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The rhizosphere is a complex environment where roots interact with physical, chemical and biological properties of soil. Structural and functional characteristics of roots contribute to rhizosphere processes and both have significant influence on the capacity of roots to acquire nutrients. Roots also interact extensively with soil microorganisms which further impact on plant nutrition either directly, by influencing nutrient availability and uptake, or indirectly through plant (root) growth promotion. In this paper, features of the rhizosphere that are important for nutrient acquisition from soil are reviewed, with specific emphasis on the characteristics of roots that influence the availability and uptake of phosphorus and nitrogen. The interaction of roots with soil microorganisms, in particular with mycorrhizal fungi and non-symbiotic plant growth promoting rhizobacteria, is also considered in relation to nutrient availability and through the mechanisms that are associated with plant growth promotion.

Objectives: Afforestation changes soil chemical properties over several decades. In contrast, microbial community structure can be shifted within the first decade and so, the direct effects of tree species can be revealed. The aim of this study was to determine the alteration of soil microbial community composition 10 years after afforestation by trees with contrasting functional traits. Methods: The study was conducted at the BangorDIVERSE temperate forest experiment. Soil samples were collected under single, two and three species mixtures of alder and birch, beech and oak - early and secondary successional species, respectively, and contiguous agricultural field. Soil was analysed for total carbon (C) and nitrogen (N) contents, and microbial community structure (phospholipid fatty acids (PLFAs) analysis). Results and conclusions: The total PLFAs content (370-640 nmol g⁻¹ soil) in forest plots increased for 30 to 110 % compared to the agricultural soil (290 nmol g⁻¹ soil). In contrast, soil C, N and C/N ratios were altered over 10 years much less - increased only up to 20 % or even decreased (for beech forest). Afforestation increased bacterial PLFAs by 20-120 %, whereas it had stronger impact on the development of fungal communities (increased by 50-200 %). These effects were proved for all forests, but were more pronounced under the monocultures compared to mixtures. This indicates that species identity has a stronger effect than species diversity. Principal component analysis of PLFAs revealed that under mono and three species mixtures similar microbial communities were formed. In contrast, gram-positive PLFAs and actinomycete PLFAs contributed mainly to differentiation of two species mixtures from other forests. Thus, at the early afforestation stage: i) soil biological properties are altered more than chemical, and ii) tree species identity affects more than species amount on both processes.

One of the biggest challenges in tissue engineering is the manufacturing of porous structures that are customized in size and shape and that mimic natural bone structure. Additive manufacturing is known as a sufficient method to produce 3D porous structures used as bone substitutes in large segmental bone defects. The literature indicates that the mechanical and biological properties of scaffolds highly depend on geometrical features of structure (pore size, pore shape, porosity), surface morphology, and chemistry. The objective of this review is to present the latest advances and trends in the development of titanium scaffolds concerning the relationships between applied materials, manufacturing methods, and interior architecture determined by porosity, pore shape, and size, and the mechanical, biological, chemical, and physical properties. Such a review is assumed to show the real achievements and, on the other side, shortages in so far research.

Nowadays, various drugs on the market are becoming more and more resistant to numerous diseases, thus declining their efficacy for treatment purposes in human beings. Antibiotic resistance is one among the top listed threat around the world which eventually urged the discovery of new potent drugs followed by an increase in the number of deaths caused by cancer due to chemotherapy resistance as well. Accordingly, marine cyanobacteria, being the oldest prokaryotic microorganisms belonging to a monophyletic group, have proven themselves as being able to generate pharmaceutically important natural products. They have long been known to produce distinct and structurally complex secondary metabolites including peptides, polyketides, alkaloids, lipids, and terpenes with potent biological properties and applications. As such, this review will focus on recently published novel compounds isolated from marine cyanobacteria along with their potential bioactivities such as antibacterial, antifungal, anticancer, anti-tuberculosis, immunosuppressive and anti-inflammatory capacities. Moreover, various structural classes, as well as their technological uses will also be discussed.

Aims Areas affected by wildfire comprise spatially complex mosaics of burned patches in which a wide range of burn severities coexist. Rapid diagnosis of the different levels of soil burn severity and their extents is essential for designing emergency post-fire rehabilitation treatments. The main objective of this study was to determine whether visual signs of soil burn severity levels are related to changes in soil chemical and microbial properties immediately after fire. Methods Eight areas affected by wildfires in NW Spain were selected immediately after fire, and soil chemical and biological properties (pH, extractable Ca, K, Mg and P, SOC, total N, δC, basal soil respiration, Cmic, phosphatase activity, extractable NH₄⁺ and NO₃⁻, ammonification and nitrification rates and potential N mineralization) were analysed in relation to five levels of soil burn severity (0: Unburned; 1: Oa layer partially or totally intact; 2: Oa layer totally charred; 3: Bare soil and soil structure unaffected; 4: Bare soil and soil structure affected; 5: Bare soil and surface soil structure and colour altered). Results The five visually assessed levels of soil burn severity adequately reflected changes in SOC, pH, and phosphatase activity, which varied gradually with increasing soil burn severity. However, alterations in certain indicators related to the soil organic quality (C/N, Cmic/SOC, qCO₂, δ¹³C) were only detected in the most severely burned areas. Discriminant analysis revealed that the best combination of variables was acid phosphatase activity, SOC and pH, which correctly classified between 64 and 76 % of samples, depending on the levels of soil burn severity considered. Conclusions The results showed that the proposed soil burn severity categories may be useful for indicating the degree of degradation of important soil chemical and microbiological properties in sites similar to the study area. This, in combination with other factors, will allow prioritization of areas for rehabilitation.

Among the various compounds of natural origin, usnic acid (UA) is one of the best studied. It has several pharmacological activities, standing out as an antimicrobial, antitumor, antiviral, and antiparasitic agent, and despite these relevant properties, it is a toxic molecule. In this context, research has driven the development of innovative alternatives, such as their encapsulation in controlled release systems, an attractive tool for pharmaceutical nanotechnology. These systems allow the active ingredient to be released at the optimal yield speed and reduce the dosing regimen. Consequently, they are able to increase therapeutic efficacy by minimizing side effects. Given the above, this paper presents a review of the literature on chemical and biological properties, analytical methods, mechanism of action and toxicology of UA, and discusses the use of nanotechnology as a tool to overcome the obstacles of its pharmacological application.

The benefits of conservation practices increased the interest of farmers in the cultivation of cover crops (CCs). This review aims to present and analyze the state of the art on the cultivation of legume CCs, including their importance in protecting crops against weeds, as well as their effects on organic matter and nitrogen content in the soil, physical and biological properties of the soil, and its erosion. The multi-purpose character of legume CCs is visible in their positive effect on reducing weed infestation, but also on the soil: reducing its compaction and erosion, improving its structural and hydraulic properties, increasing the content of organic matter and activity of soil microorganisms, or increasing its nitrogen content due to symbiotic N2 fixing. This review demonstrates that a wider use of legume CCs in organic farming is needed. The benefits of legume CCs for successive crops in these cultivation conditions, both in terms of inhibiting weed populations and improving fertility and soil properties, also need to be identified. Further research is also needed to determine the potential impact of legume CCs on the improvement of the quality of degraded soils, or those with less favorable physicochemical properties.

Physical fractionation methods are based on the premise that soil organic matter (SOM) can be divided into pools of functional relevance. Physically uncomplexed organic matter (OM) is isolated on the basis of particle size and/or density. Our objective here is to review research on the biological and chemical characteristics of physically uncomplexed OM that demonstrates its value (or otherwise) as a meaningful pool of SOM. Chemical characterization indicates that fractions isolated by size are not identical to those separated by density; even materials separated using variations of a particular fractionation method (i.e., different sizes or different densities) have different chemical and biological properties. Physically uncomplexed OM often contains a substantial portion of whole soil carbon (C) and nitrogen (N) and, compared with the whole soil or heavy fraction, has a wide C/N ratio and high O-alkyl (i.e., carbohydrates) and low carbonyl (i.e., proteins) C contents. The response of physically uncomplexed OM to changes in land use and management practices is greater than that of other labile OM fractions or the whole soil C and N. Studies to elucidate the nutrient availability of physically uncomplexed OM suggest that it is not an immediate source of nutrients. That the quantity of physically uncomplexed OM is not always related to the amount of plant residue inputs suggests that other factors may control its accumulation in soil. Thus the quantity and the biological and chemical properties of physically uncomplexed OM are affected by the amount, composition, and accessibility of plant residues entering the soil; environmental conditions that may enhance or constrain decomposition; and the fractionation technique used.

  Diazotrophs can help minimize the use of synthetic nitrogen fertilizers by fixing atmospheric dinitrogen in agricultural ecosystems. However, the diazotroph community affected by biochar application is still poorly explored in the paddy fields. Here, a field study with three different biochar application rates, namely control (CK, no biochar amendment), low (LB, 24 t ha −1 applied once), and high (HB, 48 t ha −1 applied once), was employed in a double rice paddy. The impacts of biochar on diazotrophic abundance/community composition, soil chemical and biological properties, and rice biomass were examined 3‒4 years after application. The abundance and community composition of diazotrophs were measured with quantitative polymerase chain reaction and amplicon sequencing, respectively. Biochar application significantly enhanced the diazotrophic abundance by 13.1–94.2% compared with CK, which might result from increased stubble and root biomass, soil Olsen-P, total P, and total organic C. Compared to HB, LB significantly increased diazotrophic abundance by 5.6–20.8% three years post-addition, which was probably due to the increased stubble and root biomass. The variations in the alpha diversity index in diazotroph community composition from biochar treatments was decreased over time, relative to CK. Diazotrophic community Bradyrhizobium , Geobacter , Azospirillum , and Pseudodesulfovibrio had a significantly higher relative abundance in biochar treatments than in CK, which can endophytically colonize the rice roots or utilize a wide range of organic carbon sources. Our results demonstrate that biochar amendment could be a useful measure to promote soil available N pool in double rice paddies.

In this age of intensive industrialization and urbanization, mankind’s highest concern should be to analyze the effect of all metals accumulating in the environment, both those considered toxic and trace elements. With this aim in mind, a unique study was conducted to determine the potentially negative impact of Sn 2+ , Co 2+ , and Mo 5+ in optimal and increased doses on soil biological properties. These metals were applied in the form of aqueous solutions of Sn 2+ (SnCl 2 . 2H 2 O), Co 2+ (CoCl 2  · 6H 2 O), and Mo 5+ (MoCl 5 ), each in the doses of 0, 25, 50, 100, 200, 400, and 800 mg kg −1 soil DM. The activity of dehydrogenases, urease, acid phosphatase, alkaline phosphatase, arylsulfatase, and catalase and the counts of twelve microorganism groups were determined on the 25th and 50th day of experiment duration. Moreover, to present the studied problem comprehensively, changes in the biochemical activity and yield of spring barley were shown using soil and plant resistance indices—RS. The study shows that Sn 2+ , Co 2+ , and Mo 5+ disturb the state of soil homeostasis. Co 2+ and Mo 5+ proved the greatest soil biological activity inhibitors. The residence of these metals in soil, particularly Co 2+ , also generated a drastic decrease in the value of spring barley resistance. Only Sn 2+ did not disrupt its yielding. The studied enzymes can be arranged as follows for their sensitivity to Sn 2+ , Co 2+ , Mo 5+ : Deh > Ure > Aryl > Pal > Pac > Cat. Dehydrogenases and urease may be reliable soil health indicators.