Absence Of NaCl Research Articles

Copper and zinc sulfides bioleaching by an extremely thermophilic archaeon in high NaCl concentration

Chloride bioleaching has received attention of several mineral processing industries, particularly in countries where there is scarcity of freshwater and only chloride-containing waters can be used. Therefore, the present work investigated the effect of NaCl (1.0 mol L−1) on the bioleaching of three sulfide minerals: chalcopyrite, bornite, and sphalerite by the thermophilic archaea Sulfolobus acidocaldarius. Chalcopyrite dissolution was only 25 % in the biotic experiment in the absence of chloride, but reached 90 % in the presence of both microorganisms and chloride, while less than 60 % extraction was observed in the abiotic experiment with chloride. In the experiments of bornite bioleaching, 86 % and 77 % of copper were extracted in the biotic and abiotic tests with chloride, respectively. In the absence of NaCl, the biotic and abiotic experiments presented similar copper dissolution (∼35 %). Finally, bioleaching experiments carried out with sphalerite showed zinc extractions below 35 % in all conditions tested. The main contribution from the archaea was its ability to produce low concentrations of ferric ion, which was partially precipitated as jarosite, resulting in low redox potential values (< 450 mV vs. Ag/AgCl), and efficiently bioleached bornite and chalcopyrite. Furthermore, XRD and SEM-EDS analyses demonstrated that sphalerite was practically not leached while bornite was transformed into new copper sulfide phases (CuS and Cu3FeS4). Jarosite and elemental sulfur were products of chalcopyrite and bornite bioleaching in the presence of chloride.

Mycovorax composti gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from button mushroom compost.

Two Gram-stain-negative, aerobic, rod-shaped, orange-coloured bacterial strains, designated strain C216T and strain M2295, were isolated from mature mushroom compost from composting facilities in Victoria and South Australia, Australia, respectively. External structures such as flagella or pili were not observed on the cells under scanning electron microscopy. Optimal growth was found to occur at 45 °C, at pH 7.25 and in the absence of NaCl on Emerson's 350 YpSs medium. The genome sequence of strain C216T was 3 342 126 bp long with a G+C content of 40.5 mol%. Functional analysis of the genome of strain C216T revealed genes encoding chitinolytic and hemi-cellulolytic functions, with 166 predicted genes associated with carbohydrate metabolism (8.9% of the predicted genes). These functions are important for survival in the mushroom compost environment, which is rich in hemicelluloses. No antibiotic resistance genes were found in the genome sequence. The major fatty acids of strain C216T were iso-C15 : 0 (56.7%), iso-C17 : 0 3-OH (15.6%), C16 : 1 ω7c/iso-C15 : 0 2-OH (7.3%) and iso-C15 : 1 G (6.1%). The only respiratory quinone was MK-7. The major polar lipid of strain C216T was phosphatidylethanolamine, but three unidentified phospholipids, four unidentified aminophospholipids/aminolipids and one unidentified glycolipid were also detected. Phylogenetic analysis based on proteins encoded by the core genome (bac120, 120 conserved bacterial genes) showed that strain C216T forms a distinct lineage in the family Chitinophagaceae and that the closest identified relative is Niabella soli (69.69% ANI). These data demonstrate that strain C216T represents a novel genus and novel species within the family Chitinophagaceae, for which we propose the name Mycovorax composti. The type strain is C216T (=DSM 114558T=LMG 32998T).

Roseateles caseinilyticus sp. nov. and Roseateles cellulosilyticus sp. nov., isolated from rice paddy field soil.

Two novel Gram-stain-negative strains designated P7T and P8T, were isolated from the soil of a paddy field in Goyang, Republic of Korea, and identified as new species within the genus Roseateles through a polyphasic taxonomic approach. These aerobic, rod-shaped, non-sporulating strains demonstrated optimal growth at 30°C, pH 7, and in the absence of NaCl (0% w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated close relationships with Roseateles saccharophilus DSM654T (98.7%) and Roseateles puraquae CCUG 52769T (98.96%), respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the isolates with the most closely related strains with publicly available whole genomes were 82.0-85.5% and 25.0-30.2%, respectively. The predominant fatty acids identified were C16:0 and summed feature 3 (composed of C16:1 ω6c and/or C16:1 ω7c), with minor amounts of C12:0, C10:0 3-OH and summed feature 8 (composed of C18:1 ω7c and/or C18:1 ω6c; 26.4%). Ubiquinone 8 was the main quinone, and the polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, two unidentified phosphoaminolipids, one unidentified phosphoglycolipid, three unidentified phospholipids, and one unidentified aminolipid. The draft genome sequences revealed genomic DNA G + C contents of 70.1% for P7T and 68.2% for P8T. Comprehensive physiological, biochemical, and 16S rRNA sequence analyses confirm these isolates as novel species of the genus Roseateles, proposed to be named Roseateles caseinilyticus sp. nov for strain P7T (= KACC 22504T = TBRC 15694T) and Roseateles cellulosilyticus sp. nov. for strain P8T (= KACC 22505T = TBRC 15695T).

Degradation of Dimethyl Phthalate and Diethyl Phthalate by Bacteria Isolated from Jazan, Saudi Arabia

P hthalate esters (PAEs) are commonly utilized in commercial, industrial, and medical applications. Various concentrations of PAEs have been detected in seawater samples and treated wastewater obtained from wastewater treatment plants in Saudi Arabia. Since these compounds pose adverse effects to human health, it is vital to develop efficient strategies to eliminate phthalate contamination from environments. In the present study, an enrichment technique was used to isolate phthalate-degrading bacteria from seawater and from activated sludge collected at Jazan Wastewater Treatment Plant, Saudi Arabia. Bacteria with the capability of degrading dimethyl phthalate (DMP) or diethyl phthalate (DEP) were isolated using minimum salt medium supplemented with these compounds as the sole carbon and energy source. High-performance liquid chromatography (HPLC) was utilized to evaluate the residual concentration of DMP and DEP. Using the 16S rRNA gene sequencing technique, the isolates with maximum DMP biodegradation activity were identified as Achromobacter sp. M1 and Pseudomonas sp. M2, while the isolates with maximum DEP biodegradation activity were identified as Pseudomonas sp. E2 and Pseudomonas sp. E3. The optimum bacterial growth was achieved at 30°C, pH 7.0, and 2% NaCl, except for Pseudomonas sp. E3, which demonstrated its maximum growth in the absence of NaCl. The highest biodegradation rate for all the bacterial strains (&gt; 99.0%) was achieved at 30°C, pH 7.0, and up to 2% NaCl within 4 days. Concurrently, Pseudomonas sp. M2 and Pseudomonas sp. E2 exhibited remarkable degradation rates (97.5% and 56.7%, respectively) at 4% NaCl whereas Pseudomonas sp. E3 showed its highest DEP degradation (82.4%) after 4 days in the absence of NaCl. This study offers potential candidates, including Achromobacter sp. M1, Pseudomonas sp. M2, Pseudomonas sp. E2, and Pseudomonas sp. E3, for the proficient biodegradation of DMP and DEP.

Oleispirillum naphthae gen. nov., sp. nov., a bacterium isolated from oil sludge, and proposal of Oleispirillaceae fam. nov.

A microaerophilic, Gram-negative, motile, and spiral-shaped bacterium, designated Y-M2T, was isolated from oil sludge of Shengli oil field. The optimal growth condition of strain Y-M2T was at 25 °C, pH 7.0, and in the absence of NaCl. The major polar lipid was phosphatidylethanolamine. The main cellular fatty acid was iso-C17 : 0 3-OH. It contained Q-9 and Q-10 as the predominant quinones. The DNA G+C content was 68.1 mol%. Strain Y-M2T showed the highest 16S rRNA gene sequence similarity to Telmatospirillum siberiense 26-4bT (91.1 %). Phylogenetic analyses based on 16S rRNA gene and genomes showed that strain Y-M2T formed a distinct cluster in the order Rhodospirillales. Genomic analysis showed that Y-M2T possesses a complete nitrogen-fixation cluster which is phylogenetically close to that of methanogene. The nif cluster, encompassing the nitrogenase genes, was found in every N2-fixing strain within the order Rhodospirillales. Phylogeny, phenotype, chemotaxonomy, and genomic results demonstrated that strain Y-M2T represents a novel species of a novel genus in a novel family Oleispirillaceae fam. nov. in the order Rhodospirillales, for which the name Oleispirillum naphthae gen. nov., sp. nov. was proposed. The type strain is Y-M2T (=CCAM 827T=JCM 34765T).

Amycolatopsis mongoliensis sp. nov., a novel actinobacterium with antifungal activity isolated from a coal mining site in Mongolia.

A novel filamentous actinobacterium designated strain 4-36T showing broad-spectrum antifungal activity was isolated from a coal mining site in Mongolia, and its taxonomic position was determined using polyphasic approach. Optimum growth occurred at 30 °C, pH 7.5 and in the absence of NaCl. Aerial and substrate mycelia were abundantly formed on agar media. The colour of aerial mycelium was white and diffusible pigments were not formed. Phylogenetic analyses based on 16S rRNA gene sequence showed that strain 4-36T formed a distinct clade within the genus Amycolatopsis. The 16S rRNA gene sequence similarity showed that the strain was mostly related to Amycolatopsis lexingtonensis DSM 44544T and Amycolatopsis rifamycinica DSM 46095T with 99.3 % sequence similarity. However, the highest digital DNA-DNA hybridization value to closest species was 44.1 %, and the highest average nucleotide identity value was 90.2 %, both of which were well below the species delineation thresholds. Chemotaxonomic properties were typical of the genus Amycolatopsis, as the major fatty acids were C15 : 0, iso-C16 : 0 and C16 : 0, the cell-wall diamino acid was meso-diaminopimelic acid, the quinone was MK-9(H4), and the main polar lipids were diphosphatidylglycerol, phosphatidylmethanolamine and phosphatidylethanolamine. The in silico prediction of chemotaxonomic markers was also carried out by phylogenetic analysis. The genome mining for biosynthetic gene clusters of secondary metabolites in strain 4-36T revealed the presence of 34 gene clusters involved in the production of polyketide synthase, nonribosomal peptide synthetase, ribosomally synthesized and post-translationally modified peptide, lanthipeptide, terpenes, siderophore and many other unknown clusters. Strain 4-36T showed broad antifungal activity against several filamentous fungi. The phenotypic, biochemical and chemotaxonomic properties indicated that the strain could be clearly distinguished from other species of Amycolatopsis, and thus the name Amycolatopsis mongoliensis sp. nov. is proposed accordingly (type strain, 4-36T=KCTC 39526T=JCM 30565T).

Description of Chryseobacterium fluminis sp. nov., a keratinolytic bacterium isolated from a freshwater river.

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated MMS21-Ot14T, was isolated from a freshwater river, and shown to represent a novel species of the genus Chryseobacterium on the basis of the results from a polyphasic approach. The 16S rRNA gene sequence analysis revealed that MMS21-Ot14T represented a member of the genus Chryseobacterium of the family Weeksellaceae and was closely related to Chryseobacterium hagamense RHA2-9T (97.52 % sequence similarity), Chryseobacterium gwangjuense THG A18T (97.46 %) and Chryseobacterium gregarium P 461/12T (97.27 %). The optimal growth of MMS21-Ot14T occurred at 25-30 °C, pH 6.0-7.0 and in the absence of NaCl. MMS21-Ot14T was capable of hydrolysing casein, starch, DNA, Tween 20 and tyrosine. The strain also showed keratinolytic activity with keratin azure and decolourising activity with remazol brilliant blue R (RBBR), which indicated potential ability to degrade keratin and lignin. The main polar lipids of MMS21-Ot14T were phosphatidylethanolamine, unidentified aminophospholipids, unidentified aminolipids, an unidentified phospholipid and several unidentified lipids. The predominant fatty acids of MMS21-Ot14T were iso-C15 : 0 and iso-C17 : 0 3-OH, and the major isoprenoid quinone was menaquinone 6 (MK-6). The whole genome of MMS21-Ot14T was 5 062 016 bp in length with a DNA G+C content of 37.7 %. The average nucleotide identity and digital DNA-DNA hybridisation values between MMS21-Ot14T and phylogenetically related members of the genus Chryseobacterium were well below the threshold values for species delineation. It is evident from the results of this study that MMS21-Ot14T should be classified as representing a novel species of the genus Chryseobacterium, for which the name Chryseobacterium fluminis sp. nov. (type strain, MMS21-Ot14T = KCTC 92255T = LMG 32529T) is proposed.

Extracellular G-quadruplexes and Z-DNA protect biofilms from DNase I, and G-quadruplexes form a DNAzyme with peroxidase activity.

Many bacteria form biofilms to protect themselves from predators or stressful environmental conditions. In the biofilm, bacteria are embedded in a protective extracellular matrix composed of polysaccharides, proteins and extracellular DNA (eDNA). eDNA most often is released from lysed bacteria or host mammalian cells, and it is the only matrix component most biofilms appear to have in common. However, little is known about the form DNA takes in the extracellular space, and how different non-canonical DNA structures such as Z-DNA or G-quadruplexes might contribute to its function in the biofilm. The aim of this study was to determine if non-canonical DNA structures form in eDNA-rich staphylococcal biofilms, and if these structures protect the biofilm from degradation by nucleases. We grew Staphylococcus epidermidis biofilms in laboratory media supplemented with hemin and NaCl to stabilize secondary DNA structures and visualized their location by immunolabelling and fluorescence microscopy. We furthermore visualized the macroscopic biofilm structure by optical coherence tomography. We developed assays to quantify degradation of Z-DNA and G-quadruplex DNA oligos by different nucleases, and subsequently investigated how these enzymes affected eDNA in the biofilms. Z-DNA and G-quadruplex DNA were abundant in the biofilm matrix, and were often present in a web-like structures. In vitro, the structures did not form in the absence of NaCl or mechanical shaking during biofilm growth, or in bacterial strains deficient in eDNA or exopolysaccharide production. We thus infer that eDNA and polysaccharides interact, leading to non-canonical DNA structures under mechanical stress when stabilized by salt. We also confirmed that G-quadruplex DNA and Z-DNA was present in biofilms from infected implants in a murine implant-associated osteomyelitis model. Mammalian DNase I lacked activity against Z-DNA and G-quadruplex DNA, while Micrococcal nuclease could degrade G-quadruplex DNA and S1 Aspergillus nuclease could degrade Z-DNA. Micrococcal nuclease, which originates from Staphylococcus aureus, may thus be key for dispersal of biofilm in staphylococci. In addition to its structural role, we show for the first time that the eDNA in biofilms forms a DNAzyme with peroxidase-like activity in the presence of hemin. While peroxidases are part of host defenses against pathogens, we now show that biofilms can possess intrinsic peroxidase activity in the extracellular matrix.

Study on unconfined compressive strength and deformation characteristics of chlorine saline soil

The distribution of saline soil is wide and the area is large in China. The saline soil in different regions shows their own characteristics. The saline soil of single salt is configured by adding different contents of NaCl to the loess in Xi'an. The effects of chlorine content and water content on soil strength and volume change in a large water content range was studied, and the change mechanism was analyzed by scanning electron microscopy. The results show that the strength of chloride saline soil increases with the decrease of water content. The moisture content of 12% is the critical point of strength change of chloride saline soil. When the moisture content is greater than 12%, the strength of soil decreases with the increase of salt content. When the water content is less than 12%, the strength of saline soil is 3% NaCl content > 1% NaCl content > 5% NaCl content > 0% NaCl content. The volume change of the sample consists of three parts: elastic deformation during sample pressing, volume shrinkage during water loss and salt expansion. In the absence of NaCl and 1% NaCl content, the sample was in the state of shrinkage during the loading process, in which with the decrease of moisture content shrinkage rate slowed down. The volume change rate of 3% and 5% NaCl showed an inflection point from negative to positive when the water content was 15%. When the water content is less than 12%, the saline soil with 3% NaCl content has the characteristics of high strength and unobvious salt expansion. The method of adding 3% NaCl to loess in Xi 'an area can be used to simulate the cement between soil particles, which provides a reference for artificially preparing structural soil. According to the microstructure analysis, the higher the salt content of saline soil, the smaller the soil pores, and the contact form of soil particles gradually develops from the point contact between soil particles to the salt-wrapped structure.

Monte Carlo dynamics simulation of nanoparticles for enhanced oil recovery

ABSTRACT This research used density functional theory (DFT)-based simulation software to investigate the potential of emerging nanotechnology to alter the physical–chemical interactions of a reservoir system so that a favourable condition for oil displacement could be created. This reservoir was modelled using sandstone (as rock), oil (as any of the hydrocarbon molecules including Decane, Dodecene, Tetradecene and Hexadecene), a particular type of nanoparticles (graphene (GNPs), magnetite (MNPs), zinc oxide (ZNPs), copper oxide (CNPs)) and sodium chloride (NaCl) for nanofluid. From the analysis of adsorption results, we observed that oil adsorption can be reduced to −18.81 from −28.53 Kcal/mol. This was the case for the MNPs in the absence of NaCl. In the presence of NaCl, GNPs showed better performance than others. Arguably, salinity is thus an important factor contributing to the performance of nanofluid as an enhanced oil recovery agent or specifically a wettability modifier. The main mechanisms of the enhanced changes are assumed to be the inhibition of oil adsorption and the profile control capability of GNPs.

Environmental distribution and genomic characteristics of Solirubrobacter, with proposal of two novel species.

Solirubrobacter spp. were abundant in soil samples collected from deserts and other areas with high UV radiation. In addition, a novel Solirubrobacter species, with strain CPCC 204708T as the type, was isolated and identified from sandy soil sample collected from the Badain Jaran Desert of the Inner Mongolia autonomous region. Strain CPCC 204708T was Gram-stain positive, rod-shaped, non-motile, non-spore-forming, and grew optimally at 28-30°C, pH 7.0-8.0, and in the absence of NaCl. Analysis of the 16S rRNA gene sequence of strain CPCC 204708T showed its identity within the genus Solirubrobacter, with highest nucleotide similarities (97.4-98.2%) to other named Solirubrobacter species. Phylogenetic and genomic analyses indicated that the strain was most closely related to Solirubrobacter phytolaccae KCTC 29190T, while represented a distinct species, as confirmed from physiological properties and comparison. The name Solirubrobacter deserti sp. nov. was consequently proposed, with CPCC 204708T (= DSM 105495T = NBRC 112942T) as the type strain. Genomic analyses of the Solirubrobacter spp. also suggested that Solirubrobacter sp. URHD0082 represents a novel species, for which the name Candidatus "Solirubrobacter pratensis" sp. nov. was proposed. Genomic analysis of CPCC 204708T revealed the presence of genes related to its adaptation to the harsh environments of deserts and may also harbor genes functional in plant-microbe interactions. Pan-genomic analysis of available Solirubrobacter spp. confirmed the presence of many of the above genes as core components of Solirubrobacter genomes and suggests they may possess beneficial potential for their associate plant and may be important resources for bioactive compounds.

Alicyclobacillus sp. SO9, a novel halophilic acidophilic iron-oxidizing bacterium isolated from a tailings-contaminated beach, and its effect on copper extraction from chalcopyrite in the presence of high chloride concentration

Many acidophilic iron-oxidizing bacteria used in the mining industry for the bioleaching of sulfidic minerals are intolerant to high chloride concentrations, resulting in problems where chloride occurs in the deposit at high concentrations or only seawater is available. In search for strains tolerating such conditions a tetrathionate- and iron-oxidizing bacterium was isolated from a tailings-contaminated beach sample at Portman Bay, Cartagena-La Union mining district, Spain, in the presence of 20 g l−1 (0.34 M) sodium chloride. The isolate was able to form spores, did not grow in the absence of NaCl, and oxidized ferrous iron in the presence of up to 1.5 M (∼87 g l−1) NaCl. Genome sequencing based on a combination of Illumina and PacBio reads revealed two contigs, a circular bacterial chromosome of 5.2 Mbp and a plasmid of 90 kbp, respectively. The chromosome comprised seven different 16S rRNA genes. Submission of the chromosome to the Type (Strain) Genome Server (TYGS) without preselection of similar sequences revealed exclusively type strains of the genus Alicyclobacillus. In the TYGS analyses the respective most similar species were dependent on whether the final tree was derived from just 16S rRNA, from the genomes, or from the proteomes. Thus, TYGS analysis clearly showed that isolate SO9 represents a novel species of the genus Alicyclobacillus. In the presence of artificial seawater with almost 0.6 M chloride, the addition of Alicyclobacillus sp. SO9 improved copper dissolution from chalcopyrite (CuFeS2) compared to abiotic leaching without bacteria. The new isolate SO9, therefore, has potential for bioleaching at elevated chloride concentrations.

Flavobacterium psychrotrophum sp. nov. and Flavobacterium panacagri sp. nov., Isolated from Freshwater and Soil.

Two novel bacterial strains CJ74T and CJ75T belonging to the genus Flavobacterium were isolated from freshwater of Han River and ginseng soil, South Korea, respectively. Strain CJ74T was Gram-stain-negative, aerobic, rod-shaped, non-motile, and non-flagellated, and did not produce flexirubin-type pigments. Strain CJ75T was Gram-stain-negative, aerobic, rod-shaped, motile by gliding, and non-flagellated, and produced flexirubin-type pigments. Both strains were shown to grow optimally at 30°C in the absence of NaCl on R2A medium. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains CJ74T and CJ75T belonged to the genus Flavobacterium and were most closely related to Flavobacterium niveum TAPW14T and Flavobacterium foetidum CJ42T with 96.17% and 97.29% 16S rRNA sequence similarities, respectively. Genomic analyses including the reconstruction of phylogenomic tree, average nucleotide identity, and digital DNA-DNA hybridization suggested that they were novel species of the genus Flavobacterium. Both strains contained menaquinone 6 (MK-6) as the primary respiratory quinone and phosphatidylethanolamine as a major polar lipid. The predominant fatty acids of both strains were iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). Based on the polyphasic taxonomic study, strains CJ74T and CJ75T represent novel species of the genus Flavobacterium, for which names Flavobacterium psychrotrophum sp. nov. and Flavobacterium panacagri sp. nov. are proposed, respectively. The type strains are CJ74T (=KACC 19819T =JCM 32889T) and CJ75T (=KACC 23149T =JCM 36132T).

Use of Pyrolysed Almond and Walnut Shells (PAS and PWS) for the Adsorption of Cationic Dye: Reusing Agro-Waste for Sustainable Development

Agro-wastes are recognised as a carbon-rich source, which can be converted into value-added products in sustainable development. In this study, the effect of pH, contact time, initial concentration, and ionic strength were evaluated in Methylene Blue (MB) adsorption by using an activated carbon obtained from pyrolysed almond (PAS) and walnut shells (PWS). The characterisation of PAS and PWS was conducted by SEM-EDX, FT-IR and BET analysis. The removal efficiency of 6 mg/L initial MB concentration improved from 10.6% to 50.42% for PAS, when the adsorbent dose was increased from 0.5 g to 3.5 g in 1 L dye solution. It also improved from 14.8% to 48.7% for PWS, when the adsorbent dose was increased from 0.5 g to 3.5 g. The adsorption fits well with the Freundlich isotherm model and the second-order kinetic model is more favourable. In the adsorption experiments using PWS, 48% removal efficiency was obtained in the absence of NaCl. Depending on the increasing NaCl concentration, the removal efficiencies showed a decrease. 36% removal efficiency was obtained for PWS when 2500 mg/L NaCl was used. In the adsorption experiments using PAS, 40% removal efficiency was obtained in the absence of NaCl. When 500 mg/L NaCl was used, the maximum removal efficiency improved to 48%. However, with the increase in ionic strength, removal efficiencies decreased to approximately 39%. This study revealed that PAS and PWS could be used effectively instead of commercial activated carbon, which also provides an advantageous option from an economic point of view.

Macromonas nakdongensis sp. nov., Isolated from Freshwater and Characterization of Bacteriophage BK-30P-The First Phage That Infects Genus Macromonas.

A Gram-stain-negative, non-motile, non-pigmented, rod-shaped bacterium was isolated from a freshwater sample of Nakdong River in South Korea and designated as strain BK-30T. An analysis of the 16S rRNA gene sequence of strain BK-30T revealed its closest phylogenetic neighbors were members of the genus Macromonas. Specifically, the strain formed a robust clade with Macromonas bipunctata DSM 12705T, sharing 98.4% similarity in their 16S rRNA gene sequences. The average nucleotide identity value between strain BK-30T and M. bipunctata DSM 12705T was 79.8%, and the genome-to-genome distance averaged 21.3%, indicating the representation of a novel genomic species. Strain BK-30T exhibited optimum growth at 30 °C and pH 7.0, in the absence of NaCl. The major respiratory isoprenoid quinone identified was ubiquinone-8 (Q-8). The principal fatty acids detected were C16:1ω7c and/or C16:1ω6c (49.6%), C16:0 (27.5%), and C18:1ω7c and/or C18:1 ω6c (9.2%). The DNA G+C content of the strain was determined to be 67.3 mol%. Based on these data, we propose a novel species within the genus Macromonas, named Macromonas nakdongensis sp. nov., to accommodate the bacterial isolate. Strain BK-30T is designated as the type strain (=KCTC 52161T = JCM 31376T = FBCC-B1). Additionally, we present the isolation and complete genome sequence of a lytic phage infecting strain BK-30T, named BK-30P. This bacteriophage is the first reported to infect Macromonas, leading us to propose the name "Macromonasphage".

Compatible Solutes Accumulated by &lt;i&gt;Glutamicibacter&lt;/i&gt; sp. Strain SMB32 in Response to Abiotic Environmental Factors

Abstract—Proton magnetic resonance spectroscopy was used for investigation of the pool of compatible solutes accumulated in the cells of Glutamicibacter sp. strain SMB32 in response to abiotic environmental factors. The original habitat of the strain was anthropogenically salinated soil at the Verkhnekamsk deposit of potassium and magnesium salts (Perm krai, Russia). The strain grew within the temperature range from 5 to 35°C. At 5 and 32°C, the intracellular content of trehalose in the cells of Glutamicibacter sp. SMB32 was significantly higher than at 25°C. Glutamicibacter sp. SMB32 was able to grow both in the absence of NaCl and at its concentrations up to 11%. Glutamate predominated in the cells growth without NaCl. At high salinity (8% NaCl), predominant compounds in the studied strain cells were trehalose, proline, glutamine, and glutamate. Increasing salinity of the growth medium resulted in higher levels of intracellular proline. This is the first report of ability of a Glutamicibacter strain to synthesize mannitol; its accumulation was found to depend on the aeration mode. Thus, Glutamicibacter sp. strain SMB32 possesses high metabolic plasticity and is able to adapt to the action of unfavorable physicochemical factors.

Condicionamento de sementes com peróxido de hidrogênio melhora a tolerância da alface hidropônica ao estresse salino

ABSTRACT Brackish waters has been increasingly used in hydroponic systems for the cultivation of vegetables. However, its use can cause significant losses in crop production. Therefore, new alternatives to enhance the tolerance of plants to salt stress are being studied, including seed priming with hydrogen peroxide (H2O2). Thus, this study aimed to assess the seed priming with H2O2 at different periods of exposure for enhancing the production, water status and pigments concentration of crisp lettuce grown under salt stress. The experiment was carried out under protected conditions, in a completely randomized design, with four replicates. The plants were cultivated in a floating hydroponic system, containing nutrient solution. Five treatments were tested: control (absence of H2O2 and absence of NaCl); salt control (absence of H2O2 and presence of 100 mM NaCl); 0.1 mM H2O2 (12 hours) + 100 mM NaCl; 0.1 mM H2O2 (24 hours) + 100 mM NaCl, and 0.1 mM H2O2 (36 hours) + 100 mM NaCl. In general, salinity reduced the height, production of the fresh and dry mass of the shoot, relative water content, and chlorophylls concentration of lettuce plants. However, the application of 0.1 mM H2O2 for 12 and 36 hours on the seeds, enhanced the growth, water status, and chlorophylls concentration of the plants. Seed priming with H2O2 at a 0.1 mM concentration for 12 hours can be recommended to increase tolerance of lettuce plants grown in a hydroponic system under salt stress.

Salinity and nitrogen source affect productivity and nutritional value of edible halophytes.

Saline agriculture may contribute to food production in the face of the declining availability of fresh water and an expanding area of salinized soils worldwide. However, there is currently little known about the biomass and nutrient/antinutrient accumulation response of many edible halophytes to increasing levels of salinity and nitrogen source. To address this, two glass house experiments were carried out. The first to study the shoot biomass, and nutrient accumulation response, measured by ICP-MS analysis, of edible halophyte species, including Mesembryanthemum crystallinum (ice plant), Salsola komarovii (Land seaweed), Enchylaena tomentosa (Ruby Saltbush), Crithmum maritimum (Rock Samphire), Crambe maritima (Sea Kale) and Mertensia maritima (Oyster Plant), under increasing levels of salinity (0 to 800 mM). The second experiment studied the effects of nitrogen source combined with salinity, on levels of oxalate, measured by HPLC, in ice plant and ruby saltbush. Species differences for biomass and sodium (Na), potassium (K), chloride (Cl), nitrogen (N) and phosphorus (P) accumulation were observed across the range of salt treatments (0 to 800mM). Shoot concentrations of the anti-nutrient oxalate decreased significantly in ice plant and ruby saltbush with an increase in the proportion of N provided as NH4+ (up to 100%), while shoot oxalate concentrations in ice plant and ruby saltbush grown in the absence of NaCl were not significantly different to oxalate concentrations in plants treated with 200 mM or 400 mM NaCl. However, the lower shoot oxalate concentrations observed with the increase in NH4+ came with concurrent reductions in shoot biomass. Results suggest that there will need to be a calculated tradeoff between oxalate levels and biomass when growing these plants for commercial purposes.

Heterogeneous and Photosensitized Oxidative Degradation Kinetics of the Plastic Additive Bisphenol-A in Sea Spray Aerosol Mimics.

Plastics have become ubiquitous in the world's oceans, and recent work indicates that they can transfer from the ocean to the atmosphere in sea spray aerosol (SSA). Hazardous chemical residues in plastics, including bisphenol-A (BPA), represent a sizable fraction of consumer plastics and have been measured consistently in air over both terrestrial and marine environments. However, the chemical lifetimes of BPA and mechanisms by which plastic residues degrade with respect to photochemical and heterogeneous oxidation processes in aerosols are unknown. Here, we present the photosensitized and OH-initiated heterogeneous oxidation kinetics of BPA in the aerosol phase consisting of pure-component BPA and internal mixtures of BPA, NaCl, and dissolved photosensitizing organic matter. We found that photosensitizers enhanced BPA degradation in binary-component BPA + photosensitizer aerosol mixtures when irradiated in the absence of OH. OH-initiated degradation of BPA was enhanced in the presence of NaCl with and without photosensitizing species. We attribute this enhanced degradation to greater mobility and thus reaction probability between BPA, OH, and reactive chlorine species (RCS) formed through reaction between OH and dissolved Cl- in the more liquid-like aerosol matrix in the presence of NaCl. Addition of the photosensitizers in the ternary-component BPA + NaCl + photosensitizer aerosol led to no enhancement in the degradation of BPA following light exposure compared to the binary-component BPA + NaCl aerosol. This was attributed to quenching of triplet state formation by dissolved Cl- in the less viscous aqueous aerosol mixtures containing NaCl. Based upon measured second-order heterogeneous reaction rates, the estimated lifetime of BPA with respect to heterogeneous oxidation by OH is one week in the presence of NaCl compared to 20 days in the absence of NaCl. This work highlights the important heterogeneous and photosensitized reactions and the role of phase state, which affect the lifetimes of hazardous plastic pollutants in SSA with implications for understanding pollutant transport and exposure risks in coastal marine environments.

Sphingobium lignivorans sp. nov., isolated from river sediment downstream of a paper mill.

A bacterial isolate, B1D3AT, was isolated from river sediment collected from the Hiwassee River near Calhoun, TN, by enrichment culturing with a model 5-5' lignin dimer, dehydrodivanillate, as its sole carbon source. B1D3AT was also shown to utilize several model lignin-derived monomers and dimers as sole carbon sources in a variety of minimal media. Cells were Gram-stain-negative, aerobic, motile, rod-shaped and formed yellow/cream-coloured colonies on rich agar. Optimal growth occurred at 30 °C, pH 7-8, and in the absence of NaCl. The major fatty acids of B1D3AT were C18 : 1 ω7c and C17 : 1 ω6c. The predominant hydroxy fatty acids were C14 : 0 2-OH and C15 : 0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine and sphingoglycolipid. B1D3AT contained spermidine as the only major polyamine. The major isoprenoid quinone was Q-10 with minor amounts of Q-9 and Q-11. The genomic DNA G+C content of B1D3AT was 65.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 49 core, universal genes defined by Clusters of Orthologous Groups gene families indicated that B1D3AT was a member of the genus Sphingobium. B1D3AT was most closely related to Sphingobium sp. SYK-6, with a 100 % 16S rRNA gene sequence similarity. B1D3AT showed 78.1-89.9 % average nucleotide identity and 19.5-22.2% digital DNA-DNA hybridization identity with other type strains from the genus Sphingobium. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain B1D3AT should be classified as representing a novel species of the genus Sphingobium, for which the name Sphingobium lignivorans sp. nov. is proposed. The type strain is strain B1D3AT (ATCC TSD-279T=DSM 111877T).