Kinetic study of glyphosate biodegradation by actinobacterial consortium RH1: implications for bioremediation

Fungal Bioaugmentation and Plant-Based Biostimulation for Petroleum Hydrocarbon Degradation in Mangrove Sediments

Mangrove ecosystems are highly vulnerable to petroleum contamination, with long-lasting environmental consequences due to the persistence of complex hydrocarbon fractions. While bioremediation strategies such as bioaugmentation and biostimulation are widely studied, their comparative effectiveness in mangrove sediments remains poorly understood. This study evaluates the degradation of total petroleum hydrocarbons (TPH) in mangrove sediments contaminated with Recôncavo Basin crude oil (1% w/w) using fungal bioaugmentation (Aspergillus sp.), plant-based biostimulation, and their combination. A controlled mesocosm experiment simulated tidal dynamics over 45 days using 80 bioreactors. Significant reductions in unresolved complex mixture (UCM) and TPH concentrations were observed across all treatments, with UCM reductions reaching up to 78.4% in the biostimulation treatment. However, no statistically significant differences were found among treatments at the end of the experiment (p > 0.05). This suggests a dominant role of intrinsic biodegradation processes, indicating that natural attenuation can be as effective as engineered strategies in specific mangrove environments over the long term. Changes in diagnostic ratios (pristane/phytane and n-alkanes) confirmed the preferential degradation of linear hydrocarbons. These findings highlight the potential of low-cost, nature-based remediation and suggest that intrinsic processes may suffice for long-term recovery, emphasizing the need for extended studies to fully evaluate engineered treatment advantages.

Scaling EPS yield and bio-carrier application of Bacillus paralicheniformis UB08 for rapid lead remediation

The most potent strain, Bacillus paralicheniformis UB08 (TISTR 10842), displayed an extraordinary nominal Pb tolerance, with a minimum bactericidal concentration exceeding 9,000 ppm, and alginate bead encapsulation enables rapid and complete Pb removal, offering a promising solution for heavy metal treatment based on physical adsorption and potential biological synergies.

Ex Situ Bioremediation of PCBs-Contaminated Soils through Microbial Immobilization on Coconut Fiber

Biochemical markers and bioaccumulation capacity of cyanobacteria under fenitrothion stress: implications for aquatic bioremediation

The greater metabolic stability and adaptive capacity of A. laxa is demonstrated under the tested conditions, supporting its identification as the more robust bioremediation candidate.

Monod Kinetics for EM4-Driven Ammonia Biodegradation Under Molasses Variation and Microbial Acclimatization

Ammonia is a toxic pollutant parameter in petrochemical wastewater and can impair the quality of aquatic environments. This experimental study evaluated the kinetics of ammonia biodegradation by an Effective Microorganisms-4 (EM4) consortium using the Monod model approach, focusing on molasses concentration as an external carbon source and the effect of microbial acclimatization. This experiment was conducted in aerobic batch systems with initial ammonia concentrations of 10, 30, and 50 ppm and the addition of 5% and 10% molasses. Mixed Liquor Suspended Solids (MLSS) and pH were monitored to evaluate environmental dynamics and biomass growth. The results showed that increasing the molasses concentration from 5% to 10% increased the maximum specific growth rate (μmax) from 6.29 to 7.17 day−1 and decreased the half-saturation constant (Ks) from 23.22 to 14.01 mg/L; therefore, a lower Ks indicates higher apparent substrate affinity. The acclimatization further improved the kinetic response, yielding higher μmax and lower Ks than the non-acclimated system, alongside higher MLSS and a faster pH decrease consistent with more intensive biodegradation activity. Overall, these results confirm that the combination of microbial acclimatization and sufficient molasses addition can enhance the kinetic performance of ammonia biodegradation by EM4.

Biochar-assisted biotransformation of 2,4,6-trinitrotoluene by Pseudomonas sp. CMR5c T22: synergistic mechanisms and metabolic reprogramming.

2,4,6-Trinitrotoluene (TNT) contamination presents serious threats to ecological safety and human health due to its high toxicity, carcinogenicity, and environmental persistence. Although microbial bioremediation is eco-friendly and cost-effective, its efficiency is often limited by low removal rates and weak microbial tolerance under TNT stress. This study utilized biochar to facilitate microbial biotransformation of TNT and systematically elucidated its synergistic mechanisms. Four types of biochar from different waste sources were screened, among which the wood biochar (MBC) exhibited the optimal performance. With MBC amendment, the TNT removal efficiency increased from 46.2% (strain-only control) to 88.7% within 48 h at an initial TNT concentration of 100 mg/L. Meanwhile, the first-order kinetic rate constant rose from 0.01323 h-1 (strain-only) to 0.03987 h-1, revealing that MBC greatly accelerated the TNT removal rate. Biochar accelerated removal kinetics, alleviated TNT-induced growth inhibition of strain T22 via lowering aqueous TNT concentration, and stimulated extracellular polymeric substance secretion. Untargeted metabolomics revealed 330 up-regulated differential metabolites in the biochar-microbe system, indicating intensive metabolic reprogramming. Mechanistically, MBC directly enhanced TNT transformation via activation of the nitrotoluene degradation and cofactor biosynthesis pathways. The synergistic mechanisms were proposed to include: (1) weakened TNT exposure; (2) enhanced antioxidant metabolism; (3) activated core transformation pathways; and (4) supplemented basal metabolic supply. Although complete mineralization and soil-scale validation are beyond the present scope, our findings establish a mechanistic foundation for designing biochar-microbe systems for enhanced nitroaromatic remediation.