Production of polyhydroxybutyrate from wheat straw hydrolysate using a low-salt requiring and alkaliphilic Halomonas nigrificans X339 under non-sterile open condition.

Utilizing agricultural waste is a sustainable approach to reduce the production cost of bio-based products. Here, we report a novel haloalkaliphilic strain, Halomonas nigrificans X339, which exhibits an exceptional ability to utilize various low-cost carbon sources. Compared to other halophiles, X339 could be cultivated at an optimal salinity as low as 2 % (w/v).

Tat-fimbriae ("tafi"): An unusual type of haloarchaeal surface structure depending on the twin-arginine translocation pathway.

The surface structures of archaeal cells, many of which exist at high temperatures, high salinity, and non-physiological pH, are key factors for their adaptation to extreme living conditions. In the haloarchaeon , we have discovered a thin filamentous surface appendage called tat-fimbriae ("tafi"), which were identified to be composed of three protein subunits, TafA, TafC, and TafE, among which TafA is the major fimbrial subunit. Molecular genetic evidence demonstrates TafA was transported through the twin-arginine translocation pathway (Tat-pathway).

Engineered minimal type I CRISPR-Cas system for transcriptional activation and base editing in human cells.

Type I CRISPR-Cas systems are widespread and have exhibited high versatility and efficiency in genome editing and gene regulation in prokaryotes. However, due to the multi-subunit composition and large size, their application in eukaryotes has not been thoroughly investigated. Here, we demonstrate that the type I-F2 Cascade, the most compact among type I systems, with a total gene size smaller than that of SpCas9, can be developed for transcriptional activation in human cells.

Complete genome sequence of a haloalkaliphilic heterotrophic bacterium IM328.

The genome of a halophilic bacterium IM328 was completely sequenced in order to offer convenience for the research such as the synthesis of compatible solutes. The genome contains a circular chromosome which was sequenced by PacBio system.

The Isolation and Characterization of a Novel Psychrotolerant Cellulolytic Bacterium, sp. QXD-8.

Cellulolytic microorganisms play a crucial role in agricultural waste disposal. Strain QXD-8 was isolated from soil in northern China. Similarity analyses of the 16S rRNA gene, as well as the 120 conserved genes in the whole-genome sequence, indicate that it represents a novel species within the genus .

Members of the class Candidatus Ordosarchaeia imply an alternative evolutionary scenario from methanogens to haloarchaea.

The origin of methanogenesis can be traced to the common ancestor of non-DPANN archaea, whereas haloarchaea (or Halobacteria) are believed to have evolved from a methanogenic ancestor through multiple evolutionary events. However, due to the accelerated evolution and compositional bias of proteins adapting to hypersaline habitats, Halobacteria exhibit substantial evolutionary divergence from methanogens, and the identification of the closest methanogen (either Methanonatronarchaeia or other taxa) to Halobacteria remains a subject of debate. Here, we obtained five metagenome-assembled genomes with high completeness from soda-saline lakes on the Ordos Plateau in Inner Mongolia, China, and we proposed the name Candidatus Ordosarchaeia for this novel class.

The Role of Glutamine Synthetase in Regulating Ammonium Assimilation and Iron-Only Nitrogenase Expression in a Photosynthetic Diazotroph.

Glutamine synthetase (GS) is responsible for the ammonium assimilation into glutamine, which serves as an important nitrogen donor for the synthesis of biomolecules and also plays a key role in regulating the nitrogen fixation catalyzed by nitrogenase. Rhodopseudomonas palustris, whose genome encodes 4 putative GSs and 3 nitrogenases, is an attractive photosynthetic diazotroph for studies of nitrogenase regulation, as it can produce the powerful greenhouse gas (methane) by iron-only (Fe-only) nitrogenase using light energy. However, the primary GS enzyme for ammonium assimilation and its role in nitrogenase regulation remain elusive in R.

Comparative Genomic Insights into the Evolution of -Associated " Nanohaloarchaeota".

Members of the phylum " Nanohaloarchaeota," a representative lineage within the DPANN superphylum, are characterized by their nanosized cells and symbiotic lifestyle with . However, the development of the symbiosis remains unclear. Here, we propose two novel families, " Nanoanaerosalinaceae" and " Nanohalalkaliarchaeaceae" in ".

Identification of the Biosynthetic Pathway of Glycine Betaine That Is Responsible for Salinity Tolerance in Halophilic D301.

D301 has been widely used in the biodesulfurization process, as it is capable of oxidizing hydrogen sulfide to elemental sulfur under strongly halo-alkaline conditions. Glycine betaine contributes to the increased tolerance to extreme environments in some of species. However, the biosynthetic pathway of glycine betaine in remained unknown.

sp. nov., a haloalkaliphilic bacterium isolated from a soda lake in Inner Mongolia Autonomous Region, China.

A haloalkaliphilic strain (IM 1326) was isolated from brine sampled at a soda lake in the Inner Mongolia Autonomous Region, China. Cells of the strain were rod-shaped and motile. Strain IM 1326 was able to grow at 4-42 °C (optimum, 37 °C) with 0-13.

Rhabdonatronobacter sediminivivens gen. nov., sp. nov. isolated from the sediment of Hutong Qagan Soda Lake.

A novel Gram-stain-negative bacterium, designated as IM2376, was isolated from the sediment of Hutong Qagan Lake in the Ordos, Inner Mongolia Autonomous Region of China. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strain IM2376 had the highest similarity with Roseinatronobacter thiooxidans DSM 13087 (96.2%) and Rhodobaca bogoriensis LBB1 (96.

Metagenomic insights into the environmental adaptation and metabolism of Candidatus Haloplasmatales, one archaeal order thriving in saline lakes.

The KTK 4A-related Thermoplasmata thrives in the sediment of saline lakes; however, systematic research on its taxonomy, environmental adaptation and metabolism is lacking. Here, we detected this abundant lineage in the sediment of five artificially separated ponds (salinity 7.0%-33.

Development of whole-cell catalyst system for sulfide biotreatment based on the engineered haloalkaliphilic bacterium.

Microorganisms play an essential role in sulfide removal. Alkaline absorption solution facilitates the sulfide's dissolution and oxidative degradation, so haloalkaliphile is a prospective source for environmental-friendly and cost-effective biodesulfurization. In this research, 484 sulfide oxidation genes were identified from the metagenomes of the soda-saline lakes and a haloalkaliphilic heterotrophic bacterium Halomonas salifodinae IM328 (=CGMCC 22183) was isolated from the same habitat as the host for expression of a representative sequence.

Highly integrated adaptive mechanisms in Spiribacter halalkaliphilus, a bacterium abundant in Chinese soda-saline lakes.

Soda-saline lakes are polyextreme environments inhabited by many haloalkaliphiles, including one of the most abundant Spiribacter species. However, its mechanisms of adaptation are not ecophysiologically characterized. Based on a large-scale cultivation strategy, we obtained a representative isolate of this Spiribacter species whose relative abundance was the highest (up to 15.

Toxin-antitoxin RNA pairs safeguard CRISPR-Cas systems.

CRISPR-Cas systems provide RNA-guided adaptive immunity in prokaryotes. We report that the multisubunit CRISPR effector Cascade transcriptionally regulates a toxin-antitoxin RNA pair, CreTA. CreT (Cascade-repressed toxin) is a bacteriostatic RNA that sequesters the rare arginine tRNA (transfer RNA with anticodon UCU).

Natronorubrum halalkaliphilum sp. nov., a haloalkaliphilic archaeon isolated from soda lake in Inner Mongolia Autonomous Region, China.

A haloalkaliphilic strain JWXQ-INN-674 was isolated from the water sample of a soda lake in Inner Mongolia Autonomous Region, China. Cells of the strain were coccoid, motile, and strictly aerobic. The strain was able to grow in presence of 2.

Halalkalirubrum salinum gen. nov., sp. nov., a halophilic archaeon isolated from a saline lake.

A novel extremely halophilic archaeon, strain N1521, was isolated from a saline lake in Tibet, China. Cells of the strain were pleomorphic and Gram-stain-negative. It produced red pigments.

gen. nov., sp. nov., a haloalkaliphilic archaeon isolated from salt pond in Inner Mongolia Autonomous Region, China.

A haloalkaliphilic strain XQ-INN 246 was isolated from the sediment of a salt pond in Inner Mongolia Autonomous Region, China. Cells of the strain were rods, motile and strictly aerobic. The strain was able to grow in the presence of 2.

Insights into the metabolism pathway and functional genes of long-chain aliphatic alkane degradation in haloarchaea.

The mineralization of alkane is mainly driven by microorganisms, and the detailed mechanisms of long-chain aliphatic alkane degradation are undeciphered in archaea. We used a hexadecane-degrading haloarchaeon, Halorientalis hydrocarbonoclasticus IM1011 (= CGMCC 13754), as a model system to decode this through transcriptomic and biochemical studies. During growth on hexadecane as sole carbon source, the activity of 3-hydroxyacyl-CoA dehydrogenase, a β-oxidation pathway enzyme, was measured.

Unusual Phosphoenolpyruvate (PEP) Synthetase-Like Protein Crucial to Enhancement of Polyhydroxyalkanoate Accumulation in Haloferax mediterranei Revealed by Dissection of PEP-Pyruvate Interconversion Mechanism.

Phosphoenolpyruvate (PEP)/pyruvate interconversion is a major metabolic point in glycolysis and gluconeogenesis and is catalyzed by various sets of enzymes in different groups. In this study, we report the key enzymes that catalyze the anabolic and catabolic directions of the PEP/pyruvate interconversion in The analysis showed the presence of a potassium-dependent pyruvate kinase (PYK [HFX_0773]) and two phosphoenol pyruvate synthetase (PPS) candidates (PPS [HFX_0782] and a PPS homolog protein named PPS-like [HFX_2676]) in this strain. Expression of the gene and was induced by glycerol and pyruvate, respectively; whereas the -like gene was not induced at all.

Primed adaptation tolerates extensive structural and size variations of the CRISPR RNA guide in Haloarcula hispanica.

Recent studies on CRISPR adaptation revealed that priming is a major pathway of spacer acquisition, at least for the most prevalent type I systems. Priming is guided by a CRISPR RNA which fully/partially matches the invader DNA, but the plasticity of this RNA guide has not yet been characterized. In this study, we extensively modified the two conserved handles of a priming crRNA in Haloarcula hispanica, and altered the size of its central spacer part.

Engineering as an Efficient Platform for High Level Production of Lycopene.

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 , a halophilic archaeon, as a new lycopene producer.