Construct a novel anti-bacteria pool from hydrothermal liquefaction aqueous family

TCMD: A High-Throughput and Rapid Method for Screening Antimicrobial Ingredients from Renewable Bio-Based Resources

Antibiotic resistance and pathogenic infections underscore the importance and urgency of novel control agent development. Bio-based products represent a rich reservoir of antimicrobial agents. However, traditional strategies for screening new active compounds are time-consuming, costly, and limited by accessible resources. Here, transcriptomic combinatorial molecular docking (TCMD), a novel method enabling fast identification of antimicrobial components in complex mixtures without requiring prior knowledge is proposed. Results show that, in eukaryotic microorganism systems, TCMD demonstrates superior performances in screening antifungal compounds within hydrothermal liquefaction aqueous. The high accuracy is confirmed by molecular dynamics simulation, antifungal experiments, and RT-qPCR (reverse transcription real-time quantitative polymerase chain reaction) analysis. Furthermore, TCMD exhibits cross-system applicability, as evidenced by successful antibacterial substances screening in prokaryotic systems using plant essential oil and traditional Chinese medicine from previous studies. Compared to conventional approaches, TCMD is estimated to be 3-20 times faster and ≈10 times more cost-effective, while maintaining high-throughput capacity for analyzing thousands of compounds simultaneously. These demonstrate that TCMD is a rapid, precise, and flexible method for antimicrobial compound discovery, significantly accelerating the development of new antibacterial agents.

Sequential hydrothermal liquefaction of lignocellulose-rich livestock manure: A new perspective on enhancing the production and quality of low-phenolic biocrude

The treatment and valorization of bulk livestock manure rich in lignocellulose demand efficient processing techniques. Hydrothermal liquefaction (HTL) has emerged as a promising approach for waste-to-energy conversion, effectively transforming lignocellulosic biomass into renewable biocrude. However, the advances in the utilization of HTL-derived biocrude have been hindered by its poor oil quality due to several factors including high phenolic compound content. This study focuses on enhancing the production and quality of low-phenolic biocrude via a sequential HTL process. The results revealed that sequential HTL achieved a high biocrude yield of 59.9%, with a concurrent reduction in phenolic content to 4.2%. This represents an 84.2% decrease in phenolic content compared to biocrude derived from direct HTL (280 ℃), achieving a tradeoff between biocrude yield and quality. Notably, GC-MS revealed that the biocrude produced through sequential HTL was enriched with fatty acids and esters accounting for 80.5%, contributing to the production of hydrocarbon fuels. Additionally, FT-ICR MS revealed that sequential HTL enhanced the biocrude quality and encouraged the production of light fuels. The petroleum fractionation analysis further revealed that sequential HTL-derived biocrude was more desirable in the downstream petroleum refining industry. The model compounds experiments revealed that phenols were likely to to be transferred to the oil phase at relatively high temperatures. Overall, it is the first study to elucidate the phenols removal mechanism and quality improvement of biocrude through the sequential HTL, demonstrating its potential for sustainable disposal and valorization of waste lignocellulosic biomass, and contributing to the development of renewable energy.

Aquatic life criteria of hydrothermal liquefaction wastewater via ecotoxicity test and modeling

Wastewater resulting from hydrothermal liquefaction (HTL-AP) of biowaste is gaining attention as an emerging hazardous material. However, there is a lack of specific and systematic ecotoxicity studies on HTL-AP. This study addresses this gap by conducting acute toxicity tests on HTL-AP using typical aquatic species and integrating these results with predicted toxicity values from interspecies correlation estimation models to establish aquatic life criteria. HTL-AP exhibited significant toxicity with LC50 of 956.12-3645.4 mg/L, but demonstrated moderate toxicity compared to common freshwater pollutants like commercial microbicides, personal care products, and insect repellents. The resulting hazardous concentration for 5 % of species (HC5), the criterion maximum concentration, and the short-term water quality criteria for aquatic were 506.0, 253.0, and 168.7 mg/L, respectively. Notably, certain organisms like Misgurnus anguillicaudatus and Cipangopaludina chinensis showed high tolerance to HTL-AP, likely due to their metabolic capabilities on HTL-AP components. The significant decrease in HC5 values for some HTL-AP substances compared to pure compounds could indicate the synergistic inhibition effects among HTL-AP compositions. Furthermore, according to the established criteria, HTL-AP required significantly less diluted water (13 t) than carbendazim (1009 t) to achieve biosafety, indicating a safer release. This research establishes a preliminary water quality criterion for HTL-AP, offering a valuable reference for risk assessment and prediction in the utilization of HTL-AP within environmental contexts.

Evaluation of on-site biological treatment options for hydrothermal liquefaction aqueous phase derived from sludge in municipal wastewater treatment plants

Aerobic treatment, mesophilic anaerobic digestion, thermophilic anaerobic digestion, and dark fermentation were evaluated for on-site biological treatment of municipal sludge derived HTL aqueous. For all four described batch test scenarios, municipal sludge-derived HTL aqueous samples obtained under 290-360 °C and 0-30 min retention time were used. In the aerobic respirometric tests, HTL aqueous samples resulted in a five-day biochemical oxygen demand range of 40.75 g/L (350 °C-25.6 min) to 54 g/L (325 °C-0 min). The calculated aerobic biodegradability index showed that approximately 50 % of the organics in HTL aqueous were easily biodegradable. Mesophilic and thermophilic biochemical methane potential tests resulted in specific yields of 151-179 mL CH4/g chemical oxygen demand (COD) and 103-122 mL CH4/g COD, respectively. HTL aqueous obtained under 360 °C-15 min condition caused total inhibition in both mesophilic and thermophilic anaerobic digestion. Possible causes for this inhibition were pyridine, pyrrolidinone, piperidinone, pyridinol, and phenolic compounds, which were higher in abundance in the 360 °C-15 min sample. HTL aqueous was found unfit for hydrogen production in dark fermentation due to inhibitory composition. In summary, on-site biological treatment of HTL aqueous was found to be most suitable under aerobic and mesophilic anaerobic conditions.

Hydrothermal liquefaction of municipal sludge and its products applications

Hydrothermal liquefaction (HTL) is an effective medium-temperature, high-pressure thermochemical process to dispose municipal sludge (MS), and biocrude (a crude bio-oil) is its main product. Many efforts are continued extensively to improve conversion efficiency and to promote industrial application of this technology. This work focuses on critical influencing factors (e.g., reaction temperature, residence time, atmosphere, solvent, catalyst, and pretreatment) and fundamental transformation mechanisms of main components (i.e., lipids, proteins, and carbohydrates) in MS HTL. It also analyzes migration behavior of heavy metals during MS HTL, which can provide a reference for subsequent recovery of nutrients from HTL products. Moreover, the applications of MS HTL products are systematically expounded, and potential challenges and opportunities are highlighted as well. It is necessary to develop advanced methods of catalyst recovery and innovative biocrude upgrading methods so as to reduce HTL investment and operating costs. Reusing aqueous phase and solid phase products as reaction medium and catalyst carrier separately after MS HTL is feasible to realize resource utilization of MS. This information can provide valuable guidance to promote MS HTL industrialization.

Effects of process water obtained from hydrothermal carbonization of poultry litter on soil microbial community, nitrogen transformation, and plant nitrogen uptake

Process water (PW) obtained from hydrothermal carbonization of nitrogen-rich (N-rich) biowaste is proposed to be a renewable resource utilized as a liquid N fertilizer. However, its effects on soil microbial community, N transformation, and plant N uptake are unclear or controversial. In this study, fertilizers were prepared with different percentages of PW (poultry litter, 220 °C 1 or 8 h, PW-S or -L) and urea to supply 160 mg kg^-1 total N in a barren alkali soil. Results showed that the addition of PW relative to pure urea decreased organic N mineralization by low bio-accessibility, increased N loss by high soil pH, and decreased NO₃^--N by low nitrification substrate. It supported the lettuce in health but decreased plant N uptake by low NO₃^--N. It significantly increased the gram-positive bacteria that responded to resistant organic matter, changed the bacterial community to enhance decomposition, detoxification, ureolysis, and denitrification, and to decrease nitrification. Its inhibition effect on nitrification activity was stronger than that on nitrifiers growth. Different from PW-S, the addition of PW-L seriously and significantly decreased seed germination index and fungal biomass that responded to N retaining capacity, respectively. The best fertilizer was 50% urea +50% PW-S that supported the seed germination and seedling growth, and mildly affected microbial community.

Understand the antibacterial behavior and mechanism of hydrothermal wastewater

Unlocking the antibacterial potential is an emerging strategy to valorizing the toxic wastewater from hydrothermal liquefaction (HTL). Here, we investigated the response and biological mechanism of antibacterial properties of HTL wastewater. Four different biowastes i.e. microalgae, cornstalk, cow manure and swine manure were used as the feedstock of HTL to create wastewater with diverse molecule spectrum, whereas ten strains i.e. five gram-positive strains and five gram-negative strains were employed to represent typical pathogenic microorganism. HTL wastewater exhibited antibacterial potential and obvious reduction on cell viability at high inclusion ratio, although the minimum inhibitory concentration (MIC) and cell response intensity varied depending on different HTL feedstocks and strain species. The decreased ATP generation and increased H₂O₂ accumulation in treated cells further confirmed the inhibition of HTL wastewater on the cell metabolism. The antibacterial mechanism of HTL wastewater was confirmed, including damage to biomolecules or membranes, depletion of crucial components, disruption of metabolic circuits and imbalance of creation of redox cofactor. The complex compounds in HTL wastewater were probably attributed to the multiple inhibition pathways and the relationship among those multiple pathways was speculated. The present study contributes to the mechanism analysis of complex compound mixture and bactericide characteristics of HTL wastewater.