Fragrance Encapsulates: Effect of Polymeric Shell Purification Method on the Accuracy of Biodegradability Testing.

Fragrance encapsulates are widely used in consumer care applications such as fabric softeners or other liquid laundry products; they provide multiple benefits, from fragrance protection in the commercial product to a controlled release and improved sensorial experience for the consumers. Polymeric fragrance encapsulates are in the scope of the EU regulation restricting the use of intentionally added microplastic particles, and industry is actively working on innovation programs to find biodegradable alternatives. However, particular attention needs to be paid to claims that a fragrance encapsulation system is biodegradable, because biodegradation test results can vary considerably depending on how a test material is prepared, which can even lead to false-positive biodegradation test results, as shown in our study. We demonstrate the importance of the sample preparation phase of the process. We show how the biodegradation level can fluctuate from 0% to 91%, depending on how the test material is isolated from a given microcapsule slurry system, and we present a method that can be used to obtain trustworthy biodegradation results. Environ Toxicol Chem 2024;00:1-8. © 2024 Givaudan France SAS. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Stenotrophomonas maltophilia Isolated from the Gut Symbiotic Community of the Plastic-Eating Tenebrio molitor.

Polyvinyl chloride (PVC) waste is a major environmental challenge. In this study, we found that a PVC-eating insect, Tenebrio molitor, could survive by consuming PVC as a dietary supplement. To understand the gut symbiotic community, metagenomic analysis was performed to reveal the biodiversity of a symbiotic community in the midgut of Tenebrio molitor. Among them, seven genera were enriched from the midgut of the insect under culture conditions with PVC as carbon source. A strain of Stenotrophomonas maltophilia was isolated from the midgut symbiotic community of the plastic-eating Tenebrio molitor. To unravel the functional gene for the biodegradation enzyme, we sequenced the whole genome of Stenotrophomonas maltophilia and found that orf00390, annotated as a hydrolase, was highly expressed in the PVC culture niche.

Draft genome sequences of five Stenotrophomonas indicatrix strains isolated from soil.

Here, we present genome sequences of five Stenotrophomonas indicatrix strains, isolated from agricultural soil. Stenotrophomonas strains are commonly associated with the rhizosphere and are well-known for their ability to degrade xenobiotics. Yet, to date, knowledge about S. indicatrix is limited.

Metal-ion-controlled hydrogel dressing with enhanced adhesive and antibacterial properties for accelerated wound healing.

In order to improve the wound repair environment, this research has successfully developed a new multifunctional hydrogel dressing, which has strong adaptability and can accelerate wound healing. Pioneering the development of metal-ion-controlled hydrogel dressings, this research integrates dopamine and imidazole double crosslinked networks with metal-ion coordination. The resulting hydrogel dressing exhibits a notable antibacterial effect and exceptional mechanical properties, withstanding pressures of up to 12 kPa, tensions of 25 kPa, and maintaining skin adhesion at 6 kPa. Furthermore, the dressing can self-heal within only 7-8 s post-injection. Impressively, the hydrogel achieves complete biodegradation within a short timeframe (37 h). Notably, the use of various metal ions facilitates painless peeling during the degradation period, perfectly aligning with the requirements of an ideal wound dressing. This study has made significant progress in the fields of trauma repair and materials, providing strong solutions for dealing with harsh post-traumatic environments.

Non-targeted impact of cyantraniliprole residues on soil quality, mechanism of residue degradation, and isolation of potential bacteria for its bioremediation.

Cyantraniliprole (CY), an anthranilic diamide insecticide widely used in grape farming for controlling various sucking pests, poses ecological concerns, particularly when applied as soil drenching due to the formation of more toxic and persistent metabolites. This study established the dissipation and degradation mechanisms of CY in grape rhizosphere soil using high-resolution Orbitrap-LC/MS analysis. The persistence of CY residues beyond 60 days was observed, with dissipation following biphasic first + first-order kinetics and a half-life of 15 to 21 days. The degradation mechanism of CY in the soil was elucidated, with identified metabolites such as IN-J9Z38, IN-JCZ38, IN-N7B69, and IN-QKV54. Notably, CY was found to predominantly convert to the highly persistent metabolite IN-J9Z38, raising environmental concerns. The impact of CY residues on soil enzyme activity was investigated, revealing a negative effect on dehydrogenase, alkaline phosphatase, and acid phosphatase activity, indicating significant implications for phosphorous mineralization and soil health. Furthermore, bacterial isolates were obtained from CY-enriched soil, with five isolates (CY3, CY4, CY9, CY11, and CY20) demonstrating substantial degradation potential, ranging from 66 to 92% of CY residues. These results indicate that the identified bacteria hold potential for commercial use in addressing pesticide residue contamination in soil through bioremediation techniques.

Biodegradation of low-density polyethylene film by Bacillus gaemokensis strain SSR01 isolated from the guts of earthworm.

In recent years, low-density polyethylene (LDPE) has emerged as an essential component of the routine tasks that people engage in on a daily basis. However, over use of it resulted in environmental buildup that contaminated aquatic habitats and human health. Biodegradation is the most effective way for controlling pollution caused by synthetic plastic waste in a sustainable manner. In the present study, the LDPE degrading bacterial strain was screened from gut of Earthworms collected from plastic waste dumped area Mettur dam, Salem district, Tamil Nadu, India. The LDPE degrading bacterial strain was screened and identified genotypically. The LDPE degrading Bacillus gaemokensis strain SSR01 was submitted in NCBI. The B. gaemokensis strain SSR01 bacterial isolate degraded LDPE film after 14 days of incubation and demonstrated maximum weight loss of up to 4.98%. The study of deteriorated film using attenuated total reflection-Fourier transform infrared revealed the presence of a degraded product. The degradation of LDPE film by B. gaemokensis strain SSR01 was characterized by field-emission scanning electron microscopy analysis for surface alterations. The energy dispersive X-ray spectroscopy test confirmed that the broken-down LDPE film had basic carbon reduction. The present study of LDPE flim biodegradation by B. gaemokensis strain SSR01 has acted as a suitable candidate and will help in decreasing plastic waste.

Application of standardized methods to evaluate the environmental safety of polyvinyl alcohol disposed of down the drain.

The purpose of this research was to use polyvinyl alcohol (PVOH) 18-88 as a case study to evaluate the environmental fate, ecotoxicity, and overall safety profile of water-soluble, nonmodified PVOH polymers used in detergent films. An OECD 303A Wastewater Treatment Plant Simulation Study was conducted with dissolved organic carbon as the analytical endpoint to evaluate the removal of PVOH 18-88 during wastewater treatment. During the plateau phase, high levels of removal due to biodegradation were observed (average 97.4 ± 7.1, range: 88%-116%). The OECD 303A study quantitatively verified that surface water is the dominant receiving compartment for PVOH 18-88 post wastewater treatment. Acute algae, invertebrate, and fish embryo (fish embryo acute toxicity test [FET]) ecotoxicity studies quanitified the 50% lethal/effect concentration (L/EC50) for PVOH 18-88. Due to the potential for the chorion to impact PVOH 18-88 bioavailability, both chorionated and dechorionated FET tests were conducted. L/EC50 > 1000 mg/L for FET (chorionated and dechorionated), invertebrate, and algae were observed. The Sustainable Futures (US) and REACH (EU) frameworks were used to evaluate environmental risk. For the US assessment, the Exposure and Fate Assessment Screening Tool was used to predict the single day lowest flow over a 10-year period (1Q10) surface water concentration and the seven consecutive days of lowest flow over a 10-year period (7Q10) surface water concentration and compared with acute and chronic concentrations of concern. For the EU assessment, the European Union System for the Evaluation of Substances was used to predict local and regional exposure concentrations and compared to the predicted no effect concentration. For both regulatory assessments, the exposure concentrations were >2 orders of magnitude below the effect concentrations. Integr Environ Assess Manag 2024;00:1-13. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Neural tissue tolerance to synthetic dural mater graft implantation in a rabbit durotomy model.

In neurosurgical interventions, effective closure of the dura mater is essential to prevent cerebrospinal fluid leakage and minimize post-operative complications. Biodegradable synthetic materials have the potential to be used as dura mater grafts owing to their regenerative properties and low immunogenicity. This study evaluated the safety of ArtiFascia, a synthetic dura mater graft composed of poly(l-lactic-co-caprolactone acid) and poly(d-lactic-co-caprolactone acid), in a rabbit durotomy model. Previously, ArtiFascia demonstrated positive local tolerance and biodegradability in a 12-month preclinical trial. Here, specialized stains were used to evaluate potential brain damage associated with ArtiFascia use. Histochemical and immunohistochemical assessments included Luxol Fast Blue, cresyl Violet, Masson's Trichrome, neuronal nuclei,, Glial Fibrillary Acidic Protein, and ionized calcium-binding adaptor molecule 1 stains. The stained slides were graded based on the brain-specific reactions. The results showed no damage to the underlying brain tissue for either the ArtiFascia or control implants. Neither inflammation nor neuronal loss was evident, corroborating the safety of the ArtiFascia. This approach, combined with previous histopathological analyses, strengthens the safety profile of ArtiFascia and sets a benchmark for biodegradable material assessment in dura graft applications. This study aligns with the Food and Drug Administration guidelines and offers a comprehensive evaluation of the potential neural tissue effects of synthetic dura mater grafts.

Microaeration promotes volatile siloxanes conversion to methane and simpler monomeric products.

The ubiquitous use of volatile siloxanes in a myriad of product formulations has led to a widespread distribution of these persistent contaminants in both natural ecosystems and wastewater treatment plants. Microbial degradation under microaerobic conditions is a promising approach to mitigate D4 and D5 siloxanes while recovering energy in wastewater treatment plants. This study examined D4/D5 siloxanes biodegradation under both anaerobic and microaerobic conditions ( [Formula: see text]  = 0, 1, 3 %) using wastewater sludge. Results show that the use of microaeration in an otherwise strictly anaerobic environment significantly enhances siloxane conversion to methane. 16S rRNA gene sequencing identified potential degraders, including Clostridium lituseburense, Clostridium bifermentans and Synergistales species. Furthermore, chemical analysis suggested a stepwise siloxane conversion preceding methanogenesis under microaerobic conditions. This study demonstrates the feasibility of microaerobic siloxane biodegradation, laying groundwork for scalable removal technologies in wastewater treatment plants, ultimately highlighting the importance of using bio-based approaches in tackling persistent pollutants.

Integrated transcriptomics and metabolomics analyses reveal the aerobic biodegradation and molecular mechanisms of 2,3',4,4',5-pentachlorodiphenyl (PCB 118) in Methylorubrum sp. ZY-1.

2,3',4,4',5-pentachlorodiphenyl (PCB 118), a highly representative PCB congener, has been frequently detected in various environments, garnering much attention across the scientific community. The degradation of highly chlorinated PCBs by aerobic microorganisms is challenging due to their hydrophobicity and persistence. Herein, the biodegradation and adaptation mechanisms of Methylorubrum sp. ZY-1 to PCB 118 were comprehensively investigated using an integrative approach that combined degradation performance, product identification, metabolomic and transcriptomic analyses. The results indicated that the highest degradation efficiency of 0.5 mg L-1 PCB 118 reached 75.66% after seven days of inoculation when the bacteria dosage was 1.0 g L-1 at pH 7.0. A total of eleven products were identified during the degradation process, including low chlorinated PCBs, hydroxylated PCBs, and ring-opening products, suggesting that strain ZY-1 degraded PCB 118 through dechlorination, hydroxylation, and ring-opening pathways. Metabolomic analysis demonstrated that the energy supply and redox metabolism of strain ZY-1 was disturbed with exposure to PCB 118. To counteract this environmental stress, strain ZY-1 adjusted both the fatty acid synthesis and purine metabolism. The analysis of transcriptomics disclosed that multiple intracellular and extracellular oxidoreductases (e.g., monooxygenase, alpha/beta hydrolase and cytochrome P450) participated in the degradation of PCB 118. Besides, active efflux of PCB 118 and its degradation intermediates mediated by multiple transporters (e.g., MFS transporter and ABC transporter ATP-binding protein) might enhance bacterial resistance against these substances. These discoveries provided the inaugural insights into the biotransformation of strain ZY-1 to PCB 118 stress, illustrating its potential in the remediation of contaminated environments.

Biodegradation of polyethylene (PE), polypropylene (PP), and polystyrene (PS) microplastics by floc-forming bacteria, Bacillus cereus strain SHBF2, isolated from a commercial aquafarm.

The ubiquitous proximity of the commonly used microplastic (MP) particles particularly polyethylene (PE), polypropylene (PP), and polystyrene (PS) poses a serious threat to the environment and human health globally. Biological treatment as an environment-friendly approach to counter MP pollution has recent interest when the bio-agent has beneficial functions in their ecosystem. This study aimed to utilize beneficial floc-forming bacteria Bacillus cereus SHBF2 isolated from an aquaculture farm in reducing the MP particles (PE, PP, and PS) from their environment. The bacteria were inoculated for 60 days in a medium containing MP particle as a sole carbon source. On different days of incubation (DOI), the bacterial growth analysis was monitored and the MP particles were harvested to examine their weight loss, surface changes, and alterations in chemical properties. After 60 DOI, the highest weight loss was recorded for PE, 6.87 ± 0.92%, which was further evaluated to daily reduction rate (k), 0.00118 day-1, and half-life (t1/2), 605.08 ± 138.52 days. The OD value (1.74 ± 0.008 Abs.) indicated the higher efficiency of bacteria for PP utilization, and so for the colony formation per define volume (1.04 × 1011 CFU/mL). Biofilm formation, erosions, cracks, and fragments were evident during the observation of the tested MPs using the scanning electron microscope (SEM). The formation of carbonyl and alcohol group due to the oxidation and hydrolysis by SHBF2 strain were confirmed using the Fourier transform infrared spectroscopic (FTIR) analysis. Additionally, the alterations of pH and CO2 evolution from each of the MP type ensures the bacterial activity and mineralization of the MP particles. The findings of this study have confirmed and indicated a higher degree of biodegradation for all of the selected MP particles. B. cereus SHBF2, the floc-forming bacteria used in aquaculture, has demonstrated a great potential for use as an efficient MP-degrading bacterium in the biofloc farming system in the near future to guarantee a sustainable green aquaculture production.

An analytical review on revamping plastic waste management: exploring recycling, biodegradation, and the growing role of biobased plastics.

Globally, 90% of plastics are synthetic, made up of crude oil, natural gas, and coal. Even though plastic is extremely useful in our lives, its excessive use and mismanaged disposal are negatively affecting the ecosystem. The review highlights that the recycling process plays a critical role in controlling the problem of plastic pollution. Although plastic recycling is the most common approach used for managing plastic waste, only 2% of the total plastic waste enters the closed-loop system. However, the review suggests that along with recycling, cost-effective and environmentally friendly plastic approaches can synergistically help to control this increasing problem of plastic waste accumulation. The review further discusses the consequences of plastic pollution on humans and the environment. In particular, the review focuses on biocatalytic and bioengineering tools for the degradation of polyethylene terephthalate (PET), one of the major contributors to plastic waste in landfills and oceans. Moreover, the review presents biobased and biodegradable materials, derived from renewable feedstocks, as an alternative to petroleum-based plastics along with their complete end-of-life options. Overall, this review analyzes the current scenario of the plastic industry, from plastic production to waste generation and management, loopholes and challenges in the current management strategies, and possible solutions like recycling, biodegradation, and biobased plastics.

Electricity generation and real oily wastewater treatment by Pseudomonas citronellolis 620C in a microbial fuel cell: pyocyanin production as electron shuttle.

In the present study, the potential of Pseudomonas citronellolis 620C strain was evaluated, for the first time, to generate electricity in a standard, double chamber microbial fuel cell (MFC), with oily wastewater (OW) being the fuel at 43.625 mg/L initial chemical oxygen demand (COD). Both electrochemical and physicochemical results suggested that this P. citronellolis strain utilized efficiently the OW substrate and generated electricity in the MFC setup reaching 0.05 mW/m2 maximum power. COD removal was remarkable reaching 83.6 ± 0.1%, while qualitative and quantitative gas chromatography/mass spectrometry (GC/MS) analysis of the OW total petroleum and polycyclic aromatic hydrocarbons, and fatty acids revealed high degradation capacity. It was also determined that P. citronellolis 620C produced pyocyanin as electron shuttle in the anodic MFC chamber. To the authors' best knowledge, this is the first study showing (phenazine-based) pyocyanin production from a species other than P. aeruginosa and, also, the first time that P. citronellolis 620C has been shown to produce electricity in a MFC. The production of pyocyanin, in combination with the formation of biofilm in the MFC anode, as observed with scanning electron microscopy (SEM) analysis, makes this P. citronellolis strain an attractive and promising candidate for wider MFC applications.

Identification and recombinant expression of a cutinase from Papiliotrema laurentii that hydrolyzes natural and synthetic polyesters.

Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade nature's polymers (lignin, cutin, cellulose, etc.), fungi are adept at targeting synthetic polyesters with similar chemical composition. Microbial-influenced deterioration of xenobiotic polymeric surfaces is an area of interest for material scientists as these are important for the conservation of the underlying structural materials. Here, we describe the isolation and characterization of the Papiliotrema laurentii 5307AH (P. laurentii) cutinase, Plcut1. P. laurentii is basidiomycete yeast with the ability to disperse Impranil-DLN (Impranil), a colloidal polyester polyurethane, in agar plates. To test whether the fungal factor involved in this clearing was a secreted enzyme, we screened the ability of P. laurentii culture supernatants to disperse Impranil. Using size exclusion chromatography (SEC), we isolated fractions that contained Impranil-clearing activity. These fractions harbored a single ~22 kD band, which was excised and subjected to peptide sequencing. Homology searches using the peptide sequences identified, revealed that the protein Papla1 543643 (Plcut1) displays similarities to serine esterase and cutinase family of proteins. Biochemical assays using recombinant Plcut1 confirmed that this enzyme has the capability to hydrolyze Impranil, soluble esterase substrates, and apple cutin. Finally, we confirmed the presence of the Plcut1 in culture supernatants using a custom antibody that specifically recognizes this protein. The work shown here supports a major role for the Plcut1 in the fungal degradation of natural polyesters and xenobiotic polymer surfaces.IMPORTANCEFungi play a vital role in the execution of a broad range of biological processes that drive ecosystem function through production of a diverse arsenal of enzymes. However, the universal reactivity of these enzymes is a current problem for the built environment and the undesired degradation of polymeric materials in protective coatings. Here, we report the identification and characterization of a hydrolase from Papiliotrema laurentii 5307AH, an aircraft-derived fungal isolate found colonizing a biodeteriorated polymer-coated surface. We show that P. laurentii secretes a cutinase capable of hydrolyzing soluble esters as well as ester-based compounds forming solid surface coatings. These findings indicate that this fungus plays a significant role in biodeterioration through the production of a cutinase adept at degrading ester-based polymers, some of which form the backbone of protective surface coatings. The work shown here provides insights into the mechanisms employed by fungi to degrade xenobiotic polymers.

Compact and water flushing resistant mesh biofilms forming at short SRT disappeared naturally under extended SRT in dynamic membrane bioreactor.

Extending the solids retention time (SRT) has been demonstrated to mitigate membrane biofouling. Nevertheless, it remains an intriguing question whether the compact and water flushing resistant mesh biofilms developed at short SRT can undergo biodegradation and be removed with extended SRT. In present study, the bio-fouled mesh filter in the 10d-SRT dynamic membrane bioreactor (DMBR), with mesh surfaces and pores covered by compact and water flushing resistant biofilms exhibiting low water permeability, was reused in the 40d-SRT DMBR without any cleanings. After being reused at 40d-SRT, its flux driven by gravity occurred from the 10th day and recovered to a regular level of 36.7 L m-2·h-1 on the 27th day. Both scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) analyses indicated that the compact mesh biofilms formed at10d-SRT biodegraded and were removed at 40d-SRT, with the residual biofilms becoming removable by water flushing. As a result, the hydraulic resistance of the bio-fouled mesh filter decreased from 4.36 × 108 to 6.97 × 107 m-1, and its flux fully recovered. The protein and polysaccharides densities in mesh-biofilms decreased from 24.4 to 9.7 mg/cm2 and from 10.7 to 0.10 mg/cm2, respectively, which probably have contributed to the disappearance of compact biofilms and the decrease in adhesion. Furthermore, the sludge and mesh-biofilms in the 40d-SRT reactor contained a higher relative abundance of dominant quorum quenching bacteria, such as Rhizobium (3.52% and 1.35%), compared to those in the 10d-SRT sludge (0.096%) and mesh biofilms (0.79%), which might have been linked to a decline in extracellular polymeric substances and, consequently, the biodegradation and disappearance of compact biofilms.

Molecular-Weight-Dependent Degradation of Plastics: Deciphering Host-Microbiome Synergy Biodegradation of High-Purity Polypropylene Microplastics by Mealworms.

The biodegradation of polypropylene (PP), a highly persistent nonhydrolyzable polymer, by Tenebrio molitor has been confirmed using commercial PP microplastics (MPs) (Mn 26.59 and Mw 187.12 kDa). This confirmation was based on the reduction of the PP mass, change in molecular weight (MW), and a positive Δδ13C in the residual PP. A MW-dependent biodegradation mechanism was investigated using five high-purity PP MPs, classified into low (0.83 and 6.20 kDa), medium (50.40 and 108.0 kDa), and high (575.0 kDa) MW categories to access the impact of MW on the depolymerization pattern and associated gene expression of gut bacteria and the larval host. The larvae can depolymerize/biodegrade PP polymers with high MW although the consumption rate and weight losses increased, and survival rates declined with increasing PP MW. This pattern is similar to observations with polystyrene (PS) and polyethylene (PE), i.e., both Mn and Mw decreased after being fed low MW PP, while Mn and/or Mw increased after high MW PP was fed. The gut microbiota exhibited specific bacteria associations, such as Kluyvera sp. and Pediococcus sp. for high MW PP degradation, Acinetobacter sp. for medium MW PP, and Bacillus sp. alongside three other bacteria for low MW PP metabolism. In the host transcriptome, digestive enzymes and plastic degradation-related bacterial enzymes were up-regulated after feeding on PP depending on different MWs. The T. molitor host exhibited both defensive function and degradation capability during the biodegradation of plastics, with high MW PP showing a relatively negative impact on the larvae.

Genome analysis of a newly isolated Bacillus velezensis-YW01 for biodegrading acetaldehyde.

Acetaldehyde (AL), a primary carcinogen, not only pollutes the environment, but also endangers human health after drinking alcohol. Here a promising bacterial strain was successfully isolated from a white wine cellar pool in the province of Shandong, China, and identified as Bacillus velezensis-YW01 with 16 S rDNA sequence. Using AL as sole carbon source, initial AL of 1 g/L could be completely biodegraded by YW01 within 84 h and the cell-free extracts of YW01 has also been detected to biodegrade the AL, which indicate that YW01 is a high-potential strain for the biodegradation of AL. The optimal culture conditions and the biodegradation of AL of YW01 are at pH 7.0 and 38 °C, respectively. To further analyze the biodegradation mechanism of AL, the whole genome of YW01 was sequenced. Genes ORF1040, ORF1814 and ORF0127 were revealed in KEGG, which encode for acetaldehyde dehydrogenase. Furthermore, ORF0881 and ORF052 encode for ethanol dehydrogenase. This work provides valuable information for exploring metabolic pathway of converting ethanol to AL and subsequently converting AL to carboxylic acid compounds, which opened up potential pathways for the development of microbial catalyst against AL.

A fully biodegradable spherical nucleic acid nanoplatform for self-codelivery of doxorubicin and miR122 for innate and adaptive immunity activation.

Facile construction of a fully biodegradable spherical nucleic acid (SNA) nanoplatform is highly desirable for clinical translations but remains rarely explored. We developed herein the first polycarbonate-based biodegradable SNA nanoplatform for self-codelivery of a chemotherapeutic drug, doxorubicin (DOX), and a human liver-specific miR122 for synergistic chemo-gene therapy of hepatocellular carcinoma (HCC). Ring-opening polymerization (ROP) of a carbonate monomer leads to a well-defined polycarbonate backbone for subsequent DOX conjugation to the pendant side chains via acidic pH-cleavage Schiff base links and miR122 incorporation to the chain termini via click coupling, affording an amphiphilic polycarbonate-DOX-miR122 conjugate, PBis-Mpa30-DOX-miR122 that can self-assemble into stabilized SNA. Besides the desired biodegradability, another notable merit of this nanoplatform is the use of miR122 not only for gene therapy but also for enhanced innate immune response. Together with the ICD-triggering effect of DOX, PBis-Mpa30-DOX-miR122 SNA-mediated DOX and miR122 codelivery leads to synergistic immunogenicity enhancement, resulting in tumor growth inhibition value (TGI) of 98.1 % significantly higher than those of the groups treated with only drug or gene in a Hepa1-6-tumor-bearing mice model. Overall, this study develops a useful strategy toward biodegradable SNA construction, and presents a drug and gene-based self-codelivery SNA with synergistic immunogenicity enhancement for efficient HCC therapy. STATEMENT OF SIGNIFICANCE: Facile construction of a fully biodegradable SNA nanoplatform is useful for in vivo applications but remains relatively unexplored likely due to the synthetic challenge. We report herein construction of a polycarbonate-based SNA nanoplatform for co-delivering a chemotherapeutic drug, DOX, and a human liver-specific miR-122 for synergistic HCC treatment. In addition to the desired biodegradability properties, this SNA nanoplatform integrates DOX-triggered ICD and miR-122-enhanced innate immunity for simultaneously activating adaptive and innate immunities, which leads to potent antitumor efficiency with a TGI value of 98.1 % in a Hepa1-6-tumor-bearing mice model.

Isolation, identification, and optimization of conditions for the degradation of four sulfonamide antibiotics and their metabolic pathways in Pseudomonas stutzeri strain DLY-21.

Overuse of sulfonamides in aquaculture and agriculture leads to residual drugs that cause serious pollution of the environment. However, the residues of sulfonamides in the environment are not unique, and the existing microbial degradation technology has a relatively low degradation rate of sulfonamides. Therefore, in this study, a Pseudomonas stutzeri strain (DLY-21) with the ability to degrade four common SAs was screened and isolated from aerobic compost. Under optimal conditions, the DLY-21 strain degraded four sulfonamides simultaneously within 48 h, and the degradation rates were all over 90%, with the average degradation rates of SAs being sulfoxide (SDM) ≈ sulfachloropyridazine (SCP) > sulfa quinoxaline (SQ) > sulfadiazine (SQ). In addition, the main compounds of the strain DLY-21-degrading SAs were identified by LC-MS analysis. On this basis, four detailed reaction pathways for SA degradation were deduced. This is the first report of the use of a P. stutzeri strain to degrade four sulfonamide antibiotics (SQ, SDM, SCP, and SM1), which can improve the removal efficiency of sulfonamide antibiotic pollutants and thus ameliorate environmental pollution. The results showed that DLY-21 had a good degradation effect on four SAs (SQ, SDM, SCP, and SM1).

Exploring the potential of earthworm gut bacteria for plastic degradation.

The use of plastic mulch films in agriculture leads to the inevitable accumulation of plastic debris in soils. Here, we explored the potential of earthworm gut-inhabiting bacterial strains (Mycobacterium vanbaalenii (MV), Rhodococcus jostii (RJ), Streptomyces fulvissimus (SF), Bacillus simplex (BS), and Sporosarcina globispora (SG) to degrade plastic films (⌀ = 15 mm) made from commonly used polymers: low-density polyethylene film (LDPE-f), polylactic acid (PLA-f), polybutylene adipate terephthalate film (PBAT-f), and a commercial biodegradable mulch film, Bionov-B® (composed of Mater-Bi, a feedstock with PBAT, PLA and other chemical compounds). A 180-day experiment was conducted at room temperature (x̄ =19.4 °C) for different strain-plastic combinations under a low carbon media (0.1× tryptic soy broth). Results showed that the tested strain-plastic combinations did not facilitate the degradation of LDPE-f (treated with RJ and SF), PBAT-f (treated with BS and SG), and Bionov-B (treated with BS, MV, and SG). However, incubating PLA-f with SF triggered a reduction in the molecular weights and an increase in crystallinity. Therefore, we used PLA-f as model plastic to study the influence of temperature ("room temperature" & "30 °C"), carbon source ("carbon-free" & "low carbon supply"), and strain interactions ("single strains" & "strain mixtures") on PLA degradation. SF and SF + RJ treatments significantly fostered PLA degradation under 30 °C in a low-carbon media. PLA-f did not show any degradation in carbon-free media treatments. The competition between different strains in the same system likely hindered the performance of PLA-degrading strains. A positive correlation between the final pH of culture media and PLA-f weight loss was observed, which might reflect the pH-dependent hydrolysis mechanism of PLA. Our results situate SF and its co-culture with RJ strains as possible accelerators of PLA degradation in temperatures below PLA glass transition temperature (Tg). Further studies are needed to test the bioremediation feasibility in soils.