Climate change, inadequate possessions, and land degradation all pose obstacles to modern agriculture. In the current scenario, the agriculture industry is mainly dependent on the use of chemical-based pesticides and fertilizers that impact soil health and crop productivity. Moreover, water scarcity leads farmers in drastically affected regions to use heavy metal-enriched water sources mainly originating from industrial sources for field crops irrigation. Soil pollutants can be carried into the human body via dust and water, creating negative health effects varying from simple symptoms, e.g., nausea and diarrhea and reaching death in critical cases. Thus, to clean soil contaminants, and improve soil fertility and agricultural production, alternatives to chemical fertilizers must be developed. Therefore, using beneficial microbes found in plant-associated soil microorganisms offers an effective strategy to alleviate some of these challenges, improving soil fertility, and crop yield, and protecting plants from stress conditions. Through the use of synergistic interactions, the synthetic consortium strategy seeks to improve the stability of microbial communities. In this review, synthetic consortia and their potential use in agriculture were discussed. Further, engineering new effective synthetic consortia was suggested as an effective approach in the concept of environmental bioremediation of soil pollutants and contaminants.

In recent times, injudicious use of paclobutrazol (PBZ) in mango orchards deteriorates the soil quality and fertility by persistence nature and causes a serious ecosystem imbalance. In this study, a newKlebsiella pneumoniaestrain M6 (MW228061) was isolated from mango rhizosphere and characterized as a potent plant growth promoter, biocontrol, and PBZ degrading agent. The strain M6 efficiently utilizes PBZ as carbon, energy and nitrogen source and degrades up to 98.28% (50 mgL^-1initial conc.) of PBZ at 15^thday of incubation in MS medium. In the soil system first order degradation kinetics and linear model suggested 4.5 days was the theoretical half-life (t_1/2value) of PBZ with strain M6. Box Behnken design (BBD) model of Response surface methodology (RSM) showed pH 7.0, 31°C temperature, and 2.0 ml inoculum size (8 x 10⁹CFU mL^-1) was optimized condition for maximum PBZ degradation with strain M6. Plant growth promoting attributes such as Zn, K, PO₄solubilization IAA, HCN and NH₃production of strain M6 showed positive results and were assessed quantitatively. The relation between plant growth promotion and PBZ degradation was analyzed by heat map, principal component analysis (PCA) and, clustal correlation analysis (CCA). Strain M6 was also showing a significant biocontrol activity against pathogenic fungi such asFusarium oxysporum(MTCC–284),Colletotrichum gloeosporioides(MTCC– 2190),Pythium aphanidermatum(MTCC– 1024), Tropical race 1 (TR -1), and Tropical race 4 (TR -4). Hence, results of the study suggested that strain M6 can be utilized as an effective bio-agent to restore degraded land affected by persistent use of paclobutrazol.

This study explores the comparative effect of conventional and organic treatments on the rhizosphere microbiome of Mangifera indica cv. Dashehari. The long-term exposures (about 20 years) were monitored under a subtropical ecosystem. Based on plant growth properties and acetylene reduction assay, 12 bacterial isolates (7 from G1-organic and 5 from G2-conventional systems) were identified as Pseudomonas and Bacillus spp. In the conventional system, dehydrogenase activity significantly decreased (0.053 µg TPF formed g⁻¹ of soil h⁻¹) and adversely affected the bacterial diversity composition. In comparison, organic treatments had a good impact on dehydrogenase activity (0.784 µg TPF formed g⁻¹ of soil h⁻¹), alkaline phosphatase (139.25 µg PNP g⁻¹ soil h⁻¹), and bacterial community composition. The Metagenomics approach targeted the V3 and V4 regions to see the impact in the phylum, order, family, genus, and species for both the treatments. Results showed that phylum Acidobacteria (13.6%), Firmicutes (4.84%), and Chloroflexi (2.56%) were dominating in the G2 system whereas phylum Bacteroides (14.55%), Actinobacteria (7.45%), and Proteobacteria (10.82%) were abundantly dominated in the G1 system. Metagenome sequences are at the NCBI-GenBank sequence read archive with SRX8289747 (G1) and SRX8289748 (G2) in the study PRJNA631113. Results indicated that conventional and organic conditions affect rhizosphere microbiome and their environment.

Thiamethoxam (TMX) has been frequently used in mango orchards for protecting the fruit from insects and pests. However, its high water solubility, persistence, and ecotoxicity, presents a potential threat to ecosystems and living beings. Nevertheless, the full impact of TMX residue in soil environments remains insufficiently explored. Therefore the present study aims to restore TMX contaminated soils in eco-friendly and cost effective manner by utilizing the TMX degrading microbes. To isolate TMX-resistant bacteria the soil samples collected from mango orchard at ICAR-CISH, Lucknow, a culture enrichment technique was employed. The resistance potential of these bacterial isolates to TMX was assessed in both liquid mineral salt medium (MSM) and soil. TMX residues in MSM samples were quantified using Ultra fast liquid chromatography (UFLC), with further validation by Ultra high-performance liquid chromatography (UHPLC). To identify the localization of TMX-degrading enzymes in the selected bacterial isolates, their presence was evaluated as extracellular, intracellular, or membrane-bound. Two Pseudomonas strains (A2 and C1), isolated from the rhizospheric soil of a mango orchard, exhibited significant TMX degradation by utilizing the pesticide as their sole carbon source. Their degradation efficiency was assessed at varying TMX concentrations of two considerable lower doses (0.2 and 0.5 g kg−1) and one higher dose (1.0 g kg−1) in broth, sterile soil, and non-sterile soil over 210 days. Results showed that degradation efficiency decreased with increasing TMX concentration, with the highest degradation efficiency observed in broth (89.60–98.29%), followed by sterile soil (55.34–96.97%) and non-sterile soil (52.22–99.04%). Optimal degradation occurred at 32 °C and pH 7.0 for both strains. Enzyme localization studies revealed that TMX degradation was primarily mediated by membrane-bound enzymes (both outer and inner membranes), with limited extracellular activity, likely due to reduced enzyme-substrate interaction outside the cell. Additionally, soil health assessments, including dehydrogenase activity (DHA) and fluorescein diacetate (FDA) hydrolysis, demonstrated the strain’s positive influence on soil biochemical functioning. This research contributes to the development of novel approaches for efficient TMX degradation, with strains viz., Pseudomonas aeruginosa strain A2 and Pseudomonas sp. Strain C1 showing promise as biological agents for in situ remediation of TMX-contaminated environments. Not applicable.