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To provide the necessary nitrite for the Anaerobic Ammonium Oxidation (ANAMMOX) process, the effect of nitrite accumulation in the partial sulfide autotrophic denitrification (PSAD) process was investigated using an SBR reactor. The results revealed that the effectiveness of nitrate removal was unsatisfactory when the S/N ratio (mol/mol) fell below 0.6. The optimal conditions for nitrate removal and nitrite accumulation were achieved within the S/N ratio range of 0.7-0.8, resulting in an average Nitrate Removal Efficiency (NRE) of 95.84%±4.89% and a Nitrite Accumulation Rate (NAR) of 75.31%±6.61%, respectively. It was observed that the nitrate reduction rate was three times faster than that of nitrite reduction during a typical cycle test. Furthermore, batch tests were conducted to assess the influence of pH and temperature conditions. In the pH tests, it became evident that the PSAD process performed more effectively in alkaline environment. The highest levels of nitrate removal and nitrite accumulation were achieved at an initial pH of 8.5, resulting in a NRE of 98.30%±1.93% and a NAR of 85.83%±0.47%, respectively. In the temperature tests, the most favourable outcomes for nitrate removal and nitrite accumulation were observed at 22±1 ℃, with a NRE of 100.00% and a NAR of 81.03%±1.64%, respectively. Moreover, a comparative analysis of 16S rRNA sequencing results between the raw sludge and the sulfide-enriched culture sludge sample showed that Proteobacteria (49.51%) remained the dominant phylum, with Thiobacillus (24.72%), Prosthecobacter (2.55%), Brevundimonas (2.31%) and Ignavibacterium (2.04%) emerging as the dominant genera, assuming the good nitrogen performance of the system. [ABSTRACT FROM AUTHOR]

Thiocyanate (SCN−) exists in various industries and is detrimental to the ecosystem, necessitating cost-effective and environmentally benign treatment. In response to alleviate the bacterial toxicity of SCN−, this study developed a two-stage coupled system by tandem of anammox in reactor 1 (R1) and SCN−-driven autotrophic denitrification in reactor 2 (R2), achieving simultaneous removal of SCN− and nitrogen. The total nitrogen removal efficiency of the coupled system was 92.42 ± 1.98%, with nearly 100% of SCN− elimination. Thiobacillus was responsible for SCN− degradation. The deduced degradation pathway of SCN− was via the cyanate pathway before coupling, followed by the co-action of cyanate pathway and carbonyl sulfide pathway after coupling. Although scaling-up study is needed to validate its applicability in real-world applications, this study contributes to the advancement of sustainable and cost-effective wastewater treatment technologies, being an attractive path for low-carbon nitrogen removal and greenhouse gas emission-free technology. [ABSTRACT FROM AUTHOR]

A novel coupling process to replace the traditional multi-stage anammox process—sulfur autotrophic denitrification (SAD) coupled anaerobic ammonium oxidation (anammox) system was designed, which solved problems of nitrate produced in anammox process and low nitrate conversion rate caused by nitrite accumulation in SAD process. Different filter structures (SAD filter and anammox granular sludge) were investigated to further explore the excellent performance of the novel integrated reactor. The results of sequential batch experiments indicated that nitrite accumulation occurred during SAD, which inhibited the conversion of nitrate to dinitrogen gas. When SAD filter and anammox granular sludge were added to packed bed reactor simultaneously, the nitrate removal rate increased by 37.21% and effluent nitrite concentration decreased by 100% compared to that achieved using SAD. The stratified filter structure solved groove flow. Different proportion influence of SAD filter and anammox granular sludge on the stratified filter structure was evaluated. More suitable ratio of SAD filter to anammox granular sludge was 2:1. Proteobacteria (57.26%), Bacteroidetes (20.12%) and Chloroflexi (9.95%) were the main phyla. The dominant genera of denitrification functional bacteria were Thiobacillus (39.80%), Chlorobaculum (3.99%), norank_f_PHOs-HE36 (2.90%) and Ignavibacterium (2.64%). The dominant genus of anammox bacterium was Candidatus_Kuenenia (3.05%). [ABSTRACT FROM AUTHOR]

The climate change and consequent degradation of soil and water resources have led to difficult conditions for farmers; thus, they should make intelligent decisions to face these statuses. Managing soil nutrient and mineral uptake by plants and its feasibility under harsh environment must be considered. Therefore, the present research was conducted to investigate the response of pomegranate variety Shishe Kab to Thiobacillus bacteria (B) and sulfur (S) fertilization. Treatments included sulfur fertilization (three levels: 0, 500 and 1000 g−1 tree) and inoculation with Thiobacillus bacteria (two levels: inoculated and non-inoculated). Totally, sulfur fertilization and inoculation with bacteria improved physiological and biochemical aspects and fruit production of pomegranate. Supplying S decreased soil pH, which the lowest value (5.2) was recorded in 500 g S tree−1 when accompanied with bacteria. Soil electrolyte leakage (EL) increased, when sulfur incorporated or when bacteria added to the soil. The interactive effects of B × S was significant on fruit diameter and weight, chlorophyll (Chl), carotenoid and potassium content, which were improved, although non-inoculated plants also showed high values of potassium content. Anthocyanin and total carbohydrate improved when bacteria inoculation was done; however, total acidity (TA) and total soluble solids (TSS) showed a significant decrease. The EL variable significantly decreased and tissue water content increased in this experiment, when inoculation or sulfur fertilization was used. The results obtained from present study emphasized on the necessity of using sulfur and Thiobacillus bacteria in increasing growth and yield and also chilling tolerance of pomegranate trees. From the experiment we found that supplying sulfur alone or accompanied with Thiobacillus bacteria gave the amazing results, lead to increase plant growth and development, yield increase and biochemical changes that are helpful under harsh environmental conditions, specifically cold and freezing stresses. [ABSTRACT FROM AUTHOR]

The nitrate removal efficiency of a 9.5 L packed bed column bioreactor was evaluated using different feeding strategies and initial concentrations. The bioreactor was filled with zeolite mineral particles and initially treated with Thiobacillus denitrificans. Several hydraulic retention times were examined to assess the effectiveness of nitrate removal. The most favorable scenario resulted in an 87% reduction in nitrate concentration from an influent of 400 mg/L within a three-hour period. To determine the optimal length of the bioreactor, a computational fluid dynamics model was developed. By comparing simulations with experimental results, the ideal height of the bioreactor for complete denitrification was determined to be 90 cm, 45 cm, 30 cm, and 20 cm for influents with nitrate concentrations of 400 mg/L, 250 mg/L, 120 mg/L, and 80 mg/L, respectively. [ABSTRACT FROM AUTHOR]

Pulp-paper mills (PPMs) are known for consistently generating a wide variety of pollutants, that are often unidentified and highly resistant to environmental degradation. The current study aims to investigate the changes in the indigenous bacterial communities profile grown in the sediment co-contaminated with organic and inorganic pollutants discharged from the PPMs. The two sediment samples, designated PPS-1 and PPS-2, were collected from two different sites. Physico-chemical characterization of PPS-1 and PPS-2 revealed the presence of heavy metals (mg kg-1) like Cu (0.009-0.01), Ni (0.005-0.002), Mn (0.078-0.056), Cr (0.015-0.009), Pb (0.008-0.006), Zn (0.225-0.086), Fe (2.124-0.764), Al (3.477-22.277), and Ti (99.792-45.012) along with high content of chlorophenol, and lignin. The comparative analysis of organic pollutants in sediment samples using gas chromatography-mass spectrometry (GC-MS) revealed the presence of major highly refractory compounds, such as stigmasterol, β-sitosterol, hexadecanoic acid, octadecanoic acid; 2,4-di-tert-butylphenol; heptacosane; dimethyl phthalate; hexachlorobenzene; 1-decanol, 2-hexyl; furane 2,5-dimethyl, etc in sediment samples which are reported as a potential toxic compounds. Simultaneously, high-throughput sequencing targeting the V3-V4 hypervariable region of the 16S rRNA genes, resulted in the identification of 1,249 and 1,345 operational taxonomic units (OTUs) derived from a total of 115,665 and 119,386 sequences read, in PPS-1 and PPS-2, respectively. Analysis of rarefaction curves indicated a diversity in OTU abundance between PPS-1 (1,249 OTUs) and PPS-2 (1,345 OTUs). Furthermore, taxonomic assignment of metagenomics sequence data showed that Proteobacteria (55.40%; 56.30%), Bacteoidetes (11.30%; 12.20%), and Planctomycetes (5.40%; 4.70%) were the most abundant phyla; Alphproteobacteria (20.50%; 23.50%), Betaproteobacteria (16.00%; 12.30%), and Gammaproteobacteria were the most recorded classes in PPS-1 and PPS-2, respectively. At the genus level, Thiobacillus (7.60%; 4.50%) was the most abundant genera grown in sediment samples. The results indicate significant differences in both the diversity and relative abundance of taxa in the bacterial communities associated with PPS-2 when compared to PPS-1. This study unveils key insights into contaminant characteristics and shifts in bacterial communities within contaminated environments. It highlights the potential for developing efficient bioremediation techniques to restore ecological balance in pulp-paper mill waste-polluted areas, stressing the importance of identifying a significant percentage of unclassified genera and species to explore novel genes. [ABSTRACT FROM AUTHOR]

IntroductionLavender (Lavandula officinalis L.) belonging to the Lamiaceae family is a plant with economic, medicinal and ornamental value. Its essential oil is used as a raw material for many industries, including perfumery, cosmetics, and pharmaceutical industries. Drought stress as a limiting factor reduces growth and productivity in plants. This issue is especially important in arid and semi-arid regions of the world such as Iran. One of the basic solutions to adjust or reduce the effect of water stress in agricultural plants is the use of different types of biological fertilizers. Also, its low diffusion speed in the soil can play an important role in the lack of its ions in the solution in the soil of the root development area. In most agricultural systems, due to the low mobility of phosphorus in the soil, absorption by the plant is low. In order to investigate the effect of biofertilizers and phosphorus on reducing the effects of irrigation deficiency in lavender, an experiment was conducted in the form of split plots in a randomized complete block design with 3 replications at the Research Station of the Faculty of Agriculture, Islamic Azad University of Tabriz in 2019-2020.Materials and methodsExperimental factors including irrigation levels (irrigation after 60, 90 and 120 mm from Class A evaporation pan) as the main factor and inoculation with biofertilizer including four levels (inoculation with Thiobacillus, Pseudomonas and Thiobacillus + Pseudomonas and no inoculation As control) and phosphorus fertilizer levels at two levels (0 and 50 kg ha-1) as a secondary factor. The studied traits included leaf dry weight, flower dry weight, cell membrane leakage rate, relative leaf water content, soluble sugars and proline content, catalase and superoxide dismutase enzymes and peroxidase and MDA. To measure the activity of antioxidant enzymes, leaf samples kept at -80 degrees Celsius were used. The activity of catalase was measured using the method described by (Aebi, 1984; Ezhilmathi, 2007). The measurement of superoxide dismutase (SOD) enzyme was calculated according to the method (Giannopolitis and Ries, 1977) based on enzyme unit per milligram per body weight. The determination of malondialdehyde (MDA) was based on Aston and Sidney's method (Aston and Sidney, 1987). Proline content in the youngest leaf was also determined by the method of Bates et al. (1973). SAS version 8 software was used to analyze the variance of the data, MSTATC version 2 software was used to compare the averages, and Excel software was used to draw the figures.Results and discussionThe results showed that at all levels of irrigation, phosphorus consumption and inoculation with integrated biofertilizers increased the dry weight of flowers compared to the control. Irrigation after 60 mm of evaporation from the pan with the application of 50 kg of phosphorus per hectare and application of Thiobacillus + Pseudomonas obtained the highest dry weight of flowers (833.3 g ha-1). The highest leaf dry weight was proline, catalase, peroxidase, superoxide dismutase and malondialdehyde at 60 ml of evaporation with 50 kg ha-1 application and application of Thiobacillus + Pseudomonas. The results of this study also showed that the effects of interaction between irrigation, phosphorus and biofertilizer levels on cell membrane leakage, leaf dry weight and relative leaf water content were not significant.ConclusionBased on the results of this experiment, it can be said that in water stress conditions, the use of biological fertilizers combined with the use of phosphorus fertilizers can greatly reduce the incidence of malnutrition in lavender medicinal plant. The accumulation of soluble sugars, proline and the increase in the activity of antioxidant enzymes in this plant in the face of drought stress can be considered as drought tolerance mechanisms. The combined use of Thiobacillus and Pseudomonas bacteria had better results than the use of these bacteria alone; Therefore, if the intensity of water deficit stress in this plant is not high, the effects of water deficit stress can be reduced by using biological fertilizers and phosphorus fertilizer.

In this study, we investigated the effects of salinity on elemental sulfur-driven autotrophic denitrification (SAD) efficiency, and microbial communities. The results revealed that when the salinity was≤6 g/L, the nitrate removal efficiency in SAD increased with the increasing salinity reaching 95.53% at 6 g/L salinity. Above this salt concentration, the performance of SAD gradually decreased, and the nitrate removal efficiency decreased to 33.63% at 25 g/L salinity. Approximately 5mg/L of the hazardous nitrite was detectable at 15 g/L salinity, but decreased at 25 g/L salinity, accompanied by the generation of ammonium. When the salinity was ≥15 g/L, the abundance of the salt-tolerant microorganisms, Thiobacillus and Sulfurimonas, increased, while that of other microbial species decreased. This study provides support for the practical application of elemental sulfur-driven autotrophic denitrification in saline nitrate wastewater. [ABSTRACT FROM AUTHOR]

Pulp-paper mills (PPMs) are known for consistently generating a wide variety of pollutants, that are often unidentified and highly resistant to environmental degradation. The current study aims to investigate the changes in the indigenous bacterial communities profile grown in the sediment co-contaminated with organic and inorganic pollutants discharged from the PPMs. The two sediment samples, designated PPS-1 and PPS-2, were collected from two different sites. Physico-chemical characterization of PPS-1 and PPS-2 revealed the presence of heavy metals (mg kg−1) like Cu (0.009–0.01), Ni (0.005–0.002), Mn (0.078–0.056), Cr (0.015–0.009), Pb (0.008–0.006), Zn (0.225–0.086), Fe (2.124–0.764), Al (3.477–22.277), and Ti (99.792–45.012) along with high content of chlorophenol, and lignin. The comparative analysis of organic pollutants in sediment samples using gas chromatography–mass spectrometry (GC–MS) revealed the presence of major highly refractory compounds, such as stigmasterol, β-sitosterol, hexadecanoic acid, octadecanoic acid; 2,4-di-tert-butylphenol; heptacosane; dimethyl phthalate; hexachlorobenzene; 1-decanol,2-hexyl; furane 2,5-dimethyl, etc in sediment samples which are reported as a potential toxic compounds. Simultaneously, high-throughput sequencing targeting the V3–V4 hypervariable region of the 16S rRNA genes, resulted in the identification of 1,249 and 1,345 operational taxonomic units (OTUs) derived from a total of 115,665 and 119,386 sequences read, in PPS-1 and PPS-2, respectively. Analysis of rarefaction curves indicated a diversity in OTU abundance between PPS-1 (1,249 OTUs) and PPS-2 (1,345 OTUs). Furthermore, taxonomic assignment of metagenomics sequence data showed that Proteobacteria (55.40%; 56.30%), Bacteoidetes (11.30%; 12.20%), and Planctomycetes (5.40%; 4.70%) were the most abundant phyla; Alphproteobacteria (20.50%; 23.50%), Betaproteobacteria (16.00%; 12.30%), and Gammaproteobacteria were the most recorded classes in PPS-1 and PPS-2, respectively. At the genus level, Thiobacillus (7.60%; 4.50%) was the most abundant genera grown in sediment samples. The results indicate significant differences in both the diversity and relative abundance of taxa in the bacterial communities associated with PPS-2 when compared to PPS-1. This study unveils key insights into contaminant characteristics and shifts in bacterial communities within contaminated environments. It highlights the potential for developing efficient bioremediation techniques to restore ecological balance in pulp-paper mill waste-polluted areas, stressing the importance of identifying a significant percentage of unclassified genera and species to explore novel genes.

Purpose: This study was to investigate the regulation of sulfur status in continuous-cropping soybean soil by Funneliformis mosseae and Thiobacillus thioparus and promote the absorption of sulfur in soybean. To explore the interactions among F. mosseae, T. thioparus and soybean plants, this study laid a theoretical foundation for the application of F. mosseae and T. thioparus as biological agents in agricultural production. Methods: Pot culture, a two-compartment system and shake-flask culture were used in the experiment. Using F. mosseae and T. thioparus as experimental inoculants, the effects of F. mosseae on sulfur oxide of T. thioparus and their interaction on the growth of soybean plants were studied from the aspects of soil sulfur content, sulfur functional genes and the growth of soybean and sulfur-oxidizing bacteria. Results: The F. mosseae and T. thioparus inoculation significantly increased the abundance of sulfur-oxidizing bacteria and available sulfur content in the soil, stimulated the expression of sulfate transporter genes in soybean roots, and promoted the absorption of sulfur nutrients in soybean. F. mosseae stimulated the expression of the T. thioparus sulfur-oxidation gene and enhanced the sulfur-oxidation capacity, while T. thioparus enhanced F. mosseae colonization of soybean roots. Thus, F. mosseae and T. thioparus promoted soil sulfur cycling and sulfate transport in soybean roots, which proved that F. mosseae could effectively improve the sulfur-oxidation capacity of T. thioparus. Conclusion: Double inoculation with F. mosseae and T. thioparus significantly promoted soybean plant growth and increased soil sulfur utilization. [ABSTRACT FROM AUTHOR]

Objective: Environmental stress, especially drought stress, is one of the most important factors that reduce the growth and development of oil plants such as rapeseed in arid and semi-arid regions. The purpose of this research is to investigate the effect of biochar and biosulfur on seed yield and some ecophysiological traits of rapeseed under drought stress conditions in winter cultivation. Methods: This research was carried out in form of a factorial split-plot with randomized complete block design having three replications in 2019 in Karaj. In this experiment, irrigation treatment witnessed three levels of 30%, 60%, and 100% of crop capacity as main plots, while biochar treatment saw three levels of no application and application of three and six tons per hectare and biosulfur treatment, two levels of application and non-application as plots. Subsidiaries were considered. Results: It was found that drought stress had a significant effect on the seed and oil yield of rapeseed. Thus, the amount of these traits in drought stress showed a decrease of 50% and 52%, respectively, compared to the control. Also, the use of six tons per hectare of biochar had increased by 49% and 36% in terms of its number of pods per plant and the number of seeds per pod. Also, the interaction effect of biosulfur application and the use of six tons of biochar had the greatest effect on the traits of the number of pods per plant and harvest index. Conclusion: The results showed that the use of biofertilizers can be used as a suitable method to increase the yield of rapeseed. Increasing oil percentage and grain yield will ultimately increase the field and economic yield (oil) of the rapeseed plant. [ABSTRACT FROM AUTHOR]

Sulfur (S) deficiency is becoming more common in agro-ecosystems worldwide due to factors such as agronomic practices, high biomass production, reduced sulfur emissions, and the use of non-sulfur fertilizers. This review explores the natural occurrence and commercial exploitation of sulfur pools in nature, the mineralization and immobilization of sulfur, the physiological role of sulfur in plants, and its deficiency symptoms. Additionally, the organic and inorganic forms of sulfur in soil, their transformations, and the process of microbiological oxidation of sulfur are discussed. The review also addresses the diversity of sulfur-oxidizing bacteria (SOB) and the various biochemical mechanisms involved in their role in plant productivity and soil reclamation. The measurement of S oxidation rate in soil and the variables that influence the process are also examined. Typically, the rate of oxidation of added elemental S is around 40%–51%, which is available for plant uptake. These characteristics of SOB demonstrate their potential as bioinoculants for increasing plant growth, indicating their use as biofertilizers for sustainable crop production in agro-ecosystems. [ABSTRACT FROM AUTHOR]

Anaerobic digestion produces biogas which usually contains 60-70% of methane (CH4), 30-40%of carbon-di-oxide (CO2), and 10-2,000 ppm hydrogen sulfide (H2S). The concentration of H2S depends upon the type of substrate. H2S tends to corrode pipes and machines carrying them. The high concentrations of H2S present in biogas may adversely affect electricity generation. Hence, the removal of H2S and enrichment of biogas with CH4 is an essential step towards higher energy production. In the present study, the biological method of removing H2S using Thiobacillus sp. was demonstrated for a one cu.m anaerobic co-digestion (ACD) unit running on an organic fraction of municipal solid waste (OFMSW) and septage sludge. Initial lab scale studies were conducted by collecting the biogas generated from 1 cu.m digesters, and continuous experiments were optimized for the process parameters such as flow rate, the volume of medium with culture, time, the height of the column, column composition, etc. The raw biogas was purged in a liquid medium (LM) with a culture containing Thiobacillus sp. The studies with the LM containing Thiobacillus sp. cultureshowed a 68% removal of H2S in the first 8 min, and the saturation occurred at 75 min when the time-dependent experiment was studied. The smaller flow rate (0.48 L.min-1) and highest volume of culture (500 mL) showed better results than other parameters. The highest and average oxidation rates of sulfate were recorded as 39 and 40.3 ppm.sec-1, respectively, for 0.48 L.min-1 flow rate and 500 mL of the culture volume. In the column studies, a column containing cocopeat (CP) was studied for its efficiency in removing H2S. At a flow rate of 0.9 L.min-1, 25% adsorption was encountered and reached saturation at 90 min. The bed height of 9 inches with CP and plastic support (PS) showed a 20% H2S removal. The filling ratio of CP and PS (1:1) was the best ratio for proper gas passage with optimal time for adsorption/absorption. The kinetic, isotherm, and continuous models helped to understand the capacity of the adsorbent. Freundlich, Yoon-Nelson, and BDST model were best fit for the present study. A pilot scale setup for one cu.m biogas reactor showed an average of 50% removal of H2S for LM with culture, and an additional 20% removal was possible by the introduction of a column along with the liquid bed in series. An overall efficiency of 70-75% of H2S removal was achieved. No significant CH4 loss was encountered during the study. [ABSTRACT FROM AUTHOR]

The ultimate purpose of phytoextraction is not only to remove heavy metals from soil but also to improve soil quality. Here, we evaluated how the joint effect of Streptomyces pactum (strain Act12) and inorganic (Hoagland's solution) and organic (humic acid and peat) nutrients affected the phytoextraction practice of cadmium (Cd) and zinc (Zn) by potherb mustard, and the microbial community composition within rhizosphere was also investigated. The results indicated that the nutrients exerted synergistically with Act12, all increasing the plant biomass and Cd/Zn uptakes. The inoculation of Act12 alone significantly increased dehydrogenase activity of rhizosphere soil (P < 0.05), while urease and alkaline phosphatase activities varied in different dosage of Act12. Combined application of microbial strain with nutrients increased enzymatic activities with the elevated dosage of Act12. 16S ribosomal RNA high-throughput sequencing analysis revealed that Act12 inoculation reduced the diversity of rhizosphere bacteria. The Act12 and nutrients did not change dominant phyla i.e. , Proteobacteria, Bacteroidetes, Gemmatimonadetes, Actinobacteria and Acidobacteria, but their relative abundance differed among the treatments with: Peat > Act12 > Humic acid > Hoagland's solution. Comparatively, Sphingomonas replaced Thiobacillus as dominant genus after Act12 application. The increase in the Sphingomonas and Flavisolibacter abundances under Act12 and nutrients treatments gave rise to growth-promoting effect on plant. Our results revealed the important role for rhizosphere microbiota in mediating soil biochemical traits and plant growth, and our approach charted a path toward the development of Act12 combined with soil nutrients to enhance soil quality and phytoextraction efficiency in Cd/Zn-contaminated soils. [Display omitted] [ABSTRACT FROM AUTHOR]

A high rate of elemental sulfur (S0) accumulation from sulfide-containing wastewater has great significance in terms of resource recovery and pollution control. This experimental study used Thiobacillus denitrificans and denitrifying bacteria incorporated with signal molecules (C6 and OHHL) for simultaneous sulfide (S2–) and nitrate (NO3–) removal in synthetic wastewater. Also, the effects on S0 accumulation due to changes in organic matter composition and bacteria proportion through signal molecules were analyzed. The 99.0% of S2– removal and 99.3% of NO3– was achieved with 66% of S0 accumulation under the active S2– removal group. The S0 accumulation, S2– and NO3– removal mainly occurred in 0–48 h. The S0 accumulation in the active S2– removal group was 2.0-6.3 times higher than the inactive S2– removal groups. In addition, S0/SO42- ratio exhibited that S0 conversion almost linearly increased with reaction time under the active S2– removal group. The proportion of Thiobacillus denitrificans and H+ consumption showed a positive correlation with S0 accumulation. However, a very high or low ratio of H+/S0 is not suitable for S0 accumulation. The signal molecules greatly increased the concentration of protein-I and protein-II, which resulted in the high proportion of Thiobacillus denitrificans. Therefore, high S0 accumulation was achieved as Thiobacillus denitrificans regulated the H+ consumption and electron transfer rate and provided suppressed oxygen environment. This technology is cost-effective and commercially applicable for recovering S0 from wastewater. [ABSTRACT FROM AUTHOR]

The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be suitable for handling soluble sulfur in wastewater. The purpose of this study is to evaluate the effect of nutrient (SO42−, PO43−, and Fe2+) concentration on BSRU performance, particularly on the conversion of sulfide to elemental sulfur. This study shows that the variation of SO42− concentration does not significantly affect the conversion process, while a small increment of PO43− (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+ also significantly affected the formation and conversion rate of elemental sulfur. [ABSTRACT FROM AUTHOR]

Biological treatment processes are an effective method for removing the nitrogen-containing contaminants that exist in coking wastewater. However, little is known about microbial composition and keystone taxa involved in biological nitrogen removal processes. In order to improve the removal efficiency of nitrogen-containing contaminants in anaerobic-aerobic-hydrolytic-aerobic (A/O1/H/O2) system, the microbial composition and interactions of keystone taxa should be clarified. The present work clarifies the removal performance of nitrogen-containing contaminants in the A/O1/H/O2 system, identifies the microbial community involved in various bioreactors, and reveals the keystone taxa within the microbial communities. Combined the processes of ammoniation, denitrification, and nitrification, total nitrogen decreased from 248 to 31 mg L−1 and achieved a removal efficiency of 87.5% in the full-scale A/O1/H/O2 system. High-throughput MiSeq sequencing revealed that Proteobacteria was the most abundant phylum in the A/O1/H/O2 system with relative abundances of 24%–50%. Thiobacillus dominated in bioreactors A and O1 with relative abundances of 2.90% and 4.44%, respectively, while Nitrospira was identified as the most dominant genus in bioreactors H and O2, accounting for 13.33% and 18.38%, respectively. The microbial community composition and co-occurrence network analysis showed that the keystone taxa belonged to Thiobacillus, Nitrospira, Bdellovibrio, Planctomyces, Desulfotomaculum , and Sphingobium , which are related to nitrogen degradation. [ABSTRACT FROM AUTHOR]

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Fertilization managements have important impacts on soil P transformation, turnover, and bioavailability. Thus, long-term fertilization experiments (~38 years) with the application of different inorganic and organic fertilizers in paddy red soils were conducted to determine their effect on P pool accumulation and microbial communities, especially for phosphate solubilizing microorganisms (PSM). Long-term inorganic P fertilization increased the concentrations of total P (~479 mg/kg), available P (~417 mg/kg), and inorganic P (~18 mg/kg), but manure fertilization accelerated the accumulation of organic P, especially for orthophosphate monoesters (e.g. myo-IHP, ~12 mg/kg). Long-term mineral fertilization decreased bacterial richness, evenness, and complexation of bacterial networks. In contrast, long-term manure fertilization and rhizosphere accumulated more amounts of total carbon, total nitrogen, and organic carbon, as well as regulated the soil pH, thus improving the separation of bacterial communities. Unlike bacteria, the responses of fungi to those factors were not sensitive. Furthermore, PSM compositions were greatly influenced by fertilization managements and rhizosphere. For example, inorganic P fertilization increased the abundance of Thiobacillus (i.e. the most abundant phosphate solubilizing bacteria (PSB) in this study) and shifted the community structure of PSB. Correspondingly, the concentrations of inorganic and total P were the key factors for the variation of PSB community structure. These findings are beneficial for understanding P accumulation, responses of PSB, and soil P sustainable fertility under different fertilization strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • An efficient HNAD was successfully initiated by thiosulfate and sodium acetate. • PCMX improved but BEC and mixed disinfectants inhibited denitrification activity. • PCMX elevated the levels of EPS, which was damaged by BEC and mixed disinfectants. • P-HSAD had the most enriched iRGs, and PB-HSAD led to a more complex spread of RGs. • Reduced Sulfurimonas led to inhibition of denitrification in B-HSAD and PB-HSAD. The effects of typical disinfectants chloroxylenol (PCMX) and benzethonium chloride (BEC) on heterotrophic/sulfur autotrophic denitrification (HSAD) systems under single and mixed stress were studied. PCMX increased the system's denitrification activity, but BEC and mixed disinfectants, particularly mixed disinfectants, significantly reduced denitrification activity. PCMX elevated the content of extracellular polymeric substances (EPS) in HSAD system, and the structure of EPS was tight and stable. Whereas the other two systems had lower EPS content and looser structure, highlighting the greater damaging effects of BEC and mixed disinfectants. PCMX led to the enrichment of more than half of the resistance genes (RGs), while mixed disinfectants resulted in the fewest RGs enriched and the lowest correlations between bacteria and RGs of three systems. The transformation of extracellular qacE was induced by PCMX. BEC caused RGs to leak out of bacteria, and mixed disinfectants contributed to transformation and efflux of RGs. PCMX increased the abundance of Thiobacillus and Sulfurimonas. Thiobacillus was more abundant in low doses of BEC and mixed disinfectants, but it reduced at high concentrations, while the amount of Sulfurimonas continued to decrease. This study provided an insight into the effects of single and mixed disinfectants on HSAD systems, and guided future efforts to control disinfectants and RGs pollution in wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The accumulation efficiency of NO 2 −-N and S0 reached 89.40% and 93.41%, respectively. • O 2 changes the ORP value, leading to a decrease in the accumulation of S0 and NO 2 −. • O 2 entry accelerates the oxidation of S2−, but limits the reduction of NO 3 −-N. • DO promoted the synergistic effect of Thiobacillus and Azoarcus without Nitrospia. Understanding the effect of O 2 on the accumulation characteristics of NO 2 −-N and S0 in the sulfur autotrophic denitrification (DSSADN) system is crucial for enhancing the denitrification efficiency of partial nitrification-anammox using DSSADN. The results revealed that in an environment without O 2 entry, the NO 2 −-N accumulation efficiency (NiAE) and S0 accumulation efficiency (S0AE) of the DSSADN system reached 89.40 % and 93.41 %, respectively. Once system entered O 2 , ORP value kept increasing. When ORP increased to −59.9 mV (DO = 0.1 mg/L), soxB and nirK gene expression rose and as well NiAE and S0AE continuously decreased to 48.13 % and 29.35 %. When ORP was above 30.9 mV (DO >0.2 mg/L) but below 81.0 mV (DO<0.4 mg/L), narG gene expression reduced and the relatively high sqr gene expression allowed NiAE and S0AE remained at 45.08 % and 33.31 %. O 2 promoted the synergistic effect of Thiobacillus and Azoarcus without the proliferation of nitrite oxidizing bacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • Targeted treatment of nitrate groundwater was achieved without deterioration. • S0 as electron donor-driven MFC has high electron utilization rate and economic. • Flavin and cytochrome c as electron mediators for accelerating electron transfer. • Current additionally encouraged changes in the protein's secondary structure. • Thiobacillus and Desulfocapsa as main genus contributed to denitrification. Sulfur (S0)-driven autotrophic denitrification system has obvious advantages in economy and performance in treating the low carbon/nitrogen groundwater. However, the by-products produced from S0 oxidation will cause disturbance to the water quality. In this study, a dual-chamber microbial fuel cell was driven by S0 (S0-MFC) to separate the S0 and nitrate, the electrons generated by the oxidation of S0 in the anodic chamber transferred to the cathode for nitrate reduction. Under the action of the anode microorganisms, the S0 was directly oxidized to sulfate. The maximum nitrate removal rate (NRR) in the cathodic chamber was 2.31 ± 0.03 mg N/L/h, and the anode electron utilization rate could reached to 19.69 %. Electrochemical results showed that flavin and c-type cytochrome could acted as electron mediators promote the electron transfer processes. The presence of loop current contributed to the enhancement of microbial metabolic activity, thus improving the stability of sludge and NRR. The denitrifiers (Thiobacillus and Denitratisoma) and sulfur autotrophs (Desulfocapsa and Acidithiobacillus) played an important role in the high NRR. A low-cost and pollution-free method for removing nitrate from groundwater was realized in this study. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evidence for direct electron transfer denitrification (DETD) was observed. • The nitrogen removal rate reached 60.17 mmol NO 3 −-N L−1 day−1 m−2. • Thiobacillus highly expressed extracellular multiheme c -type cytochrome genes. Cathodes can play a pivotal role as electron donors for denitrification in wastewater treatment plants, facilitating the removal of nitrogen-containing compounds such as nitrate. Denitrifying bacteria can either accept electrons directly from the electrode or indirectly via electron shuttling intermediaries generated at the cathode. In this study, comparative analyses were conducted between two denitrifying electrochemical reactors with biocathodes poised at different potentials, one that generated H 2 through water electrolysis and one that did not (−500 mV and −800 mV vs. SHE). Nitrogen removal efficiencies were much higher in the −500 mV (vs. SHE) system, >93 % compared to only 20 %. Notably, a biofilm formed exclusively on the −500 mV (vs. SHE) cathode, predominantly composed of Thiobacillus species, with the majority most similar to Thiobacillus strain 65-29. Metatranscriptomics showed that genes from Thiobacillus strain 65-29 encoding outer surface c -type cytochrome and porin proteins that could facilitate direct electron uptake, were markedly up-regulated in the −500 mV (vs. SHE) reactor. Reduced sulfur species generated by the cathode and sulfate reducing bacteria might have also provided a source of electrons for nitrate reduction. In fact, Thiobacillus in the −500 mV (vs. SHE) system exhibited elevated expression of genes involved in thiosulfate (soxABXYZ), sulfite (soeABC), and sulfide (fccAB) oxidation. These findings offer valuable insights into the mechanisms of autotrophic denitrification by Thiobacillus in mixed culture systems and provide practical guidance for engineering applications. [ABSTRACT FROM AUTHOR]

Background: Remediation of petroleum hydrocarbons from the soil is one of the essential factors. This study was conducted to test the impact of sulfur granular Municipal Soil Waste (sulfur granular MSW), foliar application of iron sulfate on biodegradation of diesel oil in a cadmium (Cd)-polluted soil in the presence of thiobacillus bacteria.Methods: Treatments consisted of applying sulfur granular MSW at the rates of 0 and 15 t/ha and foliar application of iron sulfate (0 and 500 mg/L) in a Cd-polluted (0, 10, and 20 mg Cd/kg) soil that simultaneously contaminated with diesel oil (0%, 4%, and 8% w/w) in the presence of thiobacillus bacteria. After 60 days, the corns were harvested, and the plants’ Fe and Cd concentration was measured using Atomic Absorption Spectroscopy (AAS). In addition, thebiodegradation of diesel oil in the soil was measured.Results: Soil application of sulfur granular MSW (15 t/ha) significantly increased the biodegradation of diesel oil in the soil by 16.1%. However, soil contamination with Cd had an adverse effect on the biodegradation of diesel oil in the soil. The presence of thiobacillus bacteria had a considerable effect on reducing the Fe and Cd concentration of the plant by 16.1% and 17.3%, respectively.Conclusion: Based on the study results, using sulfur granular MSW and foliar application of iron sulfate has a significant effect on the biodegradation of diesel oil in the heavy metal polluted soil. However, the role of plant physiology, the type, and the amount of pollution on phytoremediation efficiency cannot be ignored.

The heterotrophic and autotrophic synergistic denitrification (HAD) system can effectively remove sulfide, nitrate, and organic carbon pollutants from municipal wastewater. However, the effect of sulfide on the functional bacteria in the denitrification system is still unclear. To better understand the mechanism of sulfide affected on bacteria in the system, the up-flow anaerobic sludge blanket (UASB) reactor was operated continuously under heterotrophic (no sulfide added) and mixotrophic conditions (with increased sulfide contents) for 120 days. The contents of protein (PN) in extracellular polymeric substances (EPS) were significantly increased with the addition of sulfide, which enhanced the flocculation of sludge and was beneficial to the formation of high-density microorganism communities. The dominant bacteria showed large differences under different nutrient conditions. The abundances of Thauera increased from 4.13% to over 12.94%, and that of Dechloromonas and Thiobacillus were 2.61–3.01% and 1.04–2.66% respectively after added sulfide. And the efficient performance of the system in mixotrophic conditions was accomplished with the interaction of heterotrophic sulfide-oxidizing, nitrate-reducing bacteria (Thauera, Dechloromonas), autotrophic sulfide-oxidizing, nitrate-reducing bacteria (Thiobacillus) and heterotrophic nitrate-reducing bacteria (Rubrivivax, Acidovorax, Simplicispira, Alicycliphilus). Moreover, the abundances of Nar G, Nap A, Nir S, Nor B, and Nos Z were significantly enhanced in mixotrophic conditions, indicating that the nitrogen metabolism potential of the system was also improved after added sulfide. These results elucidated the reasons for the enhanced denitrifying capacity of the system by adding S2− from the microbiological point of view and provided a theoretical basis for the establishment of an efficient denitrification system. [ABSTRACT FROM AUTHOR]

Nitrate contamination of groundwater and surface water has become a serious problem. Zero-capacity iron (Fe0) nanoparticles are of great interest for the purification of toxic compounds from water. The aim of this study was to synthesis and optimize starch-coated "St" and carbon quantum dot-coated "CQD" Fe0 nanoparticles (St-Fe0 and CQD-Fe0) and investigate their role in bio denitrification and expression of nirS, narH and recA genes using the q-PCR technique. This study has a non-treatment control. The structural and morphological characteristics of nanoparticles were determined by XRD, TEM, FE-SEM and FTIR. Two important operating parameters including temperature (̊C) and nanoparticles concentration (g l−1) influencing the bio denitrification process of Thiobacillus denitrificans in the presence of nanoparticles were optimized by the response surface method (RSM). The FTIR spectrum confirmed the formation of CQD-Fe0 bonds. The average diameter of CQD-Fe0 nanoparticles was in the range of 29.31 to 38.32 nm. Denitrification in the presence of St-Fe0 and CQD-Fe0, with increasing temperature (35 C°) and nanoparticle concentration (1 g l−1), was 71.42% and 73.43%, respectively. After determining the optimal conditions, bio denitrification in the presence of nanoparticles at different concentrations of nitrate was investigated in a moving bed bioreactor. According to the results, in the discontinuous conditions, bio denitrification efficacy of Thiobacillus denitrificans in the presence of St-Fe0 and CQD-Fe0 nanoparticles was 80.10% and 79.83%, respectively. While in the bioreactor, denitrification efficacy in the presence of St-Fe0 and CQD-Fe0 was increased to 94.07% and 95%, respectively. In other words, bio denitrification of microorganisms in the moving bed bioreactor in the presence of CQD-Fe0 was higher compared to St-Fe0. The results of this study showed that the expression of all three genes nirS, narH and recA in cells treated with St-Fe0 and CQD-Fe0 significantly increased compared to the control group, which indicates the high impact of these nanoparticles, especially CQD-Fe0 on bio denitrification of this microorganism. [ABSTRACT FROM AUTHOR]

In contrast to acid mine drainage, the microbial assembly and (bio)geochemical processes in alkaline mine conditions remain under-investigated. Here, microbe-water-mineral interactions were systematically investigated in two representative iron mines with alkaline conditions in the Panxi mining area, Southwest China. Compared to reference riverine samples less interfered by mining activities, the iron ore samples, composed of vanadium-titanium magnetite and pyroxene-rich bedrocks, exhibited elevated levels of Fe, HCl-extractable Fe(II), total sulfur, nitrate and sulfate, but lower total carbon (TC). Meanwhile, the mine drainage showed significantly higher sulfate, but lower TC concentrations than the riverine samples. Intriguingly, the Serpentinimonas spp., typically reported in serpentinites, prevailed in the microbial communities from the mine samples exhibiting higher pH. This suggests that the alkaline environments in Panxi mines result from serpentinization-like reactions. Enrichment of Thiobacillus spp. was observed in the mine-dwelling microbial communities, positively correlated with total sulfur, sulfate, nitrate, and Fe(II). Genome-resolved metagenomics suggested a chemoautotrophic lifestyle for the Thiobacillus species (e.g., carbon fixation, sulfur oxidation, and oxygen respiration), which may generate H + and mitigate alkalization. This study provides valuable insights into progressive development of alkaline mine ecosystems and offers guidance for developing appropriate engineering strategies to restore the abandoned alkaline mines., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

[Display omitted] • Using pretreated stalk in-situ loaded S-NZVI to remediate actual low C/N water body. • Stalk is crucial for TN removal by supplying carbon source to microorganisms. • S-NZVI is crucial for TP removal by forming Fe-P precipitation. • Pretreated stalk acts as a scaffold to improve dispersity and O 2 resistance of S-NZVI. • S-NZVI and Pretreated stalk synergistically boost sediment microbial activity. Sulfidated nano zero-valent iron (S-NZVI) as reductants coupled with organic carbon are promising in enhancing denitrification which is crucial for remediation of low C/N water body. Nevertheless, the dearth of research on the effectiveness of these materials in actual water remediation limits their application. Additionally, most of the studies utilizes industrial chemical-derived organic carbon, which exacerbates environmental and economic burdens. This study proposes employing pretreated stalks in-situ loaded S/Fe (SS-S/Fe) to remediate the low C/N slightly black-odorous water body. The pretreated stalk acts as carbon source replacing the industrial chemicals. The pretreatment process was carried out by using H 2 O 2 and acetic acid to decrease the lignin content. The 2, 4-dichlorophenol was utilized as a target pollutant for optimization of materials. The sediment from the water body was remediated, the impact of SS-S/Fe on water body and microbial community structure were clarified. The lignin residues in the stalk were found to enhance the dispersity, O 2 resistance, and reduction performance toward 2, 4-dichlorophenol of S/Fe. S/Fe facilitates 2, 4-dichlorophenol degradation via reduction and TP removal via forming Fe-P precipitation. SS plays a significant role in TN removal, assisting in enhancing the 2, 4-dichlorophenol and TP removal performance of S/Fe. Crucially, SS and S/Fe synergistically boost sediment microbial activity, conferring resistance to the subsequent pollution shock. The decisive role of SS in enhancing denitrification by cultivating Anaeromyxobacter , unclassified_f_Comamonadaceae , norank_f_norank_o_norank_c_Anaerolineae and Thiobacillus has been demonstrated. This study improves S-NZVI applicability in actual low C/N water bodies and provides new methods for utilizing stalk resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Original IS had lower denitrification and S cycle genes in IS than those of AS. • Biofilm inoculated by IS enriched more functional genes than by AS in SAD systems. • Biofilm domesticated by IS had more S cycle genes at high stress of S2- and SO 4 2- • Microbes for S cycle more sensitive to the toxicity of S2- than denitrifiers. To develop a reliable sulfide (S2-) autotrophic denitrification (SAD) process under S2- and SO 4 2- salinity stresses, the biofilm performance and microbial mechanisms were comparatively studied using different inocula of activated sludge (AS) and intertidal sediment (IS). Biofilm IS enriched more denitrification genes (0.34 %) and S2- oxidation genes (0.29 %) than those with AS. Higher denitrification performance was obtained under S2- (100 mg/L) and SO 4 2- (5–15 g/L Na 2 SO 4) stresses, but no significantly differences were observed under levels of 0–200 mg/L S2- and 30 g/L Na 2 SO 4. Notably, biofilm samples in SAD systems with IS still had more S2- oxidation genes at high S2- levels of 100–200 mg/L and Na 2 SO 4 level of 30 g/L. The key functional genus Thiobacillus accumulated well at 30 g/L Na 2 SO 4 , but was strongly inhibited at 200 mg/L S2-. The findings were advantage to SAD application under sulfide and salinity stresses. [ABSTRACT FROM AUTHOR]

Remediation of industrial wastewater is important for preventing environmental contamination and enabling water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN-), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN- loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN-. A second reactor was fed ammonium sulfate to mimic breakdown products of SCN-. Biomass was sampled from both reactors for metagenomics and metaproteomics, yielding a set of genomes for 144 bacteria and one rotifer that constituted the abundant community in both reactors. We analyzed the metabolic potential and temporal dynamics of these organisms across the increasing loadings. In the SCN- reactor, Thiobacillus strains capable of SCN- degradation were highly abundant, whereas the ammonium sulfate reactor contained nitrifiers and heterotrophs capable of nitrate reduction. Key organisms in the SCN- reactor expressed proteins involved in SCN- degradation, sulfur oxidation, carbon fixation, and nitrogen removal. Lower performance at higher loadings was linked to changes in microbial community composition. This work provides an example of how meta-omics can increase our understanding of industrial wastewater treatment and inform iterative process design and development.

Submerged zone in bioretention facilities for stormwater treatment has been approved to be an effective structure amendment to improve denitrification capability. However, the role and influence of water quality changes in the submerged zone under natural continuous random rainfall patterns are still not clear, especially when the rainfall is less than the pore water in the submerged zone. In this study, continuous rainfall events with different rainfall volume (light rain-light rain-heavy rain) were designed in a lab-scale woodchip mulched pyrite bioretention facility to test the effects of rainfall pattern. The results exhibited that light rain events significantly affected the pollutant removal performance of bioretention for the next rainfall. Different effects were observed during the long-term operation. In the 5th month, light rain reduced the ammonia removal efficiency of subsequent rainstorm events by 8.70%, while in the 12th month, when nitrate leakage occurred, light rain led to a 40.24% reduction in the next heavy rain event's nitrate removal efficiency. Additionally, light rain would also affect the concentration of by-products in the next rainfall. Following a light rain, the concentration of sulfate in the subsequent light rainfall can increase by 24.4 mg/L, and by 11.92 mg/L in a heavy rain. The water quality in the submerged zone and media characteristics analysis suggested that nitrogen conversion capacity of the substrate and microbes, such as Nitrospira (2.86%) and Thiobacillus (35.71%), as well as the in-situ accumulation of pollutants under light rain played important roles. This study clarifies the relationship between successive rainfall events and provides a more comprehensive understanding of bioretention facilities. This is beneficial for field study of bioretention facilities in the face of complex rainfall events. [Display omitted] • A novel rainfall pattern was proposed to evaluate the efficiency of bioretention. • Light rain significantly impacts the performance of the next heavy rainfall. • Light rain leads to nitrate and sulfate accumulation in the submerged zone. • Microorganism is the main factor of ammonia accumulation in submerged zone. • 5. Thiobacillus and Pseudomonas are the dominant bacteria in the submerged zone. [ABSTRACT FROM AUTHOR]

Magnetite mining is a significant contributor to land deterioration as well as HM-based soil contamination. The characteristics of magnetite mine tailing were examined in the present study, in addition to the positive and sustainable restoration strategy with Bougainvillaea glabra under the influence of Thiobacillus ferroxidance. The traits of test soil analysis findings demonstrated that the majority of the parameters exceeded the allowable limits (For instance: HMs such as Cr, Cu, Zn, Pb, Fe, and Co were found to be 208 ± 2.3, 131.43 ± 1.6, 185.41 ± 3.3, 312 ± 5.11, 956 ± 5.3, and 26.89 ± 2.43 mg kg−1 respectively). T. ferroxidance exhibited impressive HMs tolerance for as much as 800 g mL−1 concentrations of Cr, Cu, Zn, Pb, Fe, and Co. To prevent HMs toxic effects, the HMs contents in test soil were decreased by diluting with normal soil in the ratios of Ex-3 and Ex-2. A typical greenhouse study was carried out to assess the phytoremediation ability of B. glabra across six setups for experiments (Ex-1 to Ex-6). According to the findings of this research, the HMs tolerant T. ferroxidance from Ex-3 and Ex-2 had an outstanding impact on the growth, biomolecules level (such as chlorophylls: 65.84 & 41.1 mg g−1, proteins: 165.1 & 151.1 mg g−1, as well as carbohydrates: 227.4 & 159.3 mg g−1) as well as phytoremediation potential of B. glabra on magnetite mine soil. These findings indicated that a mixture of B. glabra as well as T. ferroxidance might serve as a valuable sustainable agent for removing HMs from contaminated soil. • The magnetite mine tailing has alkaline ph (9.41) and Cr & Cu contents are higher. • The test T. ferroxidance possess fine tolerance upto 800 μg ml−1 of various HMs. • HMs mobilization study revealed that this T. ferroxidance is a fine HMs mobilize. • T. ferroxidance presence improve the biomolecules & biomass of B. glabra. • B. glabra seed coated with T. ferroxidance showed fine phytoremediation potential. [ABSTRACT FROM AUTHOR]

• The highest total nitrogen removal efficiency of EFB-SFe was 84% • Denitrification efficiency of EFB-SFe was increased by 103% compared to EFB-S. • The dominated bacteria Ferritrophicum and Thiobacillus were enriched in EFB-SFe. • Denitrification functional genes in EFB-SFe were 12–22 times than that in EFB-S. A sulfur-iron coupled ecological floating bed (EFB-SFe) was developed to enhance the denitrification capability of sulfur-based ecological floating beds (EFB-S). The denitrification performance, kinetic process and microbial community composition were explored. Results showed that sulfur-iron coupling effectively enhanced the denitrification performance of EFB, surpassing the sum of their individual effects. The average total nitrogen removal rate ranged from 1.56 to 4.56 g·m−2·d-1, with a removal efficiency of 22–84 %. The k value for the S + Fe group increased from 0.04 to 0.18 d-1 to 0.40–0.46 d-1 relative to the S group. The sulfur-iron coupling promoted the enrichment of denitrifying bacteria (Thiobacillus and Ferritrophicum). The denitrification genes in EFB-SFe were upregulated, being 12–22 times more abundant than in EFB-S. Sulfur and iron autotrophic denitrification were identified as the main nitrogen removal processes in EFB-SFe. Overall, sulfur-iron coupling showed the potential to enhance the denitrification capacity of EFB-S for treating low-pollution water. [ABSTRACT FROM AUTHOR]

Purpose: Sulfate-reducing bacteria (SRB) are recognized by scholars as the most important class of bacteria leading to corrosion of metal materials. It is important to use the properties of microorganisms to inhibit the growth of SRB in the corrosion protection of metal materials and to protect the environment. Design/methodology/approach: In this work, the behavior of anaerobic Thiobacillus denitrificans (TDN) intracellular enzyme inhibition of SRB corrosion of EH36 steel was investigated with electrochemical impedance spectroscopy, biological detection technology and X-ray photoelectron spectroscopy. Findings: Results showed that the SRB crude intracellular enzyme affected the corrosion behavior of EH36 steel greatly and the purified TDN intracellular enzyme inhibits SRB intracellular enzyme corrosion to EH36 steel. Originality/value: A perfect enzyme activity inhibition mechanism will provide theoretical guidance for the selection and application of anticorrosion microorganisms, which is of scientific significance in the field of microbial anticorrosion research. [ABSTRACT FROM AUTHOR]

The diversity, community structure and vertical distribution characteristics of bacteria in the surface and subsurface soil and water samples of a closed landfill in Shanghai Jiading District were investigated to reveal the relationships between natural waste degradation degree and the succession of bacterial community composition. High-throughput sequencing of bacteria 16S rDNA genes was used to analyze the bacterial community structure and diversity. The results showed that the diversity of bacteria in the surface samples was higher than that in the deep samples. Proteobacteria was the dominant phylum in all the samples, and the percentage increased with depth. At the genus level, Thiobacillus, Pseudomonas, Aquabacterium, and Hydrogenophaga were the dominant genera in surface, medium, deep and ultra-deep soils, respectively. The Bray–Curtis dissimilarity of the soil bacterial communities in the same layer was small, indicating that the community composition of the samples in the same layer was similar. The RDA result showed that ammonium, nitrate, pH and C/N significantly influenced the community structure of soil bacteria. This is of great relevance to understand the effect of natural waste degradation on bacterial communities in closed landfills. [ABSTRACT FROM AUTHOR]

Gold ore processing uses cyanide (CN(-) ), which often results in large volumes of thiocyanate- (SCN(-) ) contaminated wastewater requiring treatment. Microbial communities can degrade SCN(-) and CN(-) , but little is known about their membership and metabolic potential. Microbial-based remediation strategies will benefit from an ecological understanding of organisms involved in the breakdown of SCN(-) and CN(-) into sulfur, carbon and nitrogen compounds. We performed metagenomic analysis of samples from two laboratory-scale bioreactors used to study SCN(-) and CN(-) degradation. Community analysis revealed the dominance of Thiobacillus spp., whose genomes harbour a previously unreported operon for SCN(-) degradation. Genome-based metabolic predictions suggest that a large portion of each bioreactor community is autotrophic, relying not on molasses in reactor feed but using energy gained from oxidation of sulfur compounds produced during SCN(-) degradation. Heterotrophs, including a bacterium from a previously uncharacterized phylum, compose a smaller portion of the reactor community. Predation by phage and eukaryotes is predicted to affect community dynamics. Genes for ammonium oxidation and denitrification were detected, indicating the potential for nitrogen removal, as required for complete remediation of wastewater. These findings suggest optimization strategies for reactor design, such as improved aerobic/anaerobic partitioning and elimination of organic carbon from reactor feed.

In an agri-silviculture of the plum (Prunus domestica L. Cv. Opal), the forage quality of smooth vetch (Vicia dasycarpa L.) was evaluated. For this purpose, a two-year (2016 and 2017) factorial experiment was conducted based on randomized complete block design with three replications at Urmia University, Iran. The treatments included the combined and individual application of biofertilizers {Azotobacter chroococcum (Az), Thiobacillus spp. (Th)., Rhizophagus intraradices (AMF) and control} under rainfed and once supplementary irrigation. The results showed that irrigated plants contained higher P than rainfed plants. Dual inoculation with "AMF + Az" had higher Ash, K, CP and WSC than plants with fungal or bacterial inoculation alone. In comparison with control, biofertilizers improved the forage and protein yield by 32 and 45.50% under rainfed conditions and by 47 and 60.04% under supplementary irrigation, respectively. The amount of CAT, GR, APX, and SOD were reduced in rainfed plants, but the co-inoculation of mycorrhizal plants with Az and/or Th enhanced enzymatic antioxidants. In conclusion, the combined use of AMF and Az improved smooth vetch forage quantity and quality in irrigated plants as much as rainfed did, and hence it can be desirable for sustainable agriculture. [ABSTRACT FROM AUTHOR]

The purpose of this study is to clarify the mechanism of the coupled hydrion with biology polysulfide in the simultaneous denitrification and desulfurization process. The coupled hydrion with biology polysulfide, uncoupled hydrion with biology polysulfide and no polysulfide experiments were performed in wastewater with two kinds of sulfide loads (100 and 200 mg/L). When the concentration of thiosulfate was suitable, the free H+ concentration (74.2 and 91.0 mg/L) and the proportion of Thiobacillus denitrificans (85.4% and 59.7%) were both higher under the two kinds of sulfide loading conditions (100 and 200 mg/L), and coupled hydrion with biology polysulfide was realized (the production of elemental sulfur is as high as 33 and 101 mg/L). Further analysis shown that the way of coupled hydrion with biology polysulfide were both: 2.0 S 2 − + 6.4 NO 3 − + 30.1 H + + 21.7 e − → 1.0 S 2 − + 1.0 SO 4 2 − + 3.2 N 2 + 15.0 H 2 O . In addition, for the coupled hydrion with biology polysulfide, more nitrates could be utilized to produce elemental sulfur S0, and the lower ratio of H+/S0 and SO 4 2 − / S 0 were observed (S2- = 100 mg/L: 2.3 and 0.9; S2- = 200 mg/L: 0.9 and 0.03), which could promote the growth of Thiobacillus denitrificans and increase the proportion of Thiobacillus denitrificans. This maybe one of the reasons why coupled hydrion with biology polysulfide could be achieved. [ABSTRACT FROM AUTHOR]

The biological study experiment included the effect of inoculation with sulphur-oxidizing bacteria T. thioparus and its interaction with levels of organic matter. In addition, a biological vaccine for T. thioparus and the second factor is the organic matter at three levels control by without adding (0%, 0.5%, 1 %) the results of the statistical analysis showed that the biological Inoculation. T. thioparus treatment gave the highest levels of grain yield, numbers of T. thioparus bacteria, soil content of available nitrogen and soil content of available sulphur (4.74 mg.h-1, 0.22×104 CFu gm-1 soil, 54.27 mg N kg soil-1, 3131.39 mg S kg soil-1) respectively. While treatment with the second level of organic matter 1% gave the highest levels of the numbers of T. thioparus bacteria and the nitrogen content available in the soil and the sulphur content available in the soil (0.23×104 CFu gm-1 soil, 5163 mg N kg soil-1, 2796 mg S kg soil-1) respectively. In addition to the interactive treatments of biological inoculation of T. thioparus and organic matter of B1O2 of T. thioparus numbers, nitrogen content available in soil and soil sulphur content available (0.24×104 CFu gm-1 soil, 59.40 mg N kg soil-1, 3326.87 mg S kg soil-1) respectively. [ABSTRACT FROM AUTHOR]

This work reports the possibility of uranium recovery from a post-mining uranium ore dump in Poland by a bioleaching method. The studies were conducted on the dump leaching model with the mass of 570 kg of uranium bearing mineral material from Radoniów pile and in the periodic bioreactor with a work volume of 80 dm3 and with mechanical mixing and aeration of the charge. The uranium concentration in the examined material was about 800 ppm. In this process, the consortium of microorganisms isolated from former mines was used. It was composed of the following microorganisms: Bacillius, Pseudomonas, Sphingomonas, Thiobacillus, Halothiobacillus, Thiomonas, and Geothrix. The efficiency of the uranium bioleaching process was 98% in the reactor, and a yield of 70% was obtained in the dump leaching model. The post-leaching solution contained significant amounts of uranium ions that were separated in two stages: (1) by ion chromatography and then (2) by a two-step precipitation method. The resulting solution was a source of ammonium diuranate, the precursor of yellowcake (uranium oxides). [ABSTRACT FROM AUTHOR]

The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be suitable for handling soluble sulfur in wastewater. The purpose of this study is to evaluate the effect of nutrient (SO42−, PO43−, and Fe2+) concentration on BSRU performance, particularly on the conversion of sulfide to elemental sulfur. This study shows that the variation of SO42− concentration does not significantly affect the conversion process, while a small increment of PO43− (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+ also significantly affected the formation and conversion rate of elemental sulfur.

In order to investigate the effect of organic and chemical fertilizers on quantitative and qualitative traits of Ducrosia anethifolia, a randomized complete block design was carried out with three replications. The experiment was performed with seven treatments including control (no fertilizer), manure (bovine), chemical fertilizers including nitrogen(N), phosphorus (P) and potassium (K), vermicompost fertilizer, thiobacillus bacterium, mycorrhiza fungi, and a combination of mycorrhizal fungi and thiobacillus bacterium (mycorrhiza+thiobacillus). Results showed that fertilizer treatments increased the yield and yield components of the plant compared to the control. Inoculation with thiobacillus, mycorrhiza, and thiobacillus+mycorrhiza resulted in higher levels of seed yield, essential oil yield and percentage, chlorophyll a, b and total and also carotenoids content compared to plants treated with chemical fertilizers. Generally, thiobacillus+mycorrhiza treatment led to more seed yield (8430 kg/ha) and essential oil yield (176.36 kg/ha) than other treatments, showing 62% and 52% increase in seed yield and 80% and 321% increase in essential oil yield in comparison with control and chemical fertilizers, respectively. Based on the results of this research, application of biological fertilizers can control excessive use of chemical fertilizers in sustainable agriculture. [ABSTRACT FROM AUTHOR]

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Mercury (Hg) is a toxic heavy metal that poses significant environmental and human health risks. Soils and sediments, where Hg can exist as the Hg sulfide mineral metacinnabar (β-HgS), represent major Hg reservoirs in aquatic environments. Metacinnabar has historically been considered a sink for Hg in all but severely acidic environments, and thus disregarded as a potential source of Hg back to aqueous or gaseous pools. Here, we conducted a combination of field and laboratory incubations to identify the potential for metacinnabar as a source of dissolved Hg within near neutral pH environments and the underpinning (a)biotic mechanisms at play. We show that the abundant and widespread sulfur-oxidizing bacteria of the genus Thiobacillus extensively colonized metacinnabar chips incubated within aerobic, near neutral pH creek sediments. Laboratory incubations of axenic Thiobacillus thioparus cultures led to the release of metacinnabar-hosted Hg(II) and subsequent volatilization to Hg(0). This dissolution and volatilization was greatly enhanced in the presence of thiosulfate, which served a dual role by enhancing HgS dissolution through Hg complexation and providing an additional metabolic substrate for Thiobacillus. These findings reveal a new coupled abiotic-biotic pathway for the transformation of metacinnabar-bound Hg(II) to Hg(0), while expanding the sulfide substrates available for neutrophilic chemosynthetic bacteria to Hg-laden sulfides. They also point to mineral-hosted Hg as an underappreciated source of gaseous elemental Hg to the environment.

BACKGROUND To investigate the effects of salinity as a serious environmental limiter of productivity on the yield‐related traits of Lallemantia iberica, a split‐plot experiment was performed for 2 years (2017–2018) based on a randomized complete block design with three replications at Urmia University (37°33′09″N, 45°05′53″E). The main plots included salinity stress at two levels (6.72 dS m−1, and 0.91 dS m−1 as control), and subplots were inoculants at four levels (Funneliformis mosseae, Thiobacillus sp., F. mosseae + Thiobacillus sp., and no inoculation). RESULTS: In the saline condition, serious reductions in yield and yield components (numbers of capsules per plant, seeds per capsule, and seeds per plant, 1000‐seed weight, seed and biological yields), concentrations of leaf phosphorus and potassium, and relative mycorrhizal dependency were observed, but against the harvest index the leaf sulfur and sodium contents were increased. Moreover, all morphological traits (plant height, number of branches and leaves, leaf weight, stem weight, and ratio of leaf weight to stem weight) were decreased under salinity conditions. Mycorrhizal inoculation enhanced the salinity‐induced reduction of yield and morphological traits to some extent. Inoculation with Thiobacillus had superiority in some of the yield and morphological characteristics compared with those in the non‐inoculated plants. CONCLUSION: Salinity stress can significantly affect the yield, morphological characteristics, nutrients content, and mycorrhizal dependency of L. iberica plants. This study exhibited the significant effects of single and simultaneous applications of F. mosseae and Thiobacillus on plant growth and yield in saline soils. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]