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Timothy J Williams, Michelle A Allen, Yan Liao, Mark J Raftery, Ricardo Cavicchioli
The canonical pathway for sucrose metabolism in haloarchaea utilizes a modified Embden-Meyerhof-Parnas pathway (EMP), in which ketohexokinase and 1-phosphofructokinase phosphorylate fructose released from sucrose hydrolysis. However, our survey of haloarchaeal genomes determined that ketohexokinase and 1-phosphofructokinase genes were not present in all species known to utilize fructose and sucrose, thereby indicating that alternative mechanisms exist for fructose metabolism. A fructokinase gene was identified in the majority of fructose- and sucrose-utilizing species, whereas only a small number possessed a ketohexokinase gene...
January 18, 2019: Applied and Environmental Microbiology
Dipesh Kumar Verma, Ishita Baral, Atul Kumar, Senthil E Prasad, Krishan Gopal Thakur
Interesting optical and photochemical properties make microbial rhodopsin a promising biological material suitable for various applications, but the cost-prohibitive nature of production has limited its commercialization. The aim of this study was to explore the natural biodiversity of Indian solar salterns to isolate natural bacteriorhodopsin (BR) variants that can be functionally expressed in Escherichia coli. In this study, we report the isolation, functional expression and purification of BRs from three pigmented haloarchaea, wsp3 (water sample Pondicherry), wsp5 and K1T isolated from two Indian solar salterns...
January 16, 2019: Microbial Biotechnology
Dimitry Y Sorokin, Alexander G Elcheninov, Stepan V Toshchakov, Nicole J Bale, Jaap S Sinninghe Damsté, Tatiana V Khijniak, Ilya V Kublanov
Two groups of alkaliphilic haloarchaea from hypersaline alkaline lakes in Central Asia, Egypt and North America were enriched and isolated in pure culture using chitin as growth substrate. These cultures, termed AArcht, were divided into two groups: group 1 which includes eleven isolates from highly alkaline soda lakes and group 2 which contains a single isolate obtained from the alkaline hypersaline Searles Lake. The colonies of chitin-utilizing natronoarchaea were red-pigmented and surrounded by large zones of chitin hydrolysis...
January 8, 2019: Systematic and Applied Microbiology
Zhen-Qiang Zuo, Qiong Xue, Jian Zhou, Da-He Zhao, Jing Han, Hua Xiang
Lycopene attracts increasing interests in the pharmaceutical, food, and cosmetic industries due to its anti-oxidative and anti-cancer properties. Compared with other lycopene production methods, such as chemical synthesis or direct extraction from plants, the biosynthesis approach using microbes is more economical and sustainable. In this work, we engineered Haloferax mediterranei , a halophilic archaeon, as a new lycopene producer. H. mediterranei has the de novo synthetic pathway for lycopene but cannot accumulate this compound...
2018: Frontiers in Microbiology
Arash Farhadi, Gabrielle Ho, Martin Kunth, Bill Ling, Anupama Lakshmanan, George Lu, Raymond W Bourdeau, Leif Schröder, Mikhail G Shapiro
Ultrasound and hyperpolarized magnetic resonance imaging enable the visualization of biological processes in deep tissues. However, few molecular contrast agents are available to connect these modalities to specific aspects of biological function. We recently discovered that a unique class of gas-filled protein nanostructures known as gas vesicles could serve as nanoscale molecular reporters for these modalities. However, the need to produce these nanostructures via expression in specialized cultures of cyanobacteria or haloarchaea limits their broader adoption by other laboratories and hinders genetic engineering of their properties...
August 2018: AIChE Journal
Lucia Zalazar, Pablo Pagola, María Victoria Miró, María Sandra Churio, Micaela Cerletti, Celeste Martínez, María Iniesta-Cuerda, Ana Josefa Soler Valls, Andreina Cesari, Rosana De Castro
AIMS: To examine the antioxidant activity of Bacterioruberin (Bctr)-rich extracts isolated from a hyperpigmented-genetically modified Haloferax volcanii strain (HVLON3) and to investigate the effect on cold-sensitive ram sperm cells. METHODS AND RESULTS: The strain HVLON3 produces higher Bctr amounts than most haloarchaea (220 ± 13 mg/g DW). HVLON3-Bctr extract has higher antioxidant activity than β-carotene (3-fold) as evaluated using 2,2 diphenyl-1-picrylhydrazyl combined with Electron Paramagnetic Resonance analysis (EC50 4...
November 25, 2018: Journal of Applied Microbiology
Dimitry Y Sorokin, Enzo Messina, Violetta La Cono, Manuel Ferrer, Sergio Ciordia, Maria C Mena, Stepan V Toshchakov, Peter N Golyshin, Michail M Yakimov
The ubiquity of strictly anaerobic sulfur-respiring haloarchaea in hypersaline systems with circumneutral pH has shaken a traditional concept of this group as predominantly aerobic heterotrophs. Here, we demonstrated that this functional group of haloarchaea also has its representatives in hypersaline alkaline lakes. Sediments from various hypersaline soda lakes showed high activity of sulfur reduction only partially inhibited by antibiotics. Eight pure cultures of sulfur-reducing natronoarchaea were isolated from such sediments using formate and butyrate as electron donors and sulfur as an electron acceptor...
2018: Frontiers in Microbiology
Mike Dyall-Smith, Felicitas Pfeifer, Angela Witte, Dieter Oesterhelt, Friedhelm Pfeiffer
The halophilic myohalovirus Halobacterium virus phiH (ΦH) was first described in 1982 and was isolated from a spontaneously lysed culture of Halobacterium salinarum strain R1. Until 1994, it was used extensively as a model to study the molecular genetics of haloarchaea, but only parts of the viral genome were sequenced during this period. Using Sanger sequencing combined with high-coverage Illumina sequencing, the full genome sequence of the major variant (phiH1) of this halovirus has been determined. The dsDNA genome is 58,072 bp in length and carries 97 protein-coding genes...
October 12, 2018: Genes
Zaida Montero-Lobato, Adrián Ramos-Merchante, Juan Luis Fuentes, Ana Sayago, Ángeles Fernández-Recamales, Rosa María Martínez-Espinosa, José María Vega, Carlos Vílchez, Inés Garbayo
Haloferax mediterranei produces C50 carotenoids that have strong antioxidant properties. The response surface methodology (RSM) tool helps to accurately analyze the most suitable conditions to maximize C50 carotenoids production by haloarchaea. The effects of temperature (15⁻50 °C), pH (4-10), and salinity (5⁻28% NaCl ( w / v )) on the growth and carotenoid content of H. mediterranei were analyzed using the RSM approach. Growth was determined by measuring the turbidity at 600 nm. To determine the carotenoid content, harvested cells were lysed by freeze/thawing, then re-suspended in acetone and the total carotenoid content determined by measuring the absorbance at 494 nm...
October 9, 2018: Marine Drugs
Marianna Zaretsky, Elina Roine, Jerry Eichler
N-glycosylation is a post-translational modification that occurs in all three domains. In Archaea, however, N-linked glycans present a degree of compositional diversity not observed in either Eukarya or Bacteria. As such, it is surprising that nonulosonic acids (NulOs), nine-carbon sugars that include sialic acids, pseudaminic acids, and legionaminic acids, are routinely detected as components of protein-linked glycans in Eukarya and Bacteria but not in Archaea. In the following, we report that the N-linked glycan attached to the S-layer glycoprotein of the haloarchaea Halorubrum sp...
2018: Frontiers in Microbiology
Cheng-Hong Tu, Hsiu-Ping Yi, Shiang-Yuan Hsieh, Hong-Syuan Lin, Chii-Shen Yang
Microbial rhodopsins (M-Rho) are found in Archaea, Bacteria and some species of Eukarya and serve as light-driven ion pumps or mediate phototaxis responses in various biological systems. We previously reported an expression system using a highly expressible mutant, D94N-HmBRI (HEBR) from Haloarcula marismortui, as a leading tag to assist in the expression of membrane proteins that were otherwise difficult to express in E. coli. In this study, we show a universal strategy for the expression of two M-Rho proteins, either the same or different types, as one fusion protein with the HEBR system...
September 19, 2018: Scientific Reports
Hajime Hayakawa, Kento Motoyama, Fumiaki Sobue, Tomokazu Ito, Hiroshi Kawaide, Tohru Yoshimura, Hisashi Hemmi
The modified mevalonate pathway is believed to be the upstream biosynthetic route for isoprenoids in general archaea. The partially identified pathway has been proposed to explain a mystery surrounding the lack of phosphomevalonate kinase and diphosphomevalonate decarboxylase by the discovery of a conserved enzyme, isopentenyl phosphate kinase. Phosphomevalonate decarboxylase was considered to be the missing link that would fill the vacancy in the pathway between mevalonate 5-phosphate and isopentenyl phosphate...
October 2, 2018: Proceedings of the National Academy of Sciences of the United States of America
Miriam Bader, André Rossberg, Robin Steudtner, Björn Drobot, Kay Großmann, Matthias Schmidt, Niculina Musat, Thorsten Stumpf, Atsushi Ikeda-Ohno, Andrea Cherkouk
Haloarchaea represent a predominant part of the microbial community in rock salt, which can serve as host rock for the disposal of high level radioactive waste. However, knowledge is missing about how Haloarchaea interact with radionuclides. Here, we used a combination of spectroscopic and microscopic methods to study the interactions of an extremely halophilic archaeon with uranium, one of the major radionuclides in high level radioactive waste, on a molecular level. The obtained results show that Halobacterium noricense DSM 15987T influences uranium speciation as a function of uranium concentration and incubation time...
October 18, 2018: Environmental Science & Technology
Moran Li, Jing Yin, Sha Mei, Xuhong Wang, Xiao-Feng Tang, Bing Tang
Many haloarchaea produce extracellular subtilisin-like proteases (halolysins) during late log phase; however, the physiological function and regulatory mechanism of growth phase-dependent production of halolysins are unknown. Halolysin SptA, the major extracellular protease of Natrinema sp. J7-2, is capable of intracellular self-activation to affect haloarchaeal growth. Here, we report that deletion of sptA leads to loss of extracellular and intracellular protease activities against azocasein and/or suc-AAPF-pNA, as well as a change in growth-phase transition of the haloarchaeon...
2018: Frontiers in Microbiology
Tomotsumi Fujisawa, Masahiro Abe, Jun Tamogami, Takashi Kikukawa, Naoki Kamo, Masashi Unno
Proteorhodopsin (PR) is a microbial rhodopsin functioning as a light-driven proton pump in aquatic bacteria. We performed low-temperature Raman measurements of PR to obtain the structure of the primary photoproduct, the K intermediate (PRK ). PRK showed the hydrogen-out-of-plane modes that are much less intense than those of bacteriorhodopsin as the prototypical light-driven proton pump from haloarchaea. The present results reveal the significantly relaxed chromophore structure in PRK , which can be coupled to the slow kinetics of the K intermediate...
August 11, 2018: FEBS Letters
Bernhard Tschitschko, Susanne Erdmann, Matthew Z DeMaere, Simon Roux, Pratibha Panwar, Michelle A Allen, Timothy J Williams, Sarah Brazendale, Alyce M Hancock, Emiley A Eloe-Fadrosh, Ricardo Cavicchioli
BACKGROUND: The genomes of halophilic archaea (haloarchaea) often comprise multiple replicons. Genomic variation in haloarchaea has been linked to viral infection pressure and, in the case of Antarctic communities, can be caused by intergenera gene exchange. To expand understanding of genome variation and biogeography of Antarctic haloarchaea, here we assessed genomic variation between two strains of Halorubrum lacusprofundi that were isolated from Antarctic hypersaline lakes from different regions (Vestfold Hills and Rauer Islands)...
June 20, 2018: Microbiome
Micaela Cerletti, María Ines Giménez, Christian Tröetschel, Celeste D' Alessandro, Ansgar Poetsch, Rosana Ester De Castro, Roberto A Paggi
The dynamic changes that take place along the phases of microbial growth (lag, exponential, stationary, and death) have been widely studied in bacteria at the molecular and cellular levels, but little is known for archaea. In this study, a high-throughput approach was used to analyze and compare the proteomes of two haloarchaea during exponential and stationary growth: the neutrophilic Haloferax volcanii and the alkaliphilic Natrialba magadii. Almost 2000 proteins were identified in each species (≈50% of the predicted proteome)...
July 2018: Proteomics
Raphaël Méheust, Andrew K Watson, François-Joseph Lapointe, R Thane Papke, Philippe Lopez, Eric Bapteste
BACKGROUND: Haloarchaea, a major group of archaea, are able to metabolize sugars and to live in oxygenated salty environments. Their physiology and lifestyle strongly contrast with that of their archaeal ancestors. Amino acid optimizations, which lowered the isoelectric point of haloarchaeal proteins, and abundant lateral gene transfers from bacteria have been invoked to explain this deep evolutionary transition. We use network analyses to show that the evolution of novel genes exclusive to Haloarchaea also contributed to the evolution of this group...
June 7, 2018: Genome Biology
Qiong Xue, Xiao-Bin Liu, Yeh-Hsing Lao, Lin-Ping Wu, Dong Wang, Zhen-Qiang Zuo, Jun-Yu Chen, Jing Hou, Yuan-Yuan Bei, Xue-Fei Wu, Kam W Leong, Hua Xiang, Jing Han
Implants decorated with antimicrobial peptides (AMPs) can prevent infection and reduce the risk of creating antibiotic resistance. Yet the restricted mobility of surficial AMP often compromises its activity. Here, we report a simple but effective strategy to allow a more flexible display of AMP on the biomaterial surface and demonstrate its efficacy for wound healing. The AMP, tachyplesin I (Tac), is tagged with the polyhydroxyalkanoate-granule-associated protein (PhaP) and immobilized on haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) via hydrophobic interaction...
September 2018: Biomaterials
Siham Akmoussi-Toumi, Souad Khemili-Talbi, Imen Ferioune, Salima Kebbouche-Gana
The present study investigates the purification and biochemical characterization of an extracellular lipase (HML) from Haloarchaea Haloferax mediterranei strain ATS1, isolated from the Sebkha (Medea, Algeria). The pure protein was obtained with ammonium sulfate precipitation (40-70%)-dialysis and UNO Q-6 FPLC, and characterized biochemically. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer, with a molecular mass of 45,011...
September 2018: International Journal of Biological Macromolecules
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