Microbial- and seaweed-based biopolymers: Sources, extractions and implications for soil quality improvement and environmental sustainability - A review.

Improving soil quality without creating any environmental problems is an unescapable goal of sustainable agroecosystem management, according to the United Nations 2030 Agenda for Sustainable Development. Therefore, sustainable solutions are in high demand. One of these is the use of biopolymers derived from microbes and seaweed. This paper aims to provide an overview of the sources of extraction and use of microbial (bacteria and cyanobacteria) and seaweed-based biopolymers as soil conditioners, the characteristics of biopolymer-treated soils, and their environmental concerns. A preliminary search was also carried out on the entire Scopus database on biopolymers to find out how much attention has been paid to biopolymers as biofertilizers compared to other applications of these molecules until now. Several soil quality indicators were evaluated, including soil moisture, color, structure, porosity, bulk density, temperature, aggregate stability, nutrient availability, organic matter, and microbial activity. The mechanisms involved in improving soil quality were also discussed.

Sulfur-functionalized biochar: Synthesis, characterization, and utilization for contaminated soil and water remediation-a review.

The development of innovative, eco-friendly, and cost-effective adsorbents is crucial for addressing the widespread issue of organic and inorganic pollutants in soil and water. Recent advancements in sulfur reagents-based materials, such as FeS, MoS2, MnS, S0, CS2, Na2S, Na2S2O32-, H2S, S-nZVI, and sulfidated Fe0, have shown potential in enhancing the functional properties and elemental composition of biochar for pollutant removal. This review explores the synthesis and characterization of sulfur reagents/species functionalized biochar (S-biochar), focusing on factors like waste biomass attributes, pyrolysis conditions, reagent adjustments, and experimental parameters. S-biochar is enriched with unique sulfur functional groups (e.g., C-S, -C-S-C, C=S, thiophene, sulfone, sulfate, sulfide, sulfite, elemental S) and various active sites (Fe, Mn, Mo, C, OH, H), which significantly enhance its adsorption efficiency for both organic pollutants (e.g., dyes, antibiotics) and inorganic pollutants (e.g., metal and metalloid ions). The literature analysis reveals that the choice of feedstock, influenced by its lignocellulosic content and xylem structure, critically impacts the effectiveness of pollutant removal in soil and water. Pyrolysis parameters, including temperature (200-600 °C), duration (2-10 h), carbon-to-hydrogen (C:H) and oxygen-to-hydrogen (O:H) ratios in biochar, as well as the biochar-to-sulfur reagent modification ratio, play key roles in determining adsorption performance. Additionally, solution pH (2-8) and temperature (288, 298, and 308 K) affect the efficiency of pollutant removal, though optimal dosages for adsorbents remain inconsistent. The primary removal mechanisms involve physisorption and chemisorption, encompassing adsorption, reduction, degradation, surface complexation, ion exchange, electrostatic interactions, π-π interactions, and hydrogen bonding. This review highlights the need for further research to optimize synthesis protocols and to better understand the long-term stability and optimal dosage of S-biochar for practical environmental applications.

Assessment of heavy metal distribution and bioaccumulation in soil and plants near coal mining areas: implications for environmental pollution and health risks.

Monitoring heavy metals (HMs) across source distance and depth distribution near coal mining sites is essential for preventing environmental pollution and health risks. This study investigated the distribution of selected HMs, cadmium (Cd2+), chromium (Cr2+), copper (Cu2+), manganese (Mn2+), nickel (Ni2+), lead (Pb2+), and zinc (Zn2+), in soil samples collected from ten sites (S-1-S-10) at two different depths (0-15 and 15-30 cm) and distances of 50, 100, and 200 m from a mining source. Additionally, three plant species, Prosopis spp., Justicia spp., and wheat, were collected to assess HM bioavailability and leaf accumulation. Coal mine activities' impact on soil properties and their HM associations were also explored. Results reveal HM concentrations except for Cr2+ exceeding World Health Organization (WHO) limits. In surface soil, Cd2+ (58%), Cu2+ (93%), Mn2+ (68%), Ni2+ (80%), Pb2+ (35%), and Zn2+ (88%) surpassed permissible limits. Subsurface soil also exhibited elevated Cd2+ (53%), Cu2+ (83%), Mn2+ (60%), Ni2+ (80%), Pb2+ (35%), and Zn2+ (77%). Plant species displayed varying HM levels, exceeding permissible limits, with average concentrations of 1.4, 1.34, 1.42, 4.1, 2.74, 2.0, and 1.98 mg kg-1 for Cd2+, Pb2+, Cr2+, Cu2+, Mn2+, Ni2+, and Zn2+, respectively. Bioaccumulation factors were highest in wheat, Prosopis spp., and Justicia spp. Source distance and depth distribution significantly influenced soil pH, electrical conductivity (EC), and soil organic carbon (SOC). Soil pH and EC increased with an increase in soil depth, while SOC decreased. Pearson correlation analysis revealed varying relationships between soil properties and HMs, showing a considerably negative correlation. Concentrations of HMs decreased with increasing depth and distance from mining activities, validated by regression analysis. Findings suggest crops from these soils may pose health risks for consumption.

Phytochemical Investigation and Therapeutical Potential of Cotinus coggygria Scop. in Alloxan-Induced Diabetic Mice.

Plants are a significant source for the development of new phytomedicines due to their great clinical benefits, efficiency, cost-effectiveness, fewer side effects, and more affordable therapies. Numerous plants used in traditional treatments, such as Cotinus coggygria Scop., have been effective in the treatment of diabetes mellitus (DM). Therefore, the study is aimed at assessing the phytochemical, antioxidant, and antidiabetic properties of C. coggygria. The hypoglycemic and hypolipidemic activity was evaluated in Swiss male Albino mice by administering an oral dose of 150-250 mg/kg of C. coggygria extracts in alloxan-induced diabetic mice for 15 days. The antioxidant activity and phytochemical composition of the extracts were assessed by using α, α diphenyl-ß-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays and through standard chemical procedures. The effects of extracts on blood glucose, body weight, lipid profile, and biochemical parameters like total cholesterol (TC), triglyceride (TG), low-density lipids (LDL), high-density lipids (HDL), plasma insulin, liver glycogen, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, and creatinine were determined according to standard procedures. The activities of antioxidant enzymes such as superoxide-dismutase (SOD), peroxidase (POD), and catalase (CAT) were also analyzed spectrophotometrically. The hypoglycemic and hypolipidemic effects with chloroform extracts of 250 mg/kg were found significant in the treatment of diabetes in alloxanised mice compared to the diabetic group. The haematological parameters such as TC, TG, HDL, LDL, creatinine, urea, AST, ALT, and ALP were significantly improved (p < 0.01) by the chloroform extract of 250 mg/kg compared to the diabetic group. Treatment for 15 days showed significant elevation (p < 0.01) of antioxidant enzymes. Fourier-transform infrared spectroscopic (FTIR) and gas chromatography-mass spectrometry (GC-MS), column chromatography (CC), and nuclear magnetic resonance (NMR) analyses tentatively identified different phytoconstitutents and metabolites in C. coggygria leaves, which have been reported to possess antihyperglycemic properties. In conclusion, the chloroform extract of 250 mg/kg of C. coggygria possesses significant hypoglycemic and hypolipidemic potential which may prove the claimed use of the plant in amelioration of diabetes and associated complications in folkloric medicine. Additional studies are required for the purification, characterization, and structural elucidation of bioactive compounds.

Coupling phosphate-solubilizing bacteria (PSB) with inorganic phosphorus fertilizer improves mungbean (Vigna radiata) phosphorus acquisition, nitrogen fixation, and yield in alkaline-calcareous soil.

To overcome the problems associated with soil phosphorus (P) insolubility, soil inoculation with phosphate-solubilizing bacteria (PSB) can be used. In a field experiment, we evaluated the efficacy of PSB in enhancing mungbean P acquisition, nitrogen (N) fixation, and morphological and yield traits in alkaline-calcareous soil when added together with P as single superphosphate (SSP) or rock phosphate (RP) at 45 or 90 kg P2O5 ha-1. Coupling PSB with mineral P fertilizers (SSP & RP) improved P use efficiency, mungbean P acquisition, N2 fixation, nodulation, NP uptake, and the morphological and yield-related traits of mungbeans compared with non-fertilized controls and plots received P from mineral sources alone. Soil PSB inoculation with mineral P also improved post-harvest soil fertility relative to pre-harvest by improving soil organic matter from 0.61% to 0.70%, lowering pH from 7.74 to 7.68, and improving soil total N from 0.04 to 0.09%, ABDTPA-extractable P from 2.07 to 3.44 mg kg-1, and potassium (K) concentrations from 100.27 to 129.45 mg kg-1. When combined with PSB, RP generally performed better than SSP. Moreover, there was a significant correlation between soil N and plant N, while the correlation between soil P and plant P was non-significant. The correlation between soil organic matter content and NP uptake by mungbeans was also non-significant. Therefore, adding P as RP at 45-90 kg ha-1, together with PSB inoculation, can be recommended for improving mungbean P acquisition, use efficiency, optimum N2 fixation, and yield in alkaline-calcareous soils.

Phytochemical Screening and Antidiabetic, Antihyperlipidemic, and Antioxidant Effects of Leptopus Cordifolius Decne. In Diabetic Mice.

Plants are well known in traditional herbal medicines for their hypoglycemic and hypolipidemic activities and are often used due to their accessibility, affordability, and corollary effects. Leptopus cordifolius has been reported to control diabetes in folkloric medicine, but no known scientific research has been conducted to assess the plausibility of this assertion. Therefore, the current study is aimed to investigate the antidiabetic and hypolipidemic effects of Leptopus cordifolius leaves in alloxan-induced diabetic mice. The antidiabetic and antihyperlipidemic evaluation was conducted in Swiss albino mice at doses of 150-250°mg/kg for 15°days. The blood glucose, total cholesterol, triglyceride, LDL, HDL, creatinine, ALP, SGPT, and SGOT levels were estimated according to standard procedures. Phytochemicals of leaves were analyzed using GC-MS analysis. Enzymatic antioxidant activity of the plant was investigated spectrophotometrically by carrying out superoxide dismutase, peroxidase, and catalase assays. The membrane stabilization potential of L. cordifolius leaf extracts was carried out using an in vitro haemolytic assay. The results revealed a dose response effect with the methanolic extract of L. cordifolius which had significant antihyperglycemic effects at 150-250°mg/kg in alloxan treated mice, although less than the positive control (glibenclamide). Hyperlipidemic activity was significant at 250 mg/kg. The biochemical parameters, such as total cholesterol, triglyceride, LDL, HDL, creatinine, ALP, SGPT, and SGOT, were significantly improved (p < 0.01) by the methanolic extract of 250 mg/kg compared to the diabetic group. Treatment for 15 days showed significant elevation (p < 0.01) of antioxidant enzymes. GC-MS analysis provided tentative identifications of 52 compounds in the methanolic extract of L. cordifolius, of which 12 compounds have reported antidiabetic activity. In conclusion, methanolic extract of L. cordifolius of 150 and 250°mg/kg body weight showed significant antidiabetic and antihyperlipidemic activities in alloxan-induced diabetic mice and, with further work, has the potential to be used to manage blood glucose and cholesterol levels.

Facile combinations of thiosulfate and zerovalent iron synergically immobilize cadmium in soils through mild extraction and facilitated immobilization.

Cadmium (Cd) is one of the most toxic substances released in the environment. Cd-contaminated soils usually have a large pool of bioavailable Cd species and lead to excessive Cd accumulation in planted cereal crops. Treatment methods for stable immobilization of Cd in soils are desirable. Here we reported that facile combinations of thiosulfate (STS) and zerovalent iron (ZVI) reinforced Cd immobilization in soils and reduced Cd accumulation in wheat. STS mildly activated Cd in soils through the formation of soluble Cd(S2O3)x complexes, whereas intermediates of STS (e.g., sulfate and sulfides) and ZVI synergically facilitated immobilization of Cd in soils. The synergy was ascribed to the facilitated formation of FeOOH with high Cd-binding affinity and formation of stable sulfate-Cd-FeOOH complexes and poorly available CdSx. STS-ZVI treatments increased residual Cd in soils by 101-123% and decreased Cd accumulation in wheat shoots by 13-68%, depending on chemical compositions and doses of binary reagents. Field applications of STS and ZVI (0.06-0.11 kg/m2) demonstrated 24-39% reductions of grain Cd.