Polyethylene (PE) is widely used due to its excellent properties. However, the improper disposal of PE waste has led to serious environmental pollution. Microbial degradation of PE is a low-carbon, environmentally friendly, and highly efficient method of homogeneous recycling. The use of microbial degradation technology to treat polyethylene waste has become one of the current research hotspots. As a result, employing microbial degradation technology to address polyethylene waste has become a key focus of current research. A PE-degrading strain ETX1 was screened from waste plastics in a landfill by the enrichment culture method. The strain was identified as Lysinibacillus sp.. After incubating PE powder with the strain for 20 days, a weight loss of 29.41% was observed. Fourier transform infrared spectroscopy (FTIR) showed that special absorption peaks such as carbonyl and hydroxyl groups appeared, proving that ETX1 had the effect of degrading PE. The degradation effect of this strain was characterized by the weight loss of PE film, FTIR, scanning electron microscopy, and contact angle. The results showed that ETX1 reduced the PE film weight by up to 5.23% within 120 days. The film structure was damaged, with holes formed by erosion on the film surface, and the hydrophilicity was enhanced. Additionally, a stronger carbonyl absorption peak appeared. The discovery of the PE-degrading strain ETX1 not only enriches the resources of PE plastic-degrading strains but also lays a foundation for mining efficient PE-degrading elements, obtaining degrading enzymes, and deciphering related degradation pathways.
Polyethylene/chemistry* ; Biodegradation, Environmental ; Spectroscopy, Fourier Transform Infrared ; Bacillaceae/classification* ; Plastics/metabolism*

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.
Polyethylene/metabolism* ; Bacteria/metabolism* ; Plastics/metabolism* ; Biodegradation, Environmental ; Microbial Consortia

Polyurethane (PUR) plastics is widely used because of its unique physical and chemical properties. However, unreasonable disposal of the vast amount of used PUR plastics has caused serious environmental pollution. The efficient degradation and utilization of used PUR plastics by means of microorganisms has become one of the current research hotspots, and efficient PUR degrading microbes are the key to the biological treatment of PUR plastics. In this study, an Impranil DLN-degrading bacteria G-11 was isolated from used PUR plastic samples collected from landfill, and its PUR-degrading characteristics were studied. Strain G-11 was identified as Amycolatopsis sp. through 16S rRNA gene sequence alignment. PUR degradation experiment showed that the weight loss rate of the commercial PUR plastics upon treatment of strain G-11 was 4.67%. Scanning electron microscope (SEM) showed that the surface structure of G-11-treated PUR plastics was destroyed with an eroded morphology. Contact angle and thermogravimetry analysis (TGA) showed that the hydrophilicity of PUR plastics increased along with decreased thermal stability upon treatment by strain G-11, which were consistent with the weight loss and morphological observation. These results indicated that strain G-11 isolated from landfill has potential application in biodegradation of waste PUR plastics.
Plastics/metabolism* ; Polyurethanes/chemistry* ; RNA, Ribosomal, 16S ; Bacteria/genetics* ; Biodegradation, Environmental

Although polyurethane (PUR) plastics play important roles in daily life, its wastes bring serious environmental pollutions. Biological (enzymatic) degradation is considered as an environmentally friendly and low-cost method for PUR waste recycling, in which the efficient PUR-degrading strains or enzymes are crucial. In this work, a polyester PUR-degrading strain YX8-1 was isolated from the surface of PUR waste collected from a landfill. Based on colony morphology and micromorphology observation, phylogenetic analysis of 16S rDNA and gyrA gene, as well as genome sequence comparison, strain YX8-1 was identified as Bacillus altitudinis. The results of high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed that strain YX8-1 was able to depolymerize self-synthesized polyester PUR oligomer (PBA-PU) to produce a monomeric compound 4, 4'-methylene diphenylamine. Furthermore, strain YX8-1 was able to degrade 32% of the commercialized polyester PUR sponges within 30 days. This study thus provides a strain capable of biodegradation of PUR waste, which may facilitate the mining of related degrading enzymes.
Polyurethanes/chemistry* ; Polyesters/chemistry* ; Chromatography, Liquid ; Phylogeny ; Tandem Mass Spectrometry ; Bacteria/metabolism* ; Biodegradation, Environmental

Objective:To analyze the clinic-pathological features and surgical outcomes of adult patients with hypothalamic gliomas.Methods:The adult cases pathologically confirmed as hypothalamic gliomas were analyzed from October, 2011 to January, 2022 in Beijing Tiantan Hospital.Results:There were 32 adult cases with hypothalamic gliomas, including 16 males and 16 females. Tumor was located in the hypothalamus in 6 cases, in the hypothalamus plus optic chiasma/nerve in 6 cases, in the hypothalamus plus thalamus in 9 cases, and in the hypothalamus plus the third ventricle in 11 cases. Pre-operative hydrocephalus was found in 20 cases. Five patents underwent stereotactic biopsy, 27 patients underwent craniotomy, and 11 patients underwent shunt surgery for hydrocephalus. Of 27 patients with craniotomy, trans-callosal approach was chosen for 9 patients, trans-cortical for 8 patients, via pterion approach for 4 patients, via lateral sub-frontal approach for 4 patients, via fissurae interhemisphaerica for 1 patient, and trans-sphenoidal approach for 1 patient. Twenty-two patients received gross-total or subtotal resection, 5 patients received partial resection. All the patients were pathologically confirmed, including 9 patients with high-grade and 23 patients with low-grade gliomas. Six patients died within 3 months after craniotomy, 8 patients suffered from endocrine dysfunction, 7 patients suffered from electrolyte disturbance, and 5 patients suffered from hydrocephalus. They were followed for 0.7-110.0 months, with 5-year progression-free survival rate of 63.8% and 5-year overall survival rate of 53.9% for all patients. The 5-year progression-free survival rate was 83.3% and the 5-year overall survival rate was 72.8% for low-grade gliomas.Conclusions:The peri-operative mortality is high for adult patients with hypothalamic gliomas, and protection of the hypothalamic function is important. Patients with low-grade hypothalamic gliomas have good prognoses.

Biodegradation of polyurethane (PUR) pollutants by microorganisms has received widespread attention currently. Identification of microorganisms capable of efficiently degrading PUR plastics is a key point. In this study, a strain P10 capable of degrading PUR was isolated from the plastic wastes, and identified as a bacterium belonging to the genus of Brevibacillus based on colony morphology and 16S rDNA phylogenetic analysis. Brevibacillus sp. P10 was capable of degrading 71.4% of waterborne polyurethane (Impranil DLN) after 6 days growth in MSM medium with DLN as a sole carbon source. In addition, strain P10 can use commercial PUR foam as the sole carbon source for growth. Brevibacillus sp. P10 can degrade 50 mg PUR foam after 6 days growth in MSM medium supplemented with 5% (V/V) LB after optimization of degradation conditions. This indicates that Brevibacillus sp. P10 has potential to be used in biodegradation of PUR waste.
Bacteria ; Biodegradation, Environmental ; Phylogeny ; Polyurethanes