Biodegradation最新文献

Driven by global disease challenges, the traditional Chinese medicine (TCM) industry has flourished, however, the massive surge in TCM residues has emerged as a major bottleneck to its sustainable development. Semi-permeable membrane aerobic composting provides a key technology for TCM residue valorization, which typically relies on exogenous nitrogen supplementation to optimize the carbon-to-nitrogen (C/N) balance. Nevertheless, a systematic understanding of how differentiated nitrogen sources impact this composting process remains lacking. Herein, this study introduced distinct nitrogen sources as co-substrates for semi-permeable membrane aerobic composting to elucidate their modulation of key physicochemical parameters and microecological succession. The results demonstrated that peanut meal exhibited the optimal composting performance compared to alfalfa meal, soybean meal, and urea. Specifically, its thermophilic phase (> 55°C) persisted for over 7 days, and the organic matter content degraded most rapidly and stably, achieving a reduction rate of 49.8%. At maturity, the ammonium nitrogen (NH₄⁺-N) content and electrical conductivity (EC) dropped to as low as 81 mg/kg and 2606μS/cm, respectively, while the peak total nutrient content reached 5.8%. Meanwhile, the dynamic trend of the ratio of the absorbance at 465 nm to that at 665 nm (E4/E6) aligned with typical aerobic composting patterns, indicating a high degree of humification. Community analysis revealed that Bacillus, Bifidobacterium, and Pseudomonas were the dominant bacterial taxa in the efficient treatments, whereas fungi dominated by Thermomyces, Mycothermus, and Aspergillus were consistently associated with NH₄⁺-N turnover and lignocellulose degradation, these compositional associations suggest a potential contribution of these taxa to compost maturation, which warrants direct functional verification in future studies. Overall, this study provides critical microecological insights and a practical nitrogen optimization strategy for efficient and sustainable TCM residue composting.

Hexavalent chromium [Cr(VI)] is a persistent, highly toxic, and bioaccumulative contaminant that poses serious risks to soil ecosystems and human health. This study investigated the phytoremediation potential of Pennisetum pedicellatum and characterized chromium-associated rhizospheric bacteria in Cr(VI)-contaminated soil. A 60-day greenhouse pot experiment was conducted using four Cr(VI) treatments: control (T0), 25 mg kg⁻1 (T1), 50 mg kg⁻1 (T2), and 100 mg kg⁻1 (T3). Plant and soil samples were collected at 15-day intervals to evaluate growth, biomass, biochemical responses, and chromium accumulation. Chromium uptake increased with both treatment concentration and exposure time, with the highest accumulation observed in T3, reaching 58.55 mg kg⁻1 in roots and 20.23 mg kg⁻1 in shoots. Chromium was preferentially retained in the root system, while prolonged exposure adversely affected root and shoot growth despite relatively higher biomass production under T3. The calculated bioaccumulation factor (BAF) and translocation factor (TF) confirmed P. pedicellatum’s ability to accumulate chromium, with root sequestration indicating phytostabilisation as the predominant remediation mechanism. In addition, five chromium-associated rhizospheric bacterial isolates were identified through biochemical characterization and 16S rRNA gene sequencing as Bacillus foraminis, Bacillus wudalianchiensis, Bacillus australimaris, Bacillus licheniformis, and Bacillus paramycoides. Although these isolates were successfully identified, their functional roles in chromium resistance, Cr(VI) reduction, biosorption, and plant growth promotion were not evaluated in this study. Overall, the findings demonstrate that P. pedicellatum is a promising candidate for the phytostabilization of chromium-contaminated soils and provide a foundation for future investigations into plant–microbe-assisted phytoremediation under field conditions.

Microplastics (MPs) are an emerging environment pollutant that widely distributed across various environmental matrices and pose significant risks to marine biota, invertebrates and humans. Industrial wastewater sample was collected from the Urkura industrial area, Raipur, Chhattisgarh, India to evaluate the presence as well as biodegradation of microplastics. Microplastics were extracted and characterized for size, shape and colour using stereo and fluorescence microscopy, while polymer composition was identified using Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy (RS). The analysis revealed (PE) as the predominant polymer, mainly occurring in fibre and fragment forms. Other polymers including polypropylene (PP), polystyrene (PS), low density polyethylene (LDPE) and polyethylene terephthalate (PET) were also identified. Quantitative analysis revealed a mean concentration of 64±1 particles/L (64000 particles/m³). The microplastics exhibited different colors including blue, black, red, violet, brown, grey, green, orange, and transparent, with particle sizes from 50 µm to 5000 µm. A novel bacterial strain, Bacillus paralicheniformis strain PWDS (NR_137421.1), was isolated from soil sample obtained from a plastic dumping area located in Raipur. Biodegradation was carried out for 30 days and process parameters such as pH, temperature, inoculum volume and shaking speed were optimized. The bacterial strain showed a maximum degradation efficiency of about 8.4±0.4%. The study highlights presence of microplastics in wastewater and the efficiency of microbial approaches for effective microplastic bioremediation and environmental sustainability.

Textile industries generate large volumes of effluents containing spent dyes, heavy metals, and other recalcitrant contaminants. The discharge or inappropriate disposal of textile effluents can adversely affect surface water, soil and other environmental matrices through the accumulation of dyes, heavy metals, salts, and other contaminants. For the remediation of such contaminated environments, biological approaches involving plants and microorganisms have emerged as sustainable alternatives to conventional treatment technologies. However, the rapid expansion and interdisciplinary nature of this research area have made it difficult to comprehensively assess its developmental trajectory. Therefore, this study presents a bibliometric analysis of global research on plant- and microbe-based remediation of textile effluent-contaminated environments using the Scopus database. A total of 359 publications from 1998 to 2025 were analyzed using Bibliometrix/Biblioshiny and VOSviewer. The results revealed an annual growth rate of 13.83%, with nearly half of the scientific output produced since 2020. Bibliometric life cycle analysis projected continued growth of the field, with peak scientific production expected around 2029. Keyword and thematic analyses demonstrated a progressive diversification from conventional dye decolorization studies toward broader themes involving microbial consortia, bioremediation, phytoremediation, mixed-contaminant remediation, and environmental assessment. Co-citation and coupling analyses identified a cohesive intellectual structure centered on biodegradation, wastewater treatment, and environmental remediation. These findings demonstrate increasing integration of biological remediation approaches across interconnected contaminated environments and highlight the growing importance of plant-microbe systems. Future research should prioritize contaminant transformation pathways, microbial interactions, multi-contaminant remediation, and long-term ecological consequences by integrating molecular approaches with plant- and microbe-based remediation.

The growing resistance of Pseudomonas aeruginosa to conventional antibiotics has drawn increasing attention to antivirulence strategies that inhibit biofilm development and interfere with Quorum Sensing (QS) mechanisms. This study evaluated the biological activity of B-phycoerythrin (B-PE), a phycobiliprotein extracted from the red microalga Porphyridium cruentum, against Pseudomonas aeruginosa PAO1. This phycobiliprotein significantly inhibited biofilm formation by up to 62.4% and reduced performed biofilm by over 63% at 1/2 MIC, as quantified by crystal violet staining, causing notable morphological changes observed via epifluorescence microscopy. Furthermore, B-PE affected the production of virulence factors, decreasing pyocyanin and pyoverdine synthesis and reducing cell surface hydrophobicity. RT-qPCR analysis revealed significant downregulation of lasI, lasR, rhlI, rhlR, and mvfR, indicating modulation of multiple QS-associated regulatory components. These transcriptional changes, together with the observed alterations in QS-associated phenotypes, suggest that QS-associated regulation may contribute to the biological effects of the B-PE-rich extract. Overall, this study provides evidence for the antibiofilm and antivirulence potential of the B-PE-rich extract against Pseudomonas aeruginosa, supporting its further investigation as a naturally derived preparation for biofilm control and anti-infective applications.

Numerous studies have investigated the production, characterization, and applications of biochar across diverse fields. However, a substantial gap remains in the literature regarding the optimization of biochar process parameters and the development of robust utilization models. Considering biochar as a promising tool for environmental remediation, the present study systematically examines process parameters and optimization techniques using the Preferred Reporting Items for Systematic Reviews (PRISMA) framework. Scopus was used as the primary data source, covering publications from 2008 to 2025. A total of 86 studies met the eligibility criteria for this review. The design of experiments (DOE), multi-objective optimization approaches (MOO), and machine learning (AI/ML) models were found to be predominant methodologies employed in the selected studies. Response surface methodology (RSM), particularly central composite design (CCD) and box–Behnken design (BBD) was widely and robustly applied for biochar production optimization. However, the use of primary data–driven AI/ML models remains limited, and MOO approaches beyond the desirability function approach (DFA) were sparsely explored. The findings highlight the need for hybrid frameworks that integrate DoE with advanced AI/ML techniques, supported by multi-objective optimization and Multi-Criteria Decision-Making (MCDM) methods, as promising future research avenues.

The model isobutylene (IB)-metabolizing strain Mycolicibacterium sp. ELW1 grew aerobically on diethyl ether (DEE) as a sole carbon and energy source. DEE supported an equivalent biomass yield to IB despite strong effects of DEE concentration on growth rate and lag phase. Differential expression analysis of the transcriptome revealed extensive transcriptional remodeling during growth on DEE compared to fructose, including the substantial upregulation of chromosomally-encoded alcohol and acetaldehyde dehydrogenases, and the plasmid‑encoded isobutylene monooxygenase (IMO). In resting‑cell assays, IB‑grown cells oxidized DEE twice as rapidly as DEE‑grown cells and ethanol and acetaldehyde temporarily accumulated during DEE oxidation. In contrast, no products were detected during DEE oxidation by DEE-grown cells. Loss of the megaplasmid pELW1‑1 prevented growth on both IB and DEE while activity‑based labeling (ABL) analyses suggest the plasmid-encoded IMO is the major diyne‑reactive monooxygenase in both IB and DEE-grown cells. Supplementing cultures growing on DEE with small amounts of IB increased both DEE consumption rates and biomass yields, and this effect appears to involve decreases in the lag phase associated with growth on DEE alone. In contrast to some previous studies of DEE catabolism which have concluded DEE is unable to induce expression of soluble di-iron monooxygenases (SDIMOs), collectively, our results indicate DEE catabolism leads to substantial expression of the plasmid‑encoded IMO and is supported by expression of chromosomally encoded alcohol and aldehyde dehydrogenases.

Reactive Black 5 (RB5) is a widely used azo dye in the textile industry that is highly toxic and harms both human health and the environment. The biofilm is a complex matrix comprising microorganisms and extracellular polymeric substances (EPS). Biofilm-based bioremediation is one of the most effective approaches for removing toxic RB5 from water. In this study, a biofilm-forming bacterial consortium comprising Bacillus tequilensis BS007 and Enterobacter mori BS008 was evaluated for treated RB5 dye. The consortium exhibited a specific growth rate (μ_max) of 0.265 h⁻¹ and efficient biofilm formation. The biofilm consortium achieved 98% decolorization of 100 ppm RB5 within 8 h (pH 8, 37 °C). FESEM analysis showed morphological changes in the biofilm, whereas FTIR confirmed the breakdown of azo bonds and changes in other functional groups in the dye after degradation. A biodegradation pathway was proposed based on degradation intermediates analyzed by GC–MS. Molecular modelling and dynamics simulations were performed with two enzymes primarily responsible for its degradation. RMSD and RMSF data up to 100 ns indicated stable docked structures, little structural variation, and a robust protein framework between the azoreductase enzyme and the RB5, which can correlate with the GC–MS data. Phytotoxicity assessment using Cicer arietinum demonstrated that compared to the control, seed germination increased from 40% in the untreated dye to 85% after treatment. These findings highlight the potential of the biofilm consortium as an efficient, environmentally sustainable approach for treating RB5-contaminated textile wastewater.

Polycyclic Aromatic Hydrocarbons (PAHs) are hazardous organic pollutants known for their extreme toxic implications to living beings. Their potential carcinogenicity is the major problem related to hydrocarbon contamination. The development of efficient remedy for its removal remains a challenge. Microbial degradation represents an eco-sustainable strategy to detoxify these persistent pollutants. This study employs a novel and combined approach of metabolomic and genomic (whole genome sequencing) analyses to elucidate the mechanisms involved in the biodegradation of naphthalene, phenanthrene and fluorene by Priestia aryabhattai BMRS3B. Remarkably, BMRS3B sustains its growth and efficiently utilised naphthalene, phenanthrene and fluorene at concentrations up to 100 mgmL⁻¹, highlighting its high tolerance and utilisation efficiency. The strain achieved a maximum biodegradation of the selected PAHs—naphthalene, phenanthrene and fluorene and this was evidently supported with thin layer chromatography, UV spectroscopy along with Gas Chromatography Mass Spectrometry analysis. This revealed that the strain BMRS3B completely degraded naphthalene, phenanthrene and fluorene over 72–120 h, with phthalic acid esters, dibutyl phthalate, 1,2 dibenzenedicarboxylic, bis-3,5,5-trimethylhexylpthalate and didecan-2-yl phthalate identified as the principal intermediates. Moreover, the whole genomic analysis revealed genes encoding ring-cleaving dioxygenases, catechol 2, 3-dioxygenase, cytochromes P450 monooxygenases which are instrumental in bringing aromatic ring catabolism. Finally, a pathway for biodegradation of naphthalene, phenanthrene and fluorene by the selected isolate was proposed on the basis of metabolomic and genomic profiling. These findings place the strain P. aryabhattai BMRS3B as a promising candidate for the bioremediation of PAHs in the contaminated sites.

Microbial consortia are essential for the degradation of complex hydrocarbon mixtures in coastal environments, yet the functional basis of consortium performance rarely resolved at strain level. In this study, we employed a Plackett–Burman experimental design to rationally assemble and optimize a synthetic consortium for the degradation of medium-grade crude oil in a sand–seawater microcosm. Six strains were selected: Stutzerimonas stutzeri CBC1 and CBC2, S. balearica GOM11, Pseudomonas sp. CBC3, Halomonas litopenaei GOM23 and Enterobacter kobei GOM24. After 45 days, the consortium removed 15.72% of total hydrocarbons relative to the abiotic control, with markedly higher fraction-specific removal determined by GC–MS: 94.7% of phenanthrene, 63.1% and 41.0% of the C8-C27 and C18-C27 aliphatic fractions respectively. Comparative genomic analysis revealed a non-uniform distribution of catabolic functions consistent with metabolic complementary. Stutzerimonas and Pseudomonas strains carried ring-hydroxylating dioxygenases (nah/nag-like clusters) together alkane-degrading alcohol/aldehyde dehydrogenases (alkJ, alkH), whereas H. litopenaei GOM23 and E. kobei GOM24 encoded alternative long-chain alkane-hydroxylating systems (ladA). GOM24 further carried an expanded repertoire of ABC transporters and oxidative-stress genes (ahpC/ahpF), consistent with a role in substrate uptake and stress tolerance rather than in primary ring cleavage. Enzymatic assays supported this partitioning, catechol 1,2-dioxygenase activity was confined to the same four strain that encoded the gene and was highest in CBC1 and GOM11 (0.0472 and 0.0443 U·mg⁻¹ protein, respectively). No genome carried the classical alkB alkane-monooxygenase, pointing to alternative and partially redundant alkane-oxidation routes. By combining statistically guided assembly with comparative genomics and targeted enzyme assays, this work identifies a six-strain combination that removes more crude oil than the full eleven-isolate community and resolves how its catabolic functions are partitioned among strains.