decrease in osmotic pressure, halophilic microorganisms secrete their accumulated osmolytes. This specific stress response, combined with physiochemical responses to the altered environment, influence the membrane properties and integrity of cells, with consequent effects on growth and yields in bioprocesses, such as bacterial milking. The aim of this study was to investigate changes in membrane fluidity and integrity induced by environmental stress in ectoine-secreting organisms. The halophilic ectoine-producing strains Alkalibacillus haloalkaliphilus and Chromohalobacter salexigens were treated hypo- and hyper-osmotically at several temperatures. The steady-state anisotropy of fluorescently labeled cells was measured, and membrane integrity assessed by flow cytometry and ectoine distribution. Strong osmotic downshocks slightly increased the fluidity of the bacterial membranes. As the temperature increased, the increasing membrane fluidity encouraged more ectoine release under the same osmotic shock conditions. On the other hand, combined shock treatments increased the number of disintegrated cells. From the ectoine release and membrane integrity measurements under coupled thermal and osmotic shock conditions, we could optimize the secretion conditions for both bacteria. PMID:23653110

  18. Partial characterization of an extracellular polysaccharide produced by the moderately halophilic bacterium Halomonas xianhensis SUR308.

    PubMed

    Biswas, Jhuma; Ganguly, J; Paul, A K

    2015-01-01

    A moderately halophilic bacterium, Halomonas xianhensis SUR308 (Genbank Accession No. KJ933394) was isolated from a multi-pond solar saltern at Surala, Ganjam district, Odisha, India. The isolate produced a significant amount (7.87 g l(-1)) of extracellular polysaccharides (EPS) when grown in malt extract-yeast extract medium supplemented with 2.5% NaCl, 0.5% casein hydrolysate and 3% glucose. The EPS was isolated and purified following the conventional method of precipitation and dialysis. Chromatographic analysis (paper, GC and GC-MS) of the hydrolyzed EPS confirmed its heteropolymeric nature and showed that it is composed mainly of glucose (45.74 mol%), galactose (33.67 mol %) and mannose (17.83 mol%). Fourier-transform infrared spectroscopy indicated the presence of methylene and carboxyl groups as characteristic functional groups. In addition, its proton nuclear magnetic resonance spectrum revealed functional groups specific for extracellular polysaccharides. X-ray diffraction analysis revealed the amorphous nature (CIxrd, 0.56) of the EPS. It was thermostable up to 250 °C and displayed pseudoplastic rheology and remarkable stability against pH and salts. These unique properties of the EPS produced by H. xianhensis indicate its potential to act as an agent for detoxification, emulsification and diverse biological activities. PMID:26577604

  19. Marinobacter piscensis sp. nov., a moderately halophilic bacterium isolated from salty food in Tunisia.

    PubMed

    Hedi, Abdeljabbar; Cayol, Jean Luc; Sadfi, Najla; Fardeau, Marie-Laure

    2015-04-01

    An aerobic, Gram-negative, moderately halophilic bacterium, oxidase, and catalase positive-designated Abdou3(T), was isolated from salted traditional foods (Anchovies) in Tunisia. Cells were rod-shaped, non-spore-forming and motile. Growth occurred at 15-45 °C (optimum, 37 °C), pH 5.5-8.75 (optimum, 7.3), and in the presence of 1-15 % NaCl (optimum, 10 %). Strain Abdou3(T) used glucose, D-arabinose, and sucrose. Strain Abdou3(T) had Q9 as the major respiratory quinone and C18:1 ω9c and C16:0 as predominant fatty acids. The DNA G+C content was 55.2 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA (rRNA) gene sequence indicated that strain Abdou3(T) had as its closest relative Marinobacter maritimus (identity of 96 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain Abdou3(T) is proposed as a novel species of the genus Marinobacter within the order Alteromonadales, for which the name M. piscensis sp. nov. is proposed. The type strain is Abdou3(T) (=DSM 26804(T)). PMID:25510172

  20. Genome sequence of the moderately halophilic bacterium Salinicoccus carnicancri type strain CrmT (= DSM 23852T)

    PubMed Central

    Hyun, Dong-Wook; Whon, Tae Woong; Cho, Yong-Joon; Chun, Jongsik; Kim, Min-Soo; Jung, Mi-Ja; Shin, Na-Ri; Kim, Joon-Yong; Kim, Pil Soo; Yun, Ji-Hyun; Lee, Jina; Oh, Sei Joon; Bae, Jin-Woo

    2013-01-01

    Salinicoccus carnicancri Jung et al. 2010 belongs to the genus Salinicoccus in the family Staphylococcaceae. Members of the Salinicoccus are moderately halophilic and originate from various salty environments. The halophilic features of the Salinicoccus suggest their possible uses in biotechnological applications, such as biodegradation and fermented food production. However, the genus Salinicoccus is poorly characterized at the genome level, despite its potential importance. This study presents the draft genome sequence of S. carnicancri strain CrmT and its annotation. The 2,673,309 base pair genome contained 2,700 protein-coding genes and 78 RNA genes with an average G+C content of 47.93 mol%. It was notable that the strain carried 72 predicted genes associated with osmoregulation, which suggests the presence of beneficial functions that facilitate growth in high-salt environments. PMID:23991257

  1. Genome sequence of the exopolysaccharide-producing Salipiger mucosus type strain (DSM 16094T), a moderately halophilic member of the Roseobacter clade

    PubMed Central

    Riedel, Thomas; Spring, Stefan; Fiebig, Anne; Petersen, Jörn; Kyrpides, Nikos C.; Göker, Markus; Klenk, Hans-Peter

    2014-01-01

    Salipiger mucosus Martínez-Cànovas et al. 2004 is the type species of the genus Salipiger, a moderately halophilic and exopolysaccharide-producing representative of the Roseobacter lineage within the alphaproteobacterial family Rhodobacteraceae. Members of this family were shown to be the most abundant bacteria especially in coastal and polar waters, but were also found in microbial mats and sediments. Here we describe the features of the S. mucosus strain DSM 16094T together with its genome sequence and annotation. The 5,689,389-bp genome sequence consists of one chromosome and several extrachromosomal elements. It contains 5,650 protein-coding genes and 95 RNA genes. The genome of S. mucosus DSM 16094T was sequenced as part of the activities of the Transregional Collaborative Research Center 51 (TRR51) funded by the German Research Foundation (DFG). PMID:25197501

  2. Haloanaerobium salsugo sp. nov., a moderately halophilic, anaerobic bacterium from a subterranean brine

    SciTech Connect

    Bhupathiraju, V.K.; Sharma, P.K.; Tanner, R.S.; McInerney, M.J.; Oren, A.; Woese, C.R.

    1994-07-01

    A strictly anaerobic, moderately halophilic, gram-negative bacterium was isolated from a highly saline oil field brine. The bacterium was a non-spore-forming, nonmotile rod, appearing singly, in pairs, or occasionally as long chains, and measured 0.3 to 0.4 by 2.6 to 4 {micro}m. The bacterium had a specific requirement for NaCl and grew at NaCl concentrations of between 6 and 24%, with optimal growth at 9% NaCl. The isolate grew at temperatures of between 22 and 51 C and pH values of between 5.6 and 8.0. The doubling time in a complex medium containing 10% NaCl was 9 h. Growth was inhibited by chloramphenicol, tetracycline, and penicillin but not by cycloheximide or azide. Fermentable substrates were predominantly carbohydrates. The end products of glucose fermentation were acetate, ethanol, CO{sub 2}, and H{sub 2}. The major components of the cellular fatty acids were C{sub 14:0}, C{sub 16:0}, C{sub 16:1}, and C{sub 17:0 cyc} acids. The DNA base composition of the isolate was 34 mol% G+C. Oligonucleotide catalog and sequence analyses of the 16S rRNA showed that strain VS-752{sup T} was most closely related to Haloanaerobium praevalens GSL{sup T} (ATCC 33744), the sole member of the genus Haloanaerobium. The authors propose that strain VS-752 (ATCC 51327) by established as the type strain of a new species, Haloanaerobium salsugo, in the genus Haloanaerobium. 40 refs., 3 figs, 5 tabs.

  3. Salt-dependent thermo-reversible α-amylase: cloning and characterization of halophilic α-amylase from moderately halophilic bacterium, Kocuria varians.

    PubMed

    Yamaguchi, Rui; Tokunaga, Hiroko; Ishibashi, Matsujiro; Arakawa, Tsutomu; Tokunaga, Masao

    2011-02-01

    A moderately halophilic bacterium, Kocuria varians, was found to produce active α-amylase (K. varians α-amylase (KVA)). We have observed at least six different forms of α-amylase secreted by this bacterium into the culture medium. Characterization of these KVA forms and cloning of the corresponding gene revealed that KVA comprises pre-pro-precursor form of α-amylase catalytic domain followed by the tandem repeats, which show high similarity to each other and to the starch binding domain (SBD) of other α-amylases. The observed six forms were most likely derived by various processing of the protein product. Recombinant KVA protein was successfully expressed in Escherichia coli as a fusion protein and was purified with affinity chromatography after cleavage from fusion partner. The highly acidic amino acid composition of KVA and the highly negative electrostatic potential surface map of the modeled structure strongly suggested its halophilic nature. Indeed, KVA showed distinct salt- and time-dependent thermal reversibility: when α-amylase was heat denatured at 85°C for 3 min in the presence of 2 M NaCl, the activity was recovered upon incubation on ice (50% recovery after 15 min incubation). Conversely, KVA denatured in 0.1 M NaCl was not refolded at all, even after prolonged incubation. KVA activity was inhibited by proteinaceous α-amylase inhibitor from Streptomyces nitrosporeus, which had been implicated to inhibit only animal α-amylases. KVA with putative SBD regions was found to digest raw starch. PMID:20871989

  4. Diversity and enumeration of halophilic and alkaliphilic bacteria in Spanish-style green table-olive fermentations.

    PubMed

    Lucena-Padrós, Helena; Ruiz-Barba, José Luis

    2016-02-01

    The presence and enumeration of halophilic and alkaliphilic bacteria in Spanish-style table-olive fermentations was studied. Twenty 10-tonne fermenters at two large manufacturing companies in Spain, previously studied through both culture dependent and independent (PCR-DGGE) methodologies, were selected. Virtually all this microbiota was isolated during the initial fermentation stage. A total of 203 isolates were obtained and identified based on 16S rRNA gene sequences. They belonged to 13 bacterial species, included in 11 genera. It was noticeable the abundance of halophilic and alkaliphilic lactic acid bacteria (HALAB). These HALAB belonged to the three genera of this group: Alkalibacterium, Marinilactibacillus and Halolactibacillus. Ten bacterial species were isolated for the first time from table olive fermentations, including the genera Amphibacillus, Natronobacillus, Catenococcus and Streptohalobacillus. The isolates were genotyped through RAPD and clustered in a dendrogram where 65 distinct strains were identified. Biodiversity indexes found statistically significant differences between both patios regarding genotype richness, diversity and dominance. However, Jaccard similarity index suggested that the halophilic/alkaliphilic microbiota in both patios was more similar than the overall microbiota at the initial fermentation stage. Thus, up to 7 genotypes of 6 different species were shared, suggesting adaptation of some strains to this fermentation stage. Morisita-Horn similarity index indicated a high level of codominance of the same species in both patios. Halophilic and alkaliphilic bacteria, especially HALAB, appeared to be part of the characteristic microbiota at the initial stage of this table-olive fermentation, and they could contribute to the conditioning of the fermenting brines in readiness for growth of common lactic acid bacteria. PMID:26678130

  5. Halotolerant and halophilic bacteria in the oceans of the icy satellites

    NASA Astrophysics Data System (ADS)

    Ramirez, S. I.; Montoya, L.; Avendaño, R.

    2013-05-01

    Halotolerant and halophilic prokaryotes require salt concentrations equal to or higher than those present at terrestrial oceans (Rothschild and Mancinelli, 2001). They are a particular kind of extremophiles and as expected, their halotolerance is mainly expressed in terms of a certain NaCl percentage, at least on Earth. With the discovery of putative salty liquid oceans beneath the iced surfaces of some of the satellites of Jupiter and Saturn (Mueller and McKinnon, 1988; Kargel et al., 2000; Zolotov, 2007), information about the impact of other types of salts, different from NaCl, on the growth of complex biological systems is necessary. We have found that when three specific bacteria strains are growing in media enriched with salts containing chaotropic and kosmotropic ions, their specific optimal growth value is modified (Montoya et al., 2010). The changes can be broadly explained in terms of the Hofmeister series (Zhang and Cremer, 2006). These results can be used to infer an extension in the limits of biological activity. For terrestrial organisms there is scarce information to determine the impact of another salt in the growth of an organism. In these sense we have found that when media enriched with magnesium sulfate (MgSO4) at water activity values (aw) similar to those reported as optimal for NaCl, their growth and tolerance is considerably enhanced. On the other hand, the combination of chaotropic and kosmotropic ions result in salts of astrobiological importance such as the sulphate already mentioned, carbonates or chlorides that can tentatively exist in the putative ocean of Europa, Ganymedes, or Enceladus or even at the subsurface of Mars. In this frame, we studied the growth rate of Halomonas halodurans, H. magadiensis and Bacillus pumillus when exposed to media enriched with NaCl, MgSO4, Mg(NO3)2, MgCl2, Na2SO4 and NH4SO4. Equivalent values of water activity (aw) for each salt were compared and correlated with microbial activity (Montoya et al., 2010

  6. Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum).

    PubMed

    Orhan, Furkan

    2016-01-01

    In the current study, 18 halotolerant and halophilic bacteria have been investigated for their plant growth promoting abilities in vitro and in a hydroponic culture. The bacterial strains have been investigated for ammonia, indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase production, phosphate solubilisation and nitrogen fixation activities. Of the tested bacteria, eight were inoculated with Triticum aestivum in a hydroponic culture. The investigated bacterial strains were found to have different plant-growth promoting activities in vitro. Under salt stress (200mM NaCl), the investigated bacterial strains significantly increased the root and shoot length and total fresh weight of the plants. The growth rates of the plants inoculated with bacterial strains ranged from 62.2% to 78.1%. Identifying of novel halophilic and halotolerant bacteria that promote plant growth can be used as alternatives for salt sensitive plants. Extensive research has been conducted on several halophilic and halotolerant bacterial strains to investigate their plant growth promoting activities. However, to the best of my knowledge, this is the first study to inoculate these bacterial strains with wheat. PMID:27133557

  7. Halomonas heilongjiangensis sp. nov., a novel moderately halophilic bacterium isolated from saline and alkaline soil.

    PubMed

    Dou, Guiming; He, Wei; Liu, Hongcan; Ma, Yuchao

    2015-08-01

    A moderately halophilic bacterium, designated strain 9-2(T), was isolated from saline and alkaline soil collected in Lindian county, Heilongjiang province, China. The strain was observed to be strictly aerobic, Gram-negative, rod-shaped, oxidase-positive, catalase-positive and motile. It was found to require NaCl for growth and to grow at NaCl concentrations of 0.5-14 % (w/v) (optimum, 7-10 %, w/v), at temperatures of 10-45 °C (optimum 25-30 °C) and at pH 5.0-10.0 (optimum pH 8.0). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 9-2(T) is a member of the genus Halomonas and is closely related to Halomonas desiderata DSM 9502(T) (96.68 %), Halomonas campaniensis DSM 1293(T) (96.46 %), Halomonas ventosae DSM 15911(T) (96.27 %) and Halomonas kenyensis DSM 17331(T) (96.27 %). The DNA-DNA hybridization value was 38.9 ± 0.66 % between the novel isolate 9-2(T) and H. desiderata DSM 9502(T). The predominant ubiquinones were identified as Q9 (75.1 %) and Q8 (24.9 %). The major fatty acids were identified as C16:0 (22.0 %), Summed feature 8 (C18:1 ω6c/C18:1 ω7c, 19.6 %), Summed feature 3 (C16:1 ω6c/C16:1 ω7c, 12.6 %), C12:0 3-OH (12.0 %) and C10:0 (11.7 %). The DNA G+C content was determined to be 69.7 mol%. On the basis of the evidence presented in this study, strain 9-2(T) is considered to represent a novel species of the genus Halomonas, for which the name Halomonas heilongjiangensis sp. nov. is proposed. The type strain is 9-2(T) (=DSM 26881(T) = CGMCC 1.12467(T)). PMID:26036672

  8. Halomonas urumqiensis sp. nov., a moderately halophilic bacterium isolated from a saline-alkaline lake.

    PubMed

    Zhang, Shanshan; Pan, Jiao; Lu, Weidong; Yan, Yanchun; Wang, Haisheng; Wiegel, Jurgen; Zhao, Baisuo

    2016-05-01

    A moderately halophilic, aerobic bacterium, strain BZ-SZ-XJ27T, belonging to the genus Halomonas, was isolated from a saline-alkaline lake in the Xinjiang Uyghur Autonomous Region of China. Phylogenetic analysis based on 16S rRNA gene sequences and a multilocus sequence analysis using the 16S rRNA, gyrB and rpoD genes demonstrated that strain BZ-SZ-XJ27T represents a member of the genus Halomonas. On the basis of 16S rRNA gene sequence similarity, the closest relatives were Halomonas campaniensis 5AGT, H. fontilapidosi 5CRT, H. korlensis XK1T and H. sinaiensis ALO SharmT, with similarities of 96.2-97.2 %. DNA-DNA hybridization with H. korlensis CGMCC 1.6981T (the nearest phylogenetic neighbour) and H. campaniensis DSM 15293T (the highest 16S rRNA gene sequence similarity) showed relatedness values of 53 and 38 %, respectively, demonstrating the separateness of the three taxa. The bacterium stained Gram-negative and the cells were motile and rod-shaped. The strain formed creamy-white colonies and grew under optimal conditions of 1.42 M Na+ (range 0.22-4.32 M Na+), pH 8.0-8.5 (range pH 6.0-10.0) and 39 °C (range 4-43 °C). The dominant fatty acids were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c; 36.6 %), C16 : 0 (25.9 %) and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 21.2 %). The dominant polar lipids were two unknown phospholipids, phosphatidylethanolamine and phosphatidylglycerol, and the main respiratory quinones were ubiquinone 9 (Q-9; 89 %) and ubiquinone 8 (Q-8; 10 %). The genomic DNA G+C content was 61.7 ± 0.8 mol% (Tm). On the basis of phenotypic, chemotaxonomic and phylogenetic features, strain BZ-SZ-XJ27T is proposed to represent a novel species, Halomonas urumqiensis sp. nov., within the genus Halomonas of the family Halomonadaceae. The type strain is BZ-SZ-XJ27T ( = JCM 30202T = CGMCC 1.12917T). PMID:26873696

  9. Halobacillus salicampi sp. nov., a moderately halophilic bacterium isolated from a solar saltern sediment.

    PubMed

    Kim, Su-Jin; Lee, Jae-Chan; Han, Song-Ih; Whang, Kyung-Sook

    2016-05-01

    A Gram-positive, moderately halophilic bacterium, designated strain TGS-15(T), was isolated from the sediment of a solar saltern pond located in Shinan, Korea. Strain TGS-15(T) was found to be a strictly aerobic, non-motile rod which can grow at pH 6.0-10.0 (optimum, pH 9.0), at 20-35 °C (optimum, 28 °C) and at salinities of 1-20 % (w/v) NaCl (optimum, 9 % NaCl). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain TGS-15(T) belongs to the genus Halobacillus, with sequence similarity of 98.5-96.0 % to known type strains, showing high sequence similarity to Halobacillus locisalis MSS-155(T) (98.5 %), Halobacillus faecis IGA7-4(T) (98.2 %) and Halobacillus alkaliphilus FP5(T) (98.0 %), and less than 98.0 % sequence similarity to other currently recognised type strains of the genus. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and an unidentified lipid. The cell wall peptidoglycan was found to be based on L-Orn-D-Asp, the predominant isoprenoid quinone was identified as menaquinone-7 (MK-7) and the major fatty acids were identified as anteiso-C15:0, iso-C15:0, anteiso-C17:0 and C16:1 ω7c alcohol. The DNA G+C content of this novel isolate was determined to be 45.3 mol %. Levels of DNA:DNA relatedness between strain TGS-15(T) and the type strains of 13 other species of the genus ranged from 52 to 9 %. On the basis of the polyphasic analysis conducted in this study, strain TGS-15(T) is concluded to represent a novel species of the genus Halobacillus, for which the name Halobacillus salicampi sp. nov. is proposed. The type strain is TGS-15(T) (=KACC 18264(T) = NBRC 110640(T)). PMID:26942918

  10. Marinobacter shengliensis sp. nov., a moderately halophilic bacterium isolated from oil-contaminated saline soil.

    PubMed

    Luo, Yi-Jing; Xie, Bai-Sheng; Lv, Xiang-Lin; Cai, Man; Wang, Ya-Nan; Cui, Heng-Lin; Cai, Hua; Wu, Xiao-Lei

    2015-04-01

    Two moderately halophilic strains, designated SL013A34A2(T) and SL013A24A, were isolated from oil-contaminated saline soil from Shengli Oilfield, eastern China. Cells were found to be Gram-staining negative, aerobic, rod-shaped with a single polar flagellum. The isolates were found to grow at 10-40 °C (optimum 35 °C), pH 6.0-9.0 (optimum pH 8.0), and NaCl concentrations of 0.5-18.0 % (w/v) (optimum 3.0-6.0 NaCl). The 16S rRNA gene sequence analysis indicated that the isolates belong to the genus Marinobacter. Strain SL013A34A2(T) shares the highest 16S rRNA gene sequence similarities with strain SL013A24A (99.3 %), followed by M. hydrocarbonoclasticus CGMCC 1.7683(T) (97.8 %), M. vinifirmus CGMCC 1.7265(T) (97.8 %), and M. excellens KMM 3809(T) (97.4 %), respectively, but low similarities (93.8-96.4 %) with type strains of the other numbers of genus Marinobacter. DNA-DNA relatedness values of strain SL013A34A2(T) with strains SL013A24A, M. hydrocarbonoclasticus CGMCC 1.7683(T), M. vinifirmus CGMCC 1.7265(T) and M. excellens KMM 3809(T) were 88.7, 29.2, 33.4 and 29.4 %, respectively. The major fatty acids of strain SL013A34A2(T) were identified as C18:1 ω9c, C16:0, C12:03-OH, C12:0, C16:1 ω9c and 10-methyl C18:0. The major respiratory quinone of strain SL013A34A2(T) was found to be ubiquinone-9, and its predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and unidentified glycolipid. The genomic DNA G + C content was found to be 56.1 mol %. Based on the phenotypic, genetic and chemotaxonomic characteristics, these two isolates are representatives of a novel species of the genus Marinobacter, for which the name Marinobacter shengliensis sp. nov. is proposed. The type strain is SL013A34A2(T)(=LMG 27740(T) = CGMCC 1.12758(T)). PMID:25652339

  11. Glycocaulis albus sp. nov., a moderately halophilic dimorphic prosthecate bacterium isolated from petroleum-contaminated saline soil.

    PubMed

    Lv, Xiang-Lin; Xie, Bai-Sheng; Cai, Man; Geng, Shuang; Tang, Yue-Qin; Wang, Ya-Nan; Cui, Heng-Lin; Liu, Xue-Ying; Ye, Si-Yuan; Wu, Xiao-Lei

    2014-09-01

    Two novel bacterial strains, SLG210-30A1(T) and SLG210-19A2, which shared 99.9 % 16S rRNA gene sequence similarity with each other, were isolated from petroleum-contaminated saline soil in Shengli Oilfield, eastern China. Cells were Gram-stain-negative, motile, aerobic, mesophilic and moderately halophilic. They could grow chemoheterotrophically with oxygen as an electron acceptor. Morphologically, cells were typical Caulobacteria-type dimorphic prosthecate bacteria. The genomic DNA G+C contents of strains SLG210-30A1(T) and SLG210-19A2 were 61.8 mol% and 61.6 mol% respectively. Strain SLG210-30A1(T) had Q10 as the predominant respiratory ubiquinone, and C16 : 0 (28.4 %), C17 : 0 (11.6 %), C18 : 0 (22.1 %) and C18 : 1ω7c (14.0 %) as the major cellular fatty acids. The polar lipids of the two isolates were some glycolipids, a lipid, a phospholipid, an aminoglycolipid and an aminophospholipid (all unidentified). The 16S rRNA gene sequences of strains SLG210-30A1(T) and SLG210-19A2 showed the highest similarities with Glycocaulis abyssi MCS 33(T) (99.8-99.9 %), but low sequence similarities (<94.7 %) with type strains of other members of the family Hyphomonadaceae. However, the DNA-DNA relatedness of G. abyssi MCS 33(T) to strains SLG210-30A1(T) and SLG210-19A2 was 37.4±4.4 % and 36.1±1.1 %, respectively. Based on different physiological, biochemical, and phylogenetic characteristics, strains SLG210-30A1(T) and SLG210-19A2 represent a novel species of the genus Glycocaulis. The name Glycocaulis albus is therefore proposed with strain SLG210-30A1(T) ( = LMG 27741(T) = CGMCC 1.12766(T)) as the type strain. An emended description of the genus Glycocaulis is also provided. PMID:24966201

  12. Biotransformation of Direct Blue 1 by a moderately halophilic bacterium Marinobacter sp. strain HBRA and toxicity assessment of degraded metabolites.

    PubMed

    Arun Prasad, A S; Satyanarayana, V S V; Bhaskara Rao, K V

    2013-11-15

    The ability of halophiles to survive in the extreme salt concentrations has gained them the importance of being used in the treatment of industrial waste waters. A moderately halophilic bacterial strain with the ability to degrade the complex azo dye Direct Blue-1 (DB-1) was isolated from sea water and identified as Marinobacter sp. strain HBRA. Complete decolorization of DB-1 (100 mg L(-1)) was achieved in 6h at 37 °C, pH 8 and with 70 g L(-1) NaCl. Decolorization was analyzed by UV-vis spectrophotometer. The FT-IR spectrum revealed that Marinobacter sp. strain HBRA specifically targeted azo bond (NN) at 1631 cm(-1) to break down Direct Blue-1. Formation of metabolites at different retention times in HPLC indicated degradation. Biotransformation pathway for DB-1 was proposed based on LC-MS. Phytotoxicity study revealed the less toxic nature of the metabolites compared to the dye. Genotoxicity with Allium cepa confirmed the cytotoxic nature of DB-1 by inducing several chromosomal abnormalities compared to the negligible effects of degraded metabolites. The current study is the first report on the detoxification of DB-1 by Marinobacter sp. strain HBRA. PMID:24121630

  13. Marinobacter hydrocarbonoclasticus NY-4, a novel denitrifying, moderately halophilic marine bacterium.

    PubMed

    Li, Rongpeng; Zi, Xiaoli; Wang, Xinfeng; Zhang, Xia; Gao, Haofeng; Hu, Nan

    2013-01-01

    The isolation and characterization of a novel halophilic denitrifying marine bacterium is described. The halophilic bacterium, designated as NY-4, was isolated from soil in Yancheng City, China, and identified as Marinobacter hydrocarbonoclasticus by 16S rRNA gene sequence phylogenetic analysis. This organism can grow in NaCl concentrations ranging from 20 to 120 g/L. Optimum growth occurs at 80 g/L NaCl and pH 8.0. The organism can grow on a broad range of carbon sources and demonstrated efficient denitrifying ability (94.2% of nitrate removal and 80.9% of total nitrogen removal in 48 h). During denitrification by NY-4, no NO2 (-)-N was accumulated, N2 was the only gaseous product and no harmful N2O was produced. Because of its rapid denitrification ability, broad carbon use range and ability to grow under high salinity and pH conditions, NY-4 holds promise for the treatment of saline waste waters. PMID:25538872

  14. The potential of halophilic and halotolerant bacteria for the production of antineoplastic enzymes: L-asparaginase and L-glutaminase

    PubMed Central

    Shirazian, Pejman; Asad, Sedigheh; Amoozegar, Mohammad Ali

    2016-01-01

    L-asparaginase and L-glutaminase can be effectively used for the treatment of patients who suffer from accute lymphoblastic leukemia and tumor cells. Microbial sources are the best source for the bulk production of these enzymes. However, their long-term administration may cause immunological responses, so screening for new enzymes with novel properties is required. Halophilic and halotolerant bacteria with novel enzymatic characteristics can be considered as a potential source for production of enzymes with different immunological properties. In this study, L-asparaginase and L-glutaminase production by halophilic bacteria isolated from Urmia salt lake was studied. Out of the 85 isolated halophilic and halotolerant bacterial strains, 16 (19 %) showed L-asparaginase activity and 3 strains (3.5 %) showed L-glutaminase activity. Strains with the highest activities were selected for further studies. Based on 16S rDNA sequence analysis, it was shown that the selected isolates for L-asparaginase and L-glutaminase production belong to the genus Bacillus and Salicola, respectively. Both enzymes were produced extracellularly. The strain with the most L-asparaginase production did not show L-glutaminase production which is medically important. The effects of key parameters including temperature, initial pH of the solution, and concentrations of glucose, asparagine or glutamine, and sodium chloride were evaluated by means of response surface methodology (RSM) to optimize enzymes production. Under the obtained optimal conditions, L-asparaginase and L-glutaminase production was increased up to 1.5 (61.7 unit/mL) and 2.6 fold (46.4 unit/mL), respectively. PMID:27330530

  15. Halophilic Bacteria of Lunsu Produce an Array of Industrially Important Enzymes with Salt Tolerant Activity.

    PubMed

    Gupta, Sonika; Sharma, Parul; Dev, Kamal; Sourirajan, Anuradha

    2016-01-01

    The halophilic bacterial isolates SS1, SS2, SS3, SS5, and SS8 were characterized for production of industrially important enzymes like amylase, protease, lipase, and glutaminase. Halophilic bacterial isolates SS1 and SS3 exhibited salt dependent extracellular amylase and protease activities. Both the halophilic isolates SS1 and SS3 exhibited maximum amylase and protease activities in the presence of 1.5 and 1.0 M NaCl, respectively, with the optimum pH 8 and temperature 40°C. SS2 showed maximum extracellular protease and lipase activities in the presence of 0.75 M NaCl, at optimum pH of 7, and temperature 37°C. The glutaminase activity of SS3 increased with increase in concentration of NaCl up to 2.5 M. The optimum pH and temperature for L-glutaminase activity of SS3 was 8 and 40°C, respectively. The combined hydrolytic activities of these halophilic bacterial isolates can be used for bioconversion of organic materials to useful products. PMID:26885394

  16. Halophilic Bacteria of Lunsu Produce an Array of Industrially Important Enzymes with Salt Tolerant Activity

    PubMed Central

    Gupta, Sonika; Sharma, Parul; Dev, Kamal; Sourirajan, Anuradha

    2016-01-01

    The halophilic bacterial isolates SS1, SS2, SS3, SS5, and SS8 were characterized for production of industrially important enzymes like amylase, protease, lipase, and glutaminase. Halophilic bacterial isolates SS1 and SS3 exhibited salt dependent extracellular amylase and protease activities. Both the halophilic isolates SS1 and SS3 exhibited maximum amylase and protease activities in the presence of 1.5 and 1.0 M NaCl, respectively, with the optimum pH 8 and temperature 40°C. SS2 showed maximum extracellular protease and lipase activities in the presence of 0.75 M NaCl, at optimum pH of 7, and temperature 37°C. The glutaminase activity of SS3 increased with increase in concentration of NaCl up to 2.5 M. The optimum pH and temperature for L-glutaminase activity of SS3 was 8 and 40°C, respectively. The combined hydrolytic activities of these halophilic bacterial isolates can be used for bioconversion of organic materials to useful products. PMID:26885394

  17. A diverse group of halophilic bacteria exist in Lunsu, a natural salt water body of Himachal Pradesh, India.

    PubMed

    Gupta, Sonika; Sharma, Parul; Dev, Kamal; Srivastava, Malay; Sourirajan, Anuradha

    2015-01-01

    Five halophilic bacterial isolates namely SS1, SS2, SS3, SS5 and SS8 were isolated from soil sediments of Lunsu, a salty water body. All the bacterial isolates showed growth in LB medium containing up to 8.7% NaCl, pH 7-8 and at temperature range of 30-37°C. The bacterial isolates SS1 and SS3 require at least 3.8% NaCl for their growth, indicating their strict halophilic nature. Interestingly, bacterial isolates SS2, SS5 and SS8 but not SS1 and SS3 exhibited growth in medium supplemented with KCl. Accordingly, Na(+) and K(+) ions were detected at 1.39 and 0.0035%, respectively in Lunsu water. All the bacterial isolates were analyzed by random amplification of polymorphic DNA (RAPD) using four different random primers and produced PCR fragments ranging from 0.1 to 5 kb in size. Phylogenetic tree based on RAPD finger prints showed that SS1 and SS3 formed one group, while SS2 and SS5 formed the second group, whereas SS8 was out group. Sequence analysis of 16S rDNA identified SS1 and SS3 as Halobacillus trueperi, SS2 as Shewanella algae, SS5 as Halomonas venusta, and SS8 as Marinomonas sp. were deposited in GenBank with accession numbers of KM260166, KF751761, KF751760, KF751762 and KF751763, respectively. This is the first report on the presence of diverse halophilic bacteria in the foot hills of Himalayas. PMID:26090321

  18. Bacillus oshimensis sp. nov., a moderately halophilic, non-motile alkaliphile.

    PubMed

    Yumoto, Isao; Hirota, Kikue; Goto, Toshitaka; Nodasaka, Yoshinobu; Nakajima, Kenji

    2005-03-01

    A halophilic and halotolerant, facultatively alkaliphilic strain, K11(T), was isolated from soil obtained from Oshyamanbe, Oshima, Hokkaido, Japan. The isolate grew at pH 7-10. It was non-motile, Gram-positive and aerobic. Cells comprised straight rods and produced ellipsoidal spores. The isolate grew in 0-20 % NaCl, with optimum growth at 7 % NaCl, and hydrolysed casein, gelatin, starch, DNA and Tweens 20, 40, 60 and 80. The major isoprenoid quinone was menaquinone-7, and the cellular fatty acid profile consisted of significant amounts of C(15) branched-chain acids, iso C(15 : 0) and anteiso C(15 : 0). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain K11(T) was a member of group 6 [Nielsen et al., FEMS Microbiol Lett 117 (1994), 61-66] (alkaliphiles) of the genus Bacillus. DNA-DNA hybridization revealed a low relatedness (14 %) of the isolate to its closest phylogenetic neighbour, Bacillus clausii. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic data and DNA-DNA relatedness data, it was concluded that K11(T) (=JCM 12663(T)=NCIMB 14023(T)) merits classification as the type strain of a novel species, for which the name Bacillus oshimensis sp. nov. is proposed. PMID:15774684

  19. Industrial and environmental applications of halophilic microorganisms.

    PubMed

    Oren, Aharon

    2010-01-01

    In comparison with the thermophilic and the alkaliphilic extremophiles, halophilic microorganisms have as yet found relatively few biotechnological applications. Halophiles are involved in centuries-old processes such as the manufacturing of solar salt from seawater and the production of traditional fermented foods. Two biotechnological processes involving halophiles are highly successful: the production of beta-carotene by the green alga Dunaliella and the production of ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid), used as a stabilizer for enzymes and now also applied in cosmetic products, from moderately halophilic bacteria. The potential use of bacteriorhodopsin, the retinal protein proton pump of Halobacterium, in optoelectronic devices and photochemical processes is being explored, and may well lead to commercial applications in the near future. Demand for salt-tolerant enzymes in current manufacturing or related processes is limited. Other possible uses of halophilic microorganisms such as treatment of saline and hypersaline wastewaters, and the production of exopolysaccharides, poly-beta-hydroxyalkanoate bioplastics and biofuel are being investigated, but no large-scale applications have yet been reported. PMID:20662374

  20. Marinococcus tarijensis sp. nov., a moderately halophilic bacterium isolated from a salt mine.

    PubMed

    Balderrama-Subieta, Andrea; Guzmán, Daniel; Minegishi, Hiroaki; Echigo, Akinobu; Shimane, Yasuhiro; Hatada, Yuji; Quillaguamán, Jorge

    2013-09-01

    A Gram-stain-positive, coccoid-shaped, halophilic bacterium, strain SR-1(T), was isolated from a salt crystal obtained from a mine located in Tarija, Bolivia. The strain was investigated using a polyphasic approach. The optimum conditions for growth of strain SR-1(T) were reached at 5% (w/v) NaCl, pH 7.6 and 37-40 °C. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The isoprenoid quinone was MK-7. The major cellular fatty acids of strain SR-1(T) were anteiso-C(15:0), anteiso-C(17:0) and iso-C(16:0). The DNA G+C content of strain SR-1(T) was 48.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed a close relationship between strain SR-1(T) and Marinococcus halophilus JCM 2479(T) (99.7% 16S rRNA gene sequence similarity), Marinococcus halotolerans KCTC 19045(T) (99.4%) and Marinococcus luteus KCTC 13214(T) (99.8%). However, strain SR-1(T) also showed low levels of DNA-DNA relatedness with these reference strains (47, 61 and 58%, respectively). On the basis of phenotypic differences and DNA-DNA hybridization results, strain SR-1(T) is considered to represent a novel species of the genus Marinococcus, for which the name Marinococcus tarijensis sp. nov. is proposed. The type strain is SR-1(T) ( =LMG 26930(T) =CECT 8130(T)). PMID:23504966

  1. Characterization of Lignocellulolytic Activities from a Moderate Halophile Strain of Aspergillus caesiellus Isolated from a Sugarcane Bagasse Fermentation

    PubMed Central

    Miranda-Miranda, Estefan; Sánchez-Reyes, Ayixón; Cuervo-Soto, Laura; Aceves-Zamudio, Denise; Atriztán-Hernández, Karina; Morales-Herrera, Catalina; Rodríguez-Hernández, Rocío; Folch-Mallol, Jorge

    2014-01-01

    A moderate halophile and thermotolerant fungal strain was isolated from a sugarcane bagasse fermentation in the presence of 2 M NaCl that was set in the laboratory. This strain was identified by polyphasic criteria as Aspergillus caesiellus. The fungus showed an optimal growth rate in media containing 1 M NaCl at 28°C and could grow in media added with up to 2 M NaCl. This strain was able to grow at 37 and 42°C, with or without NaCl. A. caesiellus H1 produced cellulases, xylanases, manganese peroxidase (MnP) and esterases. No laccase activity was detected in the conditions we tested. The cellulase activity was thermostable, halostable, and no differential expression of cellulases was observed in media with different salt concentrations. However, differential band patterns for cellulase and xylanase activities were detected in zymograms when the fungus was grown in different lignocellulosic substrates such as wheat straw, maize stover, agave fibres, sugarcane bagasse and sawdust. Optimal temperature and pH were similar to other cellulases previously described. These results support the potential of this fungus to degrade lignocellulosic materials and its possible use in biotechnological applications. PMID:25162614

  2. Screening of halophilic bacteria and Alteromonas species for organophosphorus hydrolyzing enzyme activity.

    PubMed

    DeFrank, J J; Beaudry, W T; Cheng, T C; Harvey, S P; Stroup, A N; Szafraniec, L L

    1993-06-01

    Previously, a G-type nerve agent degrading enzyme activity was found in a halophilic bacterial isolate designated JD6.5. This organism was tentatively identified as an unknown species of the genus Alteromonas. In order to determine whether this type of enzyme activity was common in other species of Alteromonas, a screening program was initiated. A number of Alteromonas species and five halophilic bacterial isolates were cultured and their crude cell extracts screened for hydrolytic activity against several organophosphorus chemical agents and other related compounds. The samples were also screened for cross-reactivity with a monoclonal antibody raised against the purified enzyme from JD6.5 and for hybridization with a DNA probe based on its N-terminal amino acid sequence A wide spectrum of activities and reactivities were seen, suggesting a significant heterogeneity between the functionally similar enzymes that are present in these bacterial species. Enzymes of the type described here have considerable potential for the decontamination and demilitarization of chemical warfare agents. PMID:8393735

  3. Kocuria marina BS-15 a biosurfactant producing halophilic bacteria isolated from solar salt works in India

    PubMed Central

    Sarafin, Yesurethinam; Donio, Mariathasan Birdilla Selva; Velmurugan, Subramanian; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2014-01-01

    Biosurfactant screening was made among the eight halophilic bacterial genera isolated from Kovalam solar salt works in Kanyakumari of India. After initial screening, Kocuria sp. (Km), Kurthia sp. (Ku) and Halococcus sp. (Hc) were found to have positive biosurfactant activity. Biosurfactant derived from Kocuria sp. emulsified more than 50% of the crude oil, coconut oil, sunflower oil, olive oil and kerosene when compared to the other strains. Further, Kocuria marina BS-15 derived biosurfactant was purified and characterized by TLC, FTIR and GC–MS analysis. The TLC analysis revealed that, the purified biosurfactants belong to the lipopeptide group. The IR spectrum results revealed that functional groups are R2C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 NN, alkenes and N–H. The GC–MS analysis confirmed the compound as Nonanoic acid and Cyclopropane with the retention time of 12.78 and 24.65, respectively. PMID:25473358

  4. Ribulose-1,5-bisphosphate carboxylase/oxygenase genes as a functional marker for chemolithoautotrophic halophilic sulfur-oxidizing bacteria in hypersaline habitats.

    PubMed

    Tourova, Tatjana P; Kovaleva, Olga L; Sorokin, Dimitry Yu; Muyzer, Gerard

    2010-07-01

    The presence and diversity of the cbb genes encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) (a key enzyme of the Calvin-Benson cycle of autotrophic CO(2) assimilation) were investigated in pure cultures of seven genera of halophilic chemolithoautotrophic sulfur-oxidizing bacteria (SOB) and in sediments from a hypersaline lake in which such bacteria have been recently discovered. All of the halophilic SOB strains (with the exception of Thiohalomonas nitratireducens) possessed the cbbL gene encoding RuBisCO form I, while the cbbM gene encoding RuBisCO form II was detected only in some of the pure cultures. The general topologies of the CbbL/CbbM trees and the 16S rRNA gene tree were different, but both markers showed that the halophilic SOB genera formed independent lineages in the Gammaproteobacteria. In some cases, such as with several strains of the genus Thiohalospira and with Thioalkalibacter halophilus, the cbbL clustering was incongruent with the positions of these strains on the ribosomal tree. In the cbbM tree, the clustering of Thiohalospira and Thiohalorhabdus strains was incongruent with their branching in both cbbL and 16S rRNA gene trees. cbbL and cbbM genes related to those found in the analysed halophilic SOB were also detected in a sediment from a hypersaline lake in Kulunda Steppe (Russia). Most of the cbbL and cbbM genes belonged to members of the genus Thiohalorhabdus. In the cbbL clone library, sequences related to those of Halothiobacillus and Thiohalospira were detected as minor components. Some of the environmental cbbM sequences belonged to as yet unknown phylotypes, representing deep lineages of halophilic autotrophs. PMID:20299400

  5. Genome sequence of the moderately thermophilic halophile Flexistipes sinusarabici strain (MAS10T)

    PubMed Central

    Lapidus, Alla; Chertkov, Olga; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, Natalia; Huntemann, Marcel; Mavromatis, Konstantinos; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Brambilla, Evelyne-Marie; Rohde, Manfred; Abt, Birte; Spring, Stefan; Göker, Markus; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C.; Klenk, Hans-Peter; Woyke, Tanja

    2011-01-01

    Flexistipes sinusarabici Fiala et al. 2000 is the type species of the genus Flexistipes in the family Deferribacteraceae. The species is of interest because of its isolated phylogenetic location in a genomically under-characterized region of the tree of life, and because of its origin from a multiply extreme environment; the Atlantis Deep brines of the Red Sea, where it had to struggle with high temperatures, high salinity, and a high concentrations of heavy metals. This is the fourth completed genome sequence to be published of a type strain of the family Deferribacteraceae. The 2,526,590 bp long genome with its 2,346 protein-coding and 53 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project. PMID:22180813

  6. Genome sequence of the moderately thermophilic halophile Flexistipes sinusarabici strain (MAS10T)

    SciTech Connect

    Lapidus, Alla L.; Chertkov, Olga; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Huntemann, Marcel; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Brambilla, Evelyne-Marie; Rohde, Manfred; Abt, Birte; Spring, Stefan; Goker, Markus; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Woyke, Tanja

    2011-01-01

    Flexistipes sinusarabici Fiala et al. 2000 is the type species of the genus Flexistipes in the fami- ly Deferribacteraceae. The species is of interest because of its isolated phylogenetic location in a genomically under-characterized region of the tree of life, and because of its origin from a multiply extreme environment; the Atlantis Deep brines of the Red Sea, where it had to struggle with high temperatures, high salinity, and a high concentrations of heavy metals. This is the fourth completed genome sequence to be published of a type strain of the family Deferribacteraceae. The 2,526,590 bp long genome with its 2,346 protein-coding and 53 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  7. Halophilic bacteria are colonizing the exhibition areas of the Capuchin Catacombs in Palermo, Italy.

    PubMed

    Piñar, G; Kraková, L; Pangallo, D; Piombino-Mascali, D; Maixner, F; Zink, A; Sterflinger, K

    2014-07-01

    The Capuchin Catacombs of Palermo, Italy, contain over 1800 mummies dating from the 16th to 20th centuries AD. Their environment is not conducive to the conservation of the remains due to, among other factors, water infiltration, which is producing salt efflorescences on the walls. A multiphasic approach was applied to investigate the halophilic microbiota present in the Catacombs. Enrichment cultures were conducted on media containing different NaCl concentrations, ranging from 3 to 20 %. For screening of the strains, the following two PCR-based methods were used and compared: fluorescence internal transcribed spacer PCR (f-ITS) and random amplification of polymorphic DNA (RAPD) analyses. Results derived from RAPD profiles were shown to be slightly more discriminative than those derived from f-ITS. In addition, the proteolytic and cellulolytic abilities were screened through the use of plate assays, gelatin agar and Ostazin Brilliant Red H-3B (OBR-HEC), respectively. Many of the strains isolated from the wall samples displayed proteolytic activities, such as all strains belonging to the genera Bacillus, Virgibacillus and Arthrobacter, as well as some strains related to the genera Oceanobacillus, Halobacillus and Idiomarina. In addition, many of the strains isolated from materials employed to stuff the mummies showed cellulolytic activities, such as those related to species of the genera Chromohalobacter and Nesterenkonia, as well as those identified as Staphylococcus equorum and Halomonas sp. Furthermore, many of the strains were pigmented ranging from yellow to a strong pink color, being directly related to the discoloration displayed by the materials. PMID:24863363

  8. Bacillus coahuilensis sp. nov., a moderately halophilic species from a desiccation lagoon in the Cuatro Ciénegas Valley in Coahuila, Mexico.

    PubMed

    Cerritos, René; Vinuesa, Pablo; Eguiarte, Luis E; Herrera-Estrella, Luis; Alcaraz-Peraza, Luis D; Arvizu-Gómez, Jackeline L; Olmedo, Gabriela; Ramirez, Enrique; Siefert, Janet L; Souza, Valeria

    2008-04-01

    A moderately halophilic, Gram-positive and rod-shaped bacterium, strain m4-4T, was isolated from a Chihuahuan desert lagoon in Cuatro Ciénegas, Coahuila, Mexico. Strain m4-4T was found to grow optimally at 30-37 degrees C, pH 7.0-8.0 and 5 % NaCl and to tolerate from 0.5 % to 10 % NaCl. It was shown to be aerobic. The genomic DNA G+C content was about 37 mol%. Strain m4-4T exhibited minimal or no growth on most sugars tested. Its major cellular fatty acids were C14 : 0, C16 : 0 and C18 : 1. Based on phylogenetic analysis of 16S rRNA and recA gene sequences, we observed that the closest relatives of the isolate are moderately halophilic Bacillus species, with 16S rRNA gene sequence similarity ranging from 96.6 to 97.4 % (Bacillus marisflavi, Bacillus aquimaris and Bacillus vietnamensis). Additionally, using genomic data it was determined that the type strain contains a total of nine rRNA operons with three slightly different sequences. On the basis of phenotypic and molecular properties, strain m4-4T represents a novel species within the genus Bacillus, for which the name Bacillus coahuilensis sp. nov. is proposed, with the type strain m4-4T (=NRRL B-41737T =CECT 7197T). PMID:18398195

  9. Proteinase-producing halophilic lactic acid bacteria isolated from fish sauce fermentation and their ability to produce volatile compounds.

    PubMed

    Udomsil, Natteewan; Rodtong, Sureelak; Tanasupawat, Somboon; Yongsawatdigul, Jirawat

    2010-07-15

    Halophilic lactic acid bacteria were isolated from fish sauce mashes fermented at 1 to 12 months. Seven out of sixty-four isolates were selected according to their proteolytic activity and growth at 25% NaCl for characterization and investigation of volatile compound production. All selected isolates were Gram-positive cocci with pairs/tetrads and grew at 0-25% NaCl, pH 4.5-9.0. Results of 16S rRNA gene sequence analysis showed 99% homology to Tetragenococcus halophilus ATCC 33315. The restriction fragment length polymorphism (RFLP) patterns of all isolates were also similar to those of T. halophilus ATCC 33315. These isolates were, thus, identified as T. halophilus. All isolates hydrolyzed fish protein in the medium containing 25% NaCl. Intracellular aminopeptidase of 7 isolates exhibited the highest activity of 2.85-3.67 U/ml toward Ala-p-nitroanilide (Ala-pNA). T.halophilus strains MS33 and M11 showed the highest alanyl aminopeptidase activity (P<0.05), and produced histamine in mGYP broth containing 5 and 25% NaCl in the level of 6.62-22.55 and 13.14-20.39 mg/100ml, respectively. Predominant volatile compounds of fish broth containing 25% NaCl inoculated with T. halophilus MS33 and MRC5-5-2 were 1-propanol, 2-methylpropanal, and benzaldehyde, corresponding to major volatile compounds in fish sauce. T.halophilus appeared to play an important role in volatile compound formation during fish sauce fermentation. PMID:20541276

  10. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production by a moderate halophile Yangia sp. ND199 using glycerol as a carbon source.

    PubMed

    Van-Thuoc, Doan; Huu-Phong, Tran; Minh-Khuong, Dang; Hatti-Kaul, Rajni

    2015-03-01

    Yangia sp. ND199, a moderate halophile isolated from mangrove soil sample in Vietnam, was found to accumulate poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from unrelated carbon sources in a medium with 4.5% (w/v) NaCl. Cultivation with glycerol as carbon source and yeast extract as nitrogen source resulted in maximum cell dry weight of 5.7 g/l and PHBV content of 52.8 wt% (containing 2.9 mol% of 3HV) after 40 h. The 3HV content of the PHBV was the highest during initial stages of copolymer production and decreased with increase in the copolymer amount with time, but was not affected by changing the pH of the culture medium. Only homopolymer poly(3-hydroxybutyrate) was synthesized when monosodium glutamate was used as the nitrogen source. Fed-batch cultivation of Yangia sp. ND199 with glycerol and yeast extract gave PHBV content and productivity of 53.2 wt% and 0.44 g/l/h, respectively, which were reduced to 40.6 wt% and 0.25 g/l/h, respectively, with crude glycerol as carbon source. Both the copolymer content and productivity were improved to 56 wt% and 0.61 g/l/h, respectively, by using 1:1 mixture of crude glycerol and high fructose corn syrup. This is the first report of PHBV production by a wild-type halophilic bacterium using glycerol as carbon source. PMID:25600362

  11. Halophiles and their enzymes: negativity put to good use.

    PubMed

    DasSarma, Shiladitya; DasSarma, Priya

    2015-06-01

    Halophilic microorganisms possess stable enzymes that function in very high salinity, an extreme condition that leads to denaturation, aggregation, and precipitation of most other proteins. Genomic and structural analyses have established that the enzymes of halophilic Archaea and many halophilic Bacteria are negatively charged due to an excess of acidic over basic residues, and altered hydrophobicity, which enhance solubility and promote function in low water activity conditions. Here, we provide an update on recent bioinformatic analysis of predicted halophilic proteomes as well as experimental molecular studies on individual halophilic enzymes. Recent efforts on discovery and utilization of halophiles and their enzymes for biotechnology, including biofuel applications are also considered. PMID:26066288

  12. Distribution of compatible solutes in the halophilic methanogenic archaebacteria

    SciTech Connect

    Meichin Lai; Sowers, K.R.; Gunsalus, R.P. ); Robertson, D.E.; Roberts, M.F. )

    1991-09-01

    Accumulation of compatible solutes, by uptake or de novo synthesis, enables bacteria to reduce the difference between osmotic potentials of the cell cytoplasm and the extracellular environment. To examine this process in the halophilic and halotolerant methanogenic archaebacteria, 14 strains were tested for the accumulation of compatible solutes in response to growth in various extracellular concentrations of NaCl. In external NaCl concentrations of 0.7 to 3.4 M, the halophilic methanogens accumulated K{sup +} ion and low-molecular-weight organic compounds. {beta}-Glutamate was detected in two halotolerant strains that grew below 1.5 M NaCl. Two unusual {beta}-amino acids, N{sub {var epsilon}}-acetyl-{beta}-lysine and {beta}-glutamine (3-aminoglutaramic acid), as well as L-{alpha}-glutamate were compatible solutes among all of these strains. De novo synthesis of glycine betaine was also detected in several strains of moderately and extremely halophilic methanogens. The zwitterionic compounds ({beta}-glutamine, N{sub {var epsilon}}-acetyl-{beta}-lysine,a nd glycine betaine) and potassium were the predominant compatible solutes among the moderately and extremely halophilic methanogens. This is the first report of {beta}-glutamine as a compatible solute and de novo biosynthesis of glycine betaine in the methanogenic archaebacteria.

  13. Distribution of compatible solutes in the halophilic methanogenic archaebacteria.

    PubMed Central

    Lai, M C; Sowers, K R; Robertson, D E; Roberts, M F; Gunsalus, R P

    1991-01-01

    Accumulation of compatible solutes, by uptake or de novo synthesis, enables bacteria to reduce the difference between osmotic potentials of the cell cytoplasm and the extracellular environment. To examine this process in the halophilic and halotolerant methanogenic archaebacteria, 14 strains were tested for the accumulation of compatible solutes in response to growth in various extracellular concentrations of NaCl. In external NaCl concentrations of 0.7 to 3.4 M, the halophilic methanogens accumulated K+ ion and low-molecular-weight organic compounds. beta-Glutamate was detected in two halotolerant strains that grew below 1.5 M NaCl. Two unusual beta-amino acids, N epsilon-acetyl-beta-lysine and beta-glutamine (3-aminoglutaramic acid), as well as L-alpha-glutamate were compatible solutes among all of these strains. De novo synthesis of glycine betaine was also detected in several strains of moderately and extremely halophilic methanogens. The zwitterionic compounds (beta-glutamine, N epsilon-acetyl-beta-lysine, and glycine betaine) and potassium were the predominant compatible solutes among the moderately and extremely halophilic methanogens. This is the first report of beta-glutamine as a compatible solute and de novo biosynthesis of glycine betaine in the methanogenic archaebacteria. PMID:1909318

  14. Bioenergetic Aspects of Halophilism

    PubMed Central

    Oren, Aharon

    1999-01-01

    Examinination of microbial diversity in environments of increasing salt concentrations indicates that certain types of dissimilatory metabolism do not occur at the highest salinities. Examples are methanogenesis for H2 + CO2 or from acetate, dissimilatory sulfate reduction with oxidation of acetate, and autotrophic nitrification. Occurrence of the different metabolic types is correlated with the free-energy change associated with the dissimilatory reactions. Life at high salt concentrations is energetically expensive. Most bacteria and also the methanogenic archaea produce high intracellular concentrations of organic osmotic solutes at a high energetic cost. All halophilic microorganisms expend large amounts of energy to maintain steep gradients of NA+ and K+ concentrations across their cytoplasmic membrane. The energetic cost of salt adaptation probably dictates what types of metabolism can support life at the highest salt concentrations. Use of KCl as an intracellular solute, while requiring far-reaching adaptations of the intracellular machinery, is energetically more favorable than production of organic-compatible solutes. This may explain why the anaerobic halophilic fermentative bacteria (order Haloanaerobiales) use this strategy and also why halophilic homoacetogenic bacteria that produce acetate from H2 + CO2 exist whereas methanogens that use the same substrates in a reaction with a similar free-energy yield do not. PMID:10357854

  15. Using extremely halophilic bacteria to understand the role of surface charge and surface hydration in protein evolution, folding, and function

    NASA Astrophysics Data System (ADS)

    Hoff, Wouter; Deole, Ratnakar; Osu Collaboration

    2013-03-01

    Halophilic Archaea accumulate molar concentrations of KCl in their cytoplasm as an osmoprotectant, and have evolved highly acidic proteomes that only function at high salinity. We examine osmoprotection in the photosynthetic Proteobacteria Halorhodospira halophila. We find that H. halophila has an acidic proteome and accumulates molar concentrations of KCl when grown in high salt media. Upon growth of H. halophila in low salt media, its cytoplasmic K + content matches that of Escherichia coli, revealing an acidic proteome that can function in the absence of high cytoplasmic salt concentrations. These findings necessitate a reassessment of two central aspects of theories for understanding extreme halophiles. We conclude that proteome acidity is not driven by stabilizing interactions between K + ions and acidic side chains, but by the need for maintaining sufficient solvation and hydration of the protein surface at high salinity through strongly hydrated carboxylates. We propose that obligate protein halophilicity is a non-adaptive property resulting from genetic drift in which constructive neutral evolution progressively incorporates weakly stabilizing K + binding sites on an increasingly acidic protein surface.

  16. Draft Genome Sequence of Halobacillus sp. Strain KGW1, a Moderately Halophilic and Alkaline Protease-Producing Bacterium Isolated from the Rhizospheric Region of Phragmites karka from Chilika Lake, Odisha, India

    PubMed Central

    Panda, Ananta Narayan; Mishra, Samir R.; Ray, Lopamudra; Sahu, Neha; Acharya, Ankita; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar

    2016-01-01

    Halobacillus sp. strain KGW1 is a moderately halophilic, rod shaped, Gram-positive, yellow pigmented, alkaline protease-producing bacterium isolated from a water sample from Chilika Lake, Odisha, India. Sequencing of bacterial DNA assembled a 3.68-Mb draft genome. The genome annotation analysis showed various gene clusters for tolerance to stress, such as elevated pH, salt concentration, and toxic metals. PMID:27365341

  17. Draft Genome Sequence of Halobacillus sp. Strain KGW1, a Moderately Halophilic and Alkaline Protease-Producing Bacterium Isolated from the Rhizospheric Region of Phragmites karka from Chilika Lake, Odisha, India

    PubMed Central

    Panda, Ananta Narayan; Mishra, Samir R.; Ray, Lopamudra; Sahu, Neha; Acharya, Ankita; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar

    2016-01-01

    Halobacillus sp. strain KGW1 is a moderately halophilic, rod shaped, Gram-positive, yellow pigmented, alkaline protease-producing bacterium isolated from a water sample from Chilika Lake, Odisha, India. Sequencing of bacterial DNA assembled a 3.68-Mb draft genome. The genome annotation analysis showed various gene clusters for tolerance to stress, such as elevated pH, salt concentration, and toxic metals.

  18. Draft Genome Sequence of Halobacillus sp. Strain KGW1, a Moderately Halophilic and Alkaline Protease-Producing Bacterium Isolated from the Rhizospheric Region of Phragmites karka from Chilika Lake, Odisha, India.

    PubMed

    Panda, Ananta Narayan; Mishra, Samir R; Ray, Lopamudra; Sahu, Neha; Acharya, Ankita; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar; Raina, Vishakha

    2016-01-01

    Halobacillus sp. strain KGW1 is a moderately halophilic, rod shaped, Gram-positive, yellow pigmented, alkaline protease-producing bacterium isolated from a water sample from Chilika Lake, Odisha, India. Sequencing of bacterial DNA assembled a 3.68-Mb draft genome. The genome annotation analysis showed various gene clusters for tolerance to stress, such as elevated pH, salt concentration, and toxic metals. PMID:27365341

  19. The Genome of the Moderate Halophile Amycolicicoccus subflavus DQS3-9A1T Reveals Four Alkane Hydroxylation Systems and Provides Some Clues on the Genetic Basis for Its Adaptation to a Petroleum Environment

    PubMed Central

    Nie, Yong; Fang, Hui; Li, Yan; Chi, Chang-Qiao; Tang, Yue-Qin; Wu, Xiao-Lei

    2013-01-01

    The moderate halophile Amycolicicoccus subflavus DQS3-9A1T is the type strain of a novel species in the recently described novel genus Amycolicicoccus, which was isolated from oil mud precipitated from oil produced water. The complete genome of A. subflavus DQS3-9A1T has been sequenced and is characteristic of harboring the genes for adaption to the harsh petroleum environment with salinity, high osmotic pressure, and poor nutrient levels. Firstly, it characteristically contains four types of alkane hydroxylases, including the integral-membrane non-heme iron monooxygenase (AlkB) and cytochrome P450 CYP153, a long-chain alkane monooxygenase (LadA) and propane monooxygenase. It also accommodates complete pathways for the response to osmotic pressure. Physiological tests proved that the strain could grow on n-alkanes ranging from C10 to C36 and propane as the sole carbon sources, with the differential induction of four kinds of alkane hydroxylase coding genes. In addition, the strain could grow in 1–12% NaCl with the putative genes responsible for osmotic stresses induced as expected. These results reveal the effective adaptation of the strain DQS3-9A1T to harsh oil environment and provide a genome platform to investigate the global regulation of different alkane metabolisms in bacteria that are crucially important for petroleum degradation. To our knowledge, this is the first report to describe the co-existence of such four types of alkane hydroxylases in a bacterial strain. PMID:23967144

  20. Kushneria pakistanensis sp. nov., a novel moderately halophilic bacterium isolated from rhizosphere of a plant (Saccharum spontaneum) growing in salt mines of the Karak area in Pakistan.

    PubMed

    Bangash, Asia; Ahmed, Iftikhar; Abbas, Saira; Kudo, Takuji; Shahzad, Armghan; Fujiwara, Toru; Ohkuma, Moriya

    2015-04-01

    The taxonomic position of a Gram-stain negative, moderately halophilic bacterium, designated NCCP-934(T), was investigated using polyphasic taxonomic approach. The strain NCCP-934(T) was isolated from rhizosphere of a plant (Saccharum spontaneum, family Poaceae) growing in salt mines area in the Karak district of Khyber Pakhtunkhwa Province, Pakistan. Cells of strain NCCP-934(T) are rod shaped and motile. The bacterium is strictly aerobic, can grow at a temperature range of 10-40 °C (optimum at 30-33 °C) and in a pH range of 6.0-10.5 (optimum pH 7.0-9.0). The strain can tolerate 1-30 % (w/v) NaCl (optimal growth occurs in the presence of approximately 3-9 % NaCl). The phylogenetic analysis based on the 16S rRNA gene sequence, showed that strain NCCP-934(T) belongs to the genus Kushneria with the highest sequence similarity to K. marisflavi SW32(T) (98.9 %), K. indalinina CG2.1(T) (98.7 %), K. avicenniae MW2a(T) (98.4 %) and less than 97 % similarity with other related species (94.7 % with the type species of the genus, K. aurantia A10(T)). DNA-DNA relatedness between strain NCCP-934(T) and the type strains of the closely related species was lower than 18 %. The chemotaxonomic data (major respiratory quinone, Q9; predominant fatty acids, C18:1 ω7c and C16:0 followed by C12:0 3-OH and Summed features 3 (C16:1 ω7c/iso-C15:0 2-OH); major polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanol, phosphatidylserine, phosphatidylinositol and three polar lipid of unknown structure) supported the affiliation of strain NCCP-934(T) within the genus Kushneria. The DNA G+C content of strain NCCP-934(T) was 59.2 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain NCCP-934(T) can be distinguished from the closely related taxa and thus represents a novel species in the genus Kushneria, for which the name Kushneria pakistanensis sp. nov. is proposed, with the type strain NCCP-934(T) (=LMG 28525(T

  1. Cloning and identification of a novel NhaD-type Na+/H+ antiporter from metagenomic DNA of the halophilic bacteria in soil samples around Daban Salt Lake.

    PubMed

    Zhang, Hua; Wang, Zhenhui; Wang, Lei; Mu, Ren; Zou, Zhi; Yuan, Kun; Wang, Yuekun; Wu, Haiping; Jiang, Juquan; Yang, Lifu

    2014-01-01

    In this study, metagenomic DNA was screened for the Na(+)/H(+) antiporter gene from the halophilic bacteria in Daban Salt Lake by selection in Escherichia coli KNabc lacking three major Na(+)/H(+) antiporters. One gene designated as Hb_nhaD encoding a novel NhaD-type Na(+)/H(+) antiporter was finally cloned. The presence of Hb_NhaD conferred tolerance of E. coli KNabc to up to 0.5 M NaCl and 0.2 M LiCl, and an alkaline pH. Hb_NhaD has the highest identity (70.6%) with a putative NhaD-type Na(+)/H(+) antiporter from an uncharacterized Clostridiaceae species, and also has lower identity with known NhaD-type Na(+)/H(+) antiporters from Halomonas elongata (20.8%), Alkalimonas amylolytica (19.0%), Vibrio parahaemolyticus (18.9%) and Vibrio cholerae (18.7 %). pH-dependent Na(+)(Li(+))/H(+) antiport activity was detected from everted membrane vesicles prepared from E. coli KNabc carrying Hb_nhaD. Hb_NhaD exhibited very high Na(+)(Li(+))/H(+) antiport activity over a wide pH range from 6.5 to 9.0 with the highest activity at pH 7.0 which is significantly different from those of the above known NhaD-type Na(+)/H(+) antiporters. Also, the apparent K m values of Hb_NhaD for Na(+) and Li(+) at pH 7.0 were determined to be 1.31 and 2.16, respectively. Based on the above results, we proposed that Hb_NhaD should be categorized as a novel NhaD-type Na(+)/H(+) antiporter. PMID:24297704

  2. Isolation and molecular characterization of multidrug-resistant halophilic bacteria from shrimp farm effluents of Parangipettai coastal waters.

    PubMed

    Sundaramanickam, Arumugam; Kumar, Poominathan Suresh; Kumaresan, Saravanan; Balasubramanian, Thangavel

    2015-08-01

    Multidrug resistance of heterotrophic bacteria isolated from an aquaculture farm effluent in Parangipettai, at the southeastern coast of India, was investigated. In the initial screening, 27 antibiotic-resistant strains were isolated. All the strains were tested for antibiotic susceptibility against chloramphenicol with varying concentrations. From these, two highly resistant strains, i.e. S1 and S5, were isolated. The selected strains were identified by 16S ribosomal RNA (rRNA) sequencing techniques and confirmed as Bacillus pumilus and Bacillus flexus. Both the antibiotic-resistant strains were further utilized for multidrug susceptibility test by using various antibiotics. These two strains showed antibiotic resistance to 14 of 17 antibiotics tested. Both microdilution assay and well assay methods were used to determine the minimal inhibitory concentration (MIC) for the sensitive strains. Both the tests were shown to be almost similar. Our study highlights the occurrence of multidrug-resistant bacteria in the shrimp farm effluents. PMID:25850744

  3. Isolation and characterization of halophilic lactic acid bacteria isolated from "terasi" shrimp paste: a traditional fermented seafood product in Indonesia.

    PubMed

    Kobayashi, Takeshi; Kajiwara, Michika; Wahyuni, Mita; Kitakado, Toshihide; Hamada-Sato, Naoko; Imada, Chiaki; Watanabe, Etsuo

    2003-10-01

    Lactic acid bacteria from "terasi" shrimp paste, a highly popular fermented seafood in Indonesia were isolated and characterized. Viable cell counts were 10(4) to 10(6) cfu/g on MRS medium. All the isolates were catalase-negative, gram-positive cocci and were able to grow at 15% NaCl. Numerical phenotypic analysis showed that the isolates clustered into one group. However, they could be classified into two types: the Tetragenococcus halophilus group and the T. muriaticus group as revealed by a restriction fragment length polymorphism (RFLP) analysis and sequencing of the 16S rRNA gene. This study is the first to show that both species of Tetragenococcus are distributed in Indonesian fermented foods. PMID:14673751

  4. Structure of a highly acidic β-lactamase from the moderate halophile Chromohalobacter sp. 560 and the discovery of a Cs+-selective binding site

    PubMed Central

    Arai, Shigeki; Yonezawa, Yasushi; Okazaki, Nobuo; Matsumoto, Fumiko; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu; Adachi, Motoyasu; Tamada, Taro; Kawamoto, Masahide; Tokunaga, Hiroko; Ishibashi, Matsujiro; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2015-01-01

    Environmentally friendly absorbents are needed for Sr2+ and Cs+, as the removal of the radioactive Sr2+ and Cs+ that has leaked from the Fukushima Nuclear Power Plant is one of the most important problems in Japan. Halophilic proteins are known to have many acidic residues on their surface that can provide specific binding sites for metal ions such as Cs+ or Sr2+. The crystal structure of a halophilic β-lactamase from Chromohalobacter sp. 560 (HaBLA) was determined to resolutions of between 1.8 and 2.9 Å in space group P31 using X-ray crystallography. Moreover, the locations of bound Sr2+ and Cs+ ions were identified by anomalous X-ray diffraction. The location of one Cs+-specific binding site was identified in HaBLA even in the presence of a ninefold molar excess of Na+ (90 mM Na+/10 mM Cs+). From an activity assay using isothermal titration calorimetry, the bound Sr2+ and Cs+ ions do not significantly affect the enzymatic function of HaBLA. The observation of a selective and high-affinity Cs+-binding site provides important information that is useful for the design of artificial Cs+-binding sites that may be useful in the bioremediation of radioactive isotopes. PMID:25760604

  5. Structure of a highly acidic β-lactamase from the moderate halophile Chromohalobacter sp. 560 and the discovery of a Cs{sup +}-selective binding site

    SciTech Connect

    Arai, Shigeki; Yonezawa, Yasushi; Okazaki, Nobuo; Matsumoto, Fumiko; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu; Adachi, Motoyasu; Tamada, Taro; Kawamoto, Masahide; Tokunaga, Hiroko; Ishibashi, Matsujiro; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2015-03-01

    The tertiary structure of a β-lactamase derived from the halobacterium Chromohalobacter sp. 560 (HaBLA) was determined by X-ray crystallography. Three unique Sr{sup 2+}-binding sites and one Cs{sup +}-binding site were discovered in the HaBLA molecule. Environmentally friendly absorbents are needed for Sr{sup 2+} and Cs{sup +}, as the removal of the radioactive Sr{sup 2+} and Cs{sup +} that has leaked from the Fukushima Nuclear Power Plant is one of the most important problems in Japan. Halophilic proteins are known to have many acidic residues on their surface that can provide specific binding sites for metal ions such as Cs{sup +} or Sr{sup 2+}. The crystal structure of a halophilic β-lactamase from Chromohalobacter sp. 560 (HaBLA) was determined to resolutions of between 1.8 and 2.9 Å in space group P3{sub 1} using X-ray crystallography. Moreover, the locations of bound Sr{sup 2+} and Cs{sup +} ions were identified by anomalous X-ray diffraction. The location of one Cs{sup +}-specific binding site was identified in HaBLA even in the presence of a ninefold molar excess of Na{sup +} (90 mM Na{sup +}/10 mM Cs{sup +}). From an activity assay using isothermal titration calorimetry, the bound Sr{sup 2+} and Cs{sup +} ions do not significantly affect the enzymatic function of HaBLA. The observation of a selective and high-affinity Cs{sup +}-binding site provides important information that is useful for the design of artificial Cs{sup +}-binding sites that may be useful in the bioremediation of radioactive isotopes.

  6. RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes

    PubMed Central

    Grosjean, Henri; Gaspin, Christine; Marck, Christian; Decatur, Wayne A; de Crécy-Lagard, Valérie

    2008-01-01

    Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics) and pattern of RNA modifications (Modomics) depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation. PMID:18844986

  7. Metabolism of halophilic archaea.

    PubMed

    Falb, Michaela; Müller, Kerstin; Königsmaier, Lisa; Oberwinkler, Tanja; Horn, Patrick; von Gronau, Susanne; Gonzalez, Orland; Pfeiffer, Friedhelm; Bornberg-Bauer, Erich; Oesterhelt, Dieter

    2008-03-01

    In spite of their common hypersaline environment, halophilic archaea are surprisingly different in their nutritional demands and metabolic pathways. The metabolic diversity of halophilic archaea was investigated at the genomic level through systematic metabolic reconstruction and comparative analysis of four completely sequenced species: Halobacterium salinarum, Haloarcula marismortui, Haloquadratum walsbyi, and the haloalkaliphile Natronomonas pharaonis. The comparative study reveals different sets of enzyme genes amongst halophilic archaea, e.g. in glycerol degradation, pentose metabolism, and folate synthesis. The carefully assessed metabolic data represent a reliable resource for future system biology approaches as it also links to current experimental data on (halo)archaea from the literature. PMID:18278431

  8. Diversity of anaerobic halophilic microorganisms

    NASA Astrophysics Data System (ADS)

    Oren, Aharon; Oremland, Roland S.

    2000-12-01

    Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Some can use alternative electron acceptors such as nitrate, fumarate, dimethylsulfoxide or trimethylamine-N-oxide Halobacterium salinarum can also grow fermentatively on L-arginine, and bacteriorhodopsin-containing cells may even grow anaerobically, energized by light. Obligatory anaerobic halophilic methanogenic Archaea also exist. The bacterial domain contains many anaerobic halophiles, including sulfate reducers. There is also a group of specialized obligatory anaerobic Bacteria, phylogenetically clustering in the low G + C branch of the Firmicutes. Most representatives of this group (order Haloanaerobiales, families Haloanaerobiaceae and Halobacteroidaceae) are fermentative, using a variety of carbohydrates and amino acids. One species combines the potential for anaerobic growth at high salt concentrations with a preference for high temperatures. Others are homoacetogens; Acetohalobium arabaticum can grow anaerobically as a chemolithotroph, producing acetate from hydrogen and CO2. The Haloanaerobiales accumulate high concentrations of K+ and Cl- in their cytoplasm, thereby showing a strategy of salt adaptation similar to that used by the Halobacteriales. Recently a new representative of the Haloanaerobiales was isolated from bottom sediments of the Dead Sea (strain DSSe1), which grows anaerobically by oxidation of glycerol to acetate and CO2 while reducing selenate to selenite and elementary selenium. Other electron acceptors supporting anaerobic growth of this strain are nitrate and trimethylamine-N-oxide. The versatility of life at high salt concentrations with respect

  9. Genomic analysis reveals the biotechnological and industrial potential of levan producing halophilic extremophile, Halomonas smyrnensis AAD6T.

    PubMed

    Diken, Elif; Ozer, Tugba; Arikan, Muzaffer; Emrence, Zeliha; Oner, Ebru Toksoy; Ustek, Duran; Arga, Kazim Yalcin

    2015-01-01

    Halomonas smyrnensis AAD6T is a gram negative, aerobic, and moderately halophilic bacterium, and is known to produce high levels of levan with many potential uses in foods, feeds, cosmetics, pharmaceutical and chemical industries due to its outstanding properties. Here, the whole-genome analysis was performed to gain more insight about the biological mechanisms, and the whole-genome organization of the bacterium. Industrially crucial genes, including the levansucrase, were detected and the genome-scale metabolic model of H. smyrnensis AAD6T was reconstructed. The bacterium was found to have many potential applications in biotechnology not only being a levan producer, but also because of its capacity to produce Pel exopolysaccharide, polyhydroxyalkanoates, and osmoprotectants. The genomic information presented here will not only provide additional information to enhance our understanding of the genetic and metabolic network of halophilic bacteria, but also accelerate the research on systematical design of engineering strategies for biotechnology applications. PMID:26251777

  10. Bioleaching of metals from spent refinery petroleum catalyst using moderately thermophilic bacteria: effect of particle size.

    PubMed

    Srichandan, Haragobinda; Singh, Sradhanjali; Pathak, Ashish; Kim, Dong-Jin; Lee, Seoung-Won; Heyes, Graeme

    2014-01-01

    The present work investigated the leaching potential of moderately thermophilic bacteria in the recovery of metals from spent petroleum catalyst of varying particle sizes. The batch bioleaching experiments were conducted by employing a mixed consortium of moderate thermophilic bacteria at 45°C and by using five different particle sizes (from 45 to >2000 μm) of acetone-washed spent catalyst. The elemental mapping by FESEM confirmed the presence of Al, Ni, V and Mo along with sulfur in the spent catalyst. During bioleaching, Ni (92-97%) and V (81-91%) were leached in higher concentrations, whereas leaching yields of Al (23-38%) were found to be lowest in all particle sizes investigated. Decreasing the particle size from >2000 μm to 45-106 μm caused an increase in leaching yields of metals during initial hours. However, the final metals leaching yields were almost independent of particle sizes of catalyst. Leaching kinetics was observed to follow the diffusion-controlled model showing the linearity more close than the chemical control. The results of the present study suggested that bioleaching using moderate thermophilic bacteria was highly effective in removing the metals from spent catalyst. Moreover, bioleaching can be conducted using spent catalyst of higher particle size (>2000 μm), thus saving the grinding cost and making process attractive for larger scale application. PMID:24679088

  11. Biodeterioration Risk Threatens the 3100 Year Old Staircase of Hallstatt (Austria): Possible Involvement of Halophilic Microorganisms

    PubMed Central

    Piñar, Guadalupe; Dalnodar, Dennis; Voitl, Christian; Reschreiter, Hans; Sterflinger, Katja

    2016-01-01

    Background The prosperity of Hallstatt (Salzkammergut region, Austria) is based on the richness of salt in the surrounding mountains and salt mining, which is documented as far back as 1500 years B.C. Substantial archaeological evidence of Bronze and Iron Age salt mining has been discovered, with a wooden staircase (1108 B.C.) being one of the most impressive and well preserved finds. However, after its discovery, fungal mycelia have been observed on the surface of the staircase, most probably due to airborne contamination after its find. Objective As a basis for the further preservation of this valuable object, the active micro-flora was examined to investigate the presence of potentially biodegradative microorganisms. Results Most of the strains isolated from the staircase showed to be halotolerant and halophilic microorganisms, due to the saline environment of the mine. Results derived from culture-dependent assays revealed a high fungal diversity, including both halotolerant and halophilic fungi, the most dominant strains being members of the genus Phialosimplex (synonym: Aspergillus). Additionally, some typical cellulose degraders, namely Stachybotrys sp. and Cladosporium sp. were detected. Numerous bacterial strains were isolated and identified as members of 12 different genera, most of them being moderately halophilic species. The most dominant isolates affiliated with species of the genera Halovibrio and Marinococcus. Halophilic archaea were also isolated and identified as species of the genera Halococcus and Halorubrum. Molecular analyses complemented the cultivation assays, enabling the identification of some uncultivable archaea of the genera Halolamina, Haloplanus and Halobacterium. Results derived from fungi and bacteria supported those obtained by cultivation methods, exhibiting the same dominant members in the communities. Conclusion The results clearly showed the presence of some cellulose degraders that may become active if the requirements for

  12. Draft Genome Sequence of the Halophilic and Highly Halotolerant Gammaproteobacteria Strain MFB021.

    PubMed

    Joseph, Toms C; Baby, Anju; Reghunathan, Dinesh; Varghese, Aswathy Mary; Murugadas, V; Lalitha, K V

    2014-01-01

    We report the 4.25-Mbp first draft sequence of Gammaproteobacteria strain MFB021, a moderate halophile isolated from petroleum-contaminated soil in Cochin, India. The genome of the strain MFB021 was sequenced to understand the mechanism of hydrocarbon degradation and the halophilicity of the bacterium. PMID:25414494

  13. Anaerobic bacteria from hypersaline environments.

    PubMed Central

    Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

    1994-01-01

    Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the

  14. Identification and characterization of ectoine biosynthesis genes and heterologous expression of the ectABC gene cluster from Halomonas sp. QHL1, a moderately halophilic bacterium isolated from Qinghai Lake.

    PubMed

    Zhu, Derui; Liu, Jian; Han, Rui; Shen, Guoping; Long, Qifu; Wei, Xiaoxing; Liu, Deli

    2014-02-01

    The moderately halophilic bacterium Halomonas sp. QHL1 was identified as a member of the genus Halomonas by 16S rRNA gene sequencing. HPLC analysis showed that strain QHL1 synthesizes ectoine in its cytoplasm. The genes involved in the ectoine biosynthesis pathway were identified on the chromosome in the order ectABC. Subsequently, the ectB gene from this strain was amplified by PCR, and the entire ectABC gene cluster (3,580 bp) was cloned using genome walking. Analysis showed that the ectA (579 bp), ectB (1269 bp), and ectC (390 bp) genes were organized in a single transcriptional unit and were predicted to encode three peptides of 21.2 kDa, 46.4 kDa, and 14.7 kDa, respectively. Two putative promoters, a δ(70)-dependent promoter and a δ(38)-controlled promoter, as well as several conserved motifs with unknown function were identified. Individual ectA, ectB, and ectC genes, and the entire ectABC gene cluster were inserted into the expression plasmid pET-28a(+) to generate the recombinant plasmids pET-28a(+)-ectA, pET-28a(+)-ectB, pET-28a(+)-ectC and pET-28a(+)-ectABC, respectively. Heterologous expression of these proteins in Escherichia coli BL21 (DE3) was confirmed by SDS-PAGE. The recombinant E. coli strain BL21 (pET-28a (+)-ectABC) displayed a higher salt tolerance than native E. coli cells but produced far less ectoine than the wild-type QHL1 strain. PMID:24500478

  15. Bioleaching of chalcopyrite and bornite by moderately thermophilic bacteria: an emphasis on their interactions

    NASA Astrophysics Data System (ADS)

    Zhao, Hong-bo; Wang, Jun; Gan, Xiao-wen; Qin, Wen-qing; Hu, Ming-hao; Qiu, Guan-zhou

    2015-08-01

    Interactions between chalcopyrite and bornite during bioleaching by moderately thermophilic bacteria were investigated mainly by X-ray diffraction, scanning electron microscopy, and electrochemical measurements performed in conjunction with bioleaching experiments. The results showed that a synergistic effect existed between chalcopyrite and bornite during bioleaching by both Acidithiobacillus caldus and Leptospirillum ferriphilum and that extremely high copper extraction could be achieved when chalcopyrite and bornite coexisted in a bioleaching system. Bornite dissolved preferentially because of its lower corrosion potential, and its dissolution was accelerated by the galvanic current during the initial stage of bioleaching. The galvanic current and optimum redox potential of 390-480 mV vs. Ag/AgCl promoted the reduction of chalcopyrite to chalcocite (Cu2S), thus accelerating its dissolution.

  16. Halophilic microorganisms in deteriorated historic buildings: insights into their characteristics.

    PubMed

    Adamiak, Justyna; Otlewska, Anna; Gutarowska, Beata; Pietrzak, Anna

    2016-01-01

    Historic buildings are constantly being exposed to numerous climatic changes such as damp and rainwater. Water migration into and out of the material's pores can lead to salt precipitation and the so-called efflorescence. The structure of the material may be seriously threatened by salt crystallization. A huge pressure is produced when salt hydrates occupy larger spaces, which leads at the end to cracking, detachment and material loss. Halophilic microorganisms have the ability to adapt to high salinity because of the mechanisms of inorganic salt (KCl or NaCl) accumulation in their cells at concentrations isotonic to the environment, or compatible solutes uptake or synthesis. In this study, we focused our attention on the determination of optimal growth conditions of halophilic microorganisms isolated from historical buildings in terms of salinity, pH and temperature ranges, as well as biochemical properties and antagonistic abilities. Halophilic microorganisms studied in this paper could be categorized as a halotolerant group, as they grow in the absence of NaCl, as well as tolerate higher salt concentrations (Staphylococcus succinus, Virgibacillus halodenitrificans). Halophilic microorganisms have been also observed (Halobacillus styriensis, H. hunanensis, H. naozhouensis, H. litoralis, Marinococcus halophilus and yeast Sterigmatomyces halophilus). With respect to their physiological characteristics, cultivation at a temperature of 25-30°C, pH 6-7, NaCl concentration for halotolerant and halophilic microorganisms, 0-10% and 15-30%, respectively, provides the most convenient conditions. Halophiles described in this study displayed lipolytic, glycolytic and proteolytic activities. Staphylococcus succinus and Marinococcus halophilus showed strong antagonistic potential towards bacteria from the Bacillus genus, while Halobacillus litoralis displayed an inhibiting ability against other halophiles. PMID:26894235

  17. Organic Osmolytes in Aerobic Bacteria from Mono Lake, an Alkaline, Moderately Hypersaline Environment

    PubMed Central

    Ciulla, R. A.; Diaz, M. R.; Taylor, B. F.; Roberts, M. F.

    1997-01-01

    The identity and concentrations of intracellular organic solutes were determined by nuclear magnetic resonance spectroscopy for two strains of aerobic, gram-negative bacteria isolated from Mono Lake, Calif., an alkaline, moderately hypersaline lake. Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) was the major endogenous solute in both organisms. Concentrations of ectoine varied with external NaCl levels in strain ML-D but not in strain ML-G, where the level was high but invariant from 1.5 to 3.0 M NaCl. Hydroxyectoine also occurred in strain ML-D, especially at elevated NaCl concentrations (2.5 and 3.0 M), but at levels lower than those of ectoine. Exogenous organic solutes that might occur in Mono Lake were examined for their effects on the de novo synthesis of ectoine. Dimethylsulfoniopropionate (DMSP) (0.1 or 1 mM) did not significantly lower ectoine levels in either isolate, and only strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G and became the main organic solute. Glycine betaine (GB) was more effective than DMSP in affecting ectoine levels, principally in strain ML-D. Strain ML-D accumulated GB to 50 or 67% of its organic solute pool at 2.5 M NaCl, at an external level of 0.1 or 1 mM GB, respectively. Strain ML-D also accumulated arsenobetaine. The methylated zwitterionic compounds, probably metabolic products of phytoplankton (DMSP and GB) or brine shrimps (arsenobetaine) in Mono Lake, may function as osmolytes for indigenous bacteria when present at high concentrations or under conditions of nitrogen limitation or salt stress. PMID:16535487

  18. Single-step bioconversion of lignocellulose to hydrogen using novel moderately thermophilic bacteria

    PubMed Central

    2014-01-01

    Background Consolidated bioprocessing (CBP) of lignocellulosic biomass to hydrogen offers great potential for lower cost and higher efficiency compared to processes featuring dedicated cellulase production. Current studies on CBP-based hydrogen production mainly focus on using the thermophilic cellulolytic bacterium Clostridium thermocellum and the extremely thermophilic cellulolytic bacterium Caldicellulosiruptor saccharolyticus. However, no studies have demonstrated that the strains in the genus Thermoanaerobacterium could be used as the sole microorganism to accomplish both cellulose degradation and H2 generation. Results We have specifically screened for moderately thermophilic cellulolytic bacteria enabling to produce hydrogen directly from conversion of lignocellulosic materials. Three new strains of thermophilic cellulolytic bacteria in the genus Thermoanaerobacterium growing at a temperature of 60°C were isolated. All of them grew well on various plant polymers including microcrystalline cellulose, filter paper, xylan, glucose, and xylose. In particular, the isolated bacterium, designated as Thermoanaerobacterium thermosaccharolyticum M18, showed high cellulolytic activity and a high yield of H2. When it was grown in 0.5% microcrystalline cellulose, approximately 82% cellulose was consumed, and the H2 yield and maximum production rate reached 10.86 mmol/g Avicel and 2.05 mmol/L/h, respectively. Natural lignocellulosic materials without any physicochemical or biological pretreatment also supported appreciable growth of strain M18, which resulted in 56.07% to 62.71% of insoluble cellulose and hemicellulose polymer degradation in corn cob, corn stalk, and wheat straw with a yield of 3.23 to 3.48 mmol H2/g substrate and an average production rate of 0.10 to 0.13 mmol H2/L/h. Conclusions The newly isolated strain T. thermosaccharolyticum M18 displayed effective degradation of lignocellulose and produced large amounts of hydrogen. This is the first report

  19. The ecological distributions of N, P utilizing bacteria and heterotrophic bacteria in the moderate hypoxia zone of the Changjiang Estuary

    NASA Astrophysics Data System (ADS)

    Liu, Jingjing; Du, Ping; Zeng, Jiangning; Chen, Quanzhen; Shou, Lu; Liao, Yibo; Jiang, Zhibing

    2013-12-01

    The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria), P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Estuary, and the roles of main environmental factors in distributing bacteria, are explored with observations from two cruises in June and August 2006. Comparisons between the two important periods of initial hypoxia phase (June) and developed hypoxia phase (August) show differences in both bacterial distributions and the associated main environmental factors. First, the primary group of ammonifying bacteria has larger magnitude with spatial maximum value in the hypoxic stations related to sediment in August. The phosphobacterial abundance and detection rates in August are much lower than those in June, but the denitrifying bacterial abundance becomes greater in August. However, the difference of heterotrophic bacterial abundance between June and August is not obvious. Second, main environmental factors influencing bacteria vary from initial hypoxia phase to developed hypoxia phase. Two parameters (salinity and NO3 -) in surface water and five environmental parameters (pH, salinity, PO4 3-, NO3 - and temperature) in bottom water and surface sediment play major roles in the bacterial abundance in June, while different parameter combinations (salinity and PO4 -) in surface water and different parameter combinations (DO, DOC, NO3 -, PO4 3- and pH) in bottom water and surface sediment play major roles in August. Moreover, the bottom bacteria distributions in area south of 31°N are related to the position of the Taiwan Warm Current in June. The bacterial abundance and distribution may respond to the environmental change in the hypoxia processes of initial phase and developed phase. During the hypoxia processes, the whole structure of bacterial functional groups probably turns to different states, causing the recycling of nutrient regeneration and aggravating

  20. Antimicrobial potential of Halophilic actinomycetes against multi drug resistant (MDR) ventilator associated pneumonia causing bacterial pathogens.

    PubMed

    Aslam, Sana; Sajid, Imran

    2016-03-01

    A collection of forty halophilic actinomycetes isolated from water and mud samples of the saline lake at Kalar Kahar, salt range, Pakistan, was screened to investigate their antimicrobial potential against multi drug resistant (MDR) ventilator associated pneumonia causing bacterial pathogens. The isolates exhibited significant tolerance to alkaline conditions and grew well at pH 9-11. The taxonomic status of the isolated strains was determined by morphological, biochemical and physiological characterization and by 16s rRNA gene sequencing. The results revealed that majority of the isolates (90%) belong to the genus Streptomyces. Most of the isolates exhibited remarkable antimicrobial activity up to 20mm zone of inhibition against MDR ventilator associated pneumonia causing bacteria including Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Enterobacter and Acinetobacter spp. Additionally the isolates showed moderate to high cytotoxicity in the range of 40 to 80% larval mortality against Artemia salina in a micro well cytotoxicity assay. The chemical screening or the so called metabolic fingerprinting of the methanolic extracts of each isolate, by thin layer chromatography (TLC) using various staining reagents and by high performance liquid chromatography (HPLC-UV), indicated an impressive diversity of the compounds produced by these strains. The study reveals that these halophilic actinomycetes are a promising source of bioactive compounds. The preparative scale fermentation, isolation, purification and structure elucidation of the compounds produced by them may yield novel antimicrobial or chemotherapeutic agents. PMID:27087086

  1. Halobacterium saccharovorum sp. nov., a carbohydrate-metabolizing, extremely halophilic bacterium

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Hochstein, L. I.

    1976-01-01

    The previously described extremely halophilic bacterium, strain M6, metabolizes a variety of carbohydrates with the production of acid. In addition, the organism produces nitrite (but no gas) from nitrate, is motile, and grows most rapidly at about 50 C. These characteristics distinguish it from all previously described halophilic bacteria in the genus Halobacterium. It is suggested that it be designated as a new species, Halobacterium saccharovorum.

  2. Raman spectroscopy in halophile research.

    PubMed

    Jehlička, Jan; Oren, Aharon

    2013-01-01

    Raman spectroscopy plays a major role in robust detection of biomolecules and mineral signatures in halophile research. An overview of Raman spectroscopic investigations in halophile research of the last decade is given here to show advantages of the approach, progress made as well as limits of the technique. Raman spectroscopy is an excellent tool to monitor and identify microbial pigments and other biomolecules in extant and extinct halophile biomass. Studies of bottom gypsum crusts from salterns, native evaporitic sediments, halite inclusions, and endoliths as well as cultures of halophilic microorganisms permitted to understand the content, distribution, and behavior of important molecular species. The first papers describing Raman spectroscopic detection of microbiological and geochemical key markers using portable instruments are highlighted as well. PMID:24339823

  3. Raman spectroscopy in halophile research

    PubMed Central

    Jehlička, Jan; Oren, Aharon

    2013-01-01

    Raman spectroscopy plays a major role in robust detection of biomolecules and mineral signatures in halophile research. An overview of Raman spectroscopic investigations in halophile research of the last decade is given here to show advantages of the approach, progress made as well as limits of the technique. Raman spectroscopy is an excellent tool to monitor and identify microbial pigments and other biomolecules in extant and extinct halophile biomass. Studies of bottom gypsum crusts from salterns, native evaporitic sediments, halite inclusions, and endoliths as well as cultures of halophilic microorganisms permitted to understand the content, distribution, and behavior of important molecular species. The first papers describing Raman spectroscopic detection of microbiological and geochemical key markers using portable instruments are highlighted as well. PMID:24339823

  4. Taxonomic study of extreme halophilic archaea isolated from the "Salar de Atacama", Chile.

    PubMed

    Lizama, C; Monteoliva-Sánchez, M; Prado, B; Ramos-Cormenzana, A; Weckesser, J; Campos, V

    2001-11-01

    A large number of halophilic bacteria were isolated in 1984-1992 from the Atacama Saltern (North of Chile). For this study 82 strains of extreme halophilic archaea were selected. The characterization was performed by using the phenotypic characters including morphological, physiological, biochemical, nutritional and antimicrobial susceptibility test. The results, together with those from reference strains, were subjected to numerical analysis, using the Simple Matching (S(SM)) coefficient and clustered by the unweighted pair group method of association (UPGMA). Fifteen phena were obtained at an 70% similarity level. The results obtained reveal a high diversity among the halophilic archaea isolated. Representative strains from the phena were chosen to determine their DNA base composition and the percentage of DNA-DNA similarity compared to reference strains. The 16S rRNA studies showed that some of these strains constitutes a new taxa of extreme halophilic archaea. PMID:11822685

  5. Methanohalophilus zhilinae sp. nov., an alkaliphilic, halophilic, methylotrophic methanogen

    NASA Technical Reports Server (NTRS)

    Mathrani, I. M.; Boone, D. R.; Mah, R. A.; Fox, G. E.; Lau, P. P.

    1988-01-01

    Methanohalophilus zhilinae, a new alkaliphilic, halophilic, methylotrophic species of methanogenic bacteria, is described. Strain WeN5T (T = type strain) from Bosa Lake of the Wadi el Natrun in Egypt was designated the type strain and was further characterized. This strain was nonmotile, able to catabolize dimethylsulfide, and able to grow in medium with a methyl group-containing substrate (such as methanol or trimethylamine) as the sole organic compound added. Sulfide (21 mM) inhibited cultures growing on trimethylamine. The antibiotic susceptibility pattern of strain WeN5T was typical of the pattern for archaeobacteria, and the guanine-plus-cytosine content of the deoxyribonucleic acid was 38 mol%. Characterization of the 16S ribosomal ribonucleic acid sequence indicated that strain WeN5T is phylogenetically distinct from members of previously described genera other than Methanohalophilus and supported the partition of halophilic methanogens into their own genus.

  6. Reduction of Soluble Iron and Reductive Dissolution of Ferric Iron-Containing Minerals by Moderately Thermophilic Iron-Oxidizing Bacteria

    PubMed Central

    Bridge, Toni A. M.; Johnson, D. Barrie

    1998-01-01

    Five moderately thermophilic iron-oxidizing bacteria, including representative strains of the three classified species (Sulfobacillus thermosulfidooxidans, Sulfobacillus acidophilus, and Acidimicrobium ferrooxidans), were shown to be capable of reducing ferric iron to ferrous iron when they were grown under oxygen limitation conditions. Iron reduction was most readily observed when the isolates were grown as mixotrophs or heterotrophs with glycerol as an electron donor; in addition, some strains were able to couple the oxidation of tetrathionate to the reduction of ferric iron. Cycling of iron between the ferrous and ferric states was observed during batch culture growth in unshaken flasks incubated under aerobic conditions, although the patterns of oxidoreduction of iron varied in different species of iron-oxidizing moderate thermophiles and in strains of a single species (S. acidophilus). All three bacterial species were able to grow anaerobically with ferric iron as a sole electron acceptor; the growth yields correlated with the amount of ferric iron reduced when the isolates were grown in the absence of oxygen. One of the moderate thermophiles (identified as a strain of S. acidophilus) was able to bring about the reductive dissolution of three ferric iron-containing minerals (ferric hydroxide, jarosite, and goethite) when it was grown under restricted aeration conditions with glycerol as a carbon and energy source. The significance of iron reduction by moderately thermophilic iron oxidizers in both environmental and applied contexts is discussed. PMID:9603832

  7. Production of 5′ Nucleotide by Using Halophilic Nuclease H Preferentially Adsorbed on Flocculated Cells of the Halophile Micrococcus varians subsp. halophilus

    PubMed Central

    Onishi, Hiroshi; Kamekura, Masahiro; Yokoi, Haruhiko; Kobayashi, Takekazu

    1988-01-01

    A bioreactor with a column of flocculated cells of the moderate halophile Micrococcus varians subsp. halophilus which adsorbed the halophilic nuclease H was designed to be used in the production of 5′ nucleotides from RNA. A remarkable characteristic of the flocculated cells was that they preferentially adsorbed much exogenous nuclease, excluding adsorbed 5′ nucleotidase. Furthermore, desalting treatment of the flocculated cells in the presence of 2% MgSO4 · 7H2O gave rise to selective inactivation of 5′ nucleotidase without the loss of nuclease H activity, and 5′-guanylic acid was produced with the bioreactor. PMID:16347767

  8. Hans Georg Trüper (1936–2016) and His Contributions to Halophile Research

    PubMed Central

    Oren, Aharon

    2016-01-01

    Prof. Hans Georg Trüper, one of the most important scientists in the field of halophile research, passed away on 9 March 2016 at the age of 79. I here present a brief obituary with special emphasis on Prof. Trüper’s contributions to our understanding of the halophilic prokaryotes and their adaptations to life in hypersaline environments. He has pioneered the study of the halophilic anoxygenic phototrophic sulfur bacteria of the Ectothiorhodospira—Halorhodospira group. Some of the species he and his group isolated from hypersaline and haloalkaline environments have become model organisms for the study of the mechanisms of haloadaptation: the functions of three major organic compounds – glycine betaine, ectoine, and trehalose – known to serve as “compatible solutes” in halophilic members of the Bacteria domain, were discovered during studies of these anoxygenic phototrophs. Prof. Trüper’s studies of hypersaline alkaline environments in Egypt also led to the isolation of the first known extremely halophilic archaeon (Natronomonas pharaonis). The guest editors dedicate this special volume of Life to the memory of Prof. Hans Georg Trüper. PMID:27187481

  9. Hans Georg Trüper (1936-2016) and His Contributions to Halophile Research.

    PubMed

    Oren, Aharon

    2016-01-01

    Prof. Hans Georg Trüper, one of the most important scientists in the field of halophile research, passed away on 9 March 2016 at the age of 79. I here present a brief obituary with special emphasis on Prof. Trüper's contributions to our understanding of the halophilic prokaryotes and their adaptations to life in hypersaline environments. He has pioneered the study of the halophilic anoxygenic phototrophic sulfur bacteria of the Ectothiorhodospira-Halorhodospira group. Some of the species he and his group isolated from hypersaline and haloalkaline environments have become model organisms for the study of the mechanisms of haloadaptation: the functions of three major organic compounds - glycine betaine, ectoine, and trehalose - known to serve as "compatible solutes" in halophilic members of the Bacteria domain, were discovered during studies of these anoxygenic phototrophs. Prof. Trüper's studies of hypersaline alkaline environments in Egypt also led to the isolation of the first known extremely halophilic archaeon (Natronomonas pharaonis). The guest editors dedicate this special volume of Life to the memory of Prof. Hans Georg Trüper. PMID:27187481

  10. Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity

    PubMed Central

    Overholt, Will A.; Marks, Kala P.; Romero, Isabel C.; Hollander, David J.; Snell, Terry W.

    2015-01-01

    The Deepwater Horizon blowout in April 2010 represented the largest accidental marine oil spill and the largest release of chemical dispersants into the environment to date. While dispersant application may provide numerous benefits to oil spill response efforts, the impacts of dispersants and potential synergistic effects with crude oil on individual hydrocarbon-degrading bacteria are poorly understood. In this study, two environmentally relevant species of hydrocarbon-degrading bacteria were utilized to quantify the response to Macondo crude oil and Corexit 9500A-dispersed oil in terms of bacterial growth and oil degradation potential. In addition, specific hydrocarbon compounds were quantified in the dissolved phase of the medium and linked to ecotoxicity using a U.S. Environmental Protection Agency (EPA)-approved rotifer assay. Bacterial treatment significantly and drastically reduced the toxicity associated with dispersed oil (increasing the 50% lethal concentration [LC50] by 215%). The growth and crude oil degradation potential of Acinetobacter were inhibited by Corexit by 34% and 40%, respectively; conversely, Corexit significantly enhanced the growth of Alcanivorax by 10% relative to that in undispersed oil. Furthermore, both bacterial strains were shown to grow with Corexit as the sole carbon and energy source. Hydrocarbon-degrading bacterial species demonstrate a unique response to dispersed oil compared to their response to crude oil, with potentially opposing effects on toxicity. While some species have the potential to enhance the toxicity of crude oil by producing biosurfactants, the same bacteria may reduce the toxicity associated with dispersed oil through degradation or sequestration. PMID:26546426

  11. Halophilic life on Mars ?

    NASA Astrophysics Data System (ADS)

    Stan-Lotter, Helga; Fendrihan, Sergiu; Dornmayr-Pfaffenhuemer, Marion; Holzinger, Anita; Polacsek, Tatjana K.; Legat, Andrea; Grösbacher, Michael; Weigl, Andreas

    2010-05-01

    Background: The search for extraterrestrial life has been declared as a goal for the 21th century by several space agencies. Potential candidates are microorganisms on or in the surface of moons and planets, such as Mars. Extremely halophilic archaea (haloarchaea) are of astrobiological interest since viable strains have been isolated from million years old salt deposits (1) and halite has been found in Martian meteorites and in surface pools. Therefore, haloarchaeal responses to simulated and real space conditions were explored. Immuno assays for a potential Life Marker Chip experiment were developed with antisera against the universal enzyme ATP synthase. Methods: The focus of these studies was on the application of fluorescent probes since they provide strong signals, and detection devices are suitable for miniaturization. Viability of haloarchaeal strains (Halococcus dombrowskii and Halobacterium salinarum NRC-1) was probed with the LIVE/DEAD BacLight™ kit and the BacLight™ Bacterial Membrane Potential kit. Cyclobutane pyrimidine dimers (CPD) in the DNA, following exposure to simulated and real space conditions (UV irradiation from 200 - 400 nm; 18 months exposure on the International Space Station [ISS] within the ADAPT experiment by Dr. P. Rettberg), were detected with fluorescent Alexa-Fluor-488-coupled antibodies. Immuno assays with antisera against the A-ATPase subunits from Halorubrum saccharovorum were carried out with the highly sensitive Immun-Star ™ WesternC ™ chemiluminescent kit (Bio-Rad). Results: Using the LIVE/DEAD BacLight™ kit, the D37 (dose of 37% survival) for Hcc. dombrowskii and Hbt. salinarum NRC-1, following exposure to UV (200-400 nm) was about 400 kJ/m2, when cells were embedded in halite and about 1 kJ/m2, when cells were in liquid cultures. Fluorescent staining indicated a slightly higher cellular activity than that which was derived from the determination of colony forming units. Assessment of viability with the Bac

  12. Marinobacter aquaeolei sp. nov., a halophilic bacterium isolated from a Vietnamese oil-producing well.

    PubMed

    Huu, N B; Denner, E B; Ha, D T; Wanner, G; Stan-Lotter, H

    1999-04-01

    Several strains of moderately halophilic and mesophilic bacteria were isolated at the head of an oil-producing well on an offshore platform in southern Vietnam. Cells were Gram-negative, non-spore-forming, rod-shaped and motile by means of a polar flagellum. Growth occurred at NaCl concentrations between 0 and 20%; the optimum was 5% NaCl. One strain, which was designated VT8T, could degrade n-hexadecane, pristane and some crude oil components. It grew anaerobically in the presence of nitrate on succinate, citrate or acetate, but not on glucose. Several organic acids and amino acids were utilized as sole carbon and energy sources. The major components of its cellular fatty acids were C12:0 3-OH, C16:1, omega 9c, C16:0 and C18:1 omega 9c. The DNA G + C content was 55.7 mol%. 16S rDNA sequence analysis indicated that strain VT8T was closely related to Marinobacter sp. strain CAB (99.8% similarity) and Marinobaster hydrocarbonoclasticus (99.4% similarity). Its antibiotic resistance, isoprenoid quinones and fatty acids were similar to those of Marinobacter hydrocarbonoclasticus and Pseudomonas nautica. However, the whole-cell protein pattern of VT8T differed from that of other halophilic marine isolates, including P. nautica. DNA-DNA hybridization indicated that the level of relatedness to Marinobacter hydrocarbonoclasticus was 65% and that to P. nautica was 75%. Further differences were apparent in Fourier-transformed IR spectra of cells and lipopolysaccharide composition. It is proposed that VT8T should be the type strain of a new species and should be named Marinobacter aquaeolei. P. nautica may have been misclassified, as suggested previously, and may also belong to the genus Marinobacter. PMID:10319457

  13. Ectothiorhodospira variabilis sp. nov., an alkaliphilic and halophilic purple sulfur bacterium from soda lakes.

    PubMed

    Gorlenko, Vladimir M; Bryantseva, Irina A; Rabold, Sandra; Tourova, Tatjana P; Rubtsova, Dariya; Smirnova, Ekaterina; Thiel, Vera; Imhoff, Johannes F

    2009-04-01

    During studies of moderately halophilic strains of Ectothiorhodospira from steppe soda lakes, we found a novel group of bacteria related to Ectothiorhodospira haloalkaliphila with salt optima at 50-80 g NaCl l(-1). Phylogenetic analysis using 16S rRNA gene sequences of strains from soda lakes in Mongolia, Egypt and Siberia revealed separation of the group of new isolates from other Ectothiorhodospira species, including the closely related Ect. haloalkaliphila. DNA-DNA hybridization studies demonstrated that the new isolates form a homogeneous group at the species level, but at the same time are distinct from related species such as Ect. haloalkaliphila, Ect. vacuolata, Ect. shaposhnikovii and Ect. marina. The new isolates are considered to be strains of a novel species, for which the name Ectothiorhodospira variabilis sp. nov. is proposed, with the type strain WN22(T) (=VKM B-2479(T) =DSM 21381(T)). Photosynthetic pigments of the novel species are bacteriochlorophyll a and carotenoids of the spirilloxanthin series with spirilloxanthin and derivatives thereof, together with small amounts of lycopene and rhodopin. Gas vesicles are formed by most of the strains, particularly in media containing yeast extract (0.5 g l(-1)) and acetate (0.5-2.0 g l(-1)). Sequence analysis of nifH (nitrogenase) and cbbL (RuBisCO) confirmed the assignment of the strains to the genus Ectothiorhodospira and in particular the close relationship to Ect. haloalkaliphila. The novel species Ect. variabilis is found in soda lakes separated by great geographical distances and is an alkaliphilic and halophilic bacterium that tolerates salt concentrations up to 150-200 g NaCl l(-1). PMID:19329583

  14. Draft Genome Sequence of the Halophilic Bacterium Halobacillus sp. Strain BAB-2008

    PubMed Central

    Joshi, M. N.; Pandit, A. S.; Sharma, A.; Pandya, R. V.; Saxena, A. K.

    2013-01-01

    The Halobacillus sp. strain BAB-2008 is a moderately halophilic, rod-shaped, Gram-positive, orange-pigmented, carotenoid-producing bacterium isolated from saline soil near Zazam-Solar Park Road, Gujarat, India. Here we present the 3.7-Mb genome sequence to provide insights into its functional genomics and potential applications for carotenoid and enzyme production. PMID:23469348

  15. Draft Genome Sequence of the Halophilic Bacterium Halobacillus sp. Strain BAB-2008.

    PubMed

    Joshi, M N; Pandit, A S; Sharma, A; Pandya, R V; Saxena, A K; Bagatharia, S B

    2013-01-01

    The Halobacillus sp. strain BAB-2008 is a moderately halophilic, rod-shaped, Gram-positive, orange-pigmented, carotenoid-producing bacterium isolated from saline soil near Zazam-Solar Park Road, Gujarat, India. Here we present the 3.7-Mb genome sequence to provide insights into its functional genomics and potential applications for carotenoid and enzyme production. PMID:23469348

  16. Phytostabilization of moderate copper contaminated soils using co-inoculation of Vicia faba with plant growth promoting bacteria.

    PubMed

    Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez; Jebara, Salwa Harzalli

    2015-03-01

    There is a need to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programs. This article suggest a consortium of bacteria combining Rhizobium sp. CCNWSX0481, Rhizobium leguminosarum bv. viciae, Enterobacter cloacae and Pseudomonas sp. 2(2010) that was examined for the ability to promote Vicia faba.L. growth when cultivated on the vineyard of soil moderately contaminated with copper. Data showed that inoculation was significant in nodulation; it increases the number and the weight of nodules of 50%. Co-inoculation was also found to positively influence growth and seed yield, through increasing fresh shoot and fresh root weights by 33 and 26%, respectively, and through rising numbers of seed per pod and pods per plant. In contrast, co-inoculation produced a significant reduction of accumulated copper in roots attending 35%, however, the treatment revealed no significant effects on the copper contents in pods and seeds. The tested inoculum could be an option to promote V. faba growth and to enhance soil fertilization in moderate copper contaminated soils. Further studies on the influence of co-inoculation practices on copper migration in soil-plant systems are recommended to acquire more information for evaluation of this legume safety. PMID:24338717

  17. Halobacterium denitrificans sp. nov., an extremely halophilic denitrifying bacterium

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  18. Halobacterium denitrificans sp. nov. - An extremely halophilic denitrifying bacterium

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  19. Comparison of membrane ATPases from extreme halophiles isolated from ancient salt deposits

    NASA Astrophysics Data System (ADS)

    Stan-Lotter, Helga; Sulzner, Michael; Egelseer, Eva; Norton, Cynthia F.; Hochstein, Lawrence I.

    1993-02-01

    Halophilic microorganisms were isolated from Triassic and Permian salt deposits. Two were rods and grew as red colonies; another was a coccus and produced pink colonies. The rods lysed in solutions that lacked added sodium chloride. Growth of all isolates was inhibited by aphidicolin and their bulk proteins were acidic as judged from isoelectric focusing. Therefore, these organisms were tentatively identified as extreme halophiles. Whole cell proteins patterns of the isolates following gel electrophoresis were distinct and differed from those of representative type strains of halophilic bacteria. The membrane ATPases from the rods were similar to the enzyme fromHalobacterium saccharovorum with respect to subunit composition, enzymatic properties and immunological cross-reaction, but differed slightly in amino acid composition. If the age of the microbial isolated is similar to that of the salt deposits, they can be considered repositories of molecular information of great evolutionary interest.

  20. Comparison of Membrane ATPases from Extreme Halophiles Isolated from Ancient Salt Deposits

    NASA Technical Reports Server (NTRS)

    Stan-Lotter, Helga; Sulzner, Michael; Egelseer, Eva; Norton, Cynthia F.; Hochstein, Lawrence I.

    1993-01-01

    Halophilic microorganisms were isolated from Triassic and Permian salt deposits. Two were rods and grew as red colonies; another was a coccus and produced pink colonies. The rods lysed in solutions that lacked added sodium chloride. Growth of all isolates was inhibited by aphidicolin and their bulk proteins were acidic as judged from isoelectric focusing. Therefore, these organisms were tentatively identified as extreme halophiles. Whole cell proteins patterns of the isolates following gel electrophoresis were distinct and differed from those of representative type strains of halophilic bacteria. The membrane ATPases from the rods were similar to the enzyme from Halobacterium saccharovorum with respect to sub unit composition. enzymatic properties and immunological cross-reaction, but differed slightly in amino acid composition. If the age of the microbial isolated is similar to that of the salt deposits, they can be considered repositories of molecular information of great evolutionary interest.

  1. Comparison of membrane ATPases from extreme halophiles isolated from ancient salt deposits

    NASA Technical Reports Server (NTRS)

    Stan-Lotter, Helga; Sulzner, Michael; Egelseer, Eva; Norton, Cynthia F.; Hochstein, Lawrence I.

    1993-01-01

    Halophilic microorganisms were isolated from Triassic and Permian salt deposits. Two were rods and grew as red colonies; another was a coccus and produced pink colonies. The rods lysed in solutions that lacked added sodium chloride. Growth of all isolates was inhibited by aphidicolin and their bulk-proteins were acidic as judged from isoelectric focusing. Therefore, these organisms were tentatively identified as extreme halophiles. Whole cell proteins patterns of the isolates following gel electrophoresis were distinct and differed from those of representative type strains of halophilic bacteria. The membrane ATPases from the rods were similar to the enzyme from Halobacterium saccharovorum with respect to subunit composition, enzymatic properties and immunological cross-reaction, but differed slightly in amino acid composition. If the age of the microbial isolated is similar to that of the salt deposits, they can be considered repositories of molecular information of great evolutionary interest.

  2. Isolation and Characterization of a Phosphate-Solubilizing Halophilic Bacterium Kushneria sp. YCWA18 from Daqiao Saltern on the Coast of Yellow Sea of China

    PubMed Central

    Zhu, Fengling; Qu, Lingyun; Hong, Xuguang; Sun, Xiuqin

    2011-01-01

    Phosphate-solubilizing bacteria (PSB) function in soil phosphorus cycle, increasing the bioavailability of soil phosphorus for plants. Isolation and application of salt-tolerant or halophilic PSB will facilitate the development of saline-alkali soil-based agriculture. A moderately halophilic bacterium was isolated from the sediment of Daqiao saltern on the eastern coast of China, which also performs phosphate-solubilizing ability. The bacterium was assigned to genus Kushneria according to its 16S rRNA gene sequence, and accordingly named as Kushneria sp. YCWA18. The fastest growth was observed when the culturing temperature was 28°C and the concentration of NaCl was 6% (w/v). It was founds that the bacterium can survive at a concentration of NaCl up to 20%. At the optimum condition, the bacterium solubilized 283.16 μg/mL phosphorus in 11 days after being inoculated in 200 mL Ca3(PO4)2 containing liquid medium, and 47.52 μg/mL phosphorus in 8 days after being inoculated in 200 mL lecithin-containing liquid medium. The growth of the bacterium was concomitant with a significant decrease of acidity of the medium. PMID:21716683

  3. Halophiles, coming stars for industrial biotechnology.

    PubMed

    Yin, Jin; Chen, Jin-Chun; Wu, Qiong; Chen, Guo-Qiang

    2015-11-15

    Industrial biotechnology aims to produce chemicals, materials and biofuels to ease the challenges of shortage on petroleum. However, due to the disadvantages of bioprocesses including energy consuming sterilization, high fresh water consumption, discontinuous fermentation to avoid microbial contamination, highly expensive stainless steel fermentation facilities and competing substrates for human consumption, industrial biotechnology is less competitive compared with chemical processes. Recently, halophiles have shown promises to overcome these shortcomings. Due to their unique halophilic properties, some halophiles are able to grow in high pH and high NaCl containing medium under higher temperature, allowing fermentation processes to run contamination free under unsterile conditions and continuous way. At the same time, genetic manipulation methods have been developed for halophiles. So far, halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Increasing effects have been made to develop halophiles into a low cost platform for bioprocessing with advantages of low energy, less fresh water consumption, low fixed capital investment, and continuous production. PMID:25447783

  4. Characterization of Halophilic Bacterial Communities in Turda Salt Mine (Romania)

    NASA Astrophysics Data System (ADS)

    Carpa, Rahela; Keul, Anca; Muntean, Vasile; Dobrotă, Cristina

    2014-09-01

    Halophilic organisms are having adaptations to extreme salinity, the majority of them being Archaean, which have the ability to grow at extremely high salt concentrations, (from 3 % to 35 %). Level of salinity causes natural fluctuations in the halophilic populations that inhabit this particular habitat, raising problems in maintaining homeostasis of the osmotic pressure. Samples such as salt and water taken from Turda Salt Mine were analyzed in order to identify the eco-physiological bacterial groups. Considering the number of bacteria of each eco-physiological group, the bacterial indicators of salt quality (BISQ) were calculated and studied for each sample. The phosphatase, catalase and dehydrogenases enzymatic activities were quantitatively determined and the enzymatic indicators of salt quality (EISQ) were calculated. Bacterial isolates were analyzed using 16S rRNA gene sequence analysis. Universal bacterial primers, targeting the consensus region of the bacterial 16S rRNA gene were used. Analysis of a large fragment, of 1499 bp was performed to improve discrimination at the species level.

  5. Evolution of halophiles: A terrestrial analog for life in Brines on Mars

    NASA Astrophysics Data System (ADS)

    Mancinelli, R.

    2003-04-01

    Halophiles are salt "loving" organisms that inhabit environments with salt concentrations ranging from 15% to saturation. Representatives of halophiles occur in the Archaea, Bacteria and Eucarya. Adaptation to high salt can be achieved by the accumulation of organic osmotic solutes without the need for adaptation of the intracellular proteins. This mechanism is found in all three domains of life. The second mechanism is the intracellular accumulation of high concentrations of KCl, requiring adaptation of intracellular physiology to function in the presence of high ionic concentrations. This mechanism is found in the Archaea and in the Bacteria. The phylogenetic and physiological diversity among the halophiles suggests that it may have arisen more the once during evolution and is not a rarity. Because data from Mars missions suggest that Mars almost certainly had abundant liquid water on its surface at some time in the past. It could have harbored some form of life in its past As Mars lost its atmosphere it not only became cold but also dry due to water evaporation. As the water evaporated the dissolved minerals became more concentrated forming salty brine pockets. Because data from earth suggests that it may be relatively easy for halophilic type organisms to evolve if there were any life on mars in water there should have been some type of osmophile, or halophile. Brine pockets containing high concentrations of dissolved salts would have selected for the survival of halophiles. These brine pockets may either be an "oasis" for an extant Martian biota, or the last refuge of an extinct Martian biota. Eventually near surface brine pockets would have dried to form evaporites. Evaporites are deposits that result from the evaporation water containing salts, on earth consisting primarily of halite (NaCl) gypsum (CaSO_4 . 2H_2O) or anhydrite (CaSO_4). Evaporites containing bacterial and algal assemblages exist on earth today and are well-known in the fossil record.. Data

  6. Physiology and Molecular Phylogeny of Bacteria Isolated from Alkaline Distillery Lime.

    PubMed

    Kalwasińska, Agnieszka; Felföldi, Tamàs; Walczak, Maciej; Kosobucki, Przemysław

    2015-01-01

    This paper presents the results of the research on the number, taxonomic composition, and biochemical properties of bacterial strains isolated from the alkaline Solvay distillery lime, deposited at the repository in Janikowo (central Poland). Fifteen strains out of 17 were facultative alkaliphiles and moderate halophiles, and two were alkalitolerants and moderate halophiles. The number of aerobic bacteria cultured in alkaline lime was approximately 10(5) CFU ml(-1), and the total number of bacteria was 10(7) cells g(-1). According to 16S rRNA gene sequence analysis, nine strains belonged to the genus Bacillus, six to the genus Halomonas, one to the genus Planococcus, and one to the genus Microcella. Strains that hydrolyse starch and protein were the most numerous. Esterase (C4) and esterase lipase (C8) were detected in the majority of bacterial strains. Twelve strains exhibited α-glucosidase activity and nine, naphtol-AS-BI-phosphohydrolase activity. The present study proves that alkaliphilic bacteria of this type may constitute a source of potentially useful extremozymes. PMID:26999957

  7. Salty sisters: The women of halophiles

    PubMed Central

    Baxter, Bonnie K.; Gunde-Cimerman, Nina; Oren, Aharon

    2014-01-01

    A history of halophile research reveals the commitment of scientists to uncovering the secrets of the limits of life, in particular life in high salt concentration and under extreme osmotic pressure. During the last 40 years, halophile scientists have indeed made important contributions to extremophile research, and prior international halophiles congresses have documented both the historical and the current work. During this period of salty discoveries, female scientists, in general, have grown in number worldwide. But those who worked in the field when there were small numbers of women sometimes saw their important contributions overshadowed by their male counterparts. Recent studies suggest that modern female scientists experience gender bias in matters such as conference invitations and even representation among full professors. In the field of halophilic microbiology, what is the impact of gender bias? How has the participation of women changed over time? What do women uniquely contribute to this field? What are factors that impact current female scientists to a greater degree? This essay emphasizes the “her story” (not “history”) of halophile discovery. PMID:24926287

  8. The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater

    PubMed Central

    Cui, You-Wei; Zhang, Hong-Yu; Ding, Jie-Ran; Peng, Yong-Zhen

    2016-01-01

    With annual increases in the generation and use of saline wastewater, the need to avoid environmental problems such as eutrophication is critical. A previous study identified ways to start up a halophilic sludge domesticated from estuarine sediments to remove nitrogen from wastewater with a salinity of 30 g/L. This investigation expands that work to explore the impact of salinity on nitrogen removal. This study demonstrated that the mixed halophilic consortia removed nitrogen from wastewater with a salinity of 30–85 g/L. A kinetic analysis showed that halophilic nitrifiers selected based on hypersalinity were characterized by low Ks, μmax and specific ammonium oxidization rates. This explains the decrease in ammonium removal efficiency in the high salinity operational phases. Salinity inhibited ammonia oxidizing bacteria (AOB) activity, as well as the number of dominant AOB, but did not significantly affect the AOB dominant species. Three most dominant AOB lineages in the halophilic sludge were Nitrosomonas marina, Nitrosomonas europaea, and Nitrosococcus mobilis. Nitrosomonas europaea and Nitrosococcus mobilis were mainly affected by salinity, while nitrite accumulation and ammonia loading played the key role in determining the abundance of Nitrosococcus mobilis and Nitrosococcus europaea. The study contributes insights about shifts in halophilic nitrifying bacterial populations. PMID:27109617

  9. The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater.

    PubMed

    Cui, You-Wei; Zhang, Hong-Yu; Ding, Jie-Ran; Peng, Yong-Zhen

    2016-01-01

    With annual increases in the generation and use of saline wastewater, the need to avoid environmental problems such as eutrophication is critical. A previous study identified ways to start up a halophilic sludge domesticated from estuarine sediments to remove nitrogen from wastewater with a salinity of 30 g/L. This investigation expands that work to explore the impact of salinity on nitrogen removal. This study demonstrated that the mixed halophilic consortia removed nitrogen from wastewater with a salinity of 30-85 g/L. A kinetic analysis showed that halophilic nitrifiers selected based on hypersalinity were characterized by low Ks, μmax and specific ammonium oxidization rates. This explains the decrease in ammonium removal efficiency in the high salinity operational phases. Salinity inhibited ammonia oxidizing bacteria (AOB) activity, as well as the number of dominant AOB, but did not significantly affect the AOB dominant species. Three most dominant AOB lineages in the halophilic sludge were Nitrosomonas marina, Nitrosomonas europaea, and Nitrosococcus mobilis. Nitrosomonas europaea and Nitrosococcus mobilis were mainly affected by salinity, while nitrite accumulation and ammonia loading played the key role in determining the abundance of Nitrosococcus mobilis and Nitrosococcus europaea. The study contributes insights about shifts in halophilic nitrifying bacterial populations. PMID:27109617

  10. Regulated polyploidy in halophilic archaea.

    PubMed

    Breuert, Sebastian; Allers, Thorsten; Spohn, Gabi; Soppa, Jörg

    2006-01-01

    Polyploidy is common in higher eukaryotes, especially in plants, but it is generally assumed that most prokaryotes contain a single copy of a circular chromosome and are therefore monoploid. We have used two independent methods to determine the genome copy number in halophilic archaea, 1) cell lysis in agarose blocks and Southern blot analysis, and 2) Real-Time quantitative PCR. Fast growing H. salinarum cells contain on average about 25 copies of the chromosome in exponential phase, and their ploidy is downregulated to 15 copies in early stationary phase. The chromosome copy number is identical in cultures with a twofold lower growth rate, in contrast to the results reported for several other prokaryotic species. Of three additional replicons of H. salinarum, two have a low copy number that is not growth-phase regulated, while one replicon even shows a higher degree of growth phase-dependent regulation than the main replicon. The genome copy number of H. volcanii is similarly high during exponential phase (on average 18 copies/cell), and it is also downregulated (to 10 copies) as the cells enter stationary phase. The variation of genome copy numbers in the population was addressed by fluorescence microscopy and by FACS analysis. These methods allowed us to verify the growth phase-dependent regulation of ploidy in H. salinarum, and they revealed that there is a wide variation in genome copy numbers in individual cells that is much larger in exponential than in stationary phase. Our results indicate that polyploidy might be more widespread in archaea (or even prokaryotes in general) than previously assumed. Moreover, the presence of so many genome copies in a prokaryote raises questions about the evolutionary significance of this strategy. PMID:17183724

  11. Salt-Bridge Energetics in Halophilic Proteins

    PubMed Central

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are −3.0 kcal mol−1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of −5.0 kcal mol−1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (−10 kcal mol−1) exceeds than that of bridge term (−7 kcal mol−1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic

  12. Isolation and Characterization of Haloanaerobacter chitinovorans gen. nov., sp. nov., a Halophilic, Anaerobic, Chitinolytic Bacterium from a Solar Saltern

    PubMed Central

    Liaw, Hungming J.; Mah, Robert A.

    1992-01-01

    Two halophilic anaerobic bacteria, one of which had chitinolytic activity, were isolated from a solar saltern in southern California. These organisms were long, gram-negative, motile, flexible rods. The biochemical and physiological characteristics of these bacteria were very similar but were different from the characteristics of other haloanaerobic bacteria. Both grew at salt concentrations ranging from 0.5 to 5 M and at temperatures ranging from 23 to 50°C. They were sensitive to chloramphenicol but resistant to penicillin, carbenicillin, d-cycloserine, streptomycin, and tetracycline. An analysis of DNAs and whole-cell proteins showed that they were closely related taxonomically and distinguishable from other halophilic anaerobic bacteria. They exhibited 92.3 to 100% DNA homology as determined by DNA-DNA hybridization. The guanine-plus-cytosine contents of their DNAs were 34.8±1 mol%. The two isolates, strains W5C8 and W3C1, differed from other halophilic anaerobic bacteria sufficiently to support establishment of a new genus and species, Haloanaerobacter chitinovorans. Strain W5C8 exhibited chitinolytic activity and is designated the type strain. Two chitin-induced extracellular proteins with molecular weights of 38 × 103 and 40 × 103 were detected in strain W5C8. Images PMID:16348626

  13. Halophilic characterization of starch-binding domain from Kocuria varians α-amylase.

    PubMed

    Yamaguchi, Rui; Inoue, Yasuhiro; Tokunaga, Hiroko; Ishibashi, Matsujiro; Arakawa, Tsutomu; Sumitani, Jun-ichi; Kawaguchi, Takashi; Tokunaga, Masao

    2012-01-01

    The tandem starch-binding domains (KvSBD) located at carboxy-terminal region of halophilic α-amylase from moderate halophile, Kocuria varians, were expressed in E. coli with amino-terminal hexa-His-tag and purified to homogeneity. The recombinant KvSBD showed binding activity to raw starch granules at low to high salt concentrations. The binding activity of KvSBD to starch was fully reversible after heat-treatment at 85°C. Circular dichroism and thermal scanning experiments indicated that KvSBD showed fully reversible refolding upon cooling after complete melting at 70°C in the presence of 0.2-2.0M NaCl. The refolding rate was enhanced with higher salt concentration. PMID:22020156

  14. Halophilic archaebacteria from the Kalamkass oil field

    SciTech Connect

    Zvyagintseva, I.S.; Belyaev, S.S.; Borzenkov, I.A.; Kostrikina, N.A.; Milekhina, E.I.; Ivanov, M.V.

    1995-01-01

    Two strains of halophilic archaebacteria, growing in a medium containing from 10 to 25% NaCl, were isolated from the brines of the Kalamkass (Mangyshlak) oil field. Both strains are extremely halophilic archaebacteria according to the complex of their phenotypic properties. Strain M-11 was identified as Haloferax mediterranei on the basis of the composition of polar lipids and DNA-DNA homology. The composition of polar lipids and 16S rRNA sequence of strain M-18 allowed us to assign it to the genus Haloferax. This strain differs from the approved species of the genus Haloferax, H. volcanii, and H. mediterranei. However, to describe it as a new species, additional investigations are necessary. 13 refs., 3 figs.

  15. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor

    SciTech Connect

    Rodrigues, Michael L.M.; Leão, Versiane A.; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

    2015-07-15

    Highlights: • Copper bioleaching from PCB (20 mm) by moderate thermophiles was demonstrated. • Larger PCB sheets enable a cost reduction due to the elimination of fine grinding. • Crushing generated cracks in PCB increasing the copper extraction. • A pre-treatment step was necessary to remove the lacquer coating. • High copper extractions (85%) were possible with pulp density of up to 25.0 g/L. - Abstract: The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (−208 μm + 147 μm), ferrous iron concentration (1.25–10.0 g/L) and pH (1.5–2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0 g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20 mm-long) working with increased solids concentration (up to 25.0 g/L). Because there was as the faster leaching kinetics at 50 °C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8 days and microscopic observations by SEM–EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20 mm-size sheets.

  16. Genome-scale reconstruction of metabolic network for a halophilic extremophile, Chromohalobacter salexigens DSM 3043

    PubMed Central

    2011-01-01

    Background Chromohalobacter salexigens (formerly Halomonas elongata DSM 3043) is a halophilic extremophile with a very broad salinity range and is used as a model organism to elucidate prokaryotic osmoadaptation due to its strong euryhaline phenotype. Results C. salexigens DSM 3043's metabolism was reconstructed based on genomic, biochemical and physiological information via a non-automated but iterative process. This manually-curated reconstruction accounts for 584 genes, 1386 reactions, and 1411 metabolites. By using flux balance analysis, the model was extensively validated against literature data on the C. salexigens phenotypic features, the transport and use of different substrates for growth as well as against experimental observations on the uptake and accumulation of industrially important organic osmolytes, ectoine, betaine, and its precursor choline, which play important roles in the adaptive response to osmotic stress. Conclusions This work presents the first comprehensive genome-scale metabolic model of a halophilic bacterium. Being a useful guide for identification and filling of knowledge gaps, the reconstructed metabolic network iOA584 will accelerate the research on halophilic bacteria towards application of systems biology approaches and design of metabolic engineering strategies. PMID:21251315

  17. Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor.

    PubMed

    Rodrigues, Michael L M; Leão, Versiane A; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

    2015-07-01

    The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (-208μm+147μm), ferrous iron concentration (1.25-10.0g/L) and pH (1.5-2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20mm-long) working with increased solids concentration (up to 25.0g/L). Because there was as the faster leaching kinetics at 50°C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8days and microscopic observations by SEM-EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20mm-size sheets. PMID:25899037

  18. Discrimination of Pigments of Microalgae, Bacteria and Yeasts Using Lightweight Handheld Raman Spectrometers: Prospects for Astrobiology

    NASA Astrophysics Data System (ADS)

    Jehlicka, J.; Osterrothova, K.; Nedbalova, L.; Gunde-Cimerman, N.; Oren, A.

    2014-06-01

    Handheld Raman instrumentation with 532 nm lasers can be used to distinguish carotenoids of autotrophic microalgae, purple sulfur bacteria, halophilic Archaea and pigmented yeasts. Pigments are proposed as biomarkers for astrobiology of Mars.

  19. Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

    PubMed Central

    Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

    2014-01-01

    A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

  20. Haloadaptation: insights from comparative modeling studies of halophilic archaeal DHFRs.

    PubMed

    Kastritis, Panagiotis L; Papandreou, Nikos C; Hamodrakas, Stavros J

    2007-10-01

    Proteins of halophilic archaea function in high-salt concentrations that inactivate or precipitate homologous proteins from non-halophilic species. Haloadaptation and the mechanism behind the phenomenon are not yet fully understood. In order to obtain useful information, homology modeling studies of dihydrofolate reductases (DHFRs) from halophilic archaea were performed that led to the construction of structural models. These models were subjected to energy minimization, structural evaluation and analysis. Complementary approaches concerning calculations of the amino acid composition and visual inspection of the surfaces and cores of the models, as well as calculations of electrostatic surface potentials, in comparison to non-halophilic DHFRs were also performed. The results provide evidence that sheds some light on the phenomenon of haloadaptation: DHFRs from halophilic archaea may maintain their fold, in high-salt concentrations, by sharing highly negatively charged surfaces and weak hydrophobic cores. PMID:17675150

  1. Draft Genome Sequence of Yellow Pigmented Jeotgalibacillus alimentarius JY-13T, the First Halophile Strain of the Genus Jeotgalibacillus

    PubMed Central

    Yaakop, Amira Suriaty; Chan, Kok-Gan; Gan, Han Ming

    2015-01-01

    Jeotgalibacillus alimentarius JY-13T (=KCCM 80002T = JCM 10872T) is a moderate halophile. In 2001, this was the first strain of the newly proposed Jeotgalibacillus genus. The draft genome of J. alimentarius was found to consist of 32 contigs (N50, 315,125 bp) with a total size of 3,364,745 bp. This genome information will be helpful for studies on pigmentation as well as applications for this bacterium. PMID:26494670

  2. The occurrence of denitrification in extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Mancinelli, R. L.; Hochstein, L. I.

    1986-01-01

    The ability of Halobacterium vallismortis, Halobacterium mediterranei and Halobacterium marismortui (Ginzburg strain) to grow anaerobically and denitrify was determined. Each organism grew anaerobically only in the presence of nitrate. H. marismortui produced nitrite and dinitrogen from nitrate during exponential growth. However, as the culture entered stationary phase, dinitrogen production ceased and nitrous oxide was detected. H. vallismortis produced nitrous oxide and dinitrogen during exponential growth, with dinitrogen production ceasing at the onset of stationary phase. H. mediterranei produced dinitrogen during exponential growth and did not produce nitrous oxide. These results confirm the occurrence of denitrification in the halobacteria.

  3. Great Salt Lake halophilic microorganisms as models for astrobiology: evidence for desiccation tolerance and ultraviolet irradiation resistance

    NASA Astrophysics Data System (ADS)

    Baxter, Bonnie K.; Eddington, Breanne; Riddle, Misty R.; Webster, Tabitha N.; Avery, Brian J.

    2007-09-01

    Great Salt Lake (GSL) is home to halophiles, salt-tolerant Bacteria and Archaea, which live at 2-5M NaCl. In addition to salt tolerance, GSL halophiles exhibit resistance to both ultraviolet (UV) irradiation and desiccation. First, to understand desiccation resistance, we sought to determine the diversity of GSL halophiles capable of surviving desiccation in either recently formed GSL halite crystals or GSL Artemia (brine shrimp) cysts. From these desiccated environments, surviving microorganisms were cultured and isolated, and genomic DNA was extracted from the individual species for identification by 16S rRNA gene homology. From the surface-sterilized cysts we also extracted DNA of the whole microbial population for non-cultivation techniques. We amplified the archaeal or bacterial 16S rRNA gene from all genomic DNA, cloned the cyst population amplicons, and sequenced. These sequences were compared to gene databases for determination of closest matched species. Interestingly, the isolates from the crystal dissolution are distinct from those previously isolated from GSL brine. The cyst population results reveal species not found in crystals or brine, and may indicate microorganisms that live as endosymbionts of this hypersaline arthropod. Second, we explored UV resistance in a GSL haloarchaea species, "H. salsolis." This strain resists UV irradiation an order of magnitude better than control species, all of which have intact repair systems. To test the hypothesis that halophiles have a photoprotection system, which prevents DNA damage from occurring, we designed an immunoassay to detect thymine dimers following UV irradiation. "H. salsolis" showed remarkable resistance to dimer formation. Evidence for both UV and desiccation resistance in these salt-tolerant GSL halophiles makes them well-suited as models for Astrobiological studies in pursuit of questions about life beyond earth.

  4. Overexpression and purification of halophilic proteins in Haloferax volcanii.

    PubMed

    Allers, Thorsten

    2010-01-01

    Halophilic enzymes function optimally at high salt concentrations and are active at low water availability. Such conditions are encountered at elevated concentrations of solutes such as salts and sugars, and at high concentrations of organic solvents. However, expression in heterologous hosts such as Escherichia coli can cause problems, since halophilic proteins typically misfold and aggregate in conditions of low ionic strength. We have harnessed the sophisticated genetic tools available for the haloarchaeon Haloferax volcanii, to develop a system for the overexpression and purification of halophilic proteins under native conditions. PMID:21327063

  5. Halophilic enzyme activation induced by salts

    PubMed Central

    Ortega, Gabriel; Laín, Ana; Tadeo, Xavier; López-Méndez, Blanca; Castaño, David; Millet, Oscar

    2011-01-01

    Halophilic archea (halobacteriae) thrive in hypersaline environments, avoiding osmotic shock by increasing the ion concentration of their cytoplasm by up to 3–6 M. To remain folded and active, their constitutive proteins have evolved towards a biased amino acid composition. High salt concentration affects catalytic activity in an enzyme-dependent way and a unified molecular mechanism remains elusive. Here, we have investigated a DNA ligase from Haloferax volcanii (Hv LigN) to show that K+ triggers catalytic activity by preferentially stabilising a specific conformation in the reaction coordinate. Sodium ions, in turn, do not populate such isoform and the enzyme remains inactive in the presence of this co-solute. Our results show that the halophilic amino acid signature enhances the enzyme's thermodynamic stability, with an indirect effect on its catalytic activity. This model has been successfully applied to reengineer Hv LigN into an enzyme that is catalytically active in the presence of NaCl. PMID:22355525

  6. Perchlorate and halophilic prokaryotes: implications for possible halophilic life on Mars.

    PubMed

    Oren, Aharon; Elevi Bardavid, Rahel; Mana, Lily

    2014-01-01

    In view of the finding of perchlorate among the salts detected by the Phoenix Lander on Mars, we investigated the relationships of halophilic heterotrophic microorganisms (archaea of the family Halobacteriaceae and the bacterium Halomonas elongata) toward perchlorate. All strains tested grew well in NaCl-based media containing 0.4 M perchlorate, but at the highest perchlorate concentrations, tested cells were swollen or distorted. Some species (Haloferax mediterranei, Haloferax denitrificans, Haloferax gibbonsii, Haloarcula marismortui, Haloarcula vallismortis) could use perchlorate as an electron acceptor for anaerobic growth. Although perchlorate is highly oxidizing, its presence at a concentration of 0.2 M for up to 2 weeks did not negatively affect the ability of a yeast extract-based medium to support growth of the archaeon Halobacterium salinarum. These findings show that presence of perchlorate among the salts on Mars does not preclude the possibility of halophilic life. If indeed the liquid brines that may exist on Mars are inhabited by salt-requiring or salt-tolerant microorganisms similar to the halophiles on Earth, presence of perchlorate may even be stimulatory when it can serve as an electron acceptor for respiratory activity in the anaerobic Martian environment. PMID:24150694

  7. Astrobiological studies with extremely halophilic Archaea

    NASA Astrophysics Data System (ADS)

    Fendrihan, S.; Lotter, H. Stan

    2007-08-01

    Extremely halophilic Archaea were isolated and characterized by both classical and modern molecular biological methods from hypersaline and haloalkaline lakes, salted soils, solar salterns and rock salt deposits (1). The survival of these micro-organisms after embedding in laboratory-made halite was investigated. Their presence in fluid inclusions was demonstrated by staining with the BacLight LIVE/DEAD kit and observation of their fluorescence by microscopy. Following resuspension of cells from halite crystals, a survival of about 0.5 - 4% according to colony forming units was obtained. In previous studies which focussed on the resistance of halophilic archaea to UV radiation or the space environment, survival of a dose of 110 J/m2 (using liquid cultures) and up to 10 000 J/m2 at a range of 200 - 400 nm was reported, when dried Haloarcula sp. in a single layer were exposed on the Biopan facility (2). We exposed a few haloarchaeal strains to a Martian UV simulator lamp with a range of 200 - 400 nm and an intensity of 41.2 W/m2, obtaining a viability of about 51- 67% of cells following different exposure times. Other studies focus on the detection of haloarchaea in halite by Raman microspectroscopy and by NIR-FT-Raman spectroscopy, which are considered to be important future tools for Mars exploration (3). Using the Dilor XY Raman spectrometer with laser excitation at 514.5 nm, equipped with a confocal microscope BX40 (Olympus Corp., Japan) and a Bruker IFS 66 + FRA106 with laser excitation at 1064 nm (Bruker, Germany), instruments, we obtained characteristic carotenoid peaks contained by these microorganisms. 1. Fendrihan S., Legat A., Pfaffenhuemer M., Gruber C., Weidler G., Gerbl F. Stan Lotter H. (2006) Extremely halophilic archaea and the issue of long-term microbial survival. Review. Environ. Sci. Biotechnol. 5: 203-218. 2. Mancinelli R. L., White M. R., Rothschild L. J. (1998) Biopan survival I : exposure of the osmophiles Synechococcus sp. (Nägeli) and

  8. Insights into the sequence parameters for halophilic adaptation.

    PubMed

    Nath, Abhigyan

    2016-03-01

    The sequence parameters for halophilic adaptation are still not fully understood. To understand the molecular basis of protein hypersaline adaptation, a detailed analysis is carried out, and investigated the likely association of protein sequence attributes to halophilic adaptation. A two-stage strategy is implemented, where in the first stage a supervised machine learning classifier is build, giving an overall accuracy of 86 % on stratified tenfold cross validation and 90 % on blind testing set, which are better than the previously reported results. The second stage consists of statistical analysis of sequence features and possible extraction of halophilic molecular signatures. The results of this study showed that, halophilic proteins are characterized by lower average charge, lower K content, and lower S content. A statistically significant preference/avoidance list of sequence parameters is also reported giving insights into the molecular basis of halophilic adaptation. D, Q, E, H, P, T, V are significantly preferred while N, C, I, K, M, F, S are significantly avoided. Among amino acid physicochemical groups, small, polar, charged, acidic and hydrophilic groups are preferred over other groups. The halophilic proteins also showed a preference for higher average flexibility, higher average polarity and avoidance for higher average positive charge, average bulkiness and average hydrophobicity. Some interesting trends observed in dipeptide counts are also reported. Further a systematic statistical comparison is undertaken for gaining insights into the sequence feature distribution in different residue structural states. The current analysis may facilitate the understanding of the mechanism of halophilic adaptation clearer, which can be further used for rational design of halophilic proteins. PMID:26520112

  9. Novel Xylose Dehydrogenase in the Halophilic Archaeon Haloarcula marismortui†

    PubMed Central

    Johnsen, Ulrike; Schönheit, Peter

    2004-01-01

    During growth of the halophilic archaeon Haloarcula marismortui on d-xylose, a specific d-xylose dehydrogenase was induced. The enzyme was purified to homogeneity. It constitutes a homotetramer of about 175 kDa and catalyzed the oxidation of xylose with both NADP+ and NAD+ as cosubstrates with 10-fold higher affinity for NADP+. In addition to d-xylose, d-ribose was oxidized at similar kinetic constants, whereas d-glucose was used with about 70-fold lower catalytic efficiency (kcat/Km). With the N-terminal amino acid sequence of the subunit, an open reading frame (ORF)—coding for a 39.9-kDA protein—was identified in the partially sequenced genome of H. marismortui. The function of the ORF as the gene designated xdh and coding for xylose dehydrogenase was proven by its functional overexpression in Escherichia coli. The recombinant enzyme was reactivated from inclusion bodies following solubilization in urea and refolding in the presence of salts, reduced and oxidized glutathione, and substrates. Xylose dehydrogenase showed the highest sequence similarity to glucose-fructose oxidoreductase from Zymomonas mobilis and other putative bacterial and archaeal oxidoreductases. Activities of xylose isomerase and xylulose kinase, the initial reactions of xylose catabolism of most bacteria, could not be detected in xylose-grown cells of H. marismortui, and the genes that encode them, xylA and xylB, were not found in the genome of H. marismortui. Thus, we propose that this first characterized archaeal xylose dehydrogenase catalyzes the initial step in xylose degradation by H. marismortui. PMID:15342590

  10. Halophilic Archaea Cultivated from Surface Sterilized Middle-Late Eocene Rock Salt Are Polyploid

    PubMed Central

    Jaakkola, Salla T.; Zerulla, Karolin; Guo, Qinggong; Liu, Ying; Ma, Hongling; Yang, Chunhe; Bamford, Dennis H.; Chen, Xiangdong; Soppa, Jörg; Oksanen, Hanna M.

    2014-01-01

    Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38–41 million years ago) rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11–14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6–8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment. PMID:25338080

  11. Halophilic archaea cultivated from surface sterilized middle-late eocene rock salt are polyploid.

    PubMed

    Jaakkola, Salla T; Zerulla, Karolin; Guo, Qinggong; Liu, Ying; Ma, Hongling; Yang, Chunhe; Bamford, Dennis H; Chen, Xiangdong; Soppa, Jörg; Oksanen, Hanna M

    2014-01-01

    Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38-41 million years ago) rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11-14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6-8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment. PMID:25338080

  12. Exploring the diversity of extremely halophilic archaea in food-grade salts.

    PubMed

    Henriet, Olivier; Fourmentin, Jeanne; Delincé, Bruno; Mahillon, Jacques

    2014-11-17

    Salting is one of the oldest means of food preservation: adding salt decreases water activity and inhibits microbial development. However, salt is also a source of living bacteria and archaea. The occurrence and diversity of viable archaea in this extreme environment were assessed in 26 food-grade salts from worldwide origin by cultivation on four culture media. Additionally, metagenomic analysis of 16S rRNA gene was performed on nine salts. Viable archaea were observed in 14 salts and colony counts reached more than 10(5)CFU per gram in three salts. All archaeal isolates identified by 16S rRNA gene sequencing belonged to the Halobacteriaceae family and were related to 17 distinct genera among which Haloarcula, Halobacterium and Halorubrum were the most represented. High-throughput sequencing generated extremely different profiles for each salt. Four of them contained a single major genus (Halorubrum, Halonotius or Haloarcula) while the others had three or more genera of similar occurrence. The number of distinct genera per salt ranged from 21 to 27. Halorubrum had a significant contribution to the archaeal diversity in seven salts; this correlates with its frequent occurrence in crystallization ponds. On the contrary, Haloquadratum walsbyi, the halophilic archaea most commonly found in solar salterns, was a minor actor of the food-grade salt diversity. Our results indicate that the occurrence and diversity of viable halophilic archaea in salt can be important, while their fate in the gastrointestinal tract after ingestion remains largely unknown. PMID:25217724

  13. The Evolution of Energy-Transducing Systems. Studies with an Extremely Halophilic Archaebacterium

    NASA Technical Reports Server (NTRS)

    Stan-Lotter, Helga

    1997-01-01

    The F-type ATPases are found in remarkably similar versions in the energy-transducing membranes of bacteria, chloroplasts and mitochondria (1). Thus, it is likely that they have originated early in the evolution of life, which is consistent with their function as key enzymes of cellular metabolism. The archaea (formerly called archaebacteria) are a group of microorganisms which, as shown by molecular sequencing and biochemical data, have diverged early from the main line of prokaryotic evolution (2). From studies of members of all three major groups of archaea, the halophiles, methanogens and thermoacidophiles, it emerged that they possess a membrane ATPase, which differs from the F-ATPases. The goal of this project was a comparison of the ATPase from the halophilic archaebacterium Halobacterium saccharovorum with the well-characterized F-type ATPases on the molecular level. The results were expected to allow a decision about the nature of archaebacterial ATPases, their classification as one of the known or, alternatively, novel enzyme complex, and possibly a deduction of events during the early evolution of energy-transducing systems.

  14. Role of Central Metabolism in the Osmoadaptation of the Halophilic Bacterium Chromohalobacter salexigens*

    PubMed Central

    Pastor, José M.; Bernal, Vicente; Salvador, Manuel; Argandoña, Montserrat; Vargas, Carmen; Csonka, Laszlo; Sevilla, Ángel; Iborra, José L.; Nieto, Joaquín J.; Cánovas, Manuel

    2013-01-01

    Bacterial osmoadaptation involves the cytoplasmic accumulation of compatible solutes to counteract extracellular osmolarity. The halophilic and highly halotolerant bacterium Chromohalobacter salexigens is able to grow up to 3 m NaCl in a minimal medium due to the de novo synthesis of ectoines. This is an osmoregulated pathway that burdens central metabolic routes by quantitatively drawing off TCA cycle intermediaries. Consequently, metabolism in C. salexigens has adapted to support this biosynthetic route. Metabolism of C. salexigens is more efficient at high salinity than at low salinity, as reflected by lower glucose consumption, lower metabolite overflow, and higher biomass yield. At low salinity, by-products (mainly gluconate, pyruvate, and acetate) accumulate extracellularly. Using [1-13C]-, [2-13C]-, [6-13C]-, and [U-13C6]glucose as carbon sources, we were able to determine the main central metabolic pathways involved in ectoines biosynthesis from glucose. C. salexigens uses the Entner-Doudoroff pathway rather than the standard glycolytic pathway for glucose catabolism, and anaplerotic activity is high to replenish the TCA cycle with the intermediaries withdrawn for ectoines biosynthesis. Metabolic flux ratios at low and high salinity were similar, revealing a certain metabolic rigidity, probably due to its specialization to support high biosynthetic fluxes and partially explaining why metabolic yields are so highly affected by salinity. This work represents an important contribution to the elucidation of specific metabolic adaptations in compatible solute-accumulating halophilic bacteria. PMID:23615905

  15. Bacterial chitin utilization at halophilic conditions.

    PubMed

    Sorokin, D Y; Kolganova, T V

    2014-03-01

    Chitin is a dominant structural polymer produced in large amounts by brine shrimp Artemia in hypersaline lakes. Microbiological analysis of chitin utilization as a growth substrate in hypersaline chloride-sulfate lakes in the south Kulunda Steppe (Altai, Russia) revealed two groups of bacteria able to grow on chitin at moderate salinity. Under aerobic conditions, an enrichment culture was obtained at 2 M NaCl. Further purification resulted in the isolation of strains HCh1 and strain HCh2, identified as representatives of the genera Saccharospirillum and Arhodomonas (both in the Gammaproteobacteria). The chitin-utilizing potential has not been previously recognized in these genera. The Saccharospirillum sp. strain HCh1 grew on chitin within the salinity range from 0.5 to 3.25 M NaCl (optimum at 1 M), while Arhodomonas sp. strain HCh2 grew up to 2.5 M NaCl but had a higher salt optimum at 1.5 M. Anaerobic enrichments grew with chitin at 2 and 4 M NaCl, but growth in the latter was extremely slow and the culture eventually lost viability. The enrichment at 2 M NaCl resulted in the isolation of strain HCh-An1, identified as a distant new species of the genus Orenia in the clostridial order Halanaerobiales. It was able to grow on chitin within a salinity range from 1.0 to 2.5 M NaCl (optimum at 1.5 M). The strain is proposed as a new species of the genus Orenia-O. chitinitropha. PMID:24306781

  16. The effect of high ionic strength on neptunium (V) adsorption to a halophilic bacterium

    NASA Astrophysics Data System (ADS)

    Ams, David A.; Swanson, Juliet S.; Szymanowski, Jennifer E. S.; Fein, Jeremy B.; Richmann, Michael; Reed, Donald T.

    2013-06-01

    The mobility of neptunium (V) in subsurface high ionic strength aqueous systems may be strongly influenced by adsorption to the cell wall of the halophilic bacteria Chromohalobacter sp. This study is the first to evaluate the adsorption of neptunium (V) to the surface of a halophilic bacterium as a function of pH from approximately 2 to 10 and at ionic strengths of 2 and 4 M. This is also the first study to evaluate the effects of carbonate complexation with neptunium (V) on adsorption to whole bacterial cells under high pH conditions. A thermodynamically-based surface complexation model was adapted to describe experimental adsorption data under high ionic strength conditions where traditional corrections for aqueous ion activity are invalid. Adsorption of neptunium (V) was rapid and reversible under the conditions of the study. Adsorption was significant over the entire pH range evaluated for both ionic strength conditions and was shown to be dependent on the speciation of the sites on the bacterial surface and neptunium (V) in solution. Adsorption behavior was controlled by the relatively strong electrostatic attraction of the positively charged neptunyl ion to the negatively charged bacterial surface at pH below circum-neutral. At pH above circum-neutral, the adsorption behavior was controlled by the presence of negatively charged neptunium (V) carbonate complexes resulting in decreased adsorption, although adsorption was still significant due to the adsorption of negatively charged neptunyl-carbonate species. Adsorption in 4 M NaClO4 was enhanced relative to adsorption in 2 M NaClO4 over the majority of the pH range evaluated, likely due to the effect of increasing aqueous ion activity at high ionic strength. The protonation/deprotonation characteristics of the cell wall of Chromohalobacter sp. were evaluated by potentiometric titrations in 2 and 4 M NaClO4. Bacterial titration results indicated that Chromohalobacter sp. exhibits similar proton buffering

  17. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions.

    PubMed

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Salekdeh, Ghasem Hosseini; Karimi, Keikhosro

    2016-01-01

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated. PMID:26725518

  18. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions

    PubMed Central

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Hosseini Salekdeh, Ghasem; Karimi, Keikhosro

    2016-01-01

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated. PMID:26725518

  19. Moderately haloalkaliphilic actinomycetes in salt-affected soils

    NASA Astrophysics Data System (ADS)

    Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

    2009-12-01

    It was found that the population density of actinomycetes in solonchaks and saline desert soils varied from hundreds to tens of thousands of colony-forming units (CFUs) per 1 g of soil depending on soil type and was by 1-3 orders of magnitude lower than the number of mycelial bacteria in main soil types. Actinomycetes grow actively in saline soils, and the length of their mycelium reaches 140 m per 1 g of soil. Domination of moderately halophilic, alkaliphilic, and haloalkaliphilic actinomycetes, which grow well under 5% NaCl and pH 8-9, is a specific feature of actinomycetal complexes in saline soils. Representatives of Streptomyces and Micromonospora genera were found among the haloalkaliphilic actinomycetes. Micromonospores demonstrated lower (than streptomycetes) adaptability to high salt concentrations. Investigation of the phylogenetic position of isolated dominant haloalkaliphilic strains of streptomycetes performed on the basis of sequencing of the gene 16S rRNA enabled identifying these strains as Streptomyces pluricolorescens and S. prunicolor.

  20. Complete genome sequence of the halophilic and highly halotolerant Chromohalobacter salexigens type strain (1H11T)

    SciTech Connect

    Copeland, A; O'Connor, Kathleen; Lucas, Susan; Lapidus, Alla L.; Berry, Kerrie W.; Detter, J. Chris; Glavina Del Rio, Tijana; Hammon, Nancy; Dalin, Eileen; Tice, Hope; Pitluck, Sam; Bruce, David; Goodwin, Lynne A.; Han, Cliff; Tapia, Roxanne; Saunders, Elizabeth H; Schmutz, Jeremy; Brettin, Thomas S; Larimer, Frank W; Land, Miriam L; Hauser, Loren John; Vargas, Carmen; Nieto, Joaquin J.; Kyrpides, Nikos C; Ivanova, N; Goker, Markus; Klenk, Hans-Peter; Csonka, Laszlo N.; Woyke, Tanja

    2011-01-01

    Chromohalobacter salexigens is one of nine currently known species of the genus Chromoha- lobacter in the family Halomonadaceae. It is the most halotolerant of the so-called mod- erately halophilic bacteria currently known and, due to its strong euryhaline phenotype, it is an established model organism for prokaryotic osmoadaptation. C. salexigens strain 1H11T and Halomonas elongata are the first and the second members of the family Halomonada- ceae with a completely sequenced genome. The 3,696,649 bp long chromosome with a total of 3,319 protein-coding and 93 RNA genes was sequenced as part of the DOE Joint Genome Institute Program DOEM 2004.

  1. Support vector machine with a Pearson VII function kernel for discriminating halophilic and non-halophilic proteins.

    PubMed

    Zhang, Guangya; Ge, Huihua

    2013-10-01

    Understanding of proteins adaptive to hypersaline environment and identifying them is a challenging task and would help to design stable proteins. Here, we have systematically analyzed the normalized amino acid compositions of 2121 halophilic and 2400 non-halophilic proteins. The results showed that halophilic protein contained more Asp at the expense of Lys, Ile, Cys and Met, fewer small and hydrophobic residues, and showed a large excess of acidic over basic amino acids. Then, we introduce a support vector machine method to discriminate the halophilic and non-halophilic proteins, by using a novel Pearson VII universal function based kernel. In the three validation check methods, it achieved an overall accuracy of 97.7%, 91.7% and 86.9% and outperformed other machine learning algorithms. We also address the influence of protein size on prediction accuracy and found the worse performance for small size proteins might be some significant residues (Cys and Lys) were missing in the proteins. PMID:23764527

  2. Efficient proteolysis and application of an alkaline protease from halophilic Bacillus sp. EMB9.

    PubMed

    Sinha, Rajeshwari; Srivastava, A K; Khare, S K

    2014-10-01

    A salt-stable alkaline protease from moderately halophilic Bacillus sp. EMB9, isolated from the western coast of India, is described. This protease was capable of efficiently removing silver from used/waste X-Ray films, as well as hydrolyzing defatted soy flour with 31% degree of hydrolysis (DH). Production of the protease was optimized by using response surface methodology. Ca(2+) and NaCl were the most critical factors in enhancing the yield. Under optimized culture conditions, a maximum of 369 U protease/mL was obtained, which is quite comparable to the yields of commercial proteases. The elevated production level coupled with ability to efficiently hydrolyze protein-laden soy flour and complete recovery of silver from used X-Ray films makes it a prospective industrial enzyme. PMID:24905047

  3. A Novel Halophilic Lipase, LipBL, Showing High Efficiency in the Production of Eicosapentaenoic Acid (EPA)

    PubMed Central

    Pérez, Dolores; Martín, Sara; Fernández-Lorente, Gloria; Filice, Marco; Guisán, José Manuel; Ventosa, Antonio; García, María Teresa; Mellado, Encarnación

    2011-01-01

    Background Among extremophiles, halophiles are defined as microorganisms adapted to live and thrive in diverse extreme saline environments. These extremophilic microorganisms constitute the source of a number of hydrolases with great biotechnological applications. The interest to use extremozymes from halophiles in industrial applications is their resistance to organic solvents and extreme temperatures. Marinobacter lipolyticus SM19 is a moderately halophilic bacterium, isolated previously from a saline habitat in South Spain, showing lipolytic activity. Methods and Findings A lipolytic enzyme from the halophilic bacterium Marinobacter lipolyticus SM19 was isolated. This enzyme, designated LipBL, was expressed in Escherichia coli. LipBL is a protein of 404 amino acids with a molecular mass of 45.3 kDa and high identity to class C β-lactamases. LipBL was purified and biochemically characterized. The temperature for its maximal activity was 80°C and the pH optimum determined at 25°C was 7.0, showing optimal activity without sodium chloride, while maintaining 20% activity in a wide range of NaCl concentrations. This enzyme exhibited high activity against short-medium length acyl chain substrates, although it also hydrolyzes olive oil and fish oil. The fish oil hydrolysis using LipBL results in an enrichment of free eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), relative to its levels present in fish oil. For improving the stability and to be used in industrial processes LipBL was immobilized in different supports. The immobilized derivatives CNBr-activated Sepharose were highly selective towards the release of EPA versus DHA. The enzyme is also active towards different chiral and prochiral esters. Exposure of LipBL to buffer-solvent mixtures showed that the enzyme had remarkable activity and stability in all organic solvents tested. Conclusions In this study we isolated, purified, biochemically characterized and immobilized a lipolytic enzyme from

  4. Euryhaline Halophilic Microorganisms From the Suiyo Seamount Hydrothermal Vents.

    NASA Astrophysics Data System (ADS)

    Okamoto, T.; Kimura, H.; Maruyama, A.; Naganuma, T.

    2002-12-01

    The euryhaline halophilic microorganisms grow in a wide salinity range from <3% NaCl (seawater equivalent) to >15% NaCl or to even saturation (about 30% NaCl). A number of euryhaline halophiles have been found in a wide range of habitats from oceanic and terrestrial regimes, from deep-sea vents and seeps, and from Antarctic sea ice and terrains. We have isolated the euryhaline strains independently from a Mid-Atlantic Ridge vent fluids and Antarctic terrains are closely related species of the genus Halomonas. Some euryhaline halophiles maintain intracellular osmotic balance by controlling the concentration of compatible solute such as ectoine. This compatible solute not only stabilizes the proteins from denaturation caused by high salt concentration but also serves as a protectant against stresses such as heating, freezing and drying. The sub-seafloor structure of a hydrothermal vent is highly complicated with mosaic heterogeneity of physicochemical parameters such as temperature and salinity. This premise led us to the hypothesis that some euryhaline halophiles including Halomonas species well adapt to a wide salinity-ranged habitat in the sub-vent. To test this hypothesis, isolation and characterization of euryhaline halophiles from the Suiyo Seamount hydrothermal vents were conducted the drill-cored rock samples from the sites APSK-02, 03, and 07 and the filter-trapped fluid particle samples from the sites APSK-01 and 05 were used. For initial cultivation, a heterotrophic bacterial medium of 15% NaCl was used. The samples was added to the medium and incubated under both aerobic and anaerobic conditions at room temperature. A total of 5 euryhaline halophilic strains were obtained and phylogenetically characterized: two strains (both related to Marinobacter) from APSK-02 core section 2; one strain (related to H. meridiana) from APSK-07 core section 3; and two strains (related to H. meridiana and H. variabilis) from APSK-01 trapped particles. In addition, some

  5. Antagonistic interactions and production of halocin antimicrobial peptides among extremely halophilic prokaryotes isolated from the solar saltern of Sfax, Tunisia.

    PubMed

    Ghanmi, Fadoua; Carré-Mlouka, Alyssa; Vandervennet, Manon; Boujelben, Ines; Frikha, Doniez; Ayadi, Habib; Peduzzi, Jean; Rebuffat, Sylvie; Maalej, Sami

    2016-05-01

    Thirty-five extremely halophilic microbial strains isolated from crystallizer (TS18) and non-crystallizer (M1) ponds in the Sfax solar saltern in Tunisia were examined for their ability to exert antimicrobial activity. Antagonistic assays resulted in the selection of eleven strains that displayed such antimicrobial activity and they were further characterized. Three cases of cross-domain inhibition (archaea/bacteria or bacteria/archaea) were observed. Four archaeal strains exerted antimicrobial activity against several other strains. Three strains, for which several lines of evidence suggested the antimicrobial activity was, at least in part, due to peptide/protein agents (Halobacterium salinarum ETD5, Hbt. salinarum ETD8, and Haloterrigena thermotolerans SS1R12), were studied further. Optimal culture conditions for growth and antimicrobial production were determined. Using DNA amplification with specific primers, sequencing and RT-PCR analysis, Hbt. salinarum ETD5 and Hbt. salinarum ETD8 were shown to encode and express halocin S8, a hydrophobic antimicrobial peptide targeting halophilic archaea. Although the gene encoding halocin H4 was amplified from the genome of Htg. thermotolerans SS1R12, no transcript could be detected and the antimicrobial activity was most likely due to multiple antimicrobial compounds. This is also the first report that points to four different strains isolated from different geographical locations with the capacity to produce identical halocin S8 proteins. PMID:27074936

  6. Extreme Halophiles and Carbon Monoxide: Looking Through Windows at Earth's Past and Towards a Future on Mars

    NASA Astrophysics Data System (ADS)

    King, G.

    2015-12-01

    Carbon monoxide, which is ubiquitous on Earth, is the 2nd most abundant molecule in the universe. Members of the domain Bacteria have long been known to oxidize it, and activities of CO oxidizers in soils have been known for several decades to contribute to tropospheric CO regulation. Nonetheless, the diversity of CO oxidizers and their evolutionary history remain largely unknown. A molybdenum-dependent dehydrogenase (Mo-CODH) couples CO oxidation by most terrestrial and marine bacteria to either O2 or nitrate. Molybdenum dependence, the requirement for O2 and previous phylogenetic inferences have all supported a relatively late evolution for "aerobic" CO oxidation, presumably after the Great Oxidation Event (GOE) about 2.3 Gya. Although conundrums remain, recent discoveries suggest that Mo-CODH might have evolved before the GOE, and prior to the Bacteria-Archaea split. New phylogenetic analyses incorporating sequences from extremely halophilic CO-oxidizing Euryarchaeota isolated from salterns in the Atacama Desert, brines on Hawai`i and from the Bonneville Salt Flat suggest that Mo-CODH was present in an ancestor shared by Bacteria and Archaea. This observation is consistent with results of phylogenetic histories of genes involved in Mo-cofactor synthesis, and findings by others that Mo-nitrogenase was likely active > 3 Gya. Thus, analyses of Mo-dependent CO oxidizers provide a window on the past by raising questions about the availability of Mo and non-O2 electron acceptors. Extremely halophilic CO oxidizers also provide insights relevant for understanding the potential for extraterrestrial life. CO likely occurred at high concentrations in Mars' early atmosphere, and it occurs presently at about 800 ppm. At such high concentrations, CO represents one of the most abundant energy sources available for near-surface regolith. However, use of CO by an extant or transplanted Mars microbiota would require tolerance of low water potentials and high salt concentrations

  7. Antimicrobial susceptibility of potentially pathogenic halophilic vibrios isolated from seafood.

    PubMed

    Ottaviani, D; Bacchiocchi, I; Masini, L; Leoni, F; Carraturo, A; Giammarioli, M; Sbaraglia, G

    2001-08-01

    Susceptibility patterns to 27 antimicrobial agents and beta-lactamase production were investigated in potentially pathogenic halophilic vibrios from seafood. The effect of salinity on the response to the drugs in vitro was also studied. All isolates were uniformly sensitive to choramphenicol, imipenem, meropenem but resistant to lincomycin. All were highly sensitive to oxolinic acid, trimethoprim-sulphamethoxazole, doxycycline, flumequine, cefotaxime, nalidixic acid and ciprofloxacin. Some strains of V. harveyi, V. alginolyticus and V. parahaemolyticus apparently had mechanisms of resistance to several beta-lactam antibiotics other than by the production of beta-lactamases. Sixty-nine strains produced penicillinase but a low correlation between beta-lactamase activity and resistance to beta-lactam antibiotics was noted. The salt concentration affected the in vitro susceptibility of halophilic vibrios and the effect of salinity depended on both the individual strains and the antimicrobial tested. PMID:11516936

  8. Carotenoid Production by Halophilic Archaea Under Different Culture Conditions.

    PubMed

    Calegari-Santos, Rossana; Diogo, Ricardo Alexandre; Fontana, José Domingos; Bonfim, Tania Maria Bordin

    2016-05-01

    Carotenoids are pigments that may be used as colorants and antioxidants in food, pharmaceutical, and cosmetic industries. Since they also benefit human health, great efforts have been undertaken to search for natural sources of carotenoids, including microbial ones. The optimization of culture conditions to increase carotenoid yield is one of the strategies used to minimize the high cost of carotenoid production by microorganisms. Halophilic archaea are capable of producing carotenoids according to culture conditions. Their main carotenoid is bacterioruberin with 50 carbon atoms. In fact, the carotenoid has important biological functions since it acts as cell membrane reinforcement and it protects the microorganism against DNA damaging agents. Moreover, carotenoid extracts from halophilic archaea have shown high antioxidant capacity. Therefore, current review summarizes the effect of different culture conditions such as salt and carbon source concentrations in the medium, light incidence, and oxygen tension on carotenoid production by halophilic archaea and the strategies such as optimization methodology and two-stage cultivation already used to increase the carotenoid yield of these microorganisms. PMID:26750123

  9. Improvement of halophilic cellulase production from locally isolated fungal strain

    PubMed Central

    Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen; Gumba, Rizo Edwin

    2014-01-01

    Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett–Burman design and the Face Centered Central Composite Design (FCCCD). Plackett–Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization. PMID:26150755

  10. Improvement of halophilic cellulase production from locally isolated fungal strain.

    PubMed

    Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen; Gumba, Rizo Edwin

    2015-07-01

    Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett-Burman design and the Face Centered Central Composite Design (FCCCD). Plackett-Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization. PMID:26150755

  11. Amyloid fibril formation in vitro from halophilic metal binding protein: Its high solubility and reversibility minimized formation of amorphous protein aggregations

    PubMed Central

    Tokunaga, Yuhei; Matsumoto, Mitsuharu; Tokunaga, Masao; Arakawa, Tsutomu; Sugimoto, Yasushi

    2013-01-01

    Halophilic proteins are characterized by high net negative charges and relatively small fraction of hydrophobic amino acids, rendering them aggregation resistant. These properties are also shared by histidine-rich metal binding protein (HP) from moderate halophile, Chromohalobacter salexigens, used in this study. Here, we examined how halophilic proteins form amyloid fibrils in vitro. His-tagged HP, incubated at pH 2.0 and 58°C, readily formed amyloid fibrils, as observed by thioflavin fluorescence, CD spectra, and transmission or atomic force microscopies. Under these low-pH harsh conditions, however, His-HP was promptly hydrolyzed to smaller peptides most likely responsible for rapid formation of amyloid fibril. Three major acid-hydrolyzed peptides were isolated from fibrils and turned out to readily form fibrils. The synthetic peptides predicted to form fibrils in these peptide sequences by Waltz software also formed fibrils. Amyloid fibril was also readily formed from full-length His-HP when incubated with 10–20% 2,2,2-trifluoroethanol at pH 7.8 and 25°C without peptide bond cleavage. PMID:24038709

  12. Effects of salt and ligand concentrations on the thermal unfolding and refolding of halophilic starch-binding domain from Kocuria varians α-amylase.

    PubMed

    Yamaguchi, Rui; Arakawa, Tsutomu; Tokunaga, Hiroko; Ishibashi, Matsujiro; Tokunaga, Masao

    2012-03-01

    The starch binding domain of α-amlylase from moderate halophile was expressed in E. coli with His tag (His- SBD12) and characterized for its halophilic properties. His-SBD12 was stable up to 35°C and showed binding activity, although at reduced level, to amylose even in the absence of NaCl. Both NaCl and specific ligands exhibited insignificant influence on the secondary structure of His-SBD12, but showed significant stabilization effects against thermal unfolding concentration-dependently, showing its halophilic properties. NaCl increased thermal stability of His-SBD12 by 4°C at 0.2 M and 15°C at 2 M, and enhanced refolding rate by ~7-fold at 0.2 M and ~170-fold at 2 M. Its specific ligands, β- cyclodextrin (at 3 mM) and maltose (at 470 mM), also stabilized the protein by 11° C, most likely reflecting affinity difference between these two ligands. However, they showed marginal effects on refolding rate. These observations suggest that although binding of NaCl and specific ligands to the native structure can explain their stabilization effects on His- SBD12, it is not a sole factor for modulating their effects on folding of His-SBD12. PMID:22409499

  13. Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis.

    PubMed

    Kumar, Sumit; Khare, S K

    2015-01-01

    Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by "one-at-a-time approach." Starch was found to be the best carbon source at 5% (w/v) concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v) NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL). α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use. PMID:25667773

  14. Halophilic reactions of a stable silylene with chloro and bromocarbons.

    PubMed

    Moser, Daniel F; Bosse, Todd; Olson, Jordan; Moser, Jessica L; Guzei, Ilia A; West, Robert

    2002-04-24

    A number of disilanes have been synthesized from a stable silylene, 1 (N,N'-di-tert-butyl-1,3-diaza-2-silacyclopent-4-en-2-ylidene), and a variety of halocarbons. It is proposed that disilane formation is a result of an initial halophilic interaction between the silylene and halocarbon. Formation of disilanes from 1 and CCl4, 2a, CHCl3, 2b, CH2Cl2, 2c, benzyl chloride, 2d, and bromobenzene, 5, are described here. An X-ray crystal structure of 2b was determined. PMID:11960428

  15. Archaebacterial class I and class II aldolases from extreme halophiles

    NASA Astrophysics Data System (ADS)

    Alterkar, Wijaya; Dhar, Nenoo M.

    1988-03-01

    Both, class I (Schiff-base forming) and class II (metal requiring) fructose biphosphate aldolases were found to be distributed among halophilic archaebacteria. The aldolase activity fromHalobacterium halobium, H. salinarium, H. cutirubrum, H. mediterranei andH. volcanii exhibited properties of a bacterial class II aldolase as it was metal-dependent for activity and therefore inhibited by EDTA. In contrast, aldolase fromH. saccharovorum, Halobacterium R-113, H. vallismortis andHalobacterium CH-1 formed a Schiff-base intermediate with the substrate and therefore resembled to eukaryotic class I type. The type of aldolase did not vary by changes in the growth medium.

  16. Archaebacterial class I and class II aldolases from extreme halophiles.

    PubMed

    Altekar, W; Dhar, N M

    1988-01-01

    Both, class I (Schiff-base forming) and class II (metal requiring) fructose biphosphate aldolases were found to be distributed among halophilic archaebacteria. The aldolase activity from Halobacteriium halobium, H. salinarium, H. cutirubrum, H. mediterranei and H. volcanii exhibited properties of a bacterial class II aldolase as it was metal-dependent for activity and therefore inhibited by EDTA. In contrast, aldolase from H. saccharovorum, Halobacterium R-113, H. vallismortis and Halobacterium CH-1 formed a Schiff-base intermediate with the substrate and therefore resembled to eukaryotic class I type. The type of aldolase did not vary by changes in the growth medium. PMID:11536602

  17. Useful halophilic, thermostable and ionic liquids tolerant cellulases

    DOEpatents

    Zhang, Tao; Datta, Supratim; Simmons, Blake A.; Rubin, Edward M.

    2016-06-28

    The present invention provides for an isolated or recombinant polypeptide comprising an amino acid sequence having at least 70% identity with the amino acid sequence of a Halorhabdus utahensis cellulase, such as Hu-CBH1, wherein said amino acid sequence has a halophilic thermostable and/or thermophilic cellobiohydrolase (CBH) activity. In some embodiments, the polypeptide has a CBH activity that is resistant to up to about 20% of ionic liquids. The present invention also provides for compositions comprising and methods using the isolated or recombinant polypeptide.

  18. The effects of space relevant environmental factors on halophilic Archaea

    NASA Astrophysics Data System (ADS)

    Leuko, Stefan; Moeller, Ralf; Rettberg, Petra

    Within the last 50 years, space technology has provided tools for transporting terrestrial (microbial) life beyond Earth's protective shield in order to study its responses to selected conditions of space. Microorganisms are ubiquitous and can be found in almost every environment on Earth. They thrive and survive in a broad spectrum of environments and are true masters in adapting to rapidly changing external conditions. Although microorganisms cannot actively grow under the harsh conditions of outer space or other known planets, some microorganisms might be able to survive for a time in space or other planets as dormant, inactive spores or in similar desiccation-resistant resting states, e.g., enclosed in halite crystals or biofilms. Halite crystals are the realm of halophilic Archaea as they have adapted to life at extreme salt concentrations. They can stay entrapped in such crystals for millions of years without losing viability and therefore the family Halobacteriaceae belongs to the group of microorganisms which may survive space travel or may even be found on other planets. Several members of this family have been utilized in space relevant experiments where they were exposed to detrimental environmental conditions such as UV-C radiation, vacuum, temperature cycles (+60(°) C and -25(°) C) and heavy iron bombardment (150 MeV He, 500 MeV Ar and 500 MeV Fe ions). The viability was evaluated by colony forming unit (cfu) counts as well as with the LIFE/DEAD kit. Results revealed that UV-C radiation (up to 1.000 J/m (2) ) has a considerable effect on the viability, whereas the other tested parameters inflict little damage onto the organisms. Repair of UV-C inflicted damage is efficient and several DNA damage repair genes are up-regulated following exposure. Halophilic archaea display a strong resistance against heavy iron bombardment, with dosages of up to 2.000 Gy 500 MeV Fe ions needed to establish a visible effect on the vitality. Genomic integrity after

  19. Carotenoid Analysis of Halophilic Archaea by Resonance Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Marshall, Craig P.; Leuko, Stefan; Coyle, Candace M.; Walter, Malcolm R.; Burns, Brendan P.; Neilan, Brett A.

    2007-08-01

    Recently, halite and sulfate evaporate rocks have been discovered on Mars by the NASA rovers, Spirit and Opportunity. It is reasonable to propose that halophilic microorganisms could have potentially flourished in these settings. If so, biomolecules found in microorganisms adapted to high salinity and basic pH environments on Earth may be reliable biomarkers for detecting life on Mars. Therefore, we investigated the potential of Resonance Raman (RR) spectroscopy to detect biomarkers derived from microorganisms adapted to hypersaline environments. RR spectra were acquired using 488.0 and 514.5 nm excitation from a variety of halophilic archaea, including Halobacterium salinarum NRC-1, Halococcus morrhuae, and Natrinema pallidum. It was clearly demonstrated that RR spectra enhance the chromophore carotenoid molecules in the cell membrane with respect to the various protein and lipid cellular components. RR spectra acquired from all halophilic archaea investigated contained major features at approximately 1000, 1152, and 1505 cm-1. The bands at 1505 cm-1 and 1152 cm-1 are due to in-phase C=C (ν1 ) and C-C stretching ( ν2 ) vibrations of the polyene chain in carotenoids. Additionally, in-plane rocking modes of CH3 groups attached to the polyene chain coupled with C-C bonds occur in the 1000 cm-1 region. We also investigated the RR spectral differences between bacterioruberin and bacteriorhodopsin as another potential biomarker for hypersaline environments. By comparison, the RR spectrum acquired from bacteriorhodopsin is much more complex and contains modes that can be divided into four groups: the C=C stretches (1600-1500 cm-1), the CCH in-plane rocks (1400-1250 cm-1), the C-C stretches (1250-1100 cm-1), and the hydrogen out-of-plane wags (1000-700 cm-1). RR spectroscopy was shown to be a useful tool for the analysis and remote in situ detection of carotenoids from halophilic archaea without the need for large sample sizes and complicated extractions, which are

  20. Oligotrophic Bacteria Enhance Algal Growth under Iron-Deficient Conditions

    PubMed Central

    Keshtacher-Liebso..., E.; Hadar, Y.; Chen, Y.

    1995-01-01

    A Halomonas sp., a marine halophilic and oligotrophic bacterium, was grown on exudates of Dunaliella bardawil. The bacteria increased the solubility of Fe, thereby enhancing its availability to the algae. As a result, the algal growth rate increased. Because of these syntrophic relations, growth of the marine alga D. bardawil was facilitated at Fe levels that would otherwise induce Fe deficiency and inhibit algal growth. PMID:16535058

  1. Proton motive force and Na+/H+ antiport in a moderate halophile.

    PubMed Central

    Hamaide, F; Kushner, D J; Sprott, G D

    1983-01-01

    The influence of pH on the proton motive force of Vibrio costicola was determined by measuring the distributions of triphenylmethylphosphonium cation (membrane potential, delta psi) and either dimethyloxazolidinedione or methylamine (osmotic component, delta pH). As the pH of the medium was adjusted from 5.7 to 9.0, the proton motive force steadily decreased from about 170 to 100 mV. This decline occurred, despite a large increase in the membrane potential to its maximum value at pH 9.0, because of the loss of the pH gradient (inside alkaline). The cytoplasm and medium were of equal pH at 7.5; membrane permeability properties were lost at the pH extremes of 5.0 and 9.5. Protonophores and monensin prevented the net efflux of protons normally found when an oxygen pulse was given to an anaerobic cell suspension. A Na+/H+ antiport activity was measured for both Na+ influx and efflux and was shown to be dissipated by protonophores and monensin. These results strongly favor the concept that respiratory energy is used for proton efflux and that the resulting proton motive force may be converted to a sodium motive force through Na+/H+ antiport (driven by delta psi). A role for antiport activity in pH regulation of the cytosol can also explain the broad pH range for optimal growth, extending to the alkaline extreme of pH 9.0. PMID:6313606

  2. Marimicrobium arenosum gen. nov., sp. nov., a moderately halophilic bacterium isolated from sea sand.

    PubMed

    Konkit, Maytiya; Kim, Jong-Hwa; Kim, Wonyong

    2016-02-01

    A Gram-stain-negative, non-pigmented, non-spore-forming, non-motile, strictly aerobic bacterial strain, designated CAU 1038T, was isolated from a sea sand sample in Modo, Republic of Korea, and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1038T grew optimally at 30 °C, pH 7.5 in 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CAU 1038T formed a distinct lineage within the class Gammaproteobacteria as a separate deep branch, with 95.2 % or lower sequence similarity to representatives of the genera Haliea, Halioglobus and Chromatocurvus, and 92.3 % or lower with Luminiphilus, Pseudohaliea and Congregibacter. The major cellular fatty acids of strain CAU 1038T were C16 : 0, C16 : 1ω7c and C18 : 1ω7c. The polar lipid pattern of the isolate consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and two unidentified lipids. The strain contained lipoquinone (Q-8) as the sole respiratory quinone. The G+C content of the genomic DNA was 65 mol%. On the basis of phenotypic and chemotaxonomic data, and phylogenetic inference, strain CAU 1038T represents a novel species of a new genus in the family Halieaceae, for which the name Marimicrobium arenosum gen. nov., sp. nov. is proposed. The type strain of the type species is CAU 1038T ( = KCTC 42300T = NBRC 110727T). PMID:26611676

  3. Adjusting membrane lipids under salt stress: the case of the moderate halophilic organism Halobacillus halophilus.

    PubMed

    Lopalco, Patrizia; Angelini, Roberto; Lobasso, Simona; Köcher, Saskia; Thompson, Melanie; Müller, Volker; Corcelli, Angela

    2013-04-01

    The lipid composition of Halobacillus halophilus was investigated by combined thin-layer chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses of the total lipid extract. Main polar lipids were found to be sulfoquinovosyldiacylglycerol and phosphatidylglycerol, while cardiolipin was a minor lipid together with phosphatidic acid, alanyl-phosphatidylglycerol and two not yet fully identified lipid components. In addition the analyses of residual lipids, associated with denatured proteins after the lipid extraction, revealed the presence of significant amounts of cardiolipin, indicating that it is a not readily extractable phospholipid. Post decay source mass spectrometry analyses allowed the determination of acyl chains of main lipid components. On increasing the culture medium salinity, an increase in the shorter chains and the presence of chain unsaturations were observed. These changes in the lipid core structures might compensate for the increase in packing and rigidity of phospholipid and sulfoglycolipid polar heads in high-salt medium, therefore contributing to the homeostasis of membrane fluidity and permeability in salt stress conditions. PMID:22970819

  4. On the Response of Halophilic Archaea to Space Conditions

    PubMed Central

    Leuko, Stefan; Rettberg, Petra; Pontifex, Ashleigh L.; Burns, Brendan P.

    2014-01-01

    Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth’s protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator) have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated. PMID:25370029

  5. On the response of halophilic archaea to space conditions.

    PubMed

    Leuko, Stefan; Rettberg, Petra; Pontifex, Ashleigh L; Burns, Brendan P

    2014-01-01

    Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth's protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator) have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated. PMID:25370029

  6. Metabolic flux analysis of the halophilic archaeon Haladaptatus paucihalophilus.

    PubMed

    Liu, Guangxiu; Zhang, Manxiao; Mo, Tianlu; He, Lian; Zhang, Wei; Yu, Yi; Zhang, Qi; Ding, Wei

    2015-11-27

    This work reports the (13)C-assisted metabolic flux analysis of Haladaptatus paucihalophilus, a halophilic archaeon possessing an intriguing osmoadaption mechanism. We showed that the carbon flow is through the oxidative tricarboxylic acid (TCA) cycle whereas the reductive TCA cycle is not operative in H. paucihalophilus. In addition, both threonine and the citramalate pathways contribute to isoleucine biosynthesis, whereas lysine is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. Unexpected, the labeling patterns of glycine from the cells grown on [1-(13)C]pyruvate and [2-(13)C]pyruvate suggest that, unlike all the organisms investigated so far, in which glycine is produced exclusively from the serine hydroxymethyltransferase (SHMT) pathway, glycine biosynthesis in H. paucihalophilus involves different pathways including SHMT, threonine aldolase (TA) and the reverse reaction of glycine cleavage system (GCS), demonstrating for the first time that other pathways instead of SHMT can also make a significant contribution to the cellular glycine pool. Transcriptional analysis confirmed that both TA and GCS genes were transcribed in H. paucihalophilus, and the transcriptional level is independent of salt concentrations in the culture media. This study expands our understanding of amino acid biosynthesis and provides valuable insights into the metabolism of halophilic archaea. PMID:26441084

  7. Haloanaerobium kushneri sp. nov., an obligately halophilic, anaerobic bacterium from an oil brine

    NASA Technical Reports Server (NTRS)

    Bhupathiraju, V. K.; McInerney, M. J.; Woese, C. R.; Tanner, R. S.

    1999-01-01

    Three strains, designated VS-751T, VS-511 and VS-732, of a strictly anaerobic, moderately halophilic, Gram-negative, rod-shaped bacterium were isolated from a highly saline (15-20%) brine from an oil reservoir in central Oklahoma, USA. The optimal concentration of NaCl for growth of these three strains was 2 M (12%), and the strains also grew in the presence of an additional 1 M MgCl2. The strains were mesophilic and grew at a pH range of 6-8. Carbohydrates used by all three strains included glucose, fructose, arabinose, galactose, maltose, mannose, cellobiose, sucrose and inulin. Glucose fermentation products included ethanol, acetate, H2 and CO2, with formate produced by two of the three strains. Differences were noted among strains in the optimal temperature and pH for growth, the maximum and minimum NaCl concentration that supported growth, substrate utilization and cellular fatty acid composition. Despite the phenotypic differences among the three strains, analysis of the 16S rRNA gene sequences and DNA-DNA hybridizations showed that these three strains were members of the same genospecies which belonged to the genus Haloanaerobium. The phenotypic and genotypic characteristics of strains VS-751T, VS-511 and VS-732 are different from those of previously described species of Haloanaerobium. It is proposed that strain VS-751T (ATCC 700103T) be established as the type strain of a new species, Haloanaerobium kushneri.

  8. Production and properties of an exopolysaccharide synthesized by the extreme halophilic archaeon Haloterrigena turkmenica.

    PubMed

    Squillaci, Giuseppe; Finamore, Rosario; Diana, Paola; Restaino, Odile Francesca; Schiraldi, Chiara; Arbucci, Salvatore; Ionata, Elena; La Cara, Francesco; Morana, Alessandra

    2016-01-01

    We have isolated a novel exopolysaccharide (EPS) produced by the extreme halophilic archaeon Haloterrigena turkmenica. Some features, remarkable from an industrial point of view, such as emulsifying and antioxidant properties, were investigated. H. turkmenica excreted 20.68 mg of EPS per 100 ml of culture medium when grown in usual medium supplemented with glucose. The microorganism excreted the biopolymer mainly in the middle exponential growth phase and reached the maximal production in the stationary phase. Analyses by anion exchange chromatography and SEC-TDA Viscotek indicated that the EPS was composed of two main fractions of 801.7 and 206.0 kDa. It was a sulfated heteropolysaccharide containing glucose, galactose, glucosamine, galactosamine, and glucuronic acid. Studies performed utilizing the mixture of EPS anionic fractions showed that the biopolymer had emulsifying activity towards vegetable oils comparable or superior to that exhibited by the controls, moderate antioxidant power when tested with 2,2'-diphenyl-1-picrylhydrazyl (DPPH(·)), and moisture-retention ability higher than hyaluronic acid (HA). The EPS from H. turkmenica is the first exopolysaccharide produced by an archaea to be characterized in terms of properties that can have potential biotechnological applications. PMID:26403921

  9. Melghiribacillus thermohalophilus gen. nov., sp. nov., a novel filamentous, endospore-forming, thermophilic and halophilic bacterium.

    PubMed

    Addou, Nariman Ammara; Schumann, Peter; Spröer, Cathrin; Ben Hania, Wajdi; Hacene, Hocine; Fauque, Guy; Cayol, Jean-Luc; Fardeau, Marie-Laure

    2015-04-01

    A novel filamentous, endospore-forming, thermophilic and moderately halophilic bacterium designated strain Nari2A(T) was isolated from soil collected from an Algerian salt lake, Chott Melghir. The novel isolate was Gram-staining-positive, aerobic, catalase-negative and oxidase-positive. Optimum growth occurred at 50-55 °C, 7-10% (w/v) NaCl and pH 7-8. The strain exhibited 95.4, 95.4 and 95.2% 16S rRNA gene sequence similarity to Thalassobacillus devorans G19.1(T), Sediminibacillus halophilus EN8d(T) and Virgibacillus kekensis YIM-kkny16(T), respectively. The major menaquinone was MK-7. The polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, three unknown phosphoglycolipids and two unknown phospholipids. The predominant cellular fatty acids were iso-C(15 : 0) and iso-C(17 : 0). The DNA G+C content was 41.9 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain Nari2A(T) is considered to represent a novel species of a new genus in the family Bacillaceae , order Bacillales , for which the name Melghiribacillus thermohalophilus gen. nov., sp. nov. is proposed. The type strain of Melghiribacillus thermohalophilus is Nari2A(T) ( = DSM 25894(T) = CCUG 62543(T)). PMID:25604343

  10. Anti-methicillin Resistant Staphylococcus aureus Compound Isolation from Halophilic Bacillus amyloliquefaciens MHB1 and Determination of Its Mode of Action Using Electron Microscope and Flow Cytometry Analysis.

    PubMed

    Jeyanthi, Venkadapathi; Velusamy, Palaniyandi

    2016-06-01

    The aim of this study was to purify, characterize and evaluate the antibacterial activity of bioactive compound against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA compound was produced by a halophilic bacterial strain designated as MHB1. The MHB1 strain exhibited 99 % similarity to Bacillus amyloliquefaciens based on 16S rRNA gene analysis. The culture conditions of Bacillus amyloliquefaciens MHB1 were optimized using nutritional and environmental parameters for enhanced anti-MRSA compound production. The pure bioactive compound was isolated using silica gel column chromatography and Semi-preparative High-performance liquid chromatography (Semi-preparative HPLC). The Thin layer chromatography, Fourier transform infrared spectroscopy and proton NMR ((1)H NMR) analysis indicated the phenolic nature of the compound. The molecular mass of the purified compound was 507 Da as revealed by Liquid chromatography-mass spectrometry (LC-MS) analysis. The compound inhibited the growth of MRSA with minimum inhibitory concentration (MIC) of 62.5 µg mL(-1). MRSA bacteria exposed to 4× MIC of the compound and the cell viability was determined using flow cytometric analysis. Scanning electron microscope and Transmission electron microscope analysis was used to determine the ultrastructural changes in bacteria. This is the first report on isolation of anti-MRSA compound from halophilic B. amyloliquefaciens MHB1 and could act as a promising biocontrol agent. PMID:27570306

  11. Draft Genome Sequence of the Extremely Halophilic Phototrophic Purple Sulfur Bacterium Halorhodospira halochloris

    PubMed Central

    Singh, Kumar Saurabh; Kirksey, Jared; Hoff, Wouter D.; Deole, Ratnakar

    2014-01-01

    Halorhodospira halochloris is an extremely halophilic bacterium isolated from hypersaline Wadi Nantrun lakes in Egypt. Here we report the draft genome sequence of this gammaproteobacteria (GI number: 589289709, GenBank Accession number: CP007268). The 3.5-Mb genome encodes for photosynthesis and biosynthesis of organic osmoprotectants. Comparison with the genome of H.halophila promises to yield insights into the evolution of halophilic adaptations. PMID:25057327

  12. Osmoadaptative Strategy and Its Molecular Signature in Obligately Halophilic Heterotrophic Protists

    PubMed Central

    Harding, Tommy; Brown, Matthew W.; Simpson, Alastair G.B.; Roger, Andrew J.

    2016-01-01

    Halophilic microbes living in hypersaline environments must counteract the detrimental effects of low water activity and salt interference. Some halophilic prokaryotes equilibrate their intracellular osmotic strength with the extracellular milieu by importing inorganic solutes, mainly potassium. These “salt-in” organisms characteristically have proteins that are highly enriched with acidic and hydrophilic residues. In contrast, “salt-out” halophiles accumulate large amounts of organic solutes like amino acids, sugars and polyols, and lack a strong signature of halophilicity in the amino acid composition of cytoplasmic proteins. Studies to date have examined halophilic prokaryotes, yeasts, or algae, thus virtually nothing is known about the molecular adaptations of the other eukaryotic microbes, that is, heterotrophic protists (protozoa), that also thrive in hypersaline habitats. We conducted transcriptomic investigations to unravel the molecular adaptations of two obligately halophilic protists, Halocafeteria seosinensis and Pharyngomonas kirbyi. Their predicted cytoplasmic proteomes showed increased hydrophilicity compared with marine protists. Furthermore, analysis of reconstructed ancestral sequences suggested that, relative to mesophiles, proteins in halophilic protists have undergone fewer substitutions from hydrophilic to hydrophobic residues since divergence from their closest relatives. These results suggest that these halophilic protists have a higher intracellular salt content than marine protists. However, absence of the acidic signature of salt-in microbes suggests that Haloc. seosinensis and P. kirbyi utilize organic osmolytes to maintain osmotic equilibrium. We detected increased expression of enzymes involved in synthesis and transport of organic osmolytes, namely hydroxyectoine and myo-inositol, at maximal salt concentration for growth in Haloc. seosinensis, suggesting possible candidates for these inferred organic osmolytes. PMID:27412608

  13. Osmoadaptative Strategy and Its Molecular Signature in Obligately Halophilic Heterotrophic Protists.

    PubMed

    Harding, Tommy; Brown, Matthew W; Simpson, Alastair G B; Roger, Andrew J

    2016-01-01

    Halophilic microbes living in hypersaline environments must counteract the detrimental effects of low water activity and salt interference. Some halophilic prokaryotes equilibrate their intracellular osmotic strength with the extracellular milieu by importing inorganic solutes, mainly potassium. These "salt-in" organisms characteristically have proteins that are highly enriched with acidic and hydrophilic residues. In contrast, "salt-out" halophiles accumulate large amounts of organic solutes like amino acids, sugars and polyols, and lack a strong signature of halophilicity in the amino acid composition of cytoplasmic proteins. Studies to date have examined halophilic prokaryotes, yeasts, or algae, thus virtually nothing is known about the molecular adaptations of the other eukaryotic microbes, that is, heterotrophic protists (protozoa), that also thrive in hypersaline habitats. We conducted transcriptomic investigations to unravel the molecular adaptations of two obligately halophilic protists, Halocafeteria seosinensis and Pharyngomonas kirbyi Their predicted cytoplasmic proteomes showed increased hydrophilicity compared with marine protists. Furthermore, analysis of reconstructed ancestral sequences suggested that, relative to mesophiles, proteins in halophilic protists have undergone fewer substitutions from hydrophilic to hydrophobic residues since divergence from their closest relatives. These results suggest that these halophilic protists have a higher intracellular salt content than marine protists. However, absence of the acidic signature of salt-in microbes suggests that Haloc. seosinensis and P. kirbyi utilize organic osmolytes to maintain osmotic equilibrium. We detected increased expression of enzymes involved in synthesis and transport of organic osmolytes, namely hydroxyectoine and myo-inositol, at maximal salt concentration for growth in Haloc. seosinensis, suggesting possible candidates for these inferred organic osmolytes. PMID:27412608

  14. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    NASA Astrophysics Data System (ADS)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  15. A first record of obligate halophilic aspergilli from the dead sea.

    PubMed

    Nazareth, Sarita; Gonsalves, Valerie; Nayak, Shweta

    2012-03-01

    The isolation of obligate halophilic aspergilli from the Dead Sea and the range of salt tolerance of halophilic fungi isolated, are reported here for the first time. The mycobiota of the Dead Sea isolated in this study, was dominated by Aspergillus and Penicillium species; Cladosporium were found in lesser numbers. All three genera were obtained from the water sample; however, Aspergillus was the only genus obtained from the sediment. There was significant difference in growth of each isolate at different salt concentrations and intraspecies analysis revealed dissimilarity in response of strains to different salt concentrations in the growth medium The isolates were euryhaline, with halotolerance up to 20-25% solar salt, Aspergillus and Penicillium species showing a higher level of halotolerance, as compared to that of Cladosporium. Halophilic fungi were found in greater numbers in the sediment sample as compared to that in the water sample. Penicillium and Cladosporium species were exclusively facultative halophiles, while some species of Aspergillus were facultative halophiles. All the obligate halophiles isolated, belonged to the genus Aspergillus and were identified as A. penicillioides and A unguis, the latter being a first record of the species from the Dead Sea. PMID:23449273

  16. Salternamides A-D from a Halophilic Streptomyces sp. Actinobacterium.

    PubMed

    Kim, Seong-Hwan; Shin, Yoonho; Lee, So-Hyoung; Oh, Ki-Bong; Lee, Sang Kook; Shin, Jongheon; Oh, Dong-Chan

    2015-04-24

    Salternamides A-D (1-4), the first secondary metabolites discovered from saltern-derived actinomycetes, were isolated from a halophilic Streptomyces strain isolated from a saltern on Shinui Island in the Republic of Korea. The planar structures of the salternamides, which are new members of the manumycin family, were elucidated by a combination of spectroscopic analyses. The absolute configurations of the salternamides were determined by chemical and spectroscopic methods, including the modified Mosher's method, J-based configuration analysis, and circular dichroism spectroscopy. Salternamide A (1), which is the first chlorinated compound in the manumycin family, exhibited potent cytotoxicity against a human colon cancer cell line (HCT116) and a gastric cancer cell line (SNU638) with submicromolar IC50 values. Salternamides A and D were also determined to be weak Na(+)/K(+) ATPase inhibitors. PMID:25700232

  17. Effects of salts on the halophilic alga Dunaliella viridis.

    PubMed

    Johnson, M K; Johnson, E J; MacElroy, R D; Speer, H L; Bruff, B S

    1968-04-01

    Determinations of the salt sensitivity of enzymes extracted from the halophilic alga Dunaliella viridis revealed that pentose phosphate isomerase, ribulose diphosphate carboxylase, glucose-6-phosphate dehydrogenase, and phosphohexose isomerase were inhibited by NaCl concentrations far lower than that in the growth medium (3.75 m). The inhibition was reversible and was not prevented by preparing the extracts in the presence of salt. Potassium, lithium, and cesium chlorides were equally inhibitory. In contrast, whole cells require rather high levels of NaCl for optimal growth, whereas growth is inhibited by low levels of the other cations. The results suggest a specific mechanism for the exclusion of sodium from the interior of the cell. PMID:5646631

  18. Halophilic and thermotolerant Gymnoascus species from several special environments, China.

    PubMed

    Zhou, Nan; Zhang, Yu; Liu, Fang; Cai, Lei

    2016-01-01

    This study introduces three new Gymnoascus species (Gymnoascaceae, Onygenales), G. halophilus, G. stercorarius and G. thermotolerans, isolated from sediments in Chaka Salt Lake, compost and cornfield soil, respectively, in China, based on a polyphasic characterization including morphology, physiology and molecular phylogeny. Phylogenetic relationships were assessed based on the nuclear internal transcribed spacer (ITS = ITS1 + 5.8S + ITS2) region and a combined multilocus alignment of the ITS, 18S subunit rRNA gene and 28S subunit rRNA genes. Our study identified phylogenetic and phenotypic characters that differentiated the three new species from known species in the genus. Salinity and temperature tolerance tests revealed that G. halophilus was an obligate halophile while G. stercorarius and G. thermotolerans were halotolerant and thermotolerant. A key to accepted species of Gymnoascus is provided. PMID:26490705

  19. Halophilic Archaea determined from geothermal steam vent aerosols.

    PubMed

    Ellis, Dean G; Bizzoco, Richard W; Kelley, Scott T

    2008-06-01

    Hydrothermal vents, known as 'fumaroles', are ubiquitous features of geothermal areas. Although their geology has been extensively characterized, little is known about the subsurface microbial ecology of fumaroles largely because of the difficulty in collecting sufficient numbers of cells from boiling steam water for DNA extraction and culture isolation. Here we describe the first collection, molecular analysis and isolation of microbes from fumarole steam waters in Russia (Kamchatka) and the USA (Hawaii, New Mexico, California and Wyoming). Surprisingly, the steam vent waters from all the fumaroles contained halophilic Archaea closely related to the Haloarcula spp. found in non-geothermal salt mats, saline soils, brine pools and salt lakes around the world. Microscopic cell counting estimated the cell dispersal rate at approximately 1.6 x 10(9) cells year(-1) from a single fumarole. We also managed to enrich microbes in high-salt media from every vent sample, and to isolate Haloarcula from a Yellowstone vent in a 20% salt medium after a month-long incubation, demonstrating both salt tolerance and viability of cells collected from high-temperature steam. Laboratory tests determined that microbes enriched in salt media survived temperatures greater than 75 degrees C for between 5 and 30 min during the collection process. Hawaiian fumaroles proved to contain the greatest diversity of halophilic Archaea with four new lineages that may belong to uncultured haloarchaeal genera. This high diversity may have resulted from the leaching of salts and minerals through the highly porous volcanic rock, creating a chemically complex saline subsurface. PMID:18331336

  20. A halophilic bacterium inhabiting the warm, CaCl2-rich brine of the perennially ice-covered Lake Vanda, McMurdo Dry Valleys, Antarctica.

    PubMed

    Tregoning, George S; Kempher, Megan L; Jung, Deborah O; Samarkin, Vladimir A; Joye, Samantha B; Madigan, Michael T

    2015-03-01

    Lake Vanda is a perennially ice-covered and stratified lake in the McMurdo Dry Valleys, Antarctica. The lake develops a distinct chemocline at about a 50-m depth, where the waters transition from cool, oxic, and fresh to warm, sulfidic, and hypersaline. The bottom water brine is unique, as the highly chaotropic salts CaCl2 and MgCl2 predominate, and CaCl2 levels are the highest of those in any known microbial habitat. Enrichment techniques were used to isolate 15 strains of heterotrophic bacteria from the Lake Vanda brine. Despite direct supplementation of the brine samples with different organic substrates in primary enrichments, the same organism, a relative of the halophilic bacterium Halomonas (Gammaproteobacteria), was isolated from all depths sampled. The Lake Vanda (VAN) strains were obligate aerobes and showed broad pH, salinity, and temperature ranges for growth, consistent with the physicochemical properties of the brine. VAN strains were halophilic and quite CaCl2 tolerant but did not require CaCl2 for growth. The fact that only VAN strain-like organisms appeared in our enrichments hints that the highly chaotropic nature of the Lake Vanda brine may place unusual physiological constraints on the bacterial community that inhabits it. PMID:25576606

  1. A Halophilic Bacterium Inhabiting the Warm, CaCl2-Rich Brine of the Perennially Ice-Covered Lake Vanda, McMurdo Dry Valleys, Antarctica

    PubMed Central

    Tregoning, George S.; Kempher, Megan L.; Jung, Deborah O.; Samarkin, Vladimir A.; Joye, Samantha B.

    2015-01-01

    Lake Vanda is a perennially ice-covered and stratified lake in the McMurdo Dry Valleys, Antarctica. The lake develops a distinct chemocline at about a 50-m depth, where the waters transition from cool, oxic, and fresh to warm, sulfidic, and hypersaline. The bottom water brine is unique, as the highly chaotropic salts CaCl2 and MgCl2 predominate, and CaCl2 levels are the highest of those in any known microbial habitat. Enrichment techniques were used to isolate 15 strains of heterotrophic bacteria from the Lake Vanda brine. Despite direct supplementation of the brine samples with different organic substrates in primary enrichments, the same organism, a relative of the halophilic bacterium Halomonas (Gammaproteobacteria), was isolated from all depths sampled. The Lake Vanda (VAN) strains were obligate aerobes and showed broad pH, salinity, and temperature ranges for growth, consistent with the physicochemical properties of the brine. VAN strains were halophilic and quite CaCl2 tolerant but did not require CaCl2 for growth. The fact that only VAN strain-like organisms appeared in our enrichments hints that the highly chaotropic nature of the Lake Vanda brine may place unusual physiological constraints on the bacterial community that inhabits it. PMID:25576606

  2. Study on two methylotrophic and halophilic methanogens, Methanosarcina siciliae HI350 and Methanolobus taylorii GS-16

    SciTech Connect

    Ni, S.

    1994-01-01

    Strain HI350, similar to Methanolobus siciliae T4/M[sup T] (T = type strain) morphologically and physiologically, was isolated from an oil well in the Gulf of Mexico. Catabolic substrates included methanol, trimethylamine, dimethyl sulfide, and methane thiol, but not H[sub 2]-CO[sub 2], formate, or acetate. Growth was fastest in the presence of 0.4 to 0.6 M Na[sup +], in the presence of 60 to 200 mM Mg[sup 2+], at pH 6.5 to 6.8, and at 40[degrees]C. Methanolobus siciliae T4/M[sup T] was closely related to Methanosarcina. Transfer of Methanolobus siciliae T4/M[sup T] to the genus Methanosarcina as Methanosarcina siciliae is proposed with strain HI350 as its reference strain. Degradation of dimethyl sulfide or methane thiol by strain HI350 was complete, and stoichiometric quantities of methane and hydrogen sulfide were formed. Studies of cell-free extracts suggested that enzymes for degradation of dimethyl sulfide and methane thiol were inducible, whereas those for the degradation of methanol or trimethylamine were constitutive. Methanolobus taylorii GS-16, a moderately halophilic and alkcaliphilic methanogen, grows over a wide pH range. The key observation indicative of the involvement of K[sup +] transport in cytosolic acidification was that valinomycin (0.8 [mu]M), a K[sup +] uniporter, inhibited the growth of strain GS-16 only at alkaline pH. Experiments with resting cells indicated that, at alkaline pH, valinomycin uncoupled catabolic reactions from ATP synthesis. Thus, a K[sup +]/H[sup +] antiporter was proposed to account for the K[sup +] extrusion and the uncoupling effect of valinomycin at alkaline pH.

  3. Photoactive yellow protein from the halophilic bacterium Salinibacter ruber.

    PubMed

    Memmi, Samy; Kyndt, John; Meyer, Terry; Devreese, Bart; Cusanovich, Michael; Van Beeumen, Jozef

    2008-02-19

    A gene for photoactive yellow protein (PYP) was identified from the genome sequence of the extremely halophilic aerobic bacterium Salinibacter ruber (Sr). The sequence is distantly related to the prototypic PYP from Halorhodospira halophila (Hh) (37% identity) and contains most of the amino acid residues identified as necessary for function. However, the Sr pyp gene is not flanked by its two biosynthetic genes as in other species. To determine as to whether the Sr pyp gene encodes a functional protein, we cloned and expressed it in Escherichia coli, along with the genes for chromophore biosynthesis from Rhodobacter capsulatus. The Sr PYP has a 31-residue N-terminal extension as compared to other PYPs that appears to be important for dimerization; however, truncation of these extra residues did not change the spectral and photokinetic properties. Sr PYP has an absorption maximum at 431 nm, which is at shorter wavelengths than the prototypical Hh PYP (at 446 nm). It is also photoactive, being reversibly bleached by either blue or white light. The kinetics of dark recovery is slower than any of the PYPs reported to date (4.27 x 10(-4) s(-1) at pH 7.5). Sr PYP appears to have a normal photocycle with the I1 and I2 intermediates. The presence of the I2' intermediate is also inferred on the basis of the effects of temperature and alchohol on recovery. Sr PYP has an intermediate spectral form in equilibrium with the 431 nm form, similar to R. capsulatus PYP and the Y42F mutant of Hh PYP. Increasing ionic strength stabilizes the 431 nm form at the expense of the intermediate spectral form, and the kinetics of recovery is accelerated 6.4-fold between 0 and 3.5 M salt. This is observed with ions from both the chaotropic and the kosmotropic series. Ionic strength also stabilizes PYP against thermal denaturation, as the melting temperature is increased from 74 degrees C in buffer alone to 92 degrees C in 2 M KCl. Sr accumulates KCl in the cytoplasm, like Halobacterium, to

  4. Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam

    PubMed Central

    Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguamán, Jorge

    2012-01-01

    This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the α-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight

  5. Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam.

    PubMed

    Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguamán, Jorge

    2012-12-01

    This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the α-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight

  6. Threonine deaminase from extremely halophilic bacteria - Cooperative substrate kinetics and salt dependence.

    NASA Technical Reports Server (NTRS)

    Lieberman, M. M.; Lanyi, J. K.

    1972-01-01

    The effect of salt on the activity, stability, and allosteric properties of catabolic threonine deaminase from Halobacterium cutirubrum was studied. The enzyme exhibits sigmoidal kinetics with the substrate, threonine. The Hill slope is 1.55 at pH 10. The enzyme is activated by ADP at low substrate concentrations. In the presence of this effector, sigmoidal kinetics are no longer observed. At pH 10, in the absence of ADP, enzyme activity increases with increasing NaCl concentration from 0 to 4 M.

  7. [Purification and characterization of a halophilic urethanase from Klebsiella pneumoniae].

    PubMed

    Bu, Panpan; Chen, Jian; Du, Guocheng

    2014-03-01

    Ethyl carbamate (EC) is a carcinogenic substance in many fermented foods. Enzymatic removal of ethyl carbamate from fermented foods is an important way to eliminate its potential health damage to consumers. To study the enzymatic properties of an ethyl carbamate hydrolase (urethanase) from Klebsiella pneumoniae, a strain isolated from murine somach, we purified the enzyme using ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography. The molecular mass of this enzyme was estimated to be 55 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its K(m) was 74 mmol/L when EC was used as the substrate. Moreover, its optimal reaction temperature was 55 degrees C, and the optimum pH was 7.0. The activity was enhanced by ethylene diamine tetraacetic acid (EDTA) and dithiothreitol (DTT), but strongly inhibited by Cu2+ and Zn2+. The enzyme was halophilic and tolerant to low concentration of ethanol. Therefore, it has the potential to remove EC from fermented foods. PMID:25007576

  8. Structural and biochemical characterization of a halophilic archaeal alkaline phosphatase.

    PubMed

    Wende, Andy; Johansson, Patrik; Vollrath, Ronnald; Dyall-Smith, Mike; Oesterhelt, Dieter; Grininger, Martin

    2010-07-01

    Phosphate is an essential component of all cells that must be taken up from the environment. Prokaryotes commonly secrete alkaline phosphatases (APs) to recruit phosphate from organic compounds by hydrolysis. In this study, the AP from Halobacterium salinarum, an archaeon that lives in a saturated salt environment, has been functionally and structurally characterized. The core fold and the active-site architecture of the H. salinarum enzyme are similar to other AP structures. These generally form dimers composed of dominant beta-sheet structures sandwiched by alpha-helices and have well-accessible active sites. The surface of the enzyme is predicted to be highly negatively charged, like other proteins of extreme halophiles. In addition to the conserved core, most APs contain a crown domain that strongly varies within species. In the H. salinarum AP, the crown domain is made of an acyl-carrier-protein-like fold. Different from other APs, it is not involved in dimer formation. We compare the archaeal AP with its bacterial and eukaryotic counterparts, and we focus on the role of crown domains in enhancing protein stability, regulating enzyme function, and guiding phosphoesters into the active-site funnel. PMID:20438737

  9. Gracilibacillus kimchii sp. nov., a halophilic bacterium isolated from kimchi.

    PubMed

    Oh, Young Joon; Lee, Hae-Won; Lim, Seul Ki; Kwon, Min-Sung; Lee, Jieun; Jang, Ja-Young; Park, Hae Woong; Nam, Young-Do; Seo, Myung-Ji; Choi, Hak-Jong

    2016-09-01

    A novel halophilic bacterium, strain K7(T), was isolated from kimchi, a traditional Korean fermented food. The strain is Gram-positive, motile, and produces terminal endospores. The isolate is facultative aerobic and grows at salinities of 0.0-25.0% (w/v) NaCl (optimum 10-15% NaCl), pH 5.5-8.5 (optimum pH 7.0-7.5), and 15-42°C (optimum 37°C). The predominant isoprenoid quinone in the strain is menaquinone-7 and the peptidoglycan of the strain is meso-diaminopimelic acid. The major fatty acids of the strain are anteisio-C15:0, iso-C15:0, and, C16:0 (other components were < 10.0%), while the major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and three unidentified lipids. A phylogenetic analysis of 16S rRNA gene sequence similarity showed that the isolated strain was a cluster of the genus Gracilibacillus. High levels of gene sequence similarity were observed between strain K7(T) and Gracilibacillus orientalis XH-63(T) (96.5%), and between the present strain and Gracilibacillus xinjiangensis (96.5%). The DNA G+C content of this strain is 37.7 mol%. Based on these findings, strain K7(T) is proposed as a novel species: Gracilibacillus kimchii sp. nov. The type strain is K7(T) (KACC 18669(T); JCM 31344(T)). PMID:27572507

  10. Anaerobic bacteria

    MedlinePlus

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these ... Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's ...

  11. Progress in decontamination by halophilic microorganisms in saline wastewater and soil.

    PubMed

    Zhuang, Xuliang; Han, Zhen; Bai, Zhihui; Zhuang, Guoqiang; Shim, Hojae

    2010-05-01

    Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. PMID:20163899

  12. Immunomodulatory effect of halophilic lactic acid bacterium Tetragenococcus halophilus Th221 from soy sauce moromi grown in high-salt medium.

    PubMed

    Masuda, Susumu; Yamaguchi, Hitomi; Kurokawa, Toshiko; Shirakami, Tomoyuki; Tsuji, Ryohei F; Nishimura, Ikuko

    2008-02-10

    A halophilic lactic acid bacterium, Tetragenococcus halophilus, was found to possess an immunomodulatory activity that promotes T helper type 1 (Th1) immunity in addition to its important roles in soy sauce brewing. Strain Th221 was selected from 151 strains isolated from soy sauce (shoyu) moromi, since it induced strong interleukin (IL)-12 production by mouse peritoneal macrophages in vitro. The relationship between the salt concentration in the medium and the IL-12 production-inducing activity of this strain was investigated, and the activity was found to be strong when the bacteria were grown in medium containing > or =10% (w/v) salt. The Th1-promoting activity was also manifested in an in vivo mouse study, since Th1-dependant contact sensitivity was augmented and Th2 immunity, as evaluated by specific immunoglobulin E production, was suppressed following oral ingestion of Th221. Based on these findings, Th221 administration may be useful for improving allergic symptoms. PMID:18061297

  13. Structural evidence for solvent-stabilisation by aspartic acid as a mechanism for halophilic protein stability in high salt concentrations.

    PubMed

    Lenton, Samuel; Walsh, Danielle L; Rhys, Natasha H; Soper, Alan K; Dougan, Lorna

    2016-07-21

    Halophilic organisms have adapted to survive in high salt environments, where mesophilic organisms would perish. One of the biggest challenges faced by halophilic proteins is the ability to maintain both the structure and function at molar concentrations of salt. A distinct adaptation of halophilic proteins, compared to mesophilic homologues, is the abundance of aspartic acid on the protein surface. Mutagenesis and crystallographic studies of halophilic proteins suggest an important role for solvent interactions with the surface aspartic acid residues. This interaction, between the regions of the acidic protein surface and the solvent, is thought to maintain a hydration layer around the protein at molar salt concentrations thereby allowing halophilic proteins to retain their functional state. Here we present neutron diffraction data of the monomeric zwitterionic form of aspartic acid solutions at physiological pH in 0.25 M and 2.5 M concentration of potassium chloride, to mimic mesophilic and halophilic-like environmental conditions. We have used isotopic substitution in combination with empirical potential structure refinement to extract atomic-scale information from the data. Our study provides structural insights that support the hypothesis that carboxyl groups on acidic residues bind water more tightly under high salt conditions, in support of the residue-ion interaction model of halophilic protein stabilisation. Furthermore our data show that in the presence of high salt the self-association between the zwitterionic form of aspartic acid molecules is reduced, suggesting a possible mechanism through which protein aggregation is prevented. PMID:27327567

  14. A single aromatic core mutation converts a designed “primitive” protein from halophile to mesophile folding

    PubMed Central

    Longo, Liam M; Tenorio, Connie A; Kumru, Ozan S; Middaugh, C Russell; Blaber, Michael

    2015-01-01

    The halophile environment has a number of compelling aspects with regard to the origin of structured polypeptides (i.e., proteogenesis) and, instead of a curious niche that living systems adapted into, the halophile environment is emerging as a candidate “cradle” for proteogenesis. In this viewpoint, a subsequent halophile-to-mesophile transition was a key step in early evolution. Several lines of evidence indicate that aromatic amino acids were a late addition to the codon table and not part of the original “prebiotic” set comprising the earliest polypeptides. We test the hypothesis that the availability of aromatic amino acids could facilitate a halophile-to-mesophile transition by hydrophobic core-packing enhancement. The effects of aromatic amino acid substitutions were evaluated in the core of a “primitive” designed protein enriched for the 10 prebiotic amino acids (A,D,E,G,I,L,P,S,T,V)—having an exclusively prebiotic core and requiring halophilic conditions for folding. The results indicate that a single aromatic amino acid substitution is capable of eliminating the requirement of halophile conditions for folding of a “primitive” polypeptide. Thus, the availability of aromatic amino acids could have facilitated a critical halophile-to-mesophile protein folding adaptation—identifying a selective advantage for the incorporation of aromatic amino acids into the codon table. PMID:25297559

  15. An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

    NASA Technical Reports Server (NTRS)

    Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

    1988-01-01

    The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

  16. Complete Genome Sequence of the Anaerobic Halophilic Alkalithermophile Natranaerobius thermophilus JW/NM-WN-LFT

    SciTech Connect

    Mesbah, Noha; Dalin, Eileen; Goodwin, Lynne A.; Nolan, Matt; Pitluck, Sam; Chertkov, Olga; Han, James; Larimer, Frank W; Land, Miriam L; Hauser, Loren John; Kyrpides, Nikos C; Wiegel, Juergen

    2011-01-01

    The genome of the anaerobic halophilic alkalithermophile Natranaerobius thermophiles consists of one chromosome and two plasmids.The present study is the first to report the completely sequenced genome of polyextremophile and the harboring genes harboring genes associated with roles in regulation of intracellular osmotic pressure, pH homeostasis, and thermophilic stability.

  17. Bipyrimidine Signatures as a Photoprotective Genome Strategy in G + C-rich Halophilic Archaea.

    PubMed

    Jones, Daniel L; Baxter, Bonnie K

    2016-01-01

    Halophilic archaea experience high levels of ultraviolet (UV) light in their environments and demonstrate resistance to UV irradiation. DNA repair systems and carotenoids provide UV protection but do not account for the high resistance observed. Herein, we consider genomic signatures as an additional photoprotective strategy. The predominant forms of UV-induced DNA damage are cyclobutane pyrimidine dimers, most notoriously thymine dimers (T^Ts), which form at adjacent Ts. We tested whether the high G + C content seen in halophilic archaea serves a photoprotective function through limiting T nucleotides, and thus T^T lesions. However, this speculation overlooks the other bipyrimidine sequences, all of which capable of forming photolesions to varying degrees. Therefore, we designed a program to determine the frequencies of the four bipyrimidine pairs (5' to 3': TT, TC, CT, and CC) within genomes of halophilic archaea and four other randomized sample groups for comparison. The outputs for each sampled genome were weighted by the intrinsic photoreactivities of each dinucleotide pair. Statistical methods were employed to investigate intergroup differences. Our findings indicate that the UV-resistance seen in halophilic archaea can be attributed in part to a genomic strategy: high G + C content and the resulting bipyrimidine signature reduces the genomic photoreactivity. PMID:27598206

  18. Small-angle neutron scattering study of halophilic glyceraldehyde 3-phosphate dehydrogenase (hGAPDH)

    NASA Astrophysics Data System (ADS)

    Ebel, Christine; Krishnan, Gomathi; Altekar, Wijaya; Zaccai, Giuseppe

    1991-10-01

    hGAPDH has a radius of gyration of 32±0.5 Å in high salt concentration, and a shape similar to an oblate ellipsoid of axial ratio 0.5 but with a much larger specific surface. The enzyme dissociates and unfolds in low salt solutions. These results are discussed in terms of the halophilic character of the protein.

  19. Survival of Halophilic Archaea in the Stratosphere as a Mars Analog: A Transcriptomic Approach

    NASA Astrophysics Data System (ADS)

    DasSarma, S.; DasSarma, P.; Laye, V.; Harvey, J.; Reid, C.; Shultz, J.; Yarborough, A.; Lamb, A.; Koske-Phillips, A.; Herbst, A.; Molina, F.; Grah, O.; Phillips, T.

    2016-05-01

    On Earth, halophilic Archaea tolerate multiple extreme conditions similar to those on Mars. In order to study their survival, we launched live cultures into Earth’s stratosphere on helium balloons. The effects on survival and transcriptomes were interrogated in the lab.

  20. First Insights into the Genome Sequence of the Halophilic Archaeon Halalkalicoccus paucihalophilus (DSM 24557)

    PubMed Central

    Poehlein, Anja; Mucek, Katharina; Enders, Marieke; Pankok, Frederik

    2016-01-01

    Halalkalicoccus paucihalophilus is an extremely halophilic, Gram-negative, and nonmotile coccus-like archaeon, which was originally isolated from the Lop Nur region in the northwest of China. The genome consists of a single replicon (3.98 Mbp). H. paucihalophilus is able to utilize mannose, which is unique for members of this genus. PMID:27198019

  1. First characterization of extremely halophilic 2-deoxy-D-ribose-5-phosphate aldolase.

    PubMed

    Ohshida, Tatsuya; Hayashi, Junji; Satomura, Takenori; Kawakami, Ryushi; Ohshima, Toshihisa; Sakuraba, Haruhiko

    2016-10-01

    2-Deoxy-d-ribose-5-phosphate aldolase (DERA) catalyzes the aldol reaction between two aldehydes and is thought to be a potential biocatalyst for the production of a variety of stereo-specific materials. A gene encoding DERA from the extreme halophilic archaeon, Haloarcula japonica, was overexpressed in Escherichia coli. The gene product was successfully purified, using procedures based on the protein's halophilicity, and characterized. The expressed enzyme was stable in a buffer containing 2 M NaCl and exhibited high thermostability, retaining more than 90% of its activity after heating at 70 °C for 10 min. The enzyme was also tolerant to high concentrations of organic solvents, such as acetonitrile and dimethylsulfoxide. Moreover, H. japonica DERA was highly resistant to a high concentration of acetaldehyde and retained about 35% of its initial activity after 5-h' exposure to 300 mM acetaldehyde at 25 °C, the conditions under which E. coli DERA is completely inactivated. The enzyme exhibited much higher activity at 25 °C than the previously characterized hyperthermophilic DERAs (Sakuraba et al., 2007). Our results suggest that the extremely halophilic DERA has high potential to serve as a biocatalyst in organic syntheses. This is the first description of the biochemical characterization of a halophilic DERA. PMID:27215670

  2. First Insights into the Genome Sequence of the Halophilic Archaeon Halalkalicoccus paucihalophilus (DSM 24557).

    PubMed

    Poehlein, Anja; Mucek, Katharina; Enders, Marieke; Pankok, Frederik; Daniel, Rolf

    2016-01-01

    Halalkalicoccus paucihalophilus is an extremely halophilic, Gram-negative, and nonmotile coccus-like archaeon, which was originally isolated from the Lop Nur region in the northwest of China. The genome consists of a single replicon (3.98 Mbp). H. paucihalophilus is able to utilize mannose, which is unique for members of this genus. PMID:27198019

  3. Distribution, abundance and diversity of the extremely halophilic bacterium Salinibacter ruber

    PubMed Central

    Antón, Josefa; Peña, Arantxa; Santos, Fernando; Martínez-García, Manuel; Schmitt-Kopplin, Philippe; Rosselló-Mora, Ramon

    2008-01-01

    Since its discovery in 1998, representatives of the extremely halophilic bacterium Salinibacter ruber have been found in many hypersaline environments across the world, including coastal and solar salterns and solar lakes. Here, we review the available information about the distribution, abundance and diversity of this member of the Bacteroidetes. PMID:18957079

  4. Cultivation and molecular monitoring of halophilic microorganisms inhabiting an extreme environment presented by a salt-attacked monument

    NASA Astrophysics Data System (ADS)

    Ettenauer, Jörg; Sterflinger, Katja; Piñar, Guadalupe

    2010-01-01

    In the last few years several investigations, based on culture-dependent and -independent techniques, have shown that salt-attacked stone surfaces present a habitat for extremely salt tolerant and moderate halophilic microorganisms. The inner walls of the Chapel of St. Virgil in Vienna (Austria) are an example of this phenomenon. Salt crusts cover most of the wall surfaces and salt crystallization in the porous space of the stone is causing decohesion of material and destruction of the original medieval paintings. The salt, together with the oligotrophic conditions, creates a very special and extreme habitat for halotolerant and halophilic microorganisms. In this study we investigate and monitor the cultivable and non-cultivable members of the microbial community present on the stonework of the medieval Chapel of St. Virgil after several severe disturbances of the microbial environment caused by desalination and disinfection treatments. With this finality, a combination of culture-dependent and -independent techniques was selected. The genetic diversity of a total of 104 bacterial strains isolated from the stone samples was analysed by denaturing gradient gel electrophoresis (DGGE), random amplified polymorphic DNA (RAPD) analysis and 16S rRNA gene sequencing. Strains were distributed over 29 groups on the basis of their RAPD patterns. Only 19 groups were differentiated by DGGE. Comparative sequence analyses showed that the isolated strains belong to related species of the genera Halobacillus (47.1%), Bacillus (35.6%), Acinetobacter (4.8%), Halomonas (3.9%), Nesterenkonia (2.9%), Paucisalibacillus (2.9%), Paenibacillus (1%), Staphylococcus (1%) and Exiguobacterium (1%). In addition, polymerase chain reaction DGGE fingerprints, in combination with the creation of clone libraries and sequencing analyses, were used to monitor and identify Archaea, the non-cultivable fraction of the microbial community. The detected archaeal sequences were closely related to different

  5. Acquisition of an insertion peptide for efficient aminoacylation by a halophile tRNA synthetase.

    PubMed

    Evilia, Caryn; Hou, Ya-Ming

    2006-06-01

    Enzymes of halophilic organisms contain unusual peptide motifs that are absent from their mesophilic counterparts. The functions of these halophile-specific peptides are largely unknown. Here we have identified an unusual peptide that is unique to several halophile archaeal cysteinyl-tRNA synthetases (CysRS), which catalyze attachment of cysteine to tRNA(Cys) to generate the essential cysteinyl-tRNA(Cys) required for protein synthesis. This peptide is located near the active site in the catalytic domain and is highly enriched with acidic residues. In the CysRS of the extreme halophile Halobacterium species NRC-1, deletion of the peptide reduces the catalytic efficiency of aminoacylation by a factor of 100 that largely results from a defect in kcat, rather than the Km for tRNA(Cys). In contrast, maintaining the peptide length but substituting acidic residues in the peptide with neutral or basic residues has no major deleterious effect, suggesting that the acidity of the peptide is not important for the kcat of tRNA aminoacylation. Analysis of general protein structure under physiological high salt concentrations, by circular dichroism and by fluorescence titration of tRNA binding, indicates little change due to deletion of the peptide. However, the presence of the peptide confers tolerance to lower salt levels, and fluorescence analysis in 30% sucrose reveals instability of the enzyme without the peptide. We suggest that the stability associated with the peptide can be used to promote proper enzyme conformation transitions in various stages of tRNA aminoacylation that are associated with catalysis. The acquisition of the peptide by the halophilic CysRS suggests an enzyme adaptation to high salinity. PMID:16734420

  6. Organic compatible solutes of halotolerant and halophilic microorganisms

    PubMed Central

    Roberts, Mary F

    2005-01-01

    Microorganisms that adapt to moderate and high salt environments use a variety of solutes, organic and inorganic, to counter external osmotic pressure. The organic solutes can be zwitterionic, noncharged, or anionic (along with an inorganic cation such as K+). The range of solutes, their diverse biosynthetic pathways, and physical properties of the solutes that effect molecular stability are reviewed. PMID:16176595

  7. Mycelial bacteria of saline soils

    NASA Astrophysics Data System (ADS)

    Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

    2008-10-01

    The actinomycetal complexes of saline soils comprise the representatives of the Streptomyces and Micromonospora genera, the number of which are hundreds and thousands of CFU/g soil. Complexes of mycelial bacteria in saline soils are poorer in terms of number (by 1-3 orders of magnitude) and taxonomic composition than the complexes of the zonal soil types. A specific feature of the actinomycetal complexes of saline soils is the predominance of halophilic, alkaliphilic, and haloalkaliphilic streptomycetes that well grow at pH 8-9 and concentrations of NaCl close to 5%. Actinomycetes in saline soils grow actively, and the length of their mycelium reaches 140 m in 1 gram of soil. The haloalkaliphilic streptomycetes grow fast and inhibit the formation of spores at pH 9 and high concentrations of salts (Na2SO4 and MgCl2, 5%) as compared to their behavior on a neutral medium with a salt concentration of 0.02%. They are characterized by the maximal radial growth rate of colonies on an alkaline medium with 5% NaCl.

  8. Lipids of the ultra-thin square halophilic archaeon Haloquadratum walsbyi.

    PubMed

    Lobasso, Simona; Lopalco, Patrizia; Mascolo, Giuseppe; Corcelli, Angela

    2008-12-01

    The lipid composition of the extremely halophilic archaeon Haloquadratum walsbyi was investigated by thin-layer chromatography and electrospray ionization-mass spectrometry. The analysis of neutral lipids showed the presence of vitamin MK-8, squalene, carotene, bacterioruberin and several retinal isomers. The major polar lipids were phosphatidylglycerophosphate methyl ester, phosphatidylglycerosulfate, phosphatidylglycerol and sulfated diglycosyl diether lipid. Among cardiolipins, the tetra-phytanyl or dimeric phospholipids, only traces of bisphosphatidylglycerol were detected. When the cells were exposed to hypotonic medium, no changes in the membrane lipid composition occurred. Distinguishing it from other extreme halophiles of the Halobacteriaceae family, the osmotic stress did not induce the neo-synthesis of cardiolipins in H. walsbyi. The difference may depend on the three-laminar structure of the cell wall, which differs significantly from that of other Haloarchaea. PMID:19054744

  9. Halophilic Archaea: Life with Desiccation, Radiation and Oligotrophy over Geological Times.

    PubMed

    Stan-Lotter, Helga; Fendrihan, Sergiu

    2015-01-01

    Halophilic archaebacteria (Haloarchaea) can survive extreme desiccation, starvation and radiation, sometimes apparently for millions of years. Several of the strategies that are involved appear specific for Haloarchaea (for example, the formation of halomucin, survival in fluid inclusions of halite), and some are known from other prokaryotes (dwarfing of cells, reduction of ATP). Several newly-discovered haloarchaeal strategies that were inferred to possibly promote long-term survival-halomucin, polyploidy, usage of DNA as a phosphate storage polymer, production of spherical dormant stages-remain to be characterized in detail. More information on potential strategies is desirable, since evidence for the presence of halite on Mars and on several moons in the solar system increased interest in halophiles with respect to the search for extraterrestrial life. This review deals in particular with novel findings and hypotheses on haloarchaeal long-term survival. PMID:26226005

  10. Application of lipopeptide biosurfactant isolated from a halophile: Bacillus tequilensis CH for inhibition of biofilm.

    PubMed

    Pradhan, Arun Kumar; Pradhan, Nilotpala; Mall, Gangotri; Panda, Himadri Tanaya; Sukla, Lala Behari; Panda, Prasanna Kumar; Mishra, Barada Kanta

    2013-11-01

    Biosurfactants are amphiphilic molecules having hydrophobic and hydrophilic moieties produced by various microorganisms. These molecules trigger the reduction of surface tension or interfacial tension in liquids. A biosurfactant-producing halophile was isolated from Lake Chilika, a brackish water lake of Odisha, India (19°41'39″N, 85°18'24″E). The halophile was identified as Bacillus tequilensis CH by biochemical tests and 16S rRNA gene sequencing and assigned accession no. KC851857 by GenBank. The biosurfactant produced by B. tequilensis CH was partially characterized as a lipopeptide using thin-layer chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance techniques. The minimum effective concentration of a biosurfactant for inhibition of pathogenic biofilm (Escherichia coli and Streptococcus mutans) on hydrophilic and hydrophobic surfaces was found to be 50 μg ml(-1). This finding has potential for a variety of applications. PMID:23955294