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Increasing soil salinity, exacerbated by climate change, threatens seed germination and crop growth, causing significant agricultural losses. Using bioinoculants based on halotolerant plant growth-promoting endophytes (PGPEs) in modern agriculture is the most promising and sustainable method for supporting plant growth under salt-stress conditions. Our study evaluated the efficacy of Pseudomonas stutzeri ISE12, an endophyte derived from the extreme halophyte Salicornia europaea, in enhancing the salinity tolerance of sorghum (Sorghum bicolor L.). We hypothesized that P. stutzeri ISE12 would improve sorghum salt tolerance to salinity, with the extent of the increase in tolerance depending on the genotype's sensitivity to salt stress. Experiments were conducted for two sorghum genotypes differing in salinity tolerance (Pegah - salt tolerant, and Payam - salt sensitive), which were inoculated with a selected bacterium at different salinity concentrations (0, 100, 150, and 200mMNaCl). For germination, we measured germination percentage and index, mean germination time, vigor, shoot and root length of seedlings, and fresh and dry weight. In pot experiments, we assessed the number of leaves, leaf area, specific leaf area, leaf weight ratio, relative root weight, plantlet shoot and root length, fresh and dry weight, proline and hydrogen peroxide concentrations, and peroxidase enzyme activity. Our study demonstrated that inoculation significantly enhanced germination and growth for both sorghum genotypes. The salinity-sensitive genotype (Payam) responded better to bacterial inoculation during germination and early seedling growth stages, showing approximately 1.4 to 1.8 times greater improvement than the salinity-tolerant genotype (Pegah). Payam also displayed better performance at the plantlet growth stage, between 1.1 and 2.6 times higher than Pegah. Furthermore, inoculation significantly reduced hydrogen peroxide, peroxidase activity, and proline levels in both sorghum genotypes. These reductions were notably more pronounced in Payam, with up to 1.5, 1.3, and 1.5 times greater reductions than in Pegah. These results highlight the efficacy of P. stutzeri ISE12 in alleviating oxidative stress and reducing energy expenditure on defense mechanisms in sorghum, particularly benefiting salt-sensitive genotypes. Our findings highlight the potential of the bacterial endophyte P. stutzeri ISE12 as a valuable bioinoculant to promote sorghum growth under saline conditions. [ABSTRACT FROM AUTHOR]

Few studies have investigated the biodegradation of microplastics in marine environments. Microorganisms that can degrade microplastics in high-salinity conditions are sought after. Therefore, we aimed to isolate a halotolerant poly(ε-caprolactone) (PCL)-degrading bacterium for applications in biotechnology. The bacterium isolated from seaside soil was identified as Bacillus gibsonii via phylogenetic analysis based on 16S rRNA gene sequences and designated as KRICT-1. We tested whether the KRICT-1 strain showed halotolerance by determining the sodium chloride (NaCl) tolerance at various concentrations. The KRICT-1 strain showed growth at up to 10% NaCl on Luria–Bertani (LB) medium agar plates and 10% NaCl in liquid LB medium, indicating that KRICT-1 can grow and produce a PCL-depolymerizing enzyme under high-salt conditions. The KRICT-1 strain could depolymerize PCL with a PCL film weight loss of 2.82% at up to 10% NaCl concentration after cultivation of 7 weeks. KRICT-1 is the first strain of B. gibsonii which shows PCL-depolymerizing activity. Scanning electron microscopy and water contact angle results confirmed the degradation of PCL by the KRICT-1 strain. The extracellular enzyme produced by the KRICT-1 strain was stable over a wide range of temperatures (15–40 °C) and pH (7.0–9.5). This halotolerant PCL-degrading bacterium can be used in the degradation of biodegradable plastics present in saline soils, saline water, and wastewater. [ABSTRACT FROM AUTHOR]

An aerobic, Gram-stain negative bacterium was isolated from sediment samples of Barkol salt lake in Hami City, Xinjiang Uygur Autonomous Region, China, with the number EGI_FJ10229T. The strain is ellipse-shaped, oxidase-negative, catalase-positive, and has white, round, smooth, opaque colonies on marine 2216 E agar plate. Growth occurs at 4.0–37.0 ℃ (optimal:30.0 ℃), pH 7.0–9.0 (optimal: pH 8.0) and NaCl concentration of 0–8.0% (optimal: 3.0%). Phylogenetic analysis based on 16S rRNA gene and genome sequences indicated that the isolated strain should be assigned to the genus Aquibaculum and was most closely related to Aquibaculum arenosum CAU 1616 T. Average nucleotide identity (ANI) and Average amino-acid identity (AAI) values between the type species of the genus Aquibaculum and other related type species were lower than the threshold values recommended for bacterial species. The genomic DNA G + C content of EGI_FJ10229T was 65.41%. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylcholine, phosphatidylethanolamine and unidentified phospholipid. The major fatty acids (> 5%) were C19:0 cyclo ω8c (42.0%) and C18:1ω7c (33.78%). The respiratory quinone identified was Q-10. Differential phenotypic and genotypic characteristics of this strain and species of genus Aquibaculum showed that the strain should be classified as representing a new species belonging to this genus, for which the name Aquibaculum sediminis sp. nov. is proposed. The type strain of the proposed novel species is EGI_FJ10229T (= KCTC 8570 T = GDMCC 1.4598 T). [ABSTRACT FROM AUTHOR]

Increasing soil salinity, exacerbated by climate change, threatens seed germination and crop growth, causing significant agricultural losses. Using bioinoculants based on halotolerant plant growth-promoting endophytes (PGPEs) in modern agriculture is the most promising and sustainable method for supporting plant growth under salt-stress conditions. Our study evaluated the efficacy of Pseudomonas stutzeri ISE12, an endophyte derived from the extreme halophyte Salicornia europaea, in enhancing the salinity tolerance of sorghum (Sorghum bicolor L.). We hypothesized that P. stutzeri ISE12 would improve sorghum salt tolerance to salinity, with the extent of the increase in tolerance depending on the genotype’s sensitivity to salt stress. Experiments were conducted for two sorghum genotypes differing in salinity tolerance (Pegah - salt tolerant, and Payam - salt sensitive), which were inoculated with a selected bacterium at different salinity concentrations (0, 100, 150, and 200 mM NaCl). For germination, we measured germination percentage and index, mean germination time, vigor, shoot and root length of seedlings, and fresh and dry weight. In pot experiments, we assessed the number of leaves, leaf area, specific leaf area, leaf weight ratio, relative root weight, plantlet shoot and root length, fresh and dry weight, proline and hydrogen peroxide concentrations, and peroxidase enzyme activity. Our study demonstrated that inoculation significantly enhanced germination and growth for both sorghum genotypes. The salinity-sensitive genotype (Payam) responded better to bacterial inoculation during germination and early seedling growth stages, showing approximately 1.4 to 1.8 times greater improvement than the salinity-tolerant genotype (Pegah). Payam also displayed better performance at the plantlet growth stage, between 1.1 and 2.6 times higher than Pegah. Furthermore, inoculation significantly reduced hydrogen peroxide, peroxidase activity, and proline levels in both sorghum genotypes. These reductions were notably more pronounced in Payam, with up to 1.5, 1.3, and 1.5 times greater reductions than in Pegah. These results highlight the efficacy of P. stutzeri ISE12 in alleviating oxidative stress and reducing energy expenditure on defense mechanisms in sorghum, particularly benefiting salt-sensitive genotypes. Our findings highlight the potential of the bacterial endophyte P. stutzeri ISE12 as a valuable bioinoculant to promote sorghum growth under saline conditions.

Soil salinization is a critical issue that not only hampers the efficiency and sustainability of global agricultural production but also poses significant challenges to the achievement of sustainable development goals across environmental, economic, and social dimensions. Halotolerant plant growth-promoting rhizobacteria (HPGPR) have the potential to mitigate abiotic stress, foster plant growth, and bolster the stress resistance capabilities of crops. This study conducted the isolation, identification, and characterization of HPGPR originating from a saline-alkali orchard area in northwest China. The efficacy of the isolated bacterial strains was evaluated through potted plant experiments, assessing the growth of tomato plants under in vitro conditions and under varying salinity stress. Ultimately, the study investigated the influence of these HPGPR on soil physicochemical properties, enzymatic activities, and the structure and composition of the microbial community. Upon isolating 12 bacterial strains, we conducted an in vitro assessment of their salt tolerance, ultimately singling out three robust isolates, which exhibited exceptional salt tolerance. Detailed 16S rRNA gene sequencing and meticulous taxonomic evaluation systematically assigned these isolates to Priestia endophyticus GSCK1 (accession number: OR569048), Bacillus atrophaeus GSCK2 (accession number: OR569061), and Serratia fonticola GSCK6 (accession number: OR569062), respectively. These strains exhibited notable biochemical and plant growth-promoting traits, including enzymatic activities and the production of indole-3-acetic acid. They significantly enhanced plant growth metrics and soil fertilities, particularly strain GSCK6, which also reshaped the soil microbial community, augmenting beneficial microbe abundance. The HPGPR treatment notably improved soil pH, nutrient availability, enzymatic activities, and reduced soil electrical conductivity, underscoring their potential in agricultural resilience against salinity. The eco-friendly salt stress mitigation strategy of HPGPR not only enhances soil quality and promotes plant growth by regulating the composition and function of microbial communities, but also provides a novel solution for global agricultural production. This approach is conducive to increasing crop yield and quality, reducing the limitations of saline-alkali land on agricultural production, and promoting food security and sustainable agricultural development.

Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the soil resource. In the present study, we explored the diversity of halophilic and halotolerant microorganisms in the arable fraction of a sodic–saline soil without agricultural practices and two soils with agricultural practices (one sodic and one saline) near the geothermal area "Los Negritos" in Villamar, Michoacán state. This was achieved through their isolation and molecular identification, as well as the characterization of their potential for the production of metabolites and enzymes of biotechnological interest under saline conditions. Using culture-dependent techniques, 62 halotolerant and moderately halophilic strains belonging to the genera Bacillus, Brachybacterium, Gracilibacillus, Halobacillus, Halomonas, Kocuria, Marinococcus, Nesterenkonia, Oceanobacillus, Planococcus, Priestia, Salibactetium, Salimicrobium, Salinicoccus, Staphylococcus, Terribacillus, and Virgibacillus were isolated. The different strains synthesized hydrolytic enzymes under 15% (w/v) of salts, as well as metabolites with plant-growth-promoting (PGP) characteristics, such as indole acetic acid (IAA), under saline conditions. Furthermore, the production of biopolymers was detected among the strains; members of Bacillus, Halomonas, Staphylococcus, and Salinicoccus showed extracellular polymeric substance (EPS) production, and the strain Halomonas sp. LNSP3E3-1.2 produced polyhydroxybutyrate (PHB) under 10% (w/v) of total salts. [ABSTRACT FROM AUTHOR]

The degradation of azo dyes by conventional methods has proven ineffective due to their complex structure and synthetic nature. Bioremediation of azo dye containing textile wastewater requires an appropriate selection of potential strains to address its potential hazards. This study focuses on the biodegradation of azo dyes containing textile wastewater by isolating halotolerant bacterial strains from marine coastal soil. The rapid degradation of model dye Mordant Yellow 10 (MY10) was monitored spectrophotometrically and it was found that decolorization of MY10 by isolated strains Bacillus firmus (BA01), Pseudomonas aeroginosa (BRPO3), and Bacillus cereus (BRPO4) and mixed consortium CMBS follows zero-, second-, first-, and one-and-a-half-order kinetics, respectively. Through the batch kinetic analysis of MY10 degradation, it was observed that bacterial strain Pseudomonas aeroginosa BRPO3 was more effective with reaction rate constant and half-life as 1,024±213×10−2 mM−1 day−1 and 0.3±0.1 day , respectively. Further kinetic analysis using BRPO3 helps describe that initial dye and glucose concentration were the driving forces of the dye degradation reaction and thus were used to construct kinetic rate equation. Using a stepwise protocol, this kinetic model was applied to calculate the design parameters including optimal height and working volume of an upflow anaerobic packed bed (UAPB) reactor as 0.95 m and 4.78 L, respectively, for 85% dye conversion. Design was validated by evaluating the performance of the newly fabricated UAPB reactor for treatment of simulated wastewater containing MY10 and real textile wastewater. Complete dye removal and 94.5% total organic carbon (TOC) reduction were observed with simulated wastewater, whereas in real textile effluent 82.5% dye removal and 89% TOC reduction were achieved. Thus, the predicted results corresponded satisfactorily with the experimental data in both wastewater treatments. This study highlights the usefulness of analyzing biodegradation kinetics to improve both the construction of microbial consortia and the development of reactors for wastewater treatments in the context of bioeconomy. [ABSTRACT FROM AUTHOR]

Inflammation-related diseases are major causes of mortality and disability worldwide. This study aimed to identify and investigate probiotic bacteria that could be present in Al-Asfar Lake in Al-Ahsa City, Saudi Arabia to prevent the inflammatory responses of carrageenan-induced paw edema. In total, seven active strains were isolated, and three isolates (ASF-1, ASF-2, and ASF-3) exhibited a positive Gram stain and viable growth at 20% NaCl salinity; they also lacked catalase and hemolytic activities and had high levels of cell surface hydrophobicity (CSH). They also demonstrated potent antibacterial activity against Salmonella typhi and Staphylococcus aureus. These results revealed that ASF-2 had probiotic qualities, and it was selected for further research. ASF-2 demonstrated significant anti-inflammatory effects in an experimental model of carrageenan-induced paw edema; the experimental model showed decreased levels of pro-inflammatory markers, such as interleukin 6 (IL-6), interleukin 17 (IL-17), and transforming growth factor-β (TGF-β), and an increased level of an anti-inflammatory marker (interferon gamma (IFN-γ)). Animals in the control group saw a 45% decrease in edema when compared to mice in the carrageenan group. When comparing tissue damage and infiltration in the ASF-2-treated and non-treated mice, the histological examination of the sub-planar tissues of the hind leg revealed that the inflamed tissues had healed. The 16S rRNA sequencing method was utilized to establish that ASF-2 is, in fact, Enterococcus lactis with a 99.2% sequence similarity. These findings shed further light on ASF-2's potential as a biocompatible anti-inflammatory medication. [ABSTRACT FROM AUTHOR]

Introduction: Adverse abiotic environmental conditions including excess salt in the soil, constantly challenge plants and disrupt the function of plants, even inflict damage on plants. Salt stress is one of the major limiting factors for agricultural productivity and severe restrictions on plant growth. One of the critical ways to improve plant salt tolerance is halotolerant bacteria application. However, few such halotolerant bacteria were known and should be explored furtherly. Methods: Halophilic bacterium strain was isolated from saline soil with serial dilution and identified with classical bacteriological tests and 16S rRNA analysis. Perennial ryegrass (Lolium perenne L) was used in this study to evaluate the potential effect of the bacteria. Results and discussion: A halophilic bacterium strain GDHT17, was isolated from saline soil, which grows in the salinities media with 1.0%, 5.0%, and 10.0% (w/v) NaCl, and identified as Gracilibacillus dipsosauri. Inoculating GDHT17 can significantly promote ryegrass’s seedling height and stem diameter and increase the root length, diameter, and surface area at different salt concentrations, indicating the significant salt stress alleviating effect of GDHT17 on the growth of ryegrass. The alleviating effect on roots growth showed more effective, especially on the root length, which increased significantly by 26.39%, 42.59%, and 98.73% at salt stress of 100 mM, 200 mM, and 300 mM NaCl when the seedlings were inoculated with GDHT17. Inoculating GDHT17 also increases perennial ryegrass biomass, water content, chlorophyll and carotenoid content under salt stress. The contents of proline and malonaldehyde in the seedlings inoculated with GDHT17 increased by 83.50% and 6.87%, when treated with 300 mM NaCl; however, the contents of MDA and Pro did not show an apparent effect under salt stress of 100 mM or 200 mM NaCl. GDHT17-inoculating maintained the Na+/K+ ratio in the salt-stressed ryegrass. The Na+/K+ ratio decreased by 26.52%, 6.89%, and 29.92% in the GDHT17-inoculated seedling roots treated with 100 mM, 200 mM, and 300 mM NaCl, respectively. The GDHT17-inoculating increased the POD and SOD activity of ryegrass seedlings by 25.83% and 250.79%, respectively, at a salt stress of 300 mM NaCl, indicating the properties of GDHT17, improving the activity of antioxidant enzymes of ryegrass at the salt-stress condition. Our results suggest that G. dipsosauri GDHT17 may alleviate salt stress on ryegrass in multiple ways; hence it can be processed into microbial inoculants to increase salt tolerance of ryegrass, as well as other plants in saline soil. [ABSTRACT FROM AUTHOR]

Azo dyes are a significant class of hazardous chemicals that are extensively utilised in diverse industries. Industries that manufacture and consume reactive azo dyes generate hyper-saline wastewater. The ability of halotolerant bacteria to thrive under extreme environmental conditions thus makes them a potential candidate for reactive azo dye degradation. An efficient halotolerant bacterium (isolate SAIBP-6) with the capability to degrade 87.15% of azo dye Reactive Red 195 (RR-195) was isolated from sea sediment and identified as Halomonas meridiana SAIBP-6. Strain SAIBP-6 maintained potential decolourisation under a wide range of environmental conditions viz. 35–45°C temperature, 50–450 mg/L RR-195, pH 7–9, and 50–150 g/L NaCl. However, maximum decolourisation occurred at 40°C, 200 mg/L RR-195 dye, pH 9, and 50 g/L NaCl, under static conditions. Tyrosinase and azoreductase were responsible for dye degradation. The reaction catalysed by these enzymes followed zero-order kinetics. The maximum velocity ( V max ) of the enzymatic reaction was 4.221 mg/(L.h) and the Michaelis constant ( K m ) was 517.982 mg/L. Strain SAIBP-6 also efficiently decolourised Reactive Black-5 and Reactive Yellow-160 dye. The biodegradation process was further studied with the help of UV–Vis spectral scan, ultra-high performance liquid chromatography (UPLC), fourier-transform infra-red spectroscopy (FT–IR), and proton nuclear magnetic resonance (1H NMR) analysis. Finally, cytogenotoxicity assay conducted with the meristematic root tip cells of Allium cepa and phytotoxicity assay conducted with the seeds of Vigna mungo led to the inference that strain SAIBP-6 significantly reduced the toxicity of RR-195 after biodegradation. [ABSTRACT FROM AUTHOR]

Bacterial L-asparaginase (LA) is a chemotherapeutic drug that has remained mainstay of cancer treatment for several decades. LA has been extensively used worldwide for the treatment of acute lymphoblastic leukemia (ALL). A halotolerant bacterial strain Bacillus licheniformis sp. isolated from marine environment was used for LA production. The enzyme produced was subjected to purification and physico-chemical characterisation. Purified LA was thermotolerant and demonstrated more than 90% enzyme activity after 1 h of incubation at 80 °C. LA has also proved to be resistant against pH gradient and retained activity at pH ranging from 3.0 to 10. The enzyme also had high salinity tolerance with 90% LA activity at 10% NaCl concentration. Detergents like Triton X-100 and Tween-80 were observed to inhibit LA activity while more than 70% catalytic activity was maintained in the presence of metals. Electrophoretic analysis revealed that LA is a heterodimer (~ 63 and ~ 65 kDa) and has molecular mass of around 130 kDa in native form. The kinetic parameters of LA were tested with LA having low Km value of 1.518 µM and Vmax value of 6.94 µM/min/mL. Purified LA has also exhibited noteworthy antiproliferative activity against cancer cell lines—HeLa, SiHa, A549, and SH-SY-5Y. In addition, bench-scale LA production was conducted in a 5-L bioreactor using moringa leaves as cost-effective substrate. [ABSTRACT FROM AUTHOR]

The peculiarities of manifestation of hydrolytic activity of haloalkalitolerant bacteria Pseudomonas peli 3-T, Microbacterium kitamiense 16-DB, and Bacillus aequororis 5-DB, isolated from the ground of the territory of soda sludge storage and the soda sludge of the operating sludge reservoir of AO Berezniki Soda Plant (Perm krai, Russia) were studied. It was demonstrated that the maximum activities of extracellular lipases and amylases of three bacteria studied were manifested at pH 11 and a high concentration of sodium chloride (50–200 g/L). The cultivation of P. peli 3-T on a mineral medium with 0.5% glycerol (a source of carbon) and 0.03% urea (a source of nitrogen) allows us to obtain a biomass (6.9 g/L) and activity of extracellular (1.26 U/L) and cell-associated lipase (3.02 U/mg dry cells) with a high economic coefficient of substrate consumption (138%). The efficiency of immobilization of P. peli 3-T and B. aequororis 5-DB cells for use in lipid and starch biotransformation was demonstrated. The P. peli 3-T cells immobilized by adsorption on kaolin and entrapped into barium alginate and agarose gel preserved from 40.4 to 63.8% of the activity of cell lipase in the suspension. The B. aequororis 5-DB cells immobilized by adsorption on kaolin preserved 42.5% of lipase and 90.7% of amylase activity as compared with the initial ones. At the same time, the activities of the studied P. peli 3-T and B. aequororis 5-DB enzymes were preserved during six consecutive reactions. The amylase activity of immobilized M. kitamiense 16-DB cells during adsorption on kaolin and chitosan decreased to 2.7–3.5% of the initial one and was completely inhibited during immobilization by the entrapment into barium alginate or agarose gels. [ABSTRACT FROM AUTHOR]

Amid climate change, heatwave events are expected to increase in frequency and severity. As a result, yield losses in viticulture due to heatwave stress have increased over the years. As one of the most important crops in the world, an eco-friendly stress mitigation strategy is greatly needed. The present work aims to evaluate the physiological fitness improvement by two marine plant growth-promoting rhizobacteria consortia in Vitis vinifera cv. Antão Vaz under heatwave conditions. To assess the potential biophysical and biochemical thermal stress feedback amelioration, photochemical traits, pigment and fatty acid profiles, and osmotic and oxidative stress biomarkers were analysed. Bioaugmented grapevines exposed to heatwave stress presented a significantly enhanced photoprotection capability and higher thermo-stability, exhibiting a significantly lower dissipation energy flux than the non-inoculated plants. Additionally, one of the rhizobacterial consortia tested improved light-harvesting capabilities by increasing reaction centre availability and preserving photosynthetic efficiency. Rhizobacteria inoculation expressed an osmoprotectant promotion, revealed by the lower osmolyte concentration while maintaining leaf turgidity. Improved antioxidant mechanisms and membrane stability resulted in lowered lipid peroxidation product formation when compared to non-inoculated plants. Although the consortia were found to differ significantly in their effectiveness, these findings demonstrate that bioaugmentation induced significant heatwave stress tolerance and mitigation. This study revealed the promising usage of marine PGPR consortia to promote plant fitness and minimize heatwave impacts in grapevines. [ABSTRACT FROM AUTHOR]

Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the soil resource. In the present study, we explored the diversity of halophilic and halotolerant microorganisms in the arable fraction of a sodic–saline soil without agricultural practices and two soils with agricultural practices (one sodic and one saline) near the geothermal area “Los Negritos” in Villamar, Michoacán state. This was achieved through their isolation and molecular identification, as well as the characterization of their potential for the production of metabolites and enzymes of biotechnological interest under saline conditions. Using culture-dependent techniques, 62 halotolerant and moderately halophilic strains belonging to the genera Bacillus, Brachybacterium, Gracilibacillus, Halobacillus, Halomonas, Kocuria, Marinococcus, Nesterenkonia, Oceanobacillus, Planococcus, Priestia, Salibactetium, Salimicrobium, Salinicoccus, Staphylococcus, Terribacillus, and Virgibacillus were isolated. The different strains synthesized hydrolytic enzymes under 15% (w/v) of salts, as well as metabolites with plant-growth-promoting (PGP) characteristics, such as indole acetic acid (IAA), under saline conditions. Furthermore, the production of biopolymers was detected among the strains; members of Bacillus, Halomonas, Staphylococcus, and Salinicoccus showed extracellular polymeric substance (EPS) production, and the strain Halomonas sp. LNSP3E3-1.2 produced polyhydroxybutyrate (PHB) under 10% (w/v) of total salts.

This study aimed to screen and characterize halotolerant bacterial isolates, which could enhance plant growth performance in saline soil. Halotolerant bacteria was isolated from weeds rhizosphere grown in saline soil of coastal agricultural land located at Brondong District, Lamongan Regency, East Java Province, Indonesia. This research was conducted from June to September 2018. Seven bacterial isolates can grow in a Nutrient Agar medium containing 10% of NaCl, suggesting that these bacteria were halotolerant. Furthermore, all bacterial isolates were shown to produce indol acetic acid (IAA) and do not induce a hypersensitive response when infiltrated into tobacco leaves. These results explain that these bacteria had potency as plant growth-promoting rhizobacteria (PGPR) and were not tend to be the plant pathogen. The growth of seedlings when inoculated in cucumber seed grown in saline media were higher than those in control. This result suggests that the halotolerant bacteria can enhance the development of cucumber seedlings in saline stress conditions. Three potential halotolerant bacteria i.e., SN22, SN23, SN26 were selected and molecularly identified as Bacillus megaterium, Bacillus sp., and B. megaterium, respectively.

Salinity is one of the major environmental abiotic stress factors that limit the growth and yield of crop plants worldwide. It is crucial to understand the importance of several adaptive mechanisms in plants toward salt stress so as to increase agricultural productivity. Plant resilience toward salinity stress is improved by cohabiting with diverse microorganisms, especially bacteria. In the last few decades, increasing attention of researchers has focused on bacterial communities for promoting plant growth and fitness. The biotechnological applications of salt-tolerant plant growth-promoting rhizobacteria (PGPR) gained widespread interest for their numerous metabolites. This review provides novel insights into the importance of halotolerant (HT) bacteria associated with crop plants in enhancing plant tolerance toward salinity stress. Furthermore, the present review highlights several challenges of using HT-PGPR in the agricultural field and possible solutions to overcome those challenges for sustainable agriculture development in the future. [ABSTRACT FROM AUTHOR]

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In recent decades, membrane bioreactor (MBR) has been prevalently employed to treat high-saline organic wastewater, where the halotolerant microorganisms should be intensively utilized. However, limited works were devoted to investigating the biofouling characteristics from the perspective of the relationship between halotolerant bacteria and salts. This work filled the knowledge gap by exploring the biofouling formation mechanisms affected by high salinity. The results showed that the amount of negative charge on halotolerant bacteria surface was significantly reduced by high content of NaCl, probably leading to the obvious cell agglomeration. Despite the normal proliferation, the halotolerant bacteria still produced substantial EPS triggered by high salinity. Compared with the case of control without salt addition, the enhanced biofouling development was observed under high-saline conditions, with the fouling mechanism dramatically transformed from cake filtration to intermediate blocking. It was inferred that the halotolerant bacteria initially adhered on membrane created an extra filter layer, which contributed to the subsequent NaCl retention, resulting in the simultaneous occurrences of pore blockage and cake layer formation because of NaCl deposition both on membrane pores as well as on biofilm layer. Under high-saline environment, remarkable salt crystallization occurred on the biofilm layer, with more protein secreted by the attached halotolerant bacteria. Consequently, the potential mechanisms for the enhanced biofouling formation influenced by high salinity were proposed, which should provide new insights and enlightenments on fouling control strategies for MBR operation when treating high-saline organic wastewater. [Display omitted] • Relationship between halotolerant bacteria and NaCl during filtration was identified. • High salinity enhanced biofouling formation with salt crystals formed on biofilm. • Fouling mechanism shifted from cake filtration to intermediate blocking by NaCl. • Potential biofouling mechanisms under high salinity were proposed. • This study offers new insights into MBR biofouling in treating high-saline wastewaters. [ABSTRACT FROM AUTHOR]

Inflammation-related diseases are major causes of mortality and disability worldwide. This study aimed to identify and investigate probiotic bacteria that could be present in Al-Asfar Lake in Al-Ahsa City, Saudi Arabia to prevent the inflammatory responses of carrageenan-induced paw edema. In total, seven active strains were isolated, and three isolates (ASF-1, ASF-2, and ASF-3) exhibited a positive Gram stain and viable growth at 20% NaCl salinity; they also lacked catalase and hemolytic activities and had high levels of cell surface hydrophobicity (CSH). They also demonstrated potent antibacterial activity against Salmonella typhi and Staphylococcus aureus. These results revealed that ASF-2 had probiotic qualities, and it was selected for further research. ASF-2 demonstrated significant anti-inflammatory effects in an experimental model of carrageenan-induced paw edema; the experimental model showed decreased levels of pro-inflammatory markers, such as interleukin 6 (IL-6), interleukin 17 (IL-17), and transforming growth factor-β (TGF-β), and an increased level of an anti-inflammatory marker (interferon gamma (IFN-γ)). Animals in the control group saw a 45% decrease in edema when compared to mice in the carrageenan group. When comparing tissue damage and infiltration in the ASF-2-treated and non-treated mice, the histological examination of the sub-planar tissues of the hind leg revealed that the inflamed tissues had healed. The 16S rRNA sequencing method was utilized to establish that ASF-2 is, in fact, Enterococcus lactis with a 99.2% sequence similarity. These findings shed further light on ASF-2’s potential as a biocompatible anti-inflammatory medication.

Salinity is one of the major environmental abiotic stress factors that limit the growth and yield of crop plants worldwide. It is crucial to understand the importance of several adaptive mechanisms in plants toward salt stress so as to increase agricultural productivity. Plant resilience toward salinity stress is improved by cohabiting with diverse microorganisms, especially bacteria. In the last few decades, increasing attention of researchers has focused on bacterial communities for promoting plant growth and fitness. The biotechnological applications of salt-tolerant plant growth-promoting rhizobacteria (PGPR) gained widespread interest for their numerous metabolites. This review provides novel insights into the importance of halotolerant (HT) bacteria associated with crop plants in enhancing plant tolerance toward salinity stress. Furthermore, the present review highlights several challenges of using HT-PGPR in the agricultural field and possible solutions to overcome those challenges for sustainable agriculture development in the future.

The focus of the current study was the use of sewage wastewater to obtain PHA from a co-culture to produce a sustainable polymer. Two halotolerant bacteria, Bacillus halotolerans 14SM (MZ801771) and Bacillus aryabhattai WK31 (MT453992), were grown in a consortium to produce PHA. Sewage wastewater (SWW) was used to produce PHA, and glucose was used as a reference substrate to compare the growth and PHA production parameters. Both bacterial strains produced PHA in monoculture, but a copolymer was obtained when the co-cultures were used. The co-culture accumulated a maximum of 54% after 24 h of incubation in 10% SWW. The intracellular granules indicated the presence of nucleation sites for granule initiation. The average granule size was recorded to be 231 nm; micrographs also indicated the presence of extracellular polymers and granule-associated proteins. Fourier transform infrared spectroscopy (FTIR) analysis of the polymer produced by the consortium showed a significant peak at 1731 cm−1, representing the C=O group. FTIR also presented peaks in the region of 2800 cm−1 to 2900 cm−1, indicating C-C stretching. Proton nuclear magnetic resonance (1HNMR) of the pure polymer indicated chemical shifts resulting from the proton of hydroxy valerate and hydroxybutyrate, confirming the production of poly(3-hydroxybutyrate-co-3-hydroxy valerate) (P3HBV). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay showed that the copolymer was biocompatible, even at a high concentration of 5000 µg mL−1. The results of this study show that bacterial strains WK31 and 14SM can be used to synthesize a copolymer of butyrate and valerate using the volatile fatty acids present in the SWW, such as propionic acid or pentanoic acid. P3HBV can also be used to provide an extracellular matrix for cell-line growth without causing any cytotoxic effects. [ABSTRACT FROM AUTHOR]

A lactobionic acid (LBA)-producing bacterium isolated from seaside soils was identified as Acinetobacter halotolerans and designated as strain KRICT-1. We determined whether KRICT-1 can produce LBA at high salt concentrations. The KRICT-1 strain grew on a nutrient broth (NB) agar plate with up to 7.0% NaCl, indicating high NaCl tolerance, and 30 °C was the optimum growth temperature for LBA production. We produced LBA using the KRICT-1 strain in NB medium containing various concentrations of NaCl. While Pseudomonas taetrolens, an efficient LBA-producing bacterium, could produce LBA with up to 5.5% NaCl, the KRICT-1 strain could produce LBA at up to 7.0% NaCl and produced more LBA than P. taetrolens with over 5.5% NaCl. We produced LBA using NB medium containing 7.0% NaCl by batch fermentation of the KRICT-1 strain in a 5 L fermenter. The LBA production titer and productivity of the KRICT-1 strain were 32.1 g/L and 0.22 g/L/h, respectively, which were approximately 1.35- and 1.38-fold higher than those (23.7 g/L and 0.16 g/L/h) obtained from flask culture. Additionally, quinoprotein glucose dehydrogenase is an LBA-producing enzyme in A. halotolerans. We demonstrated that the A. halotolerans KRICT-1 strain is appropriate for LBA production at high salt concentrations. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs), as persistent organic contaminants, are a major source of concern due to their toxic effect on ecosystems and human health. This study attempted to isolate halotolerant PAHs degrading bacteria from saline oil-contaminated soils. Among the isolates, strain KDI with the highest 16S rRNA gene sequence similarity to Labedella gwakjiensis was able to reduce surface tension (ST) from 65.42 to 26.60 mN m−1 and increase the emulsification index to 81.04%, as a result of significant biosurfactant production. Response Surface Methodology (RSM) analysis was applied to optimize the factors, i.e. PAHs concentration and NaCl concentration as well as to determine the effect of these important variables on PAHs biodegradation. The Carbon Quantum Dots. Iron Oxide (CQDs.Fe3O4) nanoparticles were characterized by several popular analytical techniques, after which the effect of CQD.Fe3O4 nanoparticles on biodegradation was examined. PAHs biodegradation rate and efficiency of strain KDI to degrade PHE in the presence of CQD.Fe3O4 nanoparticles was analyzed by GC. According to the results during biodegradation both the concentration of PAHs and the amount of NaCl were effective. The biodegradation rate significantly increased in the presence of CQD.Fe3O4. The highest biodegradation of PHE occurred in the presence of 0.5 g/L of CQD.Fe3O4 which was 63.63% and 81.77% after 48 and 72 h of incubation. To the best of our knowledge, this is the first report on optimization of PAHs concentration and salinity by RSM and nanobioremediation of PHE using a bacterial strain in the presence of CQD.Fe3O4 nanoparticles. [ABSTRACT FROM AUTHOR]

Perchlorate is a contaminant that can persist in groundwater and soil, and is frequently detected in different ecosystems at concentrations relevant to human health. This study isolated and characterised halotolerant bacteria that can potentially perform perchlorate reduction. Bacterial microorganisms were isolated from marine sediments on Deception, Horseshoe and Half Moon Islands of Antarctica. The results of the 16S ribosomal RNA (rRNA) gene sequence analysis indicated that the isolates were phylogenetically related to Psychrobacter cryohalolentis, Psychrobacter urativorans, Idiomarina loihiensis, Psychrobacter nivimaris, Sporosarcina aquimarina and Pseudomonas lactis. The isolates grew at a sodium chloride concentration of up to 30% and a perchlorate concentration of up to 10,000 mg/L, which showed their ability to survive in saline conditions and high perchlorate concentrations. Between 21.6 and 40% of perchlorate was degraded by the isolated bacteria. P. cryohalolentis and P. urativorans degraded 30.3% and 32.6% of perchlorate, respectively. I. loihiensis degraded 40% of perchlorate, and P. nivimaris, S. aquimarina and P. lactis degraded 22%, 21.8% and 21.6% of perchlorate, respectively. I. loihiensis had the highest reduction in perchlorate, whereas P. lactis had the lowest reduction. This study is significant as it is the first finding of P. cryohalolentis and. P. lactis on the Antarctic continent. In conclusion, these bacteria isolated from marine sediments on Antarctica offer promising resources for the bioremediation of perchlorate contamination due to their ability to degrade perchlorate, showing their potential use as a biological system to reduce perchlorate in high-salinity ecosystems. [ABSTRACT FROM AUTHOR]

Increasing soil salinity, exacerbated by climate change, threatens seed germination and crop growth, causing significant agricultural losses. Using bioinoculants based on halotolerant plant growth-promoting endophytes (PGPEs) in modern agriculture is the most promising and sustainable method for supporting plant growth under salt-stress conditions. Our study evaluated the efficacy of Pseudomonas stutzeri ISE12, an endophyte derived from the extreme halophyte Salicornia europaea , in enhancing the salinity tolerance of sorghum ( Sorghum bicolor L.). We hypothesized that P. stutzeri ISE12 would improve sorghum salt tolerance to salinity, with the extent of the increase in tolerance depending on the genotype's sensitivity to salt stress. Experiments were conducted for two sorghum genotypes differing in salinity tolerance (Pegah - salt tolerant, and Payam - salt sensitive), which were inoculated with a selected bacterium at different salinity concentrations (0, 100, 150, and 200 mM NaCl). For germination, we measured germination percentage and index, mean germination time, vigor, shoot and root length of seedlings, and fresh and dry weight. In pot experiments, we assessed the number of leaves, leaf area, specific leaf area, leaf weight ratio, relative root weight, plantlet shoot and root length, fresh and dry weight, proline and hydrogen peroxide concentrations, and peroxidase enzyme activity. Our study demonstrated that inoculation significantly enhanced germination and growth for both sorghum genotypes. The salinity-sensitive genotype (Payam) responded better to bacterial inoculation during germination and early seedling growth stages, showing approximately 1.4 to 1.8 times greater improvement than the salinity-tolerant genotype (Pegah). Payam also displayed better performance at the plantlet growth stage, between 1.1 and 2.6 times higher than Pegah. Furthermore, inoculation significantly reduced hydrogen peroxide, peroxidase activity, and proline levels in both sorghum genotypes. These reductions were notably more pronounced in Payam, with up to 1.5, 1.3, and 1.5 times greater reductions than in Pegah. These results highlight the efficacy of P. stutzeri ISE12 in alleviating oxidative stress and reducing energy expenditure on defense mechanisms in sorghum, particularly benefiting salt-sensitive genotypes. Our findings highlight the potential of the bacterial endophyte P. stutzeri ISE12 as a valuable bioinoculant to promote sorghum growth under saline conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Rajabi Dehnavi, Piernik, Ludwiczak, Szymańska, Ciarkowska, Cárdenas Pérez and Hrynkiewicz.)

Technologies for removing azo dyes from textile wastewater have attracted increasing attention. In this study, a biological method was developed using the halotolerant bacterial consortium DAS, which was isolated from an activated sludge sample. Under optimal conditions (i.e., 40℃, pH 6.0, 15% salinity and 400 mg·L−1 peptone), the degradation rate of Brilliant Crocein (BC) (500 mg·L−1 initial concentration) was 70.67 mg·L−1·h−1, with a removal percentage of 97.43±0.15% after an incubation period of 3 days. Growth-based characterizations showed that the addition of peptone as a cosubstrate facilitated degradation by enhancing metabolic activity and increasing the total bacterial biomass. 16 S rRNA-based gene analysis showed that the addition of peptone did not increase the abundance of degrading functional bacteria in the halotolerant bacterial community DAS. The degradation could be carried out in mediums with high salinity (up to 25%), enabling direct treatment of textile wastewater without the need for the dilution step. This biological method is promising for constructing an efficient and environmentally friendly technology for textile wastewater treatment. [Display omitted] • The biological method was efficient under high salinity (up to 25%). • The co-substrate peptone promoted the biodegradation of azo dye. • Adding peptone enhanced metabolic activity and increased total bacterial biomass. [ABSTRACT FROM AUTHOR]

This study aimed to screen and characterize halotolerant bacterial isolates, which could enhance plant growth performance in saline soil. Halotolerant bacteria was isolated from weeds rhizosphere grown in saline soil of coastal agricultural land located at Brondong District, Lamongan Regency, East Java Province, Indonesia. This research was conducted from June to September 2018. Seven bacterial isolates can grow in a Nutrient Agar medium containing 10% of NaCl, suggesting that these bacteria were halotolerant. Furthermore, all bacterial isolates were shown to produce indol acetic acid (IAA) and do not induce a hypersensitive response when infiltrated into tobacco leaves. These results explain that these bacteria had potency as plant growth-promoting rhizobacteria (PGPR) and were not tend to be the plant pathogen. The growth of seedlings when inoculated in cucumber seed grown in saline media were higher than those in control. This result suggests that the halotolerant bacteria can enhance the development of cucumber seedlings in saline stress conditions. Three potential halotolerant bacteria i.e., SN22, SN23, SN26 were selected and molecularly identified as Bacillus megaterium, Bacillus sp., and B. megaterium, respectively. [ABSTRACT FROM AUTHOR]

Three halotolerant bacteria were isolated from seawater collected along the Red sea coast, Jeddah, KSA and evaluated for their capacity to reinove congo red (CR) and malachite green (MG), commonly used in paper printing and textile factories. Mixture design and response surface methodology (RSM) based on statistical design of experiments were applied to explore the region of interest and interaction between the three selected strains. Color removal were confirmed by UV-visible and Fourier transform infrared spectroscopy analysis (FTIR). Microbial enzymes related to dyes degradation were also investigated after analysis of the whole bacterial genome. Results, showed that the dye degrading strains were identified as Klebsiella pneumoniae I<2, Enterobacter sp. 1<16b and Vibrio tritonius K20. The effect of K. pneumoniae K2, Enterobacter sp. KlGb and V. tritonius K20, tested separately, induced a maximum of decolorization of 74.54%, 85.71% and 82.73% for CR and 72.67%, 74.26% and 72.73% for MG, respectively. Process optimization, showed that the higher decolorization (%) of CR and MG yields were obtained when the proportions of K. pneumoniae KZ, Enterobacter sp. 1<16b and V tritonius K20 were 21.34%, 56.35% and 22.30% for CR and 42.38%, 56.56% and 0.10%, for MG. Biodegradation of dyes was confirmed by UV-Vis spectrum and FTIR analysis. The phytotoxicity assay revealed that when the irrigation medium was supplemented with extract obtained from the respective microbial treated dyes solutions, seed germination, shoot and root lengths were not affected, indicating that selected strains have the ability not only to remove color but also to detoxify dyes solutions. Whole genome analysis confirms the presence of a valuable enzymes (reductase, dehydrogenase, kinase, hydrolase, transferase, catalase and, dioxygenase enzymes) involved in chemicals degradation, suggesting that they might be useful in biological treatment of various coloured industrial emuents. [ABSTRACT FROM AUTHOR]

Abstract Background Exceptional preservation of endogenous organics such as collagens and blood vessels has been frequently reported in Mesozoic dinosaur fossils. The persistence of these soft tissues in Mesozoic fossil bones has been challenged because of the susceptibility of proteins to degradation and because bone porosity allows microorganisms to colonize the inner microenvironments through geological time. Although protein lability has been studied extensively, the genomic diversity of microbiomes in dinosaur fossil bones and their potential roles in bone taphonomy remain underexplored. Genome-resolved metagenomics was performed, therefore, on the microbiomes recovered from a Late Cretaceous Centrosaurus bone and its encompassing mudstone in order to provide insight into the genomic potential for microbial alteration of fossil bone. Results Co-assembly and binning of metagenomic reads resulted in a total of 46 high-quality metagenome-assembled genomes (MAGs) affiliated to six bacterial phyla (Actinobacteria, Proteobacteria, Nitrospira, Acidobacteria, Gemmatimonadetes and Chloroflexi) and 1 archaeal phylum (Thaumarchaeota). The majority of the MAGs represented uncultivated, novel microbial lineages from class to species levels based on phylogenetics, phylogenomics and average amino acid identity. Several MAGs from the classes Nitriliruptoria, Deltaproteobacteria and Betaproteobacteria were highly enriched in the bone relative to the adjacent mudstone. Annotation of the MAGs revealed that the distinct putative metabolic functions of different taxonomic groups were linked to carbon, nitrogen, sulfur and iron metabolism. Metaproteomics revealed gene expression from many of the MAGs, but no endogenous collagen peptides were identified in the bone that could have been derived from the dinosaur. Estimated in situ replication rates among the bacterial MAGs suggested that most of the microbial populations in the bone might have been actively growing but at a slow rate. Conclusions Our results indicate that excavated dinosaur bones are habitats for microorganisms including novel microbial lineages. The distinctive microhabitats and geochemistry of fossil bone interiors compared to that of the external sediment enrich a microbial biomass comprised of various novel taxa that harbor multiple gene sets related to interconnected biogeochemical processes. Therefore, the presence of these microbiomes in Mesozoic dinosaur fossils urges extra caution to be taken in the science of paleontology when hunting for endogenous biomolecules preserved from deep time.

Commercial table salt is a condiment with food preservative properties by decreasing water activity and increasing osmotic pressure. Salt is also a source of halophilic bacteria and archaea. In the present research, the diversity of halotolerant and halophilic microorganisms was studied in six commercial table salts by culture-dependent and culture-independent techniques. Three table salts were obtained from marine origins: Atlantic Ocean, Mediterranean (Ibiza Island), and Odiel marshes (supermarket marine salt). Other salts supplemented with mineral and nutritional ingredients were also used: Himalayan pink, Hawaiian black, and one with dried vegetables known as Viking salt. The results of 16S rRNA gene sequencing reveal that the salts from marine origins display a similar archaeal taxonomy, but with significant variations among genera. Archaeal taxa Halorubrum , Halobacterium , Hallobellus , Natronomonas , Haloplanus , Halonotius , Halomarina , and Haloarcula were prevalent in those three marine salts. Furthermore, the most abundant archaeal genera present in all salts were Natronomonas , Halolamina , Halonotius , Halapricum , Halobacterium , Haloarcula , and uncultured Halobacterales. Sulfitobacter sp. was the most frequent bacteria, represented almost in all salts. Other genera such as Bacillus , Enterococcus , and Flavobacterium were the most frequent taxa in the Viking, Himalayan pink, and black salts, respectively. Interestingly, the genus Salinibacter was detected only in marine-originated salts. A collection of 76 halotolerant and halophilic bacterial and haloarchaeal species was set by culturing on different media with a broad range of salinity and nutrient composition. Comparing the results of 16S rRNA gene metataxonomic and culturomics revealed that culturable bacteria Acinetobacter , Aquibacillus , Bacillus , Brevundimonas , Fictibacillus , Gracilibacillus , Halobacillus , Micrococcus , Oceanobacillus , Salibacterium , Salinibacter , Terribacillus , Thalassobacillus , and also Archaea Haloarcula , Halobacterium , and Halorubrum were identified at least in one sample by both methods. Our results show that salts from marine origins are dominated by Archaea, whereas salts from other sources or salt supplemented with ingredients are dominated by bacteria. [ABSTRACT FROM AUTHOR]

Commercial table salt is a condiment with food preservative properties by decreasing water activity and increasing osmotic pressure. Salt is also a source of halophilic bacteria and archaea. In the present research, the diversity of halotolerant and halophilic microorganisms was studied in six commercial table salts by culture-dependent and culture-independent techniques. Three table salts were obtained from marine origins: Atlantic Ocean, Mediterranean (Ibiza Island), and Odiel marshes (supermarket marine salt). Other salts supplemented with mineral and nutritional ingredients were also used: Himalayan pink, Hawaiian black, and one with dried vegetables known as Viking salt. The results of 16S rRNA gene sequencing reveal that the salts from marine origins display a similar archaeal taxonomy, but with significant variations among genera. Archaeal taxa Halorubrum, Halobacterium, Hallobellus, Natronomonas, Haloplanus, Halonotius, Halomarina, and Haloarcula were prevalent in those three marine salts. Furthermore, the most abundant archaeal genera present in all salts were Natronomonas, Halolamina, Halonotius, Halapricum, Halobacterium, Haloarcula, and uncultured Halobacterales. Sulfitobacter sp. was the most frequent bacteria, represented almost in all salts. Other genera such as Bacillus, Enterococcus, and Flavobacterium were the most frequent taxa in the Viking, Himalayan pink, and black salts, respectively. Interestingly, the genus Salinibacter was detected only in marine-originated salts. A collection of 76 halotolerant and halophilic bacterial and haloarchaeal species was set by culturing on different media with a broad range of salinity and nutrient composition. Comparing the results of 16S rRNA gene metataxonomic and culturomics revealed that culturable bacteria Acinetobacter, Aquibacillus, Bacillus, Brevundimonas, Fictibacillus, Gracilibacillus, Halobacillus, Micrococcus, Oceanobacillus, Salibacterium, Salinibacter, Terribacillus, Thalassobacillus, and also Archaea Haloarcula, Halobacterium, and Halorubrum were identified at least in one sample by both methods. Our results show that salts from marine origins are dominated by Archaea, whereas salts from other sources or salt supplemented with ingredients are dominated by bacteria.

The focus of the current study was the use of sewage wastewater to obtain PHA from a co-culture to produce a sustainable polymer. Two halotolerant bacteria, Bacillus halotolerans 14SM (MZ801771) and Bacillus aryabhattai WK31 (MT453992), were grown in a consortium to produce PHA. Sewage wastewater (SWW) was used to produce PHA, and glucose was used as a reference substrate to compare the growth and PHA production parameters. Both bacterial strains produced PHA in monoculture, but a copolymer was obtained when the co-cultures were used. The co-culture accumulated a maximum of 54% after 24 h of incubation in 10% SWW. The intracellular granules indicated the presence of nucleation sites for granule initiation. The average granule size was recorded to be 231 nm; micrographs also indicated the presence of extracellular polymers and granule-associated proteins. Fourier transform infrared spectroscopy (FTIR) analysis of the polymer produced by the consortium showed a significant peak at 1731 cm−1, representing the C=O group. FTIR also presented peaks in the region of 2800 cm−1 to 2900 cm−1, indicating C-C stretching. Proton nuclear magnetic resonance (1HNMR) of the pure polymer indicated chemical shifts resulting from the proton of hydroxy valerate and hydroxybutyrate, confirming the production of poly(3-hydroxybutyrate-co-3-hydroxy valerate) (P3HBV). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay showed that the copolymer was biocompatible, even at a high concentration of 5000 µg mL−1. The results of this study show that bacterial strains WK31 and 14SM can be used to synthesize a copolymer of butyrate and valerate using the volatile fatty acids present in the SWW, such as propionic acid or pentanoic acid. P3HBV can also be used to provide an extracellular matrix for cell-line growth without causing any cytotoxic effects.

The aim of the study was to characterize halotolerant bacteria and to evaluate their plant growth promotion potential on chia and quinoa seedlings under saline stress. Isolated microorganisms were evaluated for nitrogen fixation, phosphate solubilization, and production of siderophores and indole acetic acid. Three strains and two consortia were selected: Halomonas sp. (SFS), Micrococcus luteus (SA211), Bacillus sp. (HX11), C1 (SA211 + SFS), and C2 (SA211 + HX11). In vitro assays using water agar and half-strength Murashige-Skoog plates showed that an increase in salinity led to an increased seedlings mortality and a decrease in germination (lower than 40%), in total length (varying between 16% and 87% decreases), root length (from 60% to 92% lesser length) and dry weight (from 7% to 86% lower weight). Also, the relative growth index (RGI) decreased for both crops in most treatments, except those with HX11 and C2. These treatments had the highest growth parameters and RGI values in presence of high salinity in chia (50 and 100 mmol/L NaCl) and quinoa (200 and 400 mmol/L NaCl). SA211, the highest producer of indole acetic acid, showed a detrimental effect and anomalous phenotype on plants. Our results suggest that Bacillus sp. HX11, with multiple plant growth promotion traits and tolerance to saline stress, has a great potential as a bioinoculant in saline conditions and could be used as a biofertilizer for crop production.

The rhizosphere and microbiome of halotolerant plants could be crucial for alleviating salinity stress during plant growth. The aims of this work were (1) to isolate bacteria from rhizosphere and bulk soil samples from the Salar del Hombre Muerto (Catamarca, Argentina), (2) to characterize different plant growth-promoting (PGP) activities produced by these bacterial isolates, and (3) to evaluate their effect on the initial growth of chia (Salvia hispanica L.) under saline stress. A total of 667 microorganisms were isolated, using different culture media with NaCl, and their abilities for nitrogen fixation, phosphate solubilization, siderophores production, and indole-3-acetic acid production were evaluated. Thirteen strains were selected for showing all the tested PGP activities; they belonged to the genera Kushneria, Halomonass, Pseudomonas, Planomicrobium, and Pseudarthrobacter. The strains Kushneria sp. and Halomonas sp. showed the highest salinity tolerance (from 50 to 2,000 mM NaCl) and biomass and biofilm production. Chia seeds were treated with six of the first 13 selected strains to evaluate their plant growth-promoting effect under saline stress (without and with 50 and 100 mM NaCl). Halomonas sp. 3R.12 and Kushneria sp. T3.7 produced heavier seedlings with a balanced shoot/root length ratio, while Pseudomonas sp. AN23 showed the best effect upon chia seedlings, with a morphological response similar to non-stressed seedlings. On the other hand, seedlings displayed no responses when inoculated with Planomicrobium sp. 3S.31 and Pseudarthrobacter sp. ER25. This study contributes to the knowledge on microorganisms from hypersaline environments as plant growth promoters for their use in the production of salt-sensitive crops, among other potential uses.

• A. pallidus utilizes meta -pathway to degrade hypersaline high-concentration phenol. • Four Na+/H+ antiporters synergistically contribute to high-salt stress adaptability. • Na+/H+ antiporters pump out phenol along with salt ions, affecting degradation rate. • Competitive correlation between salt-tolerance/degradation-performance is revealed. • Na+/H+-antiporter adjustment is a promising strategy for high-salt bioremediation. Phenolic-laden wastewater is typically characterized by its high toxicity and high salinity, imposing serious limits on the application of bioremediation. Although a few halotolerant microorganisms have been reported to degrade phenol, their removal efficiency on high concentrations of phenol remains unsatisfactory. What's more, the deep interaction molecular mechanism of salt-tolerance/phenol-degradation performance has not been clearly revealed. Here, a halotolerant strain Aeribacillus pallidus W-12 employed a meta -pathway to efficiently degrade high concentration of phenol even under high salinity conditions. Investigation of salt-tolerance strategy indicated that four Na+/H+ antiporters, which are widely distributed in bacteria, synergistically endowed the strain with excellent salt adaptability. All these antiporters differentially but positively responded to salinity changes and induction of phenol, forming a synergistic transport effect on salt ions and phenol. In-depth analysis revealed a competitive relationship between salt tolerance and degradation performance, which significantly impaired the degradation efficiency at relatively high salinity. The efficient degradation performance of W-12 under different phenol concentrations and salinity conditions indicated its bioremediation potential for multiple types of phenolic wastewater. Collectively, the competitive mechanism of salt tolerance and degradation performance enlightens a new strategy of introducing or re-constructing Na+/H+ antiporters to further improve bioremediation efficiency of hypersaline organic wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aims to assess the effect of five endophytic bacteria on the growth promotion of tomato plants under salt stress conditions. Twenty-five endophytic bacteria were isolated from roots of the native halophyte Stipa tenacissima L. collected from Djelfa (Algeria) and were evaluated for their halotolerant potential. Seven strong halotolerant isolates were selected and characterized for in vitro Plant Growth Promotion (PGP) including the ACC-deaminase activity, inorganic phosphate solubilization and the production of indole-3-acetic acid and siderophores. Five strains showing high PGP traits were investigated for the mitigation of salt stress and PGP of tomato (Solanum esculentum L. cv. Aïcha). Screening of the salt-tolerant isolates for PGP traits in saline condition (75 mM NaCl) under Petri-dishes experiment of tomato revealed that three isolates ST09, ST18 and ST19 improved the growth of tomato seedlings by highlighting germination rate, shoot and root lengths and biomass. Under greenhouse conditions at 0 and 75 mM NaCl, inoculation of strains ST09, ST18 and ST19 in tomato seedlings produced an increase in germination (69.23%, 73.07% and 73.07%). The isolate ST19 showed an increase of more than 90% in root elongation and 17.4% increase in biomass when compared to uninoculated tomato seedlings at 75 mM NaCl stress. Phylogenetic analysis based on the 16S rRNA gene showed that the strain ST19 belongs to the genus Kocuria , and is closely related to Kocuria arsenatis |CM1E1|KM874399T (99.29% similarity). Thus, we conclude that the inoculation of tomato plants with the strain ST19 showed its efficiency to mitigate salt stress conditions. [ABSTRACT FROM AUTHOR]

The objective of this research was to characterize halotolerant bacteria isolated from the ripened salty process of Engraulis ringens from a fishing company at Chimbote (Peru). For this, three fish samples were collected at the beginning and at the end of the process. 14 halotolerant bacteria were isolated, 12 from medium containing 5% NaCl and two from 10% NaCl. Its growth capacity was evaluated from 4 to 50 ° C and 2.5 to 12.5% NaCl, as well as its biochemical activity by oxidase, urease, indole and citrate tests, carbohydrate fermentation, hydrolysis of starch, casein and gelatin, and sensitivity to penicillin, chloramphenicol, gentamicin, tetracycline, rifampicin, sulfamethoxazole/trimethoprim, streptomycin, nalidixic acid, and novobiocin. 71% of strains grew from 25 to 44 ° C, up to 10% NaCl, and showed proteolytic and amylolytic activities. The molecular characterization was carried out by amplification and sequencing the 16S ribosomal genes and these were analyzed using BioEdit and BLASTn programs. From this characterization, the genera Bacillus (2), Staphylococcus (6), Oceanobacillus (1), Salinococcus (1), Psychrobacter (2) and Sporosarcina (2) were obtained. Five genera of isolated halotolerant bacteria (Bacillus, Oceanobacillus, Salinicoccus, Psychrobacter and Sporosarcina) were of marine origin, they are non-pathogenic or no pollution indicators. Conversely, BH1 strain of Staphylococcus showed sensitivity only to nalidixic acid, while BH14 was resistant to all antimicrobials. Therefore, it is necessary to implement measures that ensure the safety of anchovies. [ABSTRACT FROM AUTHOR]

Arachis hypogaea (Peanut) is one of the most important cash crops grown for food and oil production. Salinity is a major constraint for loss of peanut productivity, and halotolerant plant growth promoting bacteria not only enhance plant-growth but also provide tolerance against salt stress. The potential of halotolerant bacterium Stenotrophomonas maltophilia BJ01 isolated from saline-soil was explored to enhance the growth of peanut plants under salt stress conditions. Interaction of S. maltophilia BJ01 enhances the growth of the peanut plants and protects photosynthetic pigments under salt stress. Lower electrolyte leakage (about 20%), lipid peroxidation (2.1 μmol g–1 Fw), proline (2.9 μg mg–1 Fw) content and H2O2 (55 μmol g–1 Fw) content were observed in plants, co-cultivated with PGPR compared to untreated plants under stress condition. The growth hormone auxin (0.4 mg g–1 Fw) and total amino acid content (0.3 mg g–1 Fw) were enhanced in plants co-cultivated with PGPR under stress conditions. Overall, these results indicate the beneficial effect of S. maltophilia BJ01 on peanut plants under salt (100 mM NaCl) stress conditions. In conclusion, bacterium S. maltophilia BJ01 could be explored further as an efficient PGPR for growing legumes especially peanuts under salt stress conditions. However, a detailed agronomic study would be needed to ascertain its commercial role.

Arachis hypogaea (Peanut) is one of the most important cash crops grown for food and oil production. Salinity is a major constraint for loss of peanut productivity, and halotolerant plant growth promoting bacteria not only enhance plant-growth but also provide tolerance against salt stress. The potential of halotolerant bacterium Stenotrophomonas maltophilia BJ01 isolated from saline-soil was explored to enhance the growth of peanut plants under salt stress conditions. Interaction of S. maltophilia BJ01 enhances the growth of the peanut plants and protects photosynthetic pigments under salt stress. Lower electrolyte leakage (about 20%), lipid peroxidation (2.1 μmol g–1 Fw), proline (2.9 μg mg–1 Fw) content and H2O2 (55 μmol g–1 Fw) content were observed in plants, co-cultivated with PGPR compared to untreated plants under stress condition. The growth hormone auxin (0.4 mg g–1 Fw) and total amino acid content (0.3 mg g–1 Fw) were enhanced in plants co-cultivated with PGPR under stress conditions. Overall, these results indicate the beneficial effect of S. maltophilia BJ01 on peanut plants under salt (100 mM NaCl) stress conditions. In conclusion, bacterium S. maltophilia BJ01 could be explored further as an efficient PGPR for growing legumes especially peanuts under salt stress conditions. However, a detailed agronomic study would be needed to ascertain its commercial role. [ABSTRACT FROM AUTHOR]

A large portion of petrochemical wastewaters are classified as high total dissolved solids, containing bisphenol A (BPA) which makes them resistant to conventional degradation processes. In this work, a halotolerant bacterial isolate, Alcaligenes faecalis strain BPAN5 was isolated and used for biodegradation of BPA. Effect of operational parameters including initial seed size (5–20 mL), nitrogen source, salinity (2%–3.5%) and BPA concentrations (10–60 mg/L) on BPA removal was investigated. Results showed that the addition of NH4Cl in the culture medium led to the highest BPA biodegradation rate and bacterial growth. The most BPA removal of 100% and 96% were observed for the initial seed size of 15 mL and salinity of 2% for BPA concentrations of 10 and 20 mg/L, respectively. The main metabolites of BPA biodegradation were chlorobenzene, chlorothymol, hexadecanoic acid and 2,6-di-tert-butyl-4-phenylphenol. Also, the biodegradability of effluent reached 69% while the toxicity decreased to 7%. Findings of current work indicated the significant ability of Alcaligenes faecalis strain BPAN5 for biodegradation of BPA in a saline medium. [ABSTRACT FROM AUTHOR]

In this study, a halotolerant strain was isolated from high salinity leachate and identified as Bacillus cereus NT‐3. It can produce a high concentration of polyhydroxyalkanoates (PHAs) with no significant changes when NaCl concentration is up to 50 g/L. FTIR and NMR spectra of PHAs synthesized by Bacillus cereus NT‐3 were similar to the standard or previous results. Effluent from acidogenic fermentation of food waste and pure volatile fatty acids (VFAs) mixture was used as carbon source to check the effect of non‐VFAs compounds of the effluent on PHAs production. The maximum PHAs production was 0.42 g/L for effluent fermentation, whereas it was 0.34 g/L for pure VFAs fermentation, indicating that bacteria could use actual effluent in a better way. Furthermore, a mathematical model was established for describing kinetic behavior of bacteria using different carbon sources. These results provided a promising approach for PHAs biosynthesis with a low‐cost carbon source. [ABSTRACT FROM AUTHOR]

Abstract. Bakasang laor is one of the traditional fermented fishery products in Maluku, Indonesia. There are two types of bakasang laor, i.e. with and without vinegar. The microbiological research of bakasang processed use laor as raw material has never been done before. The research aimed to analyze the microbiological quality and proximate composition of two types of bakasang laor. The proximate composition can determine the nutritional value of this product for consumption by the community. The sample of bakasang laor was taken from traditional producer in Latuhalat village, Ambon. The total number of halotolerant and coliform bacteria in bakasang laor without vinegar were 1.7x106 CFU/g and 4.1x106 CFU/g, respectively, while the total of lactic acid bacteria in bakasang laor with vinegar was 6.0x106 CFU/g. The carbohydrate, protein, fat and ash contents of bakasang laor with vinegar was higher than bakasang laor without vinegar. The carbohydrate, protein and fat contents of bakasang laor with vinegar were 19.64 %, 16.23 %, and 2.42 %, respectively. Generally, microbiological quality and proximate composition of bakasang laor with vinegar was better than bakasang laor without vinegar. The bacteria that play a role in fermentation can be used as a starter in the fermentation of various food products. The results of this research to improve the quality of this fermentation product in the future. [ABSTRACT FROM AUTHOR]

Background: Exceptional preservation of endogenous organics such as collagens and blood vessels has been frequently reported in Mesozoic dinosaur fossils. The persistence of these soft tissues in Mesozoic fossil bones has been challenged because of the susceptibility of proteins to degradation and because bone porosity allows microorganisms to colonize the inner microenvironments through geological time. Although protein lability has been studied extensively, the genomic diversity of microbiomes in dinosaur fossil bones and their potential roles in bone taphonomy remain underexplored. Genome-resolved metagenomics was performed, therefore, on the microbiomes recovered from a Late Cretaceous Centrosaurus bone and its encompassing mudstone in order to provide insight into the genomic potential for microbial alteration of fossil bone. Results: Co-assembly and binning of metagenomic reads resulted in a total of 46 high-quality metagenome-assembled genomes (MAGs) affiliated to six bacterial phyla (Actinobacteria, Proteobacteria, Nitrospira, Acidobacteria, Gemmatimonadetes and Chloroflexi) and 1 archaeal phylum (Thaumarchaeota). The majority of the MAGs represented uncultivated, novel microbial lineages from class to species levels based on phylogenetics, phylogenomics and average amino acid identity. Several MAGs from the classes Nitriliruptoria, Deltaproteobacteria and Betaproteobacteria were highly enriched in the bone relative to the adjacent mudstone. Annotation of the MAGs revealed that the distinct putative metabolic functions of different taxonomic groups were linked to carbon, nitrogen, sulfur and iron metabolism. Metaproteomics revealed gene expression from many of the MAGs, but no endogenous collagen peptides were identified in the bone that could have been derived from the dinosaur. Estimated in situ replication rates among the bacterial MAGs suggested that most of the microbial populations in the bone might have been actively growing but at a slow rate. Conclusions: Our results indicate that excavated dinosaur bones are habitats for microorganisms including novel microbial lineages. The distinctive microhabitats and geochemistry of fossil bone interiors compared to that of the external sediment enrich a microbial biomass comprised of various novel taxa that harbor multiple gene sets related to interconnected biogeochemical processes. Therefore, the presence of these microbiomes in Mesozoic dinosaur fossils urges extra caution to be taken in the science of paleontology when hunting for endogenous biomolecules preserved from deep time. [ABSTRACT FROM AUTHOR]

A metabolomics method was established to analyze changes of intracellular metabolites and study the mechanism for enhancing polyhydroxyalkanoates production by halotolerant bacteria, Bacillus cereus strain HY-3, using acetic acid as carbon source. Maximum poly(3-hydroxybutyrate) (PHB) contents for the medium with 0.5 g/L and 5.0 g/L of acetic acid were 41.0 ± 0.415% and 49.2 ± 1.21%. Principal components analysis revealed clear metabolic differences in different growth stages and different concentrations of carbon source. According to statistical analysis, 3-hydroxybutyrate (3-HB), serine, threonine, malate, and pyruvate were determined as potential biomarkers for PHB production. Moreover, metabolic pathways analysis indicated that high level of 3-HB in death phase was due to the limitation of carbon source. Metabolism of glycine, serine, and threonine was influential pathway for PHB production among amino acid metabolisms. High levels of organic acids from the TCA cycle could stimulate the carbon source flux into PHB biosynthetic pathway. Metabolomics method based on GC/MS was used to analyze metabolites, aiming to find out biomarkers and reveal mechanism for enhancing PHA production. [ABSTRACT FROM AUTHOR]

We have identified 25 halotolerant strains of ortho-phthalic acid (OPC) decomposer bacteria from samples of soil, sludge, and bottom sediments taken in the area of salt mining enterprises of Uralkalij (Berezniki, Russia). Based on an analysis of the 16S rRNA gene, the isolates were assigned to the genera Rhodococcus, Dietzia, Bacillus, Halomonas, Pseudomonas, Idiomarina, Stappia, Martelella, Erythrobacter, Alcanivorax, Marinobacter, Oceanisphaera, Nitratireductor, and Breoghania. Eight OPC decomposer strains are capable of using the phthalic acid esters Dibutyl phthalate (DBP) and Diethyl phthalate (DEP) as the sole source of carbon and energy. The strains utilized 90–98% of DBP and 49–80% of DEP (the phthalate concentration is 500 mg/L), both in the absence of NaCl in the cultivation medium and with a concentration in the medium of 50 g/L. An increase in the NaCl concentration in the medium to 70 and 90 g/L did not significantly affect the utilization of phthalates. The ability of bacteria of the genera Halomonas, Martelella, and Oceanisphaera to decompose DEF and DBP has been shown for the first time. Isolated phthalate (OPC, DEP and DBP) decomposer strains are promising for the development of new methods for the bioremediation of saline soils contaminated with phthalates. [ABSTRACT FROM AUTHOR]