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Zinc oxide (ZnO) nanoparticles (NPs) coated with 1‐butyl‐3‐methylimidazolium tetrafluoroborate ionic liquid (IL) (ZnO‐[BMIM][BF4] NPs) and ZnO NPs without IL coating were both synthesized by co‐precipitation. Various analytical methods were used to characterize the synthesized NPs. X‐ray diffraction (XRD) analysis revealed that ZnO NPs had a mean crystallite size of 32 nm and that of ZnO‐[BMIM][BF4] NPs was 22 nm. IL alters the Fourier transform infrared spectroscopy (FTIR) peaks of the as‐prepared ZnO NPs. A blueshift was seen in the absorption peak of ZnO‐[BMIM][BF4] NPs as compared to bare ZnO NPs. An examination of the UV–visible (UV–Vis) spectra revealed that the optical bandgap decreases with the addition of IL to ZnO NPs. Scanning electron microscopy (SEM) and high‐resolution transmission electron microscopy (HR‐TEM) investigation revealed the morphology and size of the nanostructured particles. The chemically prepared ZnO‐[BMIM][BF4] NPs displayed the irregular spherical‐shaped morphologies in the range of nanoscale. Transmission electron microscopy (TEM) showed the conventional hexagonal wurtzite structure of ZnO‐[BMIM][BF4] NPs. Synthesized ZnO‐NPs in water have a zeta potential of −13.1 mV, showing that they are stable solutions. Thermal behaviour of ZnO NPs was studied using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The agar‐well diffusion technique was used to investigate and compare the antimicrobial activity of synthesized ZnO‐[BMIM][BF4] NPs against the following bacteria and fungi: Streptococcus aureus, Pseudomonas aeruginosa and Candida albicans. The MCF7 breast cancer cells were used to assess the anticancer capabilities of ZnO‐[BMIM][BF4] NPs at various doses (100 μg/mL, 10 μg/mL, 1 μg/mL, 100 ng/mL, 10 ng/mL and 1 ng/mL) using MTT assays. The range of cell inhibition was determined to be from 19.14% to 70.52%. The percentage of cytotoxicity increases was observed when the concentration of synthesized ZnO‐[BMIM][BF4] NPs ranges from 1 ng/mL to 100 μg/mL. [ABSTRACT FROM AUTHOR]

Diverse microbial communities play a crucial role in maintaining the proper functioning of river ecosystems and are considered important indicators of river water quality. Although the Seine River being heavily impacted by human activities, little is known about the microbial communities in its surface waters. In order to monitor water quality and promote sustainable use, we studied its microbial diversity using high-throughput sequencing technology, and explored their relationships with physico-chemical properties. The dominant phyla identified were Proteobacteria, Actinobacteriota, Bacteriodota, and Cyanobacteria. The presence of the Alphaproteobacteria and Gammaproteobacteria indicates that the Seine River water nutrient profile is mainly determined by the recalcitrant organic compounds present in WWTP effluents. Bacterial diversity showed significant temporal variability with a highly significant difference in bacterial composition between 2020 and 2021, probably due to variations in water flow favoring Cyanobacteria growth. Summer displayed higher microbial activity and abundance than autumn, attributed to temperature and orthophosphate content. Spatial variation in bacterial composition was observed between sites upstream and downstream of Paris, as well as before and after of the Seine Valenton-WWTP, subject to an accumulation phenomenon and impacted by wastewater treatment. Further assessment of emerging contaminants and other pollutants is required to better understand these variations. These results provide a basic understanding of the microbial community in the Seine River, serving as a reference for assessing the impact of implementing new wastewater disinfection techniques in the near future. [ABSTRACT FROM AUTHOR]

The activity of methanogenic Archaea in porous formations is influenced by various pore characteristics, including porosity, surface area, and the gas-liquid interfacial area. This study explores the impact of surface area on methanogenic activity using techniques such as MICP, NMR, SEM, and μCT. The cells of Methanothermococcus thermolithotrophicus , ranging from 1 to 2 μm, indicate that pores smaller than this threshold are not accessible for microbial traversal and colonization. Upon normalization of microbial activities based on pore volume and interfacial area, the findings exhibit strong correlations with specific surface areas of accessible pores in the examined rocks, as determined by MICP, NMR, and SEM. These areas ranged from 0.001 to 0.017 m2/g, 0.003–0.024 m2/g, and 0.012–0.02 m2/g, respectively. The normalized activities increase from 0.19 to 0.44 mM/(h·cm3·cm2) with an increase in the specific surface area, varying by method. Furthermore, an empirical model has been established to quantitatively evaluate hydrogen loss during underground hydrogen storage or the efficiency of bio-methanation, incorporating pore volume, specific surface area, and interfacial area. • Methanogenic activity in rocks correlates strongly with accessible surface area. • Porosity, surface area, and interfacial area impact microbial activity. • Pore characteristics correlate microbial activity in rocks and solution. • Microbial activity varies by formation and requires individual assessment. [ABSTRACT FROM AUTHOR]

Sandy soils are widespread globally and are increasingly utilized to meet the demands of a growing population and urbanization for food, fiber, energy, and other essential services. However, their poor water and nutrient retention makes crop cultivation challenging. This study evaluated the effects of integrating compost and plant growth-promoting rhizobacteria (PGPR; Azospirillum brasilense SWERI 111 and Azotobacter chroococcum OR512393) on wheat (Triticum aestivum L. var. Misr 1) grown in sandy soil under varying levels of recommended NPK (50%, 75%, and 100%) fertilization. Conducted over two growing seasons, the experiment aimed to assess soil health, nutrient uptake, microbial activity, and plant productivity in response to compost and PGPR treatments. The results demonstrated that combining compost and PGPR significantly improved soil chemical properties, such as reducing soil pH, electrical conductivity (ECe), and sodium adsorption ratio (SAR), while enhancing soil organic matter (SOM). Additionally, compost and PGPR improved soil nutrient content (N, P, K) and boosted the total bacterial and fungal counts. The combined treatment also increased urease and phosphatase enzyme activities, contributing to enhanced nutrient availability. Notably, plant productivity was enhanced with compost and PGPR, reflected by increased chlorophyll and reduced proline content, along with improved grain and straw yields. Overall, the results underscore the potential of compost and PGPR as effective, sustainable soil amendments to support wheat growth under varying NPK levels. [ABSTRACT FROM AUTHOR]

Adenosine triphosphate (ATP) assays have a faster turnaround time and higher sensitivity than traditional cultivation methods for microbial monitoring. Challenges implementing ATP testing include incompatibility with chlorine quenching agents and hold time sensitivity, which are not well-studied. Chlorinated distribution system samples were collected from two Canadian utilities, Metro Vancouver (n = 40 samples) and Halifax Water (n = 283). No significant correlations were observed between heterotrophic cell count (HPC) and cellular ATP, suggesting these do not correlate well in waters with low biological activity (median HPC < 2 CFU/mL). However, interpretation of HPC and cATP results (based on the HPC guideline of 100 CFU/mL and cATP of 10 pg/mL) yielded the same conclusion for 95% of samples, suggesting a potential decision-making framework to replace HPC with cATP. Moreover, cATP correlates better with free chlorine (p < 0.04) compared with HPC for one of the studied systems. Importantly, adding chlorine quench (10% sodium thiosulfate) did not produce significantly different cATP results, nor did analyzing at various hold times of 4-, 6-, and 24-h. This study supports the integration of ATP testing into existing sampling procedures for water utilities, as a sensitive, fast, and reliable monitoring method. [ABSTRACT FROM AUTHOR]

Simple Summary: While insect larvae production is established in the context of sustainability, meaning that larvae can utilize biogenic by-products from feed and food processing, it also turns out that in insect production, feed costs contribute considerably to overall production costs. With respect to black soldier fly larvae (BSFL) production, the main end product is protein meal, which is used as an ingredient in animal nutrition. By definition, optimizing the protein meal yield requires an understanding of the amino acid requirements of BSFL in order to balance the substrate for efficient utilization. The research reported in this article approached this topic with an amino acid reduction method, which usually allows for determining the ideal ratios between amino acids for optimal performance. Our study revealed that substantial reductions in single amino acids in substrates for BSFL did not impair the performance. However, balance calculations on the fate of dietary amino acids indicated considerable additions of these reduced amino acids by the microbiome. By quantifying these effects, we showed that these additions could be as high as 35% compared to the optimal dietary amino acid supply. Rearing black soldier fly larvae (BSFL) in order to utilize biogenic materials is of increasing interest in the context of sustainable animal production. However, little is known about the amino acid (AA) requirements of this animal species. Therefore, a feeding experiment with BSFL was conducted, in which lysine, methionine, cysteine, arginine, phenylalanine, or histidine was reduced by 65% or methionine was increased by 65%. Reductions in single AAs in the substrate did not negatively impact BSFL growth, while the addition of methionine improved the growth performance, indicating that methionine was a limiting nutritional factor for maximal productivity. Differences in dietary AA profiles had no impact on the AA profile of the BSFL biomass. However, balance calculations for individual AAs indicated that the substrate microbiome was capable of synthesizing and balancing those AAs for microbial protein synthesis. While both the BSFL and microbiome utilized all free AAs, suggesting that supplemental AAs can be effective additives in BSFL production, this microbial AA synthesis avoided the negative performance impacts of BSFL provoked by severe AA reductions. The quantification of these effects suggested that the microbiome could add up to 35% to the overall AA supply in order to overcome AA deficiency. This effect may not necessarily ensure maximal BSFL productivity, as demonstrated by the extra addition of methionine to the substrate. Our research indicated that BSFL nutrition should consider interactions between substrate composition and microbial activity. [ABSTRACT FROM AUTHOR]

Simple Summary: This study indicates that volcanic activity has a long-term impact on biological growth. The synthesis of chlorophyll a by Anabaena pseudoichthyoides was most efficient in the presence of increasing concentrations of volcanic ash leachate. Analysis of the major and trace elements in the solution before and after cultivation shows that the volcanic ash soaking solution has a higher nutrient content compared to granite. This increased nutrient content is a key factor promoting microbial growth. The findings suggest that volcanic ash significantly influences microorganisms, with lasting effects that can persist for tens of thousands to hundreds of thousands of years. The impact of volcanic activity on microorganisms has always been a hot topic of discussion during geological history. Further studies are needed on the effects of volcanic activity on microbial growth in shale and the differences in nutrients provided by volcanic ash and other weathered rocks. This study's results indicated that TOC contents at the bottom of the shale layer are 1.93–4.44% and 3.0% on average. The TOC contents at the top of the layer are 3.38–5.13% and 4.0% on average. It indicated that TOC contents at the bottom of the shale layer are smaller than the TOC contents at the top of the layer, suggesting that volcanic activity posed a long-term effect on biological growth. Seven different leachate concentrations were set in this experiment as follows: 1/10, 1/100, 1/500, 1/1000, 1/1500, 1/2000, and 1/2500. The results showed that the growth status of Pseudourostyla crassipes was affected by the addition of leachates with different concentrations compared to the control group. Additionally, the synthesis of chlorophyll a by Anabaena pseudoichthyoides was the most efficient with the 1/10 volcanic ash leachate. Through the analysis of major and trace elements in the solution before labeland after cultivation, the main elemental content of Ca2+, Mg2+, Na+, and K+ decreased by 3.8~87.24%, 75.96~92.70%, 86.56~95.67%, and 5.42~20.52% in the solution after microbial growth respectively. The trace elements B, Ba, Zn, and Fe decreased by 27.54~94.39%, 20~82.03%, 70.45~98.29%, and 99%. It was found that the B, Ba, Fe, and Zn elements decreased significantly. The nutrients from volcanic ash are the main factor promoting microbial growth. It can be indicated that the volcanic ash soaking solution has a higher content of nutrients when compared to the solubility of nutrients in volcanic ash compared to that of granite. A higher content of nutrients promotes microbial growth. The calculation results indicate that a volcanic eruption with a quantity of several 1010 m3 has a significant impact on microorganisms, lasting from tens of thousands to hundreds of thousands of years. [ABSTRACT FROM AUTHOR]

To increase biodiversity in tomato cultivation, two herbal aromatic plants, thyme (Thymus vulgaris) and basil (Ocimum basilicum L.), were introduced as companion plants. Their role was to improve crop plant growth and stress resistance. Moreover, the effect of the soil application of Trichoderma microbial preparations on tomato growth parameters and yield, in combination with companion plants, was studied. Ligno-cellulose multi-layer microcapsules with Trichoderma atroviride TRS14 spores (MIC14) and the commercial preparation Trianum G (TG) were used as microbial preparations. This experiment was carried out in a certified organic field. Tomato plants were intercropped with thyme or basil in the arrangement of two tomato rows alternating with one herbal row. In all intercropping arrangements and in the control (tomato plants grown without herbs), subplots were sectioned. The soil in the subplots was amended with the MIC14 and TG preparations used at a concentration of 104 spores g−1 of the soil and planted with tomato transplants. No control measures were applied during tomato growing, and the plants were naturally infected with late blight. Tomato plant growth parameters and yield were assessed, and late blight severity was monitored. The degree of soil colonization by Trichoderma fungi and the effect of these applications on soil microbial activity and biodiversity (dehydrogenases activity, EcoPlates AWCD, and Shannon index) were evaluated. The results clearly showed a significant influence of thyme and basil on tomato growth and yield in organic production. The cultivation of thyme adjacent to tomatoes had a beneficial effect on the development of the root system and the number of flowers and fruits on the crop plants. Basil, on the other hand, clearly decreased tomato yield and adversely affected the effect of Trichoderma applications by reducing root system development. Moreover, basil as a companion plant increased late blight symptoms. Both Trichoderma strains colonized soil, but they had no significant effect on the microbial activity or metabolic potential measured on the EcoPlates with the use of the BIOLOG system. However, a decrease in dehydrogenases activity was noted. In organic cultivation, the Trichoderma preparations used had no significant effect on tomato yield, opposite to its increase in integrated tomato production. [ABSTRACT FROM AUTHOR]

Sustainable production of carbon-based products is urgently needed. A novel directed flow-through microbial electrosynthesis (MES) reactor was designed and characterized for carbon dioxide (CO 2) conversion to C2–C6 carboxylates. Three-times denser biofilm, volumetric current density, and productivity were achieved compared with the state of the art. Biomass-specific production rates were maintained over more than 200 days, yet still an order of magnitude lower than that achieved by acetogens in syngas fermentation. Volumetric productivity in MES was comparable with that from syngas fermentation. Clostridium luticellarii and Eubacterium limosum were the dominant species. Carbon-based products are essential to society, yet producing them from fossil fuels is unsustainable. Microorganisms have the ability to take up electrons from solid electrodes and convert carbon dioxide (CO 2) to valuable carbon-based chemicals. However, higher productivities and energy efficiencies are needed to reach a viability that can make the technology transformative. Here, we show how a biofilm-based microbial porous cathode in a directed flow-through electrochemical system can continuously reduce CO 2 to even-chain C2–C6 carboxylic acids over 248 days. We demonstrate a threefold higher biofilm concentration, volumetric current density, and productivity compared with the state of the art. Most notably, the volumetric productivity (VP) resembles those achieved in laboratory-scale and industrial syngas (CO-H 2 -CO 2) fermentation and chain elongation fermentation. This work highlights key design parameters for efficient electricity-driven microbial CO 2 reduction. There is need and room to improve the rates of electrode colonization and microbe-specific kinetics to scale up the technology. Graphical abstract [Display omitted] Microbial electrosynthesis (MES) of carboxylic acids from CO 2 and electricity has been validated for over a decade, now reaching Technology Readiness Levels 3/4 in laboratory settings. However, process optimization is needed before demonstrating an industrial prototype. Key challenges for full-scale implementation include ensuring production stability. Critical areas to investigate and demonstrate are: (i) the impact of CO 2 feed stream composition and properties; (ii) the short- and long-term effects of renewable electricity supply intermittency; and (iii) the flexibility of MES operations and the integrated process, including up- and downstream processes. Moreover, a comprehensive market analysis is required for each target product. For instance, hexanoic acid, which serves as a precursor for nylon, plasticizers, lubricants, pharmaceuticals, fragrances, fuels, and animal feed, necessitates the development of business models that consider complete supply chains and systems. Carbon-based products are crucial to society. However, their production from fossil-based carbon is unsustainable. We developed a scalable microbial electrosynthesis process that produces medium-chain carboxylic acids from CO 2 and renewable electricity, using microorganisms as a catalyst. This represents a promising avenue for generating low CO 2 -footprint precursors for the chemical, fuel, feed, and food industries. [ABSTRACT FROM AUTHOR]

Corn grain with a high phosphorus (P) content (mainly in the form of phytate-P) may need to be processed to improve the digestibility of nutrients for young calves. Processing corn grains can improve the accessibility of phytate-P to the rumen enzymes and increase the bioavailability of P, which benefits the growth and development of calves. The objective of this study was to investigate the effects of feeding starter diets with steam-flaked corn (SFC) compared with ground corn (GC) with 2 P contents of 0.4% and 0.7% DM basis on intake, growth performance, nutrient digestibility, blood metabolites and urinary purine derivatives (PD) in dairy calves. A total of 48 female Holstein dairy calves (3 d old; average initial weight 39.7 ± 3.9 kg) were randomly assigned to a 2 × 2 factorial arrangement of treatments (12 calves/treatment) in a randomized complete block design. The treatment groups were: (1) a starter diet of GC with 0.4% P (GC-0.4P); (2) a starter diet of GC with 0.7% P (GC-0.7P); (3) a starter diet of SFC with 0.4% P (SFC-0.4P); (4) a starter diet of SFC with 0.7% P (SFC-0.7P). Calves received 6 L/d of transition milk on d 2 to 3 and 5 L/d of whole milk on d 4 to 30, which was increased to 7 L/d on d 31 to 45, then decreased to 5 L/d on d 46 to 60 and reduced to a single feeding of 2 L on d 61 to 62. All calves had free access to starter feed and water. All calves were weaned on d 63 and remained in the study until d 83. Rumen fluid samples were collected on d 38 (preweaning) and d 76 (postweaning). Blood samples were collected on d 40 and 80 and urine samples were collected on 4 consecutive days from d 79 to 82 to analyze urinary excretion of PD. The phytate-P content ranged from 0.23 to 0.17 for GC and SFC, respectively. In particular, the interaction between corn processing method and P content showed that the SFC-0.7P diets had a greater intake of starter feed during the pre- and postweaning periods compared with the other experimental groups. In addition, calves fed the SFC-0.7P diet had greater ADG, BW, withers height at weaning, better OM digestibility, higher blood BHB levels, and higher microbial protein synthesis compared with all other groups. Feeding the SFC diet also resulted in improved feed efficiency, improved P digestibility, and a tendency toward a lower rumen pH, albeit with a tendency toward an increase in blood glucose concentration during the preweaning period. In addition, the inclusion of 0.7% P to the starter diet resulted in increased fiber digestibility and a slight improvement in growth performance, which was particularly evident in hip height. Overall, the inclusion of SFC in the calf starter diet, especially in combination with a 0.7% DM basis P supplement, improved growth performance and nutrient utilization in dairy calves compared with GC. The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. [ABSTRACT FROM AUTHOR]

Nanobubble (NB) technology in agriculture has received increased interest due to its potential to promote soil moisture retention and plant development. Therefore, this review investigates the impact of various types of NBs—such as oxygen, carbon dioxide, and air—on soil and plant systems. Various studies revealed that nanobubble-saturated water (NBSW) increases moisture retention, microbial activity, and nutrient absorption, which contribute to better plant development. However, there are still gaps in understanding the specific roles of different gases regarding their stability, interactions with soil, and long-term agricultural impacts. This review aims to combine previous research by focusing on various types of NBs impact on soil moisture, water quality, and nutrient retention. Challenges include the quick dissolution of particular gases, limited field studies, and scalability. The analysis showed that despite these challenges, NBs have potential for enhancing agriculture by improving soil structure and crop yield. More study is needed to maximize their application, particularly in determining the most effective gas types and concentrations for certain agricultural areas. [ABSTRACT FROM AUTHOR]

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Biochar is an effective material for enhancing soil ecosystem services. However, the specific impacts of biochar on microbial indicators, particularly in degraded soils, remain poorly understood. This study aimed to evaluate the effects of biochar produced from cashew residues and sewage sludge, in a highly degraded soil, on microbial indicators. We analyzed soil chemical composition and microbial biomass C and N, enzyme activity, and stoichiometry. Cashew biochar increased soil respiration, indicating a higher availability of C to microorganisms compared to sewage sludge biochar and a better adaptation of soil microbial communities to C-rich organic material obtained from a native plant. Although the biochar differentially impacted microbial biomass C, both significantly increased N in the microbial biomass. Arylsulphatase activity did not respond to biochar application, while β-glucosidase, urease, and phosphatases showed significant changes with biochar treatments. Importantly, stoichiometry and vector analysis revealed that both types of biochar increased P limitation for soil microbes. Conversely, both biochar alleviated C and N limitations for the soil microbes. Thus, biochar applications in highly degraded soils should be supplemented with external P sources to maintain soil functions, mainly for cashew residues. Our results provide evidence that biochar can restore soil biological properties and enhance the availability of C and N to microorganisms. These findings have significant implications for restoration practices in degraded lands of semiarid regions. [ABSTRACT FROM AUTHOR]

Poorly-treated wastewater harbors harmful microorganisms, posing risks to both the environment and public health. To mitigate this, it is essential to implement robust disinfection techniques in wastewater treatment plants. The use of performic acid (PFA) oxidation has emerged as a promising alternative, due to its powerful disinfection properties and minimal environmental footprint. While PFA has been used to inactivate certain microbial indicators, its potential to tackle the entire microbial community in effluents, particularly resistant bacterial strains, remains largely unexplored. The present study evaluates the efficacy of PFA disinfection on the microbial communities of a WWTP effluent, through microbial resistance mechanisms due to their membrane structure. The effluent microbiome was quantified and identified. The results showed that the number of damaged cells increases with CT, reaching a maximum for CT = 240 mg/L•min and plateauing around 60 mg/L•min, highlighting the optimal conditions for PFA-disinfection against microbial viability. A low PFA level with a 10-min contact time significantly affected the microbial composition. It is worth noting the sensitivity of several bacterial genera such as Flavobacterium, Pedobacter, Massilia, Exiguobacterium, and Sphingorhabdus to PFA, while others, Acinetobacter, Leucobacter, Thiothrix, Paracoccus, and Cloacibacterium, showed resistance. The results detail the resistance and sensitivity of bacterial groups to PFA, correlated with their Gram-positive or Gram-negative membrane structure. These results underline PFA effectiveness in reducing microbial levels and remodeling bacterial composition, even with minimal concentrations and short contact times, demonstrating its suitability for widespread application in WWTPs. [ABSTRACT FROM AUTHOR]

Destruction of vegetation and land use change can have significant effects on the variability of soil characteristics. Based on this, the present research was conducted to study the change of land covers on the characteristics of the soil surface layer in Kohpar Nowshahr, Mazandaran province. For this purpose, different soil characteristics in land cover (Carpinus orientalis Miller.), Crataegus (Crataegus microphylla C. Koch.) and barberry (Berberis integerrima Bunge.), Rangeland with the dominance of Agropyrom longyaristatum species, Rangeland with The dominance of Cousinia commutate species, has been studied in Kohper research station. Therefore, three plots of one hectare (100 m x 100 m) were selected in each of the studied habitats. In each of the plots, 4 samples were taken from the surface layer of the soil (surface 30 cm x 30 cm, 10 cm depth) and a total of 12 soil samples from each of the studied habitats were taken to the laboratory for analysis. The results indicated the significant effects of different land uses on most physical, chemical and biological characteristics of soil; So that the highest values of the characteristics of soil stability, clay content, pH, nitrogen, phosphorus, calcium, potassium, magnesium, fine-root and corse-root biomass, fulvic and humic acids and earthworms, acarina, nematodes, protozoa, fungi and bacterial populations and microbial characteristics were observed in the soil of Carpinus, Crataegus and barberry vegetation.The results of this research confirm that land cover Carpinus, Crataegus and barberry vegetation can lead to the maintenance of soil quality indicators in the semi-arid mountainous regions of the north of the country. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) in temperate forests is a crucial part of the global C cycle. The C and nitrogen (N) inputs may greatly increase in forest ecosystems affected by atmospheric CO2 concentration, N deposition, and other climate change, which may further affect SOC dynamics in temperate forests. Nevertheless, how C and N inputs interact to influence the soil priming effect (PE) in the organic and mineral layers of temperate forests remains unclear. Here, we used easily available C and N sources, such as 13C‐glucose with 2% SOC contents and ammonium nitrate (input C:N ratio = 10), to examine the effects and mechanisms of exogenous C and N inputs on soil CO2 production and PE in both soil layers of a temperate forest. Our research revealed that exogenous C input caused a positive PE in both soil layers, with the mineral layer showing a larger PE per unit of SOC than the organic layer (OL). Although C input increased C loss from native SOC, soil net C accumulation still increased. The C and N inputs decreased the soil PE in both soil layers, suggesting that N input alleviates substrate N limitation and weakens microbial N mining in both soil layers. Meanwhile, the C and N inputs increased the exogenous C remaining in the organic layer, which was beneficial for soil C sequestration. Compared to the organic layer, the response of the mineral layer to C and N inputs was weaker. This study suggests that C and N interact to affect PE on SOC decomposition and this interaction should be considered in modeling and prediction of soil C cycling. [ABSTRACT FROM AUTHOR]

Abstract Adenosine triphosphate (ATP) assays have a faster turnaround time and higher sensitivity than traditional cultivation methods for microbial monitoring. Challenges implementing ATP testing include incompatibility with chlorine quenching agents and hold time sensitivity, which are not well-studied. Chlorinated distribution system samples were collected from two Canadian utilities, Metro Vancouver (n = 40 samples) and Halifax Water (n = 283). No significant correlations were observed between heterotrophic cell count (HPC) and cellular ATP, suggesting these do not correlate well in waters with low biological activity (median HPC

Abstract Biochar is an effective material for enhancing soil ecosystem services. However, the specific impacts of biochar on microbial indicators, particularly in degraded soils, remain poorly understood. This study aimed to evaluate the effects of biochar produced from cashew residues and sewage sludge, in a highly degraded soil, on microbial indicators. We analyzed soil chemical composition and microbial biomass C and N, enzyme activity, and stoichiometry. Cashew biochar increased soil respiration, indicating a higher availability of C to microorganisms compared to sewage sludge biochar and a better adaptation of soil microbial communities to C-rich organic material obtained from a native plant. Although the biochar differentially impacted microbial biomass C, both significantly increased N in the microbial biomass. Arylsulphatase activity did not respond to biochar application, while β-glucosidase, urease, and phosphatases showed significant changes with biochar treatments. Importantly, stoichiometry and vector analysis revealed that both types of biochar increased P limitation for soil microbes. Conversely, both biochar alleviated C and N limitations for the soil microbes. Thus, biochar applications in highly degraded soils should be supplemented with external P sources to maintain soil functions, mainly for cashew residues. Our results provide evidence that biochar can restore soil biological properties and enhance the availability of C and N to microorganisms. These findings have significant implications for restoration practices in degraded lands of semiarid regions.

Abstract This study examines the effect of phycoerythrin (PE) from a cyanobacterial Nostoc strain encapsulated with alginate as a potential prebiotic to produce synbiotic ice cream products with Lactobacillus casei. It was found that the addition of the encapsulated PE affected, mostly favourably, the physicochemical properties, antioxidant activity, probiotic survival, volatile compound contents, and sensory acceptability of the synbiotic ice cream samples before and after aging at the freezing periods of one day to eight weeks. Thus, it confirms the prebiotic potential of PE for synbiotic ice creams with L. casei.

Background: The dynamics of carbon (C), nitrogen (N), and phosphorus (P) in soils determine their fertility and crop growth in agroecosystems. These dynamics depend on microbial metabolism, which in turn depends on nutrient availability. Farmers typically apply either mineral or organic fertilizers to increase the availability of nutrients in soils. Phosphorus, which usually limits plant growth, is one of the most applied nutrients. Our knowledge is limited regarding how different forms of P impact the ability of microbes in soils to produce the enzymes required to release nutrients, such as C, N and P from different substrates. Methods: In this study, we used the arable layer of a calcareous soil obtained from an alfalfa cropland in Cuatro Cienegas, México, to perform an incubation experiment, where five different phosphate molecules were added as treatments substrates: three organic molecules (RNA, adenine monophosphate (AMP) and phytate) and two inorganic molecules (calcium phosphate and ammonium phosphate). Controls did not receive added phosphorus. We measured nutrient dynamics and soil microbial activity after 19 days of incubation. Results: Different P molecules affected potential microbial C mineralization (CO2-C) and enzyme activities, specifically in the organic treatments. P remained immobilized in the microbial biomass (Pmic) regardless of the source of P, suggesting that soil microorganisms were limited by phosphorus. Higher mineralization rates in soil amended with organic P compounds depleted dissolved organic carbon and increased nitrification. The C:N:P stoichiometry of the microbial biomass implied a change in the microbial community which affected the carbon use efficiency (CUE), threshold elemental ratio (TER), and homeostasis. Conclusion: Different organic and inorganic sources of P affect soil microbial community structure and metabolism. This modifies the dynamics of soil C, N and P. These results highlight the importance of considering the composition of organic matter and phosphate compounds used in agriculture since their impact on the microbial activity of the soil can also affect plant productivity. [ABSTRACT FROM AUTHOR]

Background and Objectives Microorganisms make changes to their lives, when they are exposed to contaminants. These changes include physiological and genetically changes. Antibiotics are widely used in the livestock industry, agriculture, as well as in medicine, and enter soils via waste waters and manure applications. Oxytetracycline (OTC) is one of the most consumed antibiotics in the livestock industry. Its half-life in soil has been reported up to 79 days depending on soil conditions. Increasing levels of antibiotics in soil environment will results in physiological or genetically changes (tolerance) in microbial communities. Although, physiological changes are usually reversible, but the genetically ones are almost permanent. Several methods have been suggested for assessing the risks of contamination of soil ecosystems, among them the pollution induced community tolerance (PICT) has been accepted as valuable procedure. The principle of the procedure is as follow. The increasing levels of a contaminant are added to the soil and incubated for a defined time period. At several time points, the microbial populations are extracted and subjected to the same levels of contaminant. The amount of microbial activity is determined using appropriate procedure, for example, determination of dehydrogenase activity in soil. The IC50 (contaminant level at which the microbial activity is inhibited by 50%) is calculated for soil samples treated with different levels of contaminant. A contaminant level at which a sharp change occurs in microbial tolerance to the contaminant at defined time point, is called PICT. Methodology In this study, the effects of different levels of oxy-tetracycline (OTC) on microbial activity were investigated in a silty loam soil. Different levels of OTC (10, 20, 30, 40 and 50 mg.kg-1) were applied to the pots containing 2 kg of soil with three replications and kept at room temperature (25±2℃) for 120 days. The soil moisture level was adjusted to 50-70% of field capacity by daily weighing and adding distilled water. Soil dehydrogenase activity as an indicator of soil microbial activity was measured at 3, 7, 15, 30, 60, 90 and 120 days of incubation. Tri-phenyl tetrazolium chloride (TTC) was use as a substrate for dehydrogenase enzyme. The amount of tri-phenyl formazan produced by the reduction of TTC, was accounted for dehydrogenase activity. The ΔIC50 diagram (PICT) was plotted against different soil OTC concentrations for each time point and the trend of microbial tolerance changes was evaluated. Findings The results showed that with increasing incubation time and concentration of OTC, induction of tolerance in the microbial population was gradually enhanced. The amount of PICT was increased by increasing OTC level in soil on day 3, but without showing critical point on the diagram. However, it was declined toward the day 7. By increasing OTC level from 30 to 40 mg.kg-1, a marked decrease in ΔIC50 was seen on day 15. Overall, the increase of tolerance in microbial population started after day 15 and reached the highest values on days 30 and 60 at OTC concentration of 50 mg.kg-1. After that, PICT levels gradually increased toward the 50 mg/kg OTC, but were very low on days 90 and 120. A marked change (critical point) in the slope of ΔIC50 was occurred on day 30 at 30 mg.kg-1 OTC. Conclusion Based on obtained results it can be concluded that the increasing of OTC concentration to 30 mg.kg-1 in soil would likely led to occurring permanent tolerance to OTC in soil microbial community after 30 days. Therefore, this concentration can be regarded as critical level of OTC in soil at this time point. Continues application of manures containing OTC residue will results in accumulation of OTC in agricultural soils, hence we should regularly assay the concentration of OTC in soil to avoid of occurring permanent tolerance (also regarded as genetically resistance) in microbial community against OTC. Although this critical concentration and time point may differ for other soils and antibiotics. [ABSTRACT FROM AUTHOR]

This study provides a critical review of Underground Hydrogen Storage (UHS), emphasizing its potential as a viable energy storage option despite several associated challenges. These challenges include microbial degradation, chemical reactivity, unique thermophysical characteristics, and geomechanics considerations. Effective and secure UHS operation requires careful site selection, management, and a thorough understanding of hydrogen's behavior under various geological and operational conditions. Our review examines the significance of hydrogen's physical properties, H 2 -fluid-rock dynamics, redox-driven geochemical interactions, microbial activities, and geomechanical risks influencing UHS performance, safety, and containment. Additionally, we discuss the importance of optimal material selection and operational strategic development to maximize UHS efficiency and minimize associated risks. While global projects and ongoing research form a solid foundation for UHS development, ensuring UHS effectiveness and safety requires further investigation. This article also identifies the main knowledge gaps and future research directions for effective deployment of UHS projects. [Display omitted] • Assessment of geological formations suitable for UHS, including salt caverns, depleted reservoirs, and saline aquifers. • Insights derived from global UHS projects inform best practices. • H 2 physical properties and the complex H 2 -fluid-rock dynamics are crucial for ensuring UHS efficiency and safety. • Geochemical reactions, microbial activities, and geomechanics may affect UHS performance and integrity. • Geologic and operational parameters are keys to achieving optimal UHS performance. [ABSTRACT FROM AUTHOR]

The present study focused on the use of pouting (Trisopterus luscus), an underutilized gadoid fish species, as a fresh product of potential commercial interest. Accordingly, non-degutted pouting specimens (145–195 g and 15–22 cm) were stored under chilling conditions (0 °C) for microbial, chemical and sensory analyses to evaluate their commercial quality and shelf life. A progressive quality loss (p < 0.05) was detected for this lean species (5.58 g lipids·kg−1 muscle) as the storage time increased, as determined through microbial (aerobes, psychrotrophs and Enterobacteriaceae counts), lipid hydrolysis (free fatty acid value), lipid oxidation (conjugated diene and triene, thiobarbituric acid reactive substance, and fluorescence values) and sensory acceptance assessment. A detailed comparison to related lean fish species revealed that the pouting exhibited a fast quality breakdown under refrigeration conditions. Thus, after 9 d of chilled storage, the psychrotroph counts exceeded the acceptable limits (8.54 log CFU·g−1), and the fish specimens were found to be rejectable, with the sensory panel, external odor and eye appearance being the limiting factors. In contrast, the pouting specimens exhibited high quality after 3 d of storage, with the quality being still acceptable after 6 d. According to the current search for novel, underutilized species, pouting is proposed as a promising source. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has led to an unprecedented increase in pharmaceutical drug consumption and plastic waste disposal from personal protective equipment. Most drugs consumed during the COVID-19 pandemic were used to treat other human and animal diseases. Hence, their nearly ubiquitous presence in the soil and the sharp increase in the last 3 years led us to investigate their potential impact on the environment. Similarly, the compulsory use of face masks has led to an enormous amount of plastic waste. Our study aims to investigate the combined effects of COVID-19 drugs and microplastics from FFP2 face masks on important soil processes using soil microcosm experiments. We used three null models (additive, multiplicative, and dominative models) to indicate potential interactions among different pharmaceutical drugs and mask MP. We found that the multiple-factor treatments tend to affect soil respiration and FDA hydrolysis more strongly than the individual treatments. We also found that mask microplastics when combined with pharmaceuticals caused greater negative effects on soil. Additionally, null model predictions show that combinations of high concentrations of pharmaceuticals and mask MP have antagonistic interactions on soil enzyme activities, while the joint effects of low concentrations of pharmaceuticals (with or without MP) on soil enzyme activities are mostly explained by null model predictions. Our study underscores the need for more attention on the environmental side effects of pharmaceutical contamination and their potential interactions with other anthropogenic global change factors. [ABSTRACT FROM AUTHOR]

The search for novel substances that promote the establishment of a microbial community and facilitate optimal humification processes while increasing soil organic matter content offers an opportunity for land restoration. The objective of study was to determine the abundance of ecological and trophic groups of soil microorganisms and the intensity of microbiological processes when subjected to probiotic treatment at various concentrations and doses in typical black soil. The eco-trophic groups of soil microorganisms were identified by inoculating dilutions of soil suspensions onto selective nutrient media. The direction and intensity of soil microbiological processes were assessed using the mineralization-immobilization, oligotrophy, and pedotrophy indexes. The results demonstrate that probiotics has a positive impact on the microbiological activity of the soil, leading to an increase in the number of ecological and trophic groups of soil microorganisms during both spring and autumn seasons. Notably, a significant effect on the soil microorganism conditions was observed after 30 days of probiotic treatment. Probiotics exhibit a favorable influence on microbiological processes within the soil, fostering conducive conditions for the development of soil microorganisms and the formation of humus. The most effective concentration of probiotics for promoting the functionality of microbial communities in black soils is determined to be 10%, accompanied by a dose of 100 l ha-1. Consequently, the application of probiotic treatment at a concentration of 10% and a dose of 100 l/ha-1 holds the potential to enhance the biological state of the soil, restore soil microbial diversity, and serve as an environmentally safe fertilizer. [ABSTRACT FROM AUTHOR]

Diversifying wheat (Triticum aestivum L.)-based cropping systems is important for the sustainability of dryland agriculture. Research has focused on the agronomic benefits of increased crop diversity in semi-arid environments, but less is known about the impacts of increased crop diversity on the soil microbial community. This work compared soil health parameters between a continuous wheat crop sequence to a diverse sequence that included pea (Pisum sativum L.), proso millet (Panicum miliaceum L.), safflower (Carthamus tinctorius, L.), and spring wheat. Respiration was higher (p <.005) in the diverse sequence while activity of N-acetyl-β-d-glucosaminidase was lower (p <.05) with a mean rate of 26.3 and 16.3 mg ρ-nitrophenol kg−1 soil h−1 for the continuous wheat and diverse sequences, respectively. The mean net nitrogen mineralized during the growing season was 33.2 ± 2.5 kg ha−1 and was not different between treatments (p >.05). No difference was observed in bacterial alpha diversity, while fungal community diversity was 52% lower in the diverse rotation. The results of this work suggest that specific crops in a rotation may impact microbial processes related to nitrogen mineralization and that the soil fungal community may be more sensitive to changes in crop sequence than the soil bacterial community. [ABSTRACT FROM AUTHOR]

Systemic plant protection products, such as neonicotinoids (NIs), are capable of being translocated throughout a plant. Although NIs are less toxic to mammals, fish, and birds, their impact on microbial and non-target insects is of concern. This study investigates the uptake, translocation, and accumulation of the NI, imidacloprid (IMI), in romaine lettuce (Lactuca sativa L. var. longipolia). Exposing 15-day-old seedlings to "10 mg/L" of IMI, the effects on microbial communities in both cultivated (CS) and non-cultivated soil (NCS) were studied along with IMI translocation within plant tissues. The concentrations of IMI in soil varied temporally and between soil types after initial application, with a decrease from 2.0 and 7.7 mg/kg on the first day of sampling to 0.5 and 2.6 mg/kg on the final sampling day (day 35) for CS and NCS, respectively. The half-life of IMI soil was 10.7 and 72.5 days in CS and NCS, respectively, indicating that IMI degraded more quickly in CS, possibly due to smaller grain size, aeration, microbial degradation, and water flow. The accumulated concentrations of IMI in lettuce tissues ranged from 12.4 ± 0.2 and 18.7± 0.9 mg/kg in CS and NCS, respectively. The highest concentration of IMI was found in the shoots, followed by the roots, whereas the soil showed the lowest IMI residuals at the end of the trial. Soil bacteria and fungi were altered by the application of IMI, with a lower abundance index within the bacterial community, indicating a negative impact on the distribution of bacteria in the soil. [ABSTRACT FROM AUTHOR]

This study examines the effect of phycoerythrin (PE) from a cyanobacterial Nostoc strain encapsulated with alginate as a potential prebiotic to produce synbiotic ice cream products with Lactobacillus casei. It was found that the addition of the encapsulated PE affected, mostly favourably, the physicochemical properties, antioxidant activity, probiotic survival, volatile compound contents, and sensory acceptability of the synbiotic ice cream samples before and after aging at the freezing periods of one day to eight weeks. Thus, it confirms the prebiotic potential of PE for synbiotic ice creams with L. casei. [ABSTRACT FROM AUTHOR]

Despite the importance of South Africa's Afromontane grasslands for ecosystem services (water supply and biodiversity), soil organic carbon (SOC) research remains limited. These grasslands evolved with fire, and fire exclusion leads to native plant afforestation. This study investigated SOC fractions and origin to understand the impact of fire‐exclusion‐driven afforestation and aspect on SOC storage in Afromontane grasslands. This study in Cathedral Peak Research Catchments, initiated in the 1940s, compared an afforested fire‐excluded site (AF) to a periodically burnt (accidental fires, 2–5 years interval) grassland (PB) within the same catchment (Catchment‐IX). Additionally, it compared a south‐facing periodically burnt grassland (Catchment‐IX) to a north‐facing biennially burnt grassland (Catchment‐VI). Soil samples collected at soil‐depth increments (0–5, 5–10, 10–15, 15–20, 20–30, 30–60 and 60–100 cm) revealed that, within Catchment IX, PB had more topsoil SOC stocks and microbial activity than AF but similar active carbon (C) concentrations. As expected, δ13C values revealed that SOC in PB originates from C4 grasses, whilst it mostly originates from C3 plants in AF. The south‐facing slope (Catchment‐IX) had more SOC stocks, microbial activity and active C compared to the north‐facing slope (Catchment‐VI). Fire‐exclusion‐driven afforestation changed SOC input from roots to litter, thus reducing SOC storage. Cooler south‐facing slopes are better C reservoirs. Afromontane grasslands show greater potential for C sequestration than afforested systems. [ABSTRACT FROM AUTHOR]

Biodegradable films are considered ideal alternatives to polyethylene films because of their advantages in increasing crop yield and controlling soil pollution. However, the influences of biodegradable film mulching on soil physicochemical environments and water productivity after long-term mulching remain poorly understood. Therefore, a field experiment after long-term mulching (since 2016) was conducted to explore the effects of black biodegradable film (BB), transparent biodegradable film (TB), and traditional polyethylene film (PE) on soil physicochemical environments, aboveground biomass accumulation, grain yield, evapotranspiration, and water productivity (WP) of maize in the 2021 and 2022 in the North China Plain. The results showed that polyethylene films and biodegradable films had a similar ability to preserve soil moisture, promote maize growth, reduce evapotranspiration, and increase WP. Moreover, the performances of BB were more equivalent to PE, and there was no significant difference on WP and yield under BB and PE. Compared with traditional flat planting without mulching (CK), BB and PE significantly increased yield (9.5 % and 12.7 % in 2021; 5.25 % and 6.37 % in 2022) and WP (11.54 % and 21.47 % in 2021; 24.28 % and 23.42 % in 2022). Film mulching treatments increased the soil organic carbon sequestration rate, and the content of soil organic carbon, microbial activity, and urease activity in the 0–20 cm soil layer compared with CK. According to structural equation modeling, the increasing soil water storage because of films mulching positively influenced yield by enhancing enzyme activities which were related to soil nutrients. Over all, these results showed that black biodegradable film is an ideal replacement for polyethylene films under long-term mulching conditions because of its comparable agronomic performance and influence on soil physicochemical environments in the North China Plain.

Soil organic carbon (SOC) loss from intensive agriculture represents a major global concern. Consequently, strategies to improve soil management to mitigate or abate SOC losses and enhance carbon (C) sequestration are urgently needed. Nutrient availability, especially nitrogen (N) and phosphorus (P), regulates soil C cycling and storage. While N effects are well studied, less is known about how soil P status and different fertilizer types affects SOC dynamics. This laboratory incubation assessed how two common P fertilizers, diammonium phosphate (DAP) and single superphosphate (SSP), affected microbial activity and C immobilization in the zone of soil directly around the fertilizer granule (prillosphere) across three contrasting agricultural soils (Inceptisol, Vertisol, Alfisol). Soils were amended with DAP or SSP granules and C turnover assessed with 14C-labeled glycine, malic acid or glucose, alongside unfertilized controls. After three weeks, soil pH, electrical conductivity (EC), Olsen-P and microbial C use efficiency (CUE) were measured. DAP increased pH in the Inceptisol (acidic soil), while SSP decreased pH in all soils. Both fertilizers increased EC and Olsen-P, but SSP enhanced Olsen-P more than DAP. Cumulative 14CO2 emissions were 19–20 % higher with P fertilizers compared to the control, with DAP stimulating faster initial C mineralization rates than SSP, except in the Alfisol. P addition reduced microbial CUE by 23–34 % across all soils and substrates versus the unfertilized control. We ascribe this reduction in CUE to an alleviation of nutrient limitation or a fertilizer-induced osmotic stress. The co-addition of N either in DAP or glycine did not alter the P-induced CUE response suggesting that P was more important than N in regulating microbial CUE in these soils. We conclude that P fertilization increased short-term C turnover and may lead to reduced C storage in soil, however, further long-term (>1 year) research is needed to identify optimum P management strategies to minimize C losses in agricultural soils.

Large quantities of cover crop residues in the soil, combined, or not, with the inoculation of seeds with diazotrophic bacteria, can increase organic matter (OM) and protect soil microorganisms, such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytic (DSE) fungi. Thus, the use of these sustainable biotechnologies can benefit microbial interactions, soil fertility and rice production in the Brazilian Cerrado region. In this study, we evaluated the effects of maize and Urochloa ruziziensis, intercropped or individually, as cover crops and an inoculation of Azospirillum brasilense on the chemical (fertility) and biological (C–microbial biomass and C–CO2 released) attributes of soil and the effects of root colonization by AMF and DSE on the yield of rice grown in succession in highlands. The experiment was conducted under field conditions, in a typical dystrophic Red Oxisol. The experimental design consisted of randomized blocks arranged in strips, incorporating a combination of eight residual cover crops: ((1) maize, (2) maize–I (I = inoculation of seeds with A. brasilense), (3) Urochloa (U. ruziziensis), (4) Urochloa–I, (5) maize + Urochloa–I, (6) maize + Urochloa–I, (7) maize–I + Urochloa and (8) maize–I + Urochloa–I). This was accompanied by two treatments of rice as a successor crop (inoculated or not with A. brasilense), with four replicates, totaling 64 experimental units. A cover crop and rice seed inoculation prompted increases in OM and AMF relative to DSE, while the inoculation of rice, regardless of the cover crop treatment, increased the soil’s P content. The combination of maize + Urochloa–I and inoculated rice as the next crop generated increases in its sum of bases (SBs) and cation exchange capacity (CEC). There was a 19% increase in rice grain yields when the seed was inoculated.

The long-term use of chemical fertilizers poses a serious threat to crop productivity and soil quality. Organic fertilizers are used to improve the soil fertility and crop productivity. The application of organic fertilizers improves soil health and plant growth by improving the soil organic matter (SOM), soil structure, aggregate stability, nutrient uptake, water-holding capacity, cation exchange capacity, nutrient use efficiency and microbial activities of soil. The intensity of abiotic stress is continuously increasing, which is a serious threat to crop productivity and global food security. However, organic fertilizers have been reported to improve tolerance against drought, salinity, heat and heavy metal (HM) stresses. The application of organic fertilizer improves the leaf water status, nutrient uptake, nutrient homeostasis, synthesis of chlorophyll, osmolytes, hormones, secondary metabolites, antioxidant activities and gene expression, resulting in improved tolerance against drought, salinity, heat, and heavy metals. In the present review, we have discussed the ability of organic fertilizers to improve soil fertility, crop yield, and the nutrient use efficiency. We have also presented the various mechanisms through which organic fertilizers improve tolerance against drought, salinity, heat, and heavy metals. Therefore, this review will put forth new directions for researchers working on the use of organic materials to improve soil fertility, crop productivity and tolerance against abiotic stresses. [ABSTRACT FROM AUTHOR]

Aims: Soil microbial and enzymatic activity have important roles in soil health, nutrient cycle and plant growth. Biochar is an excellent biomass for increasing soil water content, but some biochar compounds, due to their high pH, are harmful to the soil. This study aimed to investigate the effect of biochar and sulfur-modified biochar on improving the soil water content and biochemical properties in a millet cropping system. Methods: The field experiment was performed in a completely random design with three replications. Experimental treatments included control, 15 t ha− 1 sunflower biochar (B), and 15 t ha− 1 sulfur-modified biochar (BS). Results: Biochar (B and BS) improved the soil water content by 47% and 35%, respectively, compared to the control. B and BS treatments improved soil biological properties, including microbial biomass carbon, basal respiration, and the activity of catalase, dehydrogenase, urease, and alkaline phosphatase enzymes compared to the control. The application of B and BS treatments decreased soil EC and sodium adsorption ratios compared to the control. The highest (8.26) and lowest (7.83) values of soil pH were related to the B and BS treatments, respectively. Treatment of soil with B and BS enhanced soil dissolved organic carbon (90% and 33%), available nitrogen (74% and 48%), and available phosphorus (60% and 96%) compared to the control. The application of B and BS treatments enhanced plant nutrients (nitrogen, phosphorus, and potassium) and the leaf relative water content by 40% and 14%, respectively. Biochar (B and BS) improved millet yield by 58% and 115%, respectively, compared to the control. Conclusion: Sulfur increased the efficiency of biochar in amending saline and calcareous soil and enhanced millet yield by improving the chemical properties (pH and CEC) of biochar. [ABSTRACT FROM AUTHOR]

Large quantities of cover crop residues in the soil, combined, or not, with the inoculation of seeds with diazotrophic bacteria, can increase organic matter (OM) and protect soil microorganisms, such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytic (DSE) fungi. Thus, the use of these sustainable biotechnologies can benefit microbial interactions, soil fertility and rice production in the Brazilian Cerrado region. In this study, we evaluated the effects of maize and Urochloa ruziziensis, intercropped or individually, as cover crops and an inoculation of Azospirillum brasilense on the chemical (fertility) and biological (C–microbial biomass and C–CO2 released) attributes of soil and the effects of root colonization by AMF and DSE on the yield of rice grown in succession in highlands. The experiment was conducted under field conditions, in a typical dystrophic Red Oxisol. The experimental design consisted of randomized blocks arranged in strips, incorporating a combination of eight residual cover crops: ((1) maize, (2) maize–I (I = inoculation of seeds with A. brasilense), (3) Urochloa (U. ruziziensis), (4) Urochloa–I, (5) maize + Urochloa–I, (6) maize + Urochloa–I, (7) maize–I + Urochloa and (8) maize–I + Urochloa–I). This was accompanied by two treatments of rice as a successor crop (inoculated or not with A. brasilense), with four replicates, totaling 64 experimental units. A cover crop and rice seed inoculation prompted increases in OM and AMF relative to DSE, while the inoculation of rice, regardless of the cover crop treatment, increased the soil's P content. The combination of maize + Urochloa–I and inoculated rice as the next crop generated increases in its sum of bases (SBs) and cation exchange capacity (CEC). There was a 19% increase in rice grain yields when the seed was inoculated. [ABSTRACT FROM AUTHOR]

Hexavalent chromium (Cr(VI)) could be sequestrated by soils via microbial reduction to Cr(III) and association with minerals, however, quantitative understanding of metal reducing bacteria on the coupled kinetics of Cr and Fe minerals is still lacking. Here, microbial-mediated ferrihydrite transformation and reductive sequestration of Cr(VI) were investigated with Shewanella oneidensis MR-1 under varying Cr/Fe ratios. Quantitative results depicted that the contents of magnetite from ferrihydrite transformation decreased from 70 % to 22 % after 288 h as Cr/Fe ratios increased from 0 to 8 × 10−3, and reductive transformation rates increased with decreasing Cr/Fe ratio. Elemental mapping and line scan analyses at nano-scale revealed that Cr(VI) was evenly combined within fresh ferrihydrite, and a part of produced Cr(III) was doped into the crystal lattice of magnetite and goethite. Cr may be sequestrated by secondary Fe minerals via structural substitution, surface complexation, and physical encapsulation. Microscopy-based results exhibited that more Fe minerals adsorbed on the surface of cell and less cells were lysed at low Cr/Fe ratios. Confocal laser scanning microscopy depicted that less cells were alive at high Cr/Fe ratios. The amplification of extracellular electron transfer-associated genes was downregulated as Cr/Fe ratios increased. The Cr/Fe ratios could affect cell activity, the combination with Fe minerals, and Mtr gene expression, thus controlling the reductive sequestration of Cr(VI) and phase transformation of ferrihydrite. A kinetic model has been established by combining elementary reductions, and it could well describe Cr(VI) reduction and Cr(III) incorporation under various Cr/Fe ratios during dissimilatory Fe reduction process. These findings could broaden our knowledge of quantifying the migration and transport of Cr in anoxic Cr-contaminated soil environments, and could be useful for simulating Cr dynamic behaviors in the natural soil, aquatic, and sediment environments. [ABSTRACT FROM AUTHOR]

World is presently facing major challenges in energy industry to reduce or replace greenhouse gases (CO 2 , CH 4 , NO x etc.) emissions to net zero in the coming decades while decreasing the reliance on traditional fossil fuels. In the current scenario, hydrogen (H 2) appears to be an excellent alternative energy source to meet the criteria. Storage of H 2 over a long period of time in large quantities poses a significant challenge for its widespread uses. In order to overcome this issue, the idea of using large-scale depleted underground hydrocarbon reservoirs, salt caverns, underground aquifers, etc. is considered to be a suitable option for underground hydrogen storage. However, underground storage of H 2 for a longer time period comes up with a potentially high microbial activity where H 2 can be utilized in the microbial metabolism and converted into undesirable gases like CH 4 and H 2 S which in turn, damage the porous medium due to clogging, acid formation, and corrosion activity. This review paper explores the various scientific challenges during large-scale H 2 storage in porous medium to facilitate the global H 2 economy. Moreover, a detailed description of the effect of subsurface environment conditions such as pressure, temperature, pH, and salinity on microbes is included in this study. In addition to this, steps to counter microbial activity in stored H 2 monitoring and mitigation approaches are also discussed in this article. • Underground hydrogen storage and its mechanism are discussed. • Effect of microorganisms on stored hydrogen and porous media properties comprehensively reviewed. • The impact of microbial activity on subsurface storage environment conditions. • Monitoring and mitigation strategies to counter microbial activities comprehensively reviewed. • Latest treatment proposition of microbial activities and role of biocides in underground hydrogen storage discussed. [ABSTRACT FROM AUTHOR]

Contamination of soil and water with petroleum hydrocarbons and metals can pose a significant threat to the environment and human health. This study aimed to investigate the establishment and growth of tall fescue and agropyron in two petroleum-contaminated soils (soil S1 and soil S2) with previous landfarming treatments, and to assess the phytoremediation potential for heavy metal removal from these polluted soils. The results showed that the presence of petroleum hydrocarbons significantly (P < 0.05) reduced plant growth, but plant development was facilitated in soils with prior landfarming treatments. Urease activity in the rhizosphere of agropyron for soil S1 was about 47% higher than the unplanted control soil. The rhizosphere of agropyron and tall fescue eliminated more than 40% and 20% of total hydrocarbon amounts in soil S1, respectively, compared to the unplanted soil. Moreover, the plants grown in the landfarming treatment exhibited higher concentrations of metals (Fe, Zn, Mn, Cu, and Ni) than the control. Based on the findings, the combination of landfarming and phytoremediation techniques can provide an optimal solution for removing mixed pollutants, including petroleum hydrocarbons and metals, from the environment. [ABSTRACT FROM AUTHOR]

Vermifiltration is a promising technique that can help recover nutrients from wastewater for further use in agriculture. We conducted a field experiment to assess the effectiveness of vermicompost produced from the vermifiltration of liquid waste (manure and food production waste) and how it can affect the soil health and yield of a squash crop. We tested the effect of three rates of vermicompost (low, medium, and high) applied over two consecutive years and measured physical, chemical, and biological soil health indicators, squash yield, and nutritional status. The results showed that the use of vermicompost, especially at a high rate, increased total soil carbon, total nitrogen, potentially mineralizable nitrogen, and particulate organic matter, as well as the activity of C-N-P cycling enzymes, as compared to a control with only inorganic fertilization. The yield of the squash crop remained stable, while the crop nutritional value improved as the levels of boron and copper in the treated squash increased. These findings indicate an improvement in soil health after the use of vermicompost. Overall, results strongly support using this type of vermicompost as a sustainable management approach to recycle nutrients and enhance soil health. [ABSTRACT FROM AUTHOR]

This study investigates the feasibility of utilizing ureolytic-type bacteria in lightweight foamed concrete to enhance its compressive strength. Previous research focused on microorganisms in different types of concrete, but there is a lack of study on microorganism incorporation in low-density foamed concrete. Bacillus megaterium was introduced in the production of microbial-based lightweight foamed concrete, inducing mineral precipitation through microbial activities. Four mix proportions were prepared: a control mix (LFC-CM) and LFCs incorporated with varying concentrations of B. megaterium. All specimens underwent water curing. Results show significant improvements in compressive, flexural, and splitting tensile strengths of microbial-based LFC compared to control samples due to microbial-induced calcite precipitation. This research has implications for sustainable construction materials. The potential future directions include optimizing microbial dosage, exploring different ureolytic bacteria, and investigating the long-term durability and performance of microbial-based lightweight foamed concrete. This study contributes to knowledge on microbial-based construction materials, providing insights for sustainable concrete solutions. [ABSTRACT FROM AUTHOR]

Pesticides play a critical role in pest management and agricultural productivity; however, their misuse or overuse can lead to adverse effects on human health and the environment, including impacts on ecosystems and contamination. Currently, neonicotinoids (NNIs) are the most widely used systemic insecticides and are questioned worldwide for their possible impacts on pollinators. After NNI application, a substantial portion is not absorbed by the plant and may accumulate in the soil, affecting the soil microbial community. In this review, we explore the main studies carried out either in the laboratory or in the field about this matter. The studies report that the application of NNIs affects soil microbial activity and can act on microbial communities differently due to their unique chemical properties, degradation in soil, soil type, effects on soil properties, and methods of application. NNIs alter the diversity, structure, and abundance of soil microbes, in some cases increasing or decreasing their representativeness in soil. Bacterial phyla like Pseudomonadota, Bacillota, Actinomycetota, and Nitrospirota increase after NNI exposure, just like the families Nitrosomonadaceae, Nitrososphaeraceae, Nitrospiraceae, Sphingomonadaceae, Streptomycetaceae, and Catenulisporaceae. At the bacterial genus level, Nitrospira was associated with a decrease in nitrification processes in soil. The bacterial genera Sphingomonas, Streptomyces, Catenulispora, Brevundimonas, Pedobacter, and Hydrogenophaga are related to NNI degradation after application. Microorganisms could minimize the impacts of NNIs in agricultural soil. Therefore, the use of bioinoculation as a bioremediation tool is explored as an alternative to contribute to agricultural sustainability. [ABSTRACT FROM AUTHOR]

Mining and metallurgy are the main sources of soil contamination with harmful metals, posing a significant threat to human health and ecosystems. River floodplains in the vicinity of metal mines or industrial plants are often subject to flooding with sediments containing heavy metals, which can be harmful to the soil ecosystem. This study aimed to investigate the microbial properties of the soil at a metal-contaminated site and to determine the significant relationships between the biological and chemical properties of the soil. The study site was located near the village of Gyöngyösoroszi, in the Mátra mountain region of Northwest Hungary. A phytoremediation experiment was conducted in a metal-polluted floodplain using willow and corn plantations. The soil basal respiration, substrate-induced respiration, soil microbial biomass carbon (MBC), acid phosphatase activities, and soil chemical properties were measured. The soil of the contaminated sites had significantly higher levels of As, Pb, Zn, Cu, Cd, and Ca, whereas the unpolluted sites had significantly higher levels of phosphorus and potassium. The substrate-induced respiration showed a positive correlation with MBC and negative correlations with the metabolic quotient (qCO2). The soil plasticity index and phosphorus showed a positive correlation with MBC, whereas salinity and the presence of Cd, Pb, Zn, As, and Cu showed a negative correlation. Acid phosphomonoesterase activity negatively correlated with the plant-available phosphorus content and MBC, but was positively correlated with the contents of toxic elements, including cadmium, lead, zinc, arsenic, and copper. This study found a significant correlation between the qCO2 and the toxic element content. This suggests that an enhanced metabolic quotient (qCO2), together with a decreased MBC/SOC ratio, could be used to indicate the harmful effect of soil contamination by heavy metals in floodplain soils. [ABSTRACT FROM AUTHOR]

• Thermal pretreatment had negative/no effect on larval performance. • Mechanical pretreatment increased bioconversion rate for both substrates. • Bioconversion rate of grass clippings improved by 23–44%. • Mechanical pretreatment affected physical properties and microbial respiration. Black soldier fly larvae (BSFL , Hermetia illucens (L.)) are recognized for efficient biowaste reduction while yielding valuable proteins and fats for animals. However, lignocellulosic fibers in biowastes are difficult to digest by biowaste and larval digestive tract microorganisms as well as the larvae themselves. This study investigated two biowaste physical pretreatments (thermal, mechanical) for improving BSFL processing of fibrous biowastes. Cow manure, spent grain, and grass clippings were thermally pretreated at 90 °C for three durations (0.5, 1 and 4 h). Contrary to expectations, thermal pretreatment resulted in either no improvement or decreased larval performance on all substrates, regardless of treatment duration. In contrast, mechanical pretreatment of spent grain and grass clippings, involving milling with three screen sizes (0.5, 1 and 2 mm) showed promising results. Specifically, bioconversion rates on 0.5 mm-milled spent grain and grass clippings increased by 0–53 % and 25–44 % dry mass, respectively compared to untreated. Additionally, larval protein conversion increased by 41 % and 23 % on spent grain and grass clippings, respectively. However, mechanical pretreatment did not affect fiber degradation by larval conversion, as hemicellulose decreased by 25 % and 75 % for spent grain and grass clippings, respectively, regardless of particle size. Particle size reduction influenced substrate microbial respiration (CO 2 mg/min), with 0.5-mm milled grass clippings exhibiting higher respiration compared to untreated, although this effect was not observed for spent grain. This study highlights mechanical pretreatment's potential in enhancing BSFL bioconversion of fibrous biowastes and the importance of understanding substrate physical properties influencing substrate microorganisms and BSFL. [ABSTRACT FROM AUTHOR]

Background: Soils under organic farming systems exhibit better quality and higher biological activity than conventional systems. Manure addition, especially coupled with reduced or no tillage, significantly enhances microbial biomass and activity by improving soil physical properties and providing carbon (C) and nitrogen (N) sources. While several studies have examined the effects of transitioning from conventional to organic farming on soil chemistry and biochemistry, limited research has explored the influence of land use variations on soil fertility within long‐term organic farming systems. Aims: Therefore, the aim of this study was to assess how three different land uses—pasture, vegetable crops, and orchard—affected soil fertility under a long‐term organic farming system. Methods: Soil samples were collected from the 0 to 15 cm layer of plots used for pasture, vegetable crops and orchard, being the latter cover cropped with legumes, and analyzed to determine chemical and biochemical soil parameters. Results: Contrary to expectations, high land use intensity (vegetable crops and orchard soils) resulted in increased soil organic C and total N, compared to low intensity (pasture). Such an increase was ascribed to farmyard manure addition that counteracted the negative impact of tillage. Consequently, microbial biomass C and activity also increased. The greatest availability of organic substrates favored bacteria, particularly gram‐positive strains, shaping the microbial community. However, despite changes of microbial biomass and of the main microbial groups, microbial activity was only slightly affected, suggesting high functional redundancy of microorganisms in long‐term organic farming soil. Conclusions: Results suggested that if land use intensification provides for organic supply, its negative impact on soil fertility may be mitigated. [ABSTRACT FROM AUTHOR]

Under salinity conditions, growth and productivity of grain crops decrease, leading to inhibition and limited absorption of water and elements necessary for plant growth, osmotic imbalance, ionic stress, and oxidative stress. Microorganisms in bio-fertilizers have several mechanisms to provide benefits to crop plants and reduce the harmful effect of salinity. They can be effective in dissolving phosphate, fixing nitrogen, promoting plant growth, and can have a combination of all these qualities. During two successful agricultural seasons, two field experiments were conducted to evaluate the effect of bio-fertilizer applications, including phosphate solubilizing bacteria (PSB), nitrogen fixation bacteria and a mix of phosphate-solubilizing bacteria and nitrogen fixation bacteria with three rates, 50, 75 and 100% NPK, of the recommended dose of minimal fertilizer on agronomic traits, yield and nutrient uptake of barley (Hordeum vulgare) under saline condition in Village 13, Farafra Oasis, New Valley Governorate, Egypt. The results showed that the application of Microbein + 75% NPK recorded the highest values of plant height, spike length, number of spikes/m2, grain yield (Mg ha−1), straw yield (Mg ha−1), biological yield (Mg ha−1), protein content %, nitrogen (N), phosphorus (P), potassium (K) uptakes in grain and straw (kg ha−1), available nitrogen (mg/kg soil), available phosphorus (mg/kg soil), total microbial count of soil, antioxidant activity of soil (AOA), dehydrogenase, nitrogen fixers, and PSB counts. The application of bio-fertilizers led to an increase in plant tolerance to salt stress, plant growth, grain yield, and straw yield, in addition to the application of the bio-fertilizers, which resulted in a 25% saving in the cost of mineral fertilizers used in barley production. [ABSTRACT FROM AUTHOR]