The application of chemical dispersants in marine oil spill bioremediation remains controversial due to uncertain effects on microbial activity. This study investigated how four diverse surfactants impact n-tetradecane biodegradation by the marine hydrocarbonoclastic yeast Yarrowia lipolytica. The tested agents encompassed hydrophilic Tween 80, lipophilic Span 80, the commercial dispersant GH-2, and a biological rhamnolipid. Elevated surfactant concentrations severely suppressed biodegradation, whereas low concentrations exhibited negligible effects. Systematic characterization of macroscopic phase behaviors and microscopic interfacial dynamics elucidated the underlying mechanisms. This severe suppression is fundamentally driven by intense competitive interfacial adsorption. Surface tension, infrared spectroscopy, and zeta potential analyses confirmed a sequential displacement mechanism. Exogenous surfactants preferentially bound to the yeast cells. This initial binding altered cellular surface chemistry and amplified electrostatic repulsion. Concurrently, these molecules outcompeted the cells for interfacial sites. Confocal laser scanning microscopy and an in situ emulsion polymerization technique provided direct visual evidence. These high-resolution techniques captured extensive cellular desorption and the emergence of cell-free interfacial domains. Ultimately, physical displacement via competitive adsorption functions as a primary mechanism stalling interfacial biodegradation. However, its specific macroscopic manifestation heavily depends on inherent surfactant properties. Hydrophilic agents induce simple cellular desorption, whereas highly lipophilic surfactants trigger catastrophic phase inversion. Regardless of these macroscopic differences, this competitive behavior hinders interfacial biocatalysis by physically isolating cells from hydrophobic substrates. These findings provide critical mechanistic insights for optimizing marine dispersant application strategies.

Excessive acidity restricts the utilization of citrus pulp, a major by-product of the dried tangerine peel industry. To overcome this bottleneck, a functional microbial consortium (BsHpMrF) comprising Bacillus subtilis L4, Hanseniaspora pseudoguilliermondii B4, and Monascus ruber CGMCC 10910 was constructed for efficient biological deacidification. The consortium exhibited a synergistic effect, achieving an 88.23% reduction in total acidity and converting the acidic pulp into a neutral, bio-stabilized substrate. Untargeted metabolomics analysis revealed that this efficiency was driven by the concurrent activation of the TCA cycle and glyoxylate shunt for organic acid mineralization, coupled with membrane lipid remodeling (increased unsaturation) to enhance acid tolerance. Notably, the fermentation process functioned as a “metabolic factory”, significantly enriching the matrix with bioactive lipids (e.g., 10-HDA, nervonic acid) and indole-3-acetic acid (IAA, 414.28 mg/L). Application assays demonstrated that the fermentation products acted as a potent biostimulant for soybean sprouts, significantly promoting lateral roots and eliciting the accumulation of antioxidant phenolics and flavonoids. This study provides a sustainable “waste-to-treasure” strategy, valorizing acidic citrus pulp into a functional biostimulant for high-quality edible sprout production, thereby achieving a sustainable “waste-to-food” circular loop.

Whole-cell Pickering interfacial biocatalysis effectively overcomes the formidable mass-transfer limitations of hydrophobic substrates in aqueous systems. However, practical implementation is severely hindered by biocatalyst vulnerability under extreme industrial environments and the inherent challenge of post-reaction emulsion separation. Herein, the artificial spore concept is specifically adapted to overcome biodesulfurization bottlenecks by sequentially encapsulating Gordonia sp. WQ-01A cells with a conformal polydopamine layer and oleic acid-modified magnetic nanoparticles. The biomimetic encapsulation establishes a protective shell that significantly shields the biocatalyst from intense ultraviolet irradiation, high concentrations of organic solvents, and extreme temperature fluctuations. Concurrently, the hydrophobic outward-facing aliphatic chains drive the spontaneous assembly of ultra-stable water-in-oil Pickering emulsions, providing an expansive interfacial microhabitat for deep biodesulfurization of dibenzothiophene. Importantly, the incorporated superparamagnetic responsiveness enables rapid liquid-liquid phase separation and catalyst recycling via a low-intensity external magnetic field, avoiding the need for energy-intensive and unscalable centrifugation operations. Although the dense hierarchical coating inevitably introduces a transient transmembrane diffusion barrier that manifests as a minor initial kinetic lag phase, this phenomenon represents a practical strategic compromise. Exchanging a brief initial mass transfer delay for enduring operational stability, mitigated product toxicity, and simplified downstream recovery allows the engineered artificial spores to maintain stable and high cyclic desulfurization activity. This engineered platform establishes a functional foundation for robust and readily recoverable multiphase biocatalysis, enabling scalable applications in complex environments.

Biodesulfurization offers an energy-efficient alternative to conventional hydrodesulfurization, but its industrial efficiency is severely bottlenecked by the low bioaccessibility of hydrophobic substrates across the oil-water interface. Here, we addressed this mass-transfer challenge using exogenous-surfactant-free water-in-oil Pickering emulsions stabilized solely by Gordonia sp. WQ-01A cells. Exploiting the strain's native surface hydrophobicity (contact angle > 111°), the bacterial cells spontaneously assembled at the phase boundary to form a protective "bio-armor" without the aid of artificial barriers. Structural optimization indicated that an oil-to-water ratio of 1:4 and a cell loading of 10 g/L maximized the specific interfacial area with uniform droplets, governed by a limited coalescence mechanism that reached physical saturation at 20 g/L. Apparent kinetic modeling demonstrated a transition from a mass-transfer-limited regime to a pseudohomogeneous reaction regime, characterized by a significantly reduced apparent Michaelis constant Kmapp of 0.25 mmol/L and a maximum specific reaction rate Vmaxappof 9.96 mmol/kg-DCW/h. Consequently, the specific desulfurization rate was enhanced 3-fold to 5.17 mmol/kg-DCW/h compared to conventional aqueous systems, while maintaining over 90% activity across four consecutive 48-h cycles. This carrier-free strategy offers a practical, mechanically robust template for intensifying interfacial mass transfer in multiphase biocatalysis.

This study investigated the enhancement of Exocarpium Citri Grandis (ECG) functional properties via fermentation with Aspergillus niger and explored the underlying mechanisms through enzyme activity assay and untargeted metabolomics. Results indicated that A. niger secreted a complex enzyme system, including cellulase, pectinase, and beta-glucosidase, which drove the degradation of cell wall matrices and the biotransformation of flavonoids. Metabolomics analysis detected 870 differential metabolites and suggested a redirection of metabolic flux, where primary nutrients (amino acids and purines) were consumed, potentially supporting the biosynthesis of secondary metabolites. Pathway enrichment confirmed that flavonoid, flavonol and isoflavonoid biosynthesis were the key modulated pathways. Specifically, glycosides such as naringin appeared to be converted into higher-activity aglycones, including naringenin, kaempferol, and luteolin, which showed strong positive correlations with enhanced antioxidant and alpha-glucosidase inhibition activities. This study provides potential strategies and practical approaches for the high-value utilization of ECG and the development of fermentation-based functional foods.

This review explores the role of surfactants in enhancing or inhibiting the biodegradation of hydrophobic organic compounds (HOCs) by microorganisms. Bioavailability, the extent to which pollutants can be accessed and metabolized by microbes, is a key factor in determining degradation efficiency. Hydrophobic organic compounds, like polycyclic aromatic hydrocarbons, have limited bioavailability due to their low aqueous solubility, hindering microbial uptake. Microorganisms utilize strategies such as biofilm formation and direct adhesion to hydrophobic surfaces to overcome this limitation. Surfactants, both synthetic and biosurfactants, have been explored to improve HOC bioavailability by increasing solubility through micelles or emulsions. However, surfactants can also affect microbial adhesion by altering cell surface properties, leading to mixed results in degradation efficiency. Biosurfactants, which are more environmentally friendly, show promise in enhancing biodegradation without the toxic effects of synthetic surfactants. The review highlights the complex interactions between surfactants, microbial adhesion, and HOC biodegradation, emphasizing the need for tailored surfactant formulations to optimize bioremediation. Future research should focus on balancing the surfactant concentration and microbial surface properties to enhance biodegradation in contaminated environments.

Highly Hydrophobic and porous foams for efficient oil spill remediation were developed using Pickering high internal phase emulsions (HIPE) strategy, stabilized by surfactant-modified Mycobacterium sp. WY10 cells. The interfacial wettability of WY10 cells was systematically tuned with Triton X-100 (TX100), achieving a maximum under-oil contact angle (CA) of approximately 170.3° at 5 g/L TX100. These hydrophobically enhanced cells successfully stabilized W/O Pickering HIPEs, which were subsequently polymerized. The resulting foams exhibited an ultralight density (0.2761 g/cm3), strong macroscopic hydrophobicity (Water contact angle, WCA ∼135.56°), and effective selective oil absorption, contrasting with the hydrophilic foams derived from unmodified cells. The study revealed that TX100 concentration critically governs the foam's hierarchical porosity and, consequently, its oil uptake performance. While the WY10/TX100-0.05 foam possessed the highest specific surface area (2.313 m2/g), the optimized WY10/TX100-5 foam demonstrated a more favorable porous architecture, achieving a notable paraffin oil adsorption capacity of 2.8 g/g. This optimized foam also showed good reusability, retaining significant capacity after multiple adsorption-desorption cycles. This work establishes the modification of mycobacterial stabilizers as a key strategy to control the properties of biobased HIPE foams, offering a promising approach for treating oil spills.

Biocatalysis, leveraging the catalytic power of enzymes or whole microbial cells, has firmly established itself as a pivotal technology for sustainable chemical synthesis, environmental remediation, and the production of value-added compounds [...]

Highly acidic citrus pomace (CP) is a byproduct of Pericarpium Citri Reticulatae production and causes significant environmental damage. In this study, a newly isolated acid-tolerant strain of Serratia sp. JS-043 was used to treat CP and evaluate the effect of reduced acid citrus pomace (RACP) in passivating heavy metals. The results showed that biological treatment could remove 97.56

Based on the size of bacterial cells and bacterial surface hydrophobicity, some bacteria meet the requirements of Pickering particles to stabilize Pickering emulsions. Here, we discuss the oil-water interfaces of bacteria-stabilized Pickering emulsions as microhabitats for microbial metabolism of oil-soluble chemicals. The correlation between living bacteria-stabilized Pickering emulsions and microhabitats of living bacteria at oil-water interfaces offers a new perspective to study bioprocess engineering at the mesoscale between the cell and reactor scales, which not only provides novel parameters to optimize the bioprocess engineering, but also unravels the paradox of some natural phenomena related to living cell biocatalysis.

Polycyclic aromatic hydrocarbons (PAHs), as persistent environmental pollutants, often reside in nonaqueous-phase liquids (NAPLs). Mycobacterium sp. WY10, boasting highly hydrophobic surfaces, can adsorb to the oil-water interface, stabilizing the Pickering emulsion and directly accessing PAHs for biodegradation. We investigated the impact of Triton X-100 (TX100) on this interfacial uptake of phenanthrene (PHE) by Mycobacteria, using n-tetradecane (TET) and bis-(2-ethylhexyl) phthalate (DEHP) as NAPLs. Interfacial tension, phase behavior, and emulsion stability studies, alongside confocal laser scanning microscopy and electron microscope observations, unveiled the intricate interplay. In surfactant-free systems, Mycobacteria formed stable W/O Pickering emulsions, directly degrading PHE within the NAPLs because of their intimate contact. Introducing low-dose TX100 disrupted this relationship. Preferentially binding to the cells, the surfactant drastically increased the cell hydrophobicity, triggering desorption from the interface and phase separation. Consequently, PAH degradation plummeted due to hindered NAPL access. Higher TX100 concentrations flipped the script, creating surfactant-stabilized O/W emulsions devoid of interfacial cells. Surprisingly, PAH degradation remained efficient. This paradox can be attributed to NAPL emulsification, driven by the surfactant, which enhanced mass transfer and brought the substrate closer to the cells, despite their absence at the interface. This study sheds light on the complex effect of surfactants on Mycobacteria and PAH uptake, revealing an antagonistic effect at low concentrations that ultimately leads to enhanced degradation through emulsification at higher doses. These findings offer valuable insights into optimizing bioremediation strategies in PAH-contaminated environments.

Sol-gel synthesis of W-doped TiO2 nanoparticles (W-TiO2) as a photocatalyst for Procion Red MX-5B (MX-5B) azo dye treatment in textile wastewater was the main focus of this research. Scanning electron microscopy (SEM), Xray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) structural studies of nanostructured photocatalysts showed that W was successfully incorporated into the TiO2 lattice. According to EIS investigations, W-TiO2 has a greater rate of charge transfer and excellent charge separation capabilities compared to a sample of pure TiO2. It shows the W-TiO2 nanostructured photocatalyst sample's exceptional photocatalytic performance. The band gap energies of TiO2 and W-TiO2 were determined through optical studies to be 3.22 eV and 2.93 eV, respectively, showing an improvement in the photocatalytic activity of TiO2 in the visible light domain. Studies of the photocatalytic performance indicated that the full treatment of MX-5B molecules was achieved after 105, 100, 95, 80, 70, 85, and 90 min of exposure to visible light for pure TiO2, W0.5-TiO2, W1-TiO2, W3-TiO2, W5-TiO2, W8-TiO2, and W10-TiO2, respectively. These studies revealed the great and quick photocatalytic treatment of MX-5B in the presence of doped TiO2. The results of a study that used 400 mL of a 40 mg/L MX-5B solution prepared with deionized water as a control sample and a sample of actual textile wastewater as a real sample showed that MX-5B from actual textile wastewater was effectively photocatalytically degraded in the presence of W5-TiO2 photocatalyst.

近年来,由危化品管理和使用不当造成的高校实验室安全事故时有发生,已引起社会广泛关注.环境工程科研实验室,因交叉性强且研究生学科背景复杂,其危险品使用和管理存在较高安全风险.通过统计近 20 年高校实验室安全事故,详细分析了环境工程科研实验室危化品管理过程中存在的安全隐患,提出了提升危化品实验室安全管理水平的有效策略,并结合江西理工大学环境工程科研实验室危化品管理的实践与探索,希望能够为提升高校环境工程科研实验室危化品的安全管理提供参考.

Biocatalysis, which can be performed by whole cells and isolated enzymes, has become a topic of public interest for its potential use in the chemical industry in manufacturing, monitoring, and waste management [...]

矿冶粉尘给一线工人皮肤健康带来严重威胁.通过添加微生物灭活芽孢于清洁皂中,研究了不同芽孢添加量对清洁皂去污能力的影响,对比了硅藻土、活性炭和芽孢添加皂在粉尘去污和重金属去除方面的异同,并通过感官评价测试了三种皂在皮肤清洁方面的效果.结果表明,添加硅藻土可以达到80％的粉尘去除率.而活性炭尽管比表面积高,但微粒细小同样易于吸附于手掌纹理中,造成二次污染,故去除率最低.在基础皂中添加1％(w/w)灭活芽孢对粉尘污染的去污率达到了95％,二次洗涤可将重金属去除率从90％提高到95％以上.感官评价中,黑色活性炭的吸附作用造成了清洗后的手掌依然不够干净,观感最差;硅藻土皂的清洁效果接近日常家用皂,观感居中;而芽孢皂的清洁效果最明显,观感最佳.

A newly isolated cadmium (Cd)-resistant bacterial strain from herbicides-polluted soil in China could use atrazine as the sole carbon, nitrogen, and energy source for growth in a mineral salt medium (MSM). Based on 16S rRNA gene sequence analysis and physiochemical tests, the bacterium was identified as Arthrobacter sp. and named ST11. The biodegradation of atrazine by ST11 was investigated in experiments, with the compound present either as crystals or dissolved in di(2-ethylhexyl) phthalate (DEHP) as a non-aqueous phase liquid (NAPL). After 48 h, ST11 consumed 68% of the crystalline atrazine in MSM. After being dissolved in DEHP, the degradation ratio of atrazine was reduced to 55% under the same conditions. Obviously, the NAPL-dissolved atrazine has lower bioavailability than the crystalline atrazine. Cd2+ at concentrations of 0.05–1.5 mmol/L either had no effect (<0.3 mmol/L), slight effects (0.5–1.0 mmol/L), or significantly (1.5 mmol/L) inhibited the growth of ST11 in Luria-Bertani medium. Correspondingly, in the whole concentration range (0.05–1.5 mmol/L), Cd2+ promoted ST11 to degrade atrazine, whether crystalline or dissolved in DEHP. Refusal to adsorb Cd2+ may be the main mechanism of high Cd resistance in ST11 cells. These results may provide valuable insights for the microbial treatment of arable soil co-polluted by atrazine and Cd.

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) by micro‐organisms in the environment is often inhibited by coexisting metal ions. The aim of this work is to study a bacterial consortium for enhancing phenanthrene biodegradation under the inhibition effect of the rare earth (RE) ions Ce3+ and Y3+. This bacterial consortium was composed of two bacteria, namely, the RE‐adsorbing Bacillus subtilis MSP117 and the phenanthrene‐degrading Moraxella osloensis CFP312. Ce3+ and Y3+ at the concentration of 1·15 mmol l−1 inhibited CFP312 from degrading phenanthrene but not glucose. Using glucose as a co‐substrate could promote the proliferation of CFP312 but decreased phenanthrene degradation. Adsorption experiments and electron microscopy imaging showed that CFP312 had no RE ions adsorption capacity for RE ions and that RE elements could not be observed on its cell surfaces. MSP117 could adsorb 0·14 and 0·12 mmol g−1 wet cells of Ce3+ and Y3+ in aqueous solution, respectively, thus demonstrating considerable adsorption capacity. The MSP117 cell surface immobilized part of the free RE ions and reduced their bioaccessibility, thereby alleviating their biotoxic effect on phenanthrene degradation by CFP312. In liquid and slurry systems, glucose, which was used as the co‐substrate of the bacterial consortium, must be kept at a low level to avoid the catabolism repression of phenanthrene degradation by CFP312.

The limited bioavailability of PAHs in non-aqueous phase liquid (NAPL) limits their degradation. The biodegradation of phenanthrene in n-tetradecane by hydrophilic bacterium Moraxella sp. CFP312 was studied with the assistance of two polymers, chitosan and carboxymethyl cellulose (CMC). Both chitosan and CMC improved the cell hydrophobicity of CFP312 and increased the contact angle of CFP312 cells from 30.4 to 78.5 and 88.5, respectively. However, CMC increased the degradation ratio of phenanthrene from 45 to nearly 100%, while chitosan did not cause any improvement. We found that CMC was more effective than chitosan in promoting CFP312 to stabilize Pickering emulsion. In the bacteria-CMC complex system, oil was dispersed into small droplets to obtain a high emulsification index and large specific surface area. Moreover, according to the microscopic image of the bacteria-CMC emulsion droplet, we observed that the droplet surface was tightly covered by the CFP312 cells. Therefore, CFP312 cells joined with CMC can utilize phenanthrene in oil phase at the oil–water interface. This study will offer a new strategy for effective microbial degradation of hydrophobic compounds in NAPLs by hydrophilic bacteria. • Biodegradation of phenanthrene in Pickering emulsions • Pickering emulsions stabilized by hydrophilic CFP312 joined with CMC. • Phenanthrene was degraded by CFP312 at oil–water interface.

随着高等教育对人才培养质量要求的不断提高,大学生的学习倦怠已成为高校任课教师关注的重要问题.课程组从学习压力、情绪低落、孤独感和学业成就感这4个方面分析了发酵工程实验教学过程中大学生学习倦怠问题的主要原因,通过课程实验模式改革、强化价值观导向、加强小组交流和开展创新创业活动等方面设计了行之有效的实验教学改革策略,以达到激发学生上课热情减少倦怠的目的,提高人才培养质量.

•β-CD promotes crystalline phenanthrene biodegradation better than TX-100.•β-CD has low solubilization efficiency but can maintain complete biofilm function.•β-CD accelerates the mass transfer efficiency of crystalline phenanthrene to cells.