Genomic insights into key mechanisms for carbon, nitrogen, and phosphate assimilation by the acidophilic, halotolerant genus Acidihalobacter members.

In-depth comparative genomic analysis was conducted to predict carbon, nitrogen, and phosphate assimilation pathways in the halotolerant, acidophilic genus Acidihalobacter. The study primarily aimed to understand how the metabolic capabilities of each species can determine their roles and effects on the microbial ecology of their unique saline and acidic environments, as well as in their potential application to saline water bioleaching systems. All four genomes encoded the genes for the complete tricarboxylic acid cycle, including 2-oxoglutarate dehydrogenase, a key enzyme absent in obligate chemolithotrophic acidophiles.

Analysis of element yield, bacterial community structure and the impact of carbon sources for bioleaching rare earth elements from high grade monazite.

Rare earth element (REE) recovery from waste streams, mine tailings or recyclable components using bioleaching is gaining traction due to the shortage and security of REE supply as well as the environmental problems that occur from processing and refining. Four heterotrophic microbial species with known phosphate solubilizing capabilities were evaluated for their ability to leach REE from a high-grade monazite when provided with either galactose, fructose or maltose. Supplying fructose resulted in the greatest amount of REE leached from the ore due to the largest amount of organic acid produced.

Examining the Osmotic Response of after Exposure to Salt Stress.

is an acidophilic, halo-tolerant organism isolated from a marine environment near a hydrothermal vent, an ecosystem whereby levels of salinity and total dissolved salts are constantly fluctuating creating ongoing cellular stresses. In order to survive these continuing changes, the synthesis of compatible solutes-also known as organic osmolytes-is suspected to occur, aiding in minimising the overall impact of environmental instability. Previous studies on identified genes necessary for the accumulation of proline, betaine and ectoine, which are known to act as compatible solutes in other halophilic species.

Structure illumination microscopy imaging of lipid vesicles in live bacteria with naphthalimide-appended organometallic complexes.

There is a lack of molecular probes for imaging bacteria, in comparison to the array of such tools available for the imaging of mammalian cells. Here, organometallic molecular probes have been developed and assessed for bacterial imaging, designed to have the potential to support multiple imaging modalities. The chemical structure of the probes is designed around a metal-naphthalimide structure.

Unlocking Survival Mechanisms for Metal and Oxidative Stress in the Extremely Acidophilic, Halotolerant Genus.

Microorganisms used for the biohydrometallurgical extraction of metals from minerals must be able to survive high levels of metal and oxidative stress found in bioleaching environments. The genus consists of four species of halotolerant, iron-sulfur-oxidizing acidophiles that are unique in their ability to tolerate chloride and acid stress while simultaneously bioleaching minerals. This paper uses bioinformatic tools to predict the genes and mechanisms used by members in their defense against a wide range of metals and oxidative stress.

Genome-based classification of F5 (=DSM 105917=JCM 32255) as sp. nov.

The genus has three validated species, , and , all of which were isolated from Vulcano island, Italy. They are obligately chemolithotrophic, aerobic, acidophilic and halophilic in nature and use either ferrous iron or reduced sulphur as electron donors. Recently, a novel strain was isolated from an acidic, saline drain in the Yilgarn region of Western Australia.

Uncovering the Mechanisms of Halotolerance in the Extremely Acidophilic Members of the Genus Through Comparative Genome Analysis.

There are few naturally occurring environments where both acid and salinity stress exist together, consequently, there has been little evolutionary pressure for microorganisms to develop systems that enable them to deal with both stresses simultaneously. Members of the genus are iron- and sulfur-oxidizing, halotolerant acidophiles that have developed the ability to tolerate acid and saline stress and, therefore, have the potential to bioleach ores with brackish or saline process waters under acidic conditions. The genus consists of four members, DSM 5130, DSM 14174, F5 and "" DSM 14175.

Genome-based classification of two halotolerant extreme acidophiles, Acidihalobacter prosperus V6 (=DSM 14174 =JCM 32253) and 'Acidihalobacter ferrooxidans' V8 (=DSM 14175 =JCM 32254) as two new species, Acidihalobacter aeolianus sp. nov. and Acidihalobacter ferrooxydans sp. nov., respectively.

Phylogenomic analysis of recently released high-quality draft genome sequences of the halotolerant acidophiles, Acidihalobacter prosperus V6 (=DSM 14174=JCM 32253) and 'Acidihalobacter ferrooxidans' V8 (=DSM 14175=JCM 32254), was undertaken in order to clarify their taxonomic relationship. Sequence based phylogenomic approaches included 16S rRNA gene phylogeny, multi-gene phylogeny from the concatenated alignment of nine selected housekeeping genes and multiprotein phylogeny using clusters of orthologous groups of proteins from ribosomal protein families as well as those from complete sets of markers based on concatenated alignments of universal protein families. Non-sequence based approaches for species circumscription were based on analyses of average nucleotide identity, which was further reinforced by the correlation indices of tetra-nucleotide signatures as well as genome-to-genome distance (digital DNA-DNA hybridization) calculations.

Complete Genome Sequence of Stenotrophomonas maltophilia AB550, an Environmental Solar Radiation- and Multidrug-Resistant Strain Isolated in Western Australia.

We report here the complete genome sequence of Stenotrophomonas maltophilia AB550, a multidrug- and solar radiation-resistant strain isolated from the effluents of an urban wastewater treatment plant in Western Australia. The genome consists of a single 4.9-Mb chromosome.

Role of microorganisms in bioleaching of rare earth elements from primary and secondary resources.

In an era of environmental degradation, and water, and mineral scarcity, enhancing microbial function in sustainable mining has become a prerequisite for the future of the green economy. In recent years, the extensive use of rare earth elements (REEs) in green and smart technologies has led to an increase in the focus on recovery and separation of REEs from ore matrices. However, the recovery of REEs using traditional methods is complex and energy intensive, leading to the requirement to develop processes which are more economically feasible and environmentally friendly.

Quantitative proteomics using SWATH-MS identifies mechanisms of chloride tolerance in the halophilic acidophile Acidihalobacter prosperus DSM 14174.

In this study, the differential protein expression of the acidophilic halophile, Acidihalobacter prosperus DSM 14174 (strain V6) was studied with the aim of understanding its mechanisms of tolerance to high chloride ion stress in the presence of low pH, using Sequential Window Acquisition of all Theoretical Mass Spectra (SWATH-MS). In acidophiles, chloride stress results in both osmotic stress as well as acidification of the cytoplasm due to the ability of chloride to permeate the cell membrane and disrupt the reversed transmembrane potential which normally extrudes protons. The proteomic response of A.

Syntrophic effect of indigenous and inoculated microorganisms in the leaching of rare earth elements from Western Australian monazite.

The unique physiochemical properties exhibited by rare earth elements (REEs) and their increasing application in high-tech industries has created a demand for secure supply lines with established recovery procedures that create minimal environmental damage. Bioleaching experiments conducted on a non-sterile monazite concentrate with a known phosphate solubilising microorganism (PSM) resulted in greater mobilisation of REEs into solution in comparison to experiments conducted on sterile monazite. By combining the native consortia with an introduced PSM, a syntrophic effect between the populations effectively leached a greater amount of REEs than either a single PSM or the indigenous population alone.

Microbial Diversity and Mineralogical-Mechanical Properties of Calcitic Cave Speleothems and Biomineralization Conditions.

Natural mineral formations are a window into important processes leading to carbon storage and mineralized carbonate structures formed through abiotic and biotic processes. In the current study, we made an attempt to undertake a comprehensive approach to characterize the mineralogical, mechanical, and microbial properties of different kinds of speleothems from karstic caves; with an aim to understand the bio-geo-chemical processes in speleothem structures and their impact on nanomechanical properties. We also investigated the biomineralization abilities of speleothem surface associated microbial communities .

Draft Genome Sequence of DSM 14175 (Strain V8), a New Iron- and Sulfur-Oxidizing, Halotolerant, Acidophilic Species.

The use of halotolerant acidophiles for bioleaching provides a biotechnical approach for the extraction of metals from regions where high salinity exists in the ores and source water. Here, we describe the first draft genome of a new species of a halotolerant and iron- and sulfur-oxidizing acidophile, DSM 14175 (strain V8).

Interactions of phosphate solubilising microorganisms with natural rare-earth phosphate minerals: a study utilizing Western Australian monazite.

Many microbial species are capable of solubilising insoluble forms of phosphate and are used in agriculture to improve plant growth. In this study, we apply the use of known phosphate solubilising microbes (PSM) to the release of rare-earth elements (REE) from the rare-earth phosphate mineral, monazite. Two sources of monazite were used, a weathered monazite and mineral sand monazite, both from Western Australia.

Multiple Osmotic Stress Responses in Result in Tolerance to Chloride Ions.

Extremely acidophilic microorganisms (pH optima for growth of ≤3) are utilized for the extraction of metals from sulfide minerals in the industrial biotechnology of "biomining." A long term goal for biomining has been development of microbial consortia able to withstand increased chloride concentrations for use in regions where freshwater is scarce. However, when challenged by elevated salt, acidophiles experience both osmotic stress and an acidification of the cytoplasm due to a collapse of the inside positive membrane potential, leading to an influx of protons.

Draft Genome Sequence of the Acidophilic, Halotolerant, and Iron/Sulfur-Oxidizing Acidihalobacter prosperus DSM 14174 (Strain V6).

The principal genomic features of Acidihalobacter prosperus DSM 14174 (strain V6) are presented here. This is a mesophilic, halotolerant, and iron/sulfur-oxidizing acidophile that was isolated from seawater at Vulcano, Italy. It has potential for use in biomining applications in regions where high salinity exists in the source water and ores.

Saline-water bioleaching of chalcopyrite with thermophilic, iron(II)- and sulfur-oxidizing microorganisms.

The application of thermoacidophiles for chalcopyrite (CuFeS2) bioleaching in hot, acidic, saline solution was investigated as a possible process route for rapid Cu extraction. The study comprised a discussion of protective mechanisms employed for the survival and/or adaptation of thermoacidophiles to osmotic stress, a compilation of chloride tolerances for three genera of thermoacidophiles applied in bioleaching and an experimental study of the activities of three species in a saline bioleaching system. The data showed that the oxidation rates of iron(II) and reduced inorganic sulfur compounds (tetrathionate) were reduced in the presence of chloride levels well below chloride concentrations in seawater, limiting the applicability of these microorganisms in the bioleaching of CuFeS2 in saline water.

Bioleaching in brackish waters--effect of chloride ions on the acidophile population and proteomes of model species.

High concentrations of chloride ions inhibit the growth of acidophilic microorganisms used in biomining, a problem particularly relevant to Western Australian and Chilean biomining operations. Despite this, little is known about the mechanisms acidophiles adopt in order to tolerate high chloride ion concentrations. This study aimed to investigate the impact of increasing concentrations of chloride ions on the population dynamics of a mixed culture during pyrite bioleaching and apply proteomics to elucidate how two species from this mixed culture alter their proteomes under chloride stress.