Halobacteria H.sp.xz 515 was isolated from a salt lake in Tibet. Although proton release-and-uptake across claret membrane is in reverse order compared to bacteri-orhodopsin in purple membrane from Halobacterium Sali-...Halobacteria H.sp.xz 515 was isolated from a salt lake in Tibet. Although proton release-and-uptake across claret membrane is in reverse order compared to bacteri-orhodopsin in purple membrane from Halobacterium Sali-narum, and its efficiency of proton pump is much lower, AFM image shows that the molecules are still arranged in a two-dimensional hexagonal lattice of trimers. Primary structure of C- to G-helix of the archaerhodopsin shows that it has only 56% homology with bacteriorhodopsin. But the interactive amino acid residues at the interface between B-and D-helixes are conserved. These amino acid residues are believed to play a significant role in the stability of protein oligomers.展开更多
As a group,the halophilic archaea(class Halobacteria)are the most salt-requiring and salt-resistant microorganisms within the domain Archaea.Halophilic archaea flourish in thalassohaline and athalassohaline environmen...As a group,the halophilic archaea(class Halobacteria)are the most salt-requiring and salt-resistant microorganisms within the domain Archaea.Halophilic archaea flourish in thalassohaline and athalassohaline environments and require over 100–150 g/L NaCl for growth and structural stability.Natural hypersaline environments vary in salt concentration,chemical composition and pH,and occur in climates ranging from tropical to polar and even under-sea.Accordingly,their resident haloarchaeal species vary enormously,as do their individual population compositions and community structures.These diverse halophilic archaeal strains are precious resources for theoretical and applied research but assessing their taxonomic and metabolic novelty and diversity in natural environments has been technically difficult up until recently.Environmental DNA-based high-throughput sequencing technology has now matured sufficiently to allow inexpensive recovery of massive amounts of sequence data,revealing the distribution and community composition of halophilic archaea in different hypersaline environments.While cultivation of haloarchaea is slow and tedious,and only recovers a fraction of the natural diversity,it is the conventional means of describing new species,and provides strains for detailed study.As of the end of May 2020,the class Halobacteria contains 71 genera and 275 species,49.8%of which were first isolated from the marine salt environment and 50.2%from the inland salt environment,indicating that both thalassohaline and athalassohaline environments contain diverse halophilic archaea.However,there remain taxa that have not yet been isolated in pure culture,such as the nanohaloarchaea,which are widespread in the salt environment and may be one of the hot spots in the field of halophilic archaea research in the future.In this review,we focus on the cultivation strategies that have been used to isolate extremely halophilic archaea and point out some of the pitfalls and challenges.展开更多
This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal ...This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal protein used by archaea that come under the family of halobacteria. This retinal protein acts as a proton pump and resulting proton gradient is used to change the voltage that pass across the drain and source. The biosensor contains nano ISFET where the channel is made of a carbon nanotube for the conduction of current. The gate is replaced by bacteriorhodopsin biomembrane. Bacteriorhodopsin can be used as a molecular-level ultra fast bi-stable red / green photo switch for making 3D optical molecular memories that reliably store data with 10,000 molecules/bit. The molecules switch in femtoseconds. Biomembrane will sense 510 nm and 650 nm wavelength of light and the sensing voltage can be used to convert the data into digital signals. This molecular level memory device can be used for ‘Read-Write＇ operations. The sensor performance will also be ultra fast since it uses photons for the data storage, which are much faster than electrons used in normal memory devices, and the 3D storage capacity is much higher maximum of 10^13/cm^2.展开更多
This work analyzes bacterial communities present in evaporation ponds of solar salterns of Gran Canaria and reveals specific organisms through molecular techniques.Solar salterns are protected areas in Canary Islands ...This work analyzes bacterial communities present in evaporation ponds of solar salterns of Gran Canaria and reveals specific organisms through molecular techniques.Solar salterns are protected areas in Canary Islands where salt is produced from sea water by solarand windpowered evaporation.Salt was an important product for ancient islanders who used it for a broad field of purposes,but also has a great importance in recent time for its implications in the island economy.Based on amplifications with specific primers for 16S ribosomal DNA(16S rDNA)and subsequent nested-PCR approaches,different amplicons were obtained,and analyzed in silico.A taxonomic classification was carried out through phylogenetic trees.Results revealed different bacteria according to the evaporation grade of crystallizer ponds in saline works.It is worthstanding the presence of the genus Halobacterium in all crystallizer ponds.This opens an interesting framework for further studies and continuative molecular characterization approaches of bacterial communities in solar salterns of Gran Canaria.展开更多
The gene fragment encoding the retinal protein from helix C to helix G in a new strain of halobacteria, H.sp.xz515 has been amplified by PCR method. The nucleotide sequence of this fragment has been determined. The de...The gene fragment encoding the retinal protein from helix C to helix G in a new strain of halobacteria, H.sp.xz515 has been amplified by PCR method. The nucleotide sequence of this fragment has been determined. The deduced amino acid sequence has been compared with halobium br and other two br-like proteins, ar-1 and ar-2. Results show that those amino acid residues in br, essential for proton pumping and binding to retinal, are conserved. The residue M145 in br may be important for isomerization reaction of retinal.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 19890385, 39730150 and 19725415) the key programs of the Chinese Academy of Sciences (Grant Nos.KJ951-A1-603, KJ951-A1-409, KJ952-J1-469 and STZ-00-07).
文摘Halobacteria H.sp.xz 515 was isolated from a salt lake in Tibet. Although proton release-and-uptake across claret membrane is in reverse order compared to bacteri-orhodopsin in purple membrane from Halobacterium Sali-narum, and its efficiency of proton pump is much lower, AFM image shows that the molecules are still arranged in a two-dimensional hexagonal lattice of trimers. Primary structure of C- to G-helix of the archaerhodopsin shows that it has only 56% homology with bacteriorhodopsin. But the interactive amino acid residues at the interface between B-and D-helixes are conserved. These amino acid residues are believed to play a significant role in the stability of protein oligomers.
基金This work was financially supported by the National Natural Science Foundation of China(No.31770005,32070003)the National Science and Technology Fundamental Resources Investigation Program of China(No.2017FY100302,2019FY100700).
文摘As a group,the halophilic archaea(class Halobacteria)are the most salt-requiring and salt-resistant microorganisms within the domain Archaea.Halophilic archaea flourish in thalassohaline and athalassohaline environments and require over 100–150 g/L NaCl for growth and structural stability.Natural hypersaline environments vary in salt concentration,chemical composition and pH,and occur in climates ranging from tropical to polar and even under-sea.Accordingly,their resident haloarchaeal species vary enormously,as do their individual population compositions and community structures.These diverse halophilic archaeal strains are precious resources for theoretical and applied research but assessing their taxonomic and metabolic novelty and diversity in natural environments has been technically difficult up until recently.Environmental DNA-based high-throughput sequencing technology has now matured sufficiently to allow inexpensive recovery of massive amounts of sequence data,revealing the distribution and community composition of halophilic archaea in different hypersaline environments.While cultivation of haloarchaea is slow and tedious,and only recovers a fraction of the natural diversity,it is the conventional means of describing new species,and provides strains for detailed study.As of the end of May 2020,the class Halobacteria contains 71 genera and 275 species,49.8%of which were first isolated from the marine salt environment and 50.2%from the inland salt environment,indicating that both thalassohaline and athalassohaline environments contain diverse halophilic archaea.However,there remain taxa that have not yet been isolated in pure culture,such as the nanohaloarchaea,which are widespread in the salt environment and may be one of the hot spots in the field of halophilic archaea research in the future.In this review,we focus on the cultivation strategies that have been used to isolate extremely halophilic archaea and point out some of the pitfalls and challenges.
文摘This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal protein used by archaea that come under the family of halobacteria. This retinal protein acts as a proton pump and resulting proton gradient is used to change the voltage that pass across the drain and source. The biosensor contains nano ISFET where the channel is made of a carbon nanotube for the conduction of current. The gate is replaced by bacteriorhodopsin biomembrane. Bacteriorhodopsin can be used as a molecular-level ultra fast bi-stable red / green photo switch for making 3D optical molecular memories that reliably store data with 10,000 molecules/bit. The molecules switch in femtoseconds. Biomembrane will sense 510 nm and 650 nm wavelength of light and the sensing voltage can be used to convert the data into digital signals. This molecular level memory device can be used for ‘Read-Write＇ operations. The sensor performance will also be ultra fast since it uses photons for the data storage, which are much faster than electrons used in normal memory devices, and the 3D storage capacity is much higher maximum of 10^13/cm^2.
基金supported by the collaboration of Ministerio de Ciencia,Innovación y Universidades,and from the Universidad de Las Palmas de Gran Canaria(Grant CGL2016-78442-C2-2-R,GOBESP2017-04 ULPGC)co-funded by INTERREG MAC 2014-2020 programme programme,within the MacBio Blue project(MAC/1.1b/086).
文摘This work analyzes bacterial communities present in evaporation ponds of solar salterns of Gran Canaria and reveals specific organisms through molecular techniques.Solar salterns are protected areas in Canary Islands where salt is produced from sea water by solarand windpowered evaporation.Salt was an important product for ancient islanders who used it for a broad field of purposes,but also has a great importance in recent time for its implications in the island economy.Based on amplifications with specific primers for 16S ribosomal DNA(16S rDNA)and subsequent nested-PCR approaches,different amplicons were obtained,and analyzed in silico.A taxonomic classification was carried out through phylogenetic trees.Results revealed different bacteria according to the evaporation grade of crystallizer ponds in saline works.It is worthstanding the presence of the genus Halobacterium in all crystallizer ponds.This opens an interesting framework for further studies and continuative molecular characterization approaches of bacterial communities in solar salterns of Gran Canaria.
文摘The gene fragment encoding the retinal protein from helix C to helix G in a new strain of halobacteria, H.sp.xz515 has been amplified by PCR method. The nucleotide sequence of this fragment has been determined. The deduced amino acid sequence has been compared with halobium br and other two br-like proteins, ar-1 and ar-2. Results show that those amino acid residues in br, essential for proton pumping and binding to retinal, are conserved. The residue M145 in br may be important for isomerization reaction of retinal.
