Impact of residual antibiotics on microbial decomposition of livestock manures in Eutric Regosol: Implications for sustainable nutrient recycling and soil carbon sequestration.

The land application of livestock manure has been widely acknowledged as a beneficial approach for nutrient recycling and environmental protection. However, the impact of residual antibiotics, a common contaminant of manure, on the degradation of organic compounds and nutrient release in Eutric Regosol is not well understood. Here, we studied, how oxytetracycline (OTC) and ciprofloxacin (CIP) affect the decomposition, microbial community structure, extracellular enzyme activities and nutrient release from cattle and pig manure using litterbag incubation experiments. Results showed that OTC and CIP greatly inhibited livestock manure decomposition, causing a decreased rate of carbon (28%-87%), nitrogen (15%-44%) and phosphorus (26%-43%) release. The relative abundance of gram-negative (G-) bacteria was reduced by 4.0%-13% while fungi increased by 7.0%-71% during a 28-day incubation period. Co-occurrence network analysis showed that antibiotic exposure disrupted microbial interactions, particularly among G- bacteria, G+ bacteria, and actinomycetes. These changes in microbial community structure and function resulted in decreased activity of urease, ß-1,4-N-acetyl-glucosaminidase, alkaline protease, chitinase, and catalase, causing reduced decomposition and nutrient release in cattle and pig manures. These findings advance our understanding of decomposition and nutrient recycling from manure-contaminated antibiotics, which will help facilitate sustainable agricultural production and soil carbon sequestration.

Chromatin remodelers: a concise introduction for biophysicists.

Chromatin remodelers are molecular motors that act on nucleosomes: they move them along DNA or (dis-)assemble them. Despite the fact that they perform essential regulatory functions in cells-their deregulation can contribute to the development of cancers and lead to cell death-chromatin remodelers have only received meager attention in the biophysics community so far. In this short text, we attempt to present the key features of this interesting class of enzymes obtained with different experimental and theoretical methods, thereby providing a concise introduction for biophysicists to further stimulate interest in their properties.

Recent advances and applications of nitroreductase activable agents for tumor theranostic.

Nitroreductase activable agents offer a personalized and targeted approach to cancer theranostics by selectively activating prodrugs within the tumor microenvironment. These agents enable non-invasive tumor imaging, image-guided drug delivery, and real-time treatment monitoring. By leveraging the enzymatic action of tumor-specific nitroreductase enzymes, cytotoxic drugs are delivered directly to cancer cells while minimizing systemic toxicity. This review highlights the key features, mechanisms of action, diagnostic applications, therapeutic potentials, and future directions of nitroreductase activable agents for tumor theranostics. Integration with imaging modalities, advanced drug delivery systems, immunotherapy combinations, and theranostic biomarkers shows promise for optimizing treatment outcomes and improving patient survival in oncology. Continued research and innovation in this field are crucial for advancing novel theranostic strategies and enhancing patient care. Nitroreductase activable agents represent a promising avenue for personalized cancer therapy and have the potential to transform cancer diagnosis and treatment approaches.

Angiotensin receptor blockers versus angiotensin converting enzyme inhibitors in acute myocardial infarction without heart failure.

BACKGROUND: Whether angiotensin II receptor blocker (ARB) can be an alternative to angiotensin-converting enzyme inhibitor (ACEI) in patients without heart failure (HF) after acute myocardial infarction (MI) remains controversial. The aim of this study was to compare clinical outcomes between initial ARB and ACEI therapy in patients with MI without HF. METHODS: Between 2010 and 2016, a total of 31,013 patients who underwent coronary revascularization for MI with prescription of ARB or ACEI at hospital discharge were enrolled from the Korean nationwide medical insurance data. Patients who had HF at index MI were excluded. The primary outcome was all-cause death. The secondary outcomes included recurrent MI, hospitalization for new heart HF, stoke, and a composite of each outcome. RESULTS: Of 31,013 patients, ARBs were prescribed in 12,685 (40.9%) and ACEIs in 18,328 (59.1%). Patients receiving ARB had a lower discontinuation rate compared with those receiving ACEI (28.2% versus 43.5%, adjusted hazard ratio [HR] 0.34, 95% confidence interval [CI] 0.31-0.37, p<0.01). During a median follow-up of 2.2 years, 2,480 patients died. The incidence rate of all-cause death in patients receiving ARB and those receiving ACEI was 27.7 and 22.9 per 1,000 person-years, respectively (adjusted HR 1.04; 95% CI, 0.95-1.13; p=0.40). There were no significant differences in the secondary outcomes between patients receiving ARB and those receiving ACEI, except stroke (19.2 vs. 13.6 per 1,000 person-years; adjusted HR 1.17; 95% CI 1.04-1.32; p=0.01). In a subgroup analysis, a higher mortality was observed with ARBs compared to ACEIs in patients with diabetes. CONCLUSIONS: In this nationwide cohort, there was no significant difference in the incidence of all-cause death between ARB and ACEI as discharge medications in patients with MI without HF. ARBs would be an alternative to ACEIs for those intolerant to ACEI therapy.

[What is confirmed in the treatment of Fabry's disease?] / Was ist gesichert in der Therapie von Morbus Fabry?

Fabry's disease is a rare X chromosome-linked inherited lysosomal storage disease characterized by insufficient metabolism of the substrate globotriaosylceramide (Gb3) due to reduced alpha-galactosidase A (AGAL) activity. Lysosomal Gb3 accumulation causes a multisystemic disease which, if untreated, reduces the life expectancy in females and males by around 10 and 20 years, respectively, due to progressive renal dysfunction, hypertrophic cardiomyopathy, cardiac arrhythmia and early occurrence of cerebral infarction. The diagnosis is confirmed by determining the reduced AGAL activity in leukocytes in males and molecular genetic detection of a -mutation causing the disease in females. The treatment comprises enzyme replacement therapy (ERT), agalsidase alfa, 0.2 mg/kg body weight (BW), agalsidase beta 1.0 mg/kg BW or pegunigalsidase alfa 1.0 mg/kg BW every 2 weeks i.v. or oral chaperone therapy (one capsule of migalastat 123 mg every other day) in the presence of amenable mutations. This article summarizes the data on the treatment of Fabry's disease and on complications in practice. The current guideline recommendations are addressed and new study results that could expand the therapeutic repertoire in the future are discussed.

Structure-Assisted Design of Chitosanase Product Specificity for the Production of High-Degree Polymerization Chitooligosaccharides.

Chitosanases are valuable enzymatic tools in the food industry for converting chitosan into functional chitooligosaccharides (COSs). However, most of the chitosanases extensively characterized produced a low degree of polymerization (DP) COSs (DP = 1-3, LdpCOSs), indicating an imperative for enhancements in the product specificity for the high DP COS (DP >3, HdpCOSs) production. In this study, a chitosanase from Methanosarcina sp. 1.H.T.1A.1 (OUC-CsnA4) was cloned and expressed. Analysis of the enzyme-substrate interactions and the subsite architecture of the OUC-CsnA4 indicated that a Ser49 mutation could modify its interaction pattern with the substrate, potentially enhancing product specificity for producing HdpCOSs. Site-directed mutagenesis provided evidence that the S49I and S49P mutations in OUC-CsnA4 enabled the production of up to 24 and 26% of (GlcN)5 from chitosan, respectively─the wild-type enzyme was unable to produce detectable levels of (GlcN)5. These mutations also altered substrate binding preferences, favoring the binding of longer-chain COSs (DP >5) and enhancing (GlcN)5 production. Furthermore, molecular dynamics simulations and molecular docking studies underscored the significance of +2 subsite interactions in determining the (GlcN)4 and (GlcN)5 product specificity. These findings revealed that the positioning and interactions of the reducing end of the substrate within the catalytic cleft are crucial factors influencing the product specificity of chitosanase.

Laevicaulis stuhlmanni slugs as accumulation bio-indicators of lead metal pollution: immunotoxic, physiological, and histopathological alterations.

Trace metal pollution of soils is a widespread consequence of anthropogenic activity. Land slugs can be used as bio-indicators of the metals' pollution in the soil, so the present study aimed to determine the metal in the soil and Laevicaulis stuhlmanni land slug tissues by studying its effects on different physiological parameters. Slugs and soil samples were collected from fields in Abu-Rawash, Giza, Egypt. Slugs were identified, and the metals were determined in slug tissues and soil samples. On the other hand, slugs were reared in the laboratory and the new generation was fed on lettuce dipped in 0.027 µg/ml lead (Pb) for 10 days. The results revealed that the soil and slug tissues contained copper, manganese, lead, and zinc; the lead metal bioaccumulation factor was the highest. Also, the results showed that the hemocytes' count, testosterone, and estradiol hormones were significantly decreased. At the same time, the phagocytic index was increased considerably, and some morphological alterations in the granulocytes and hyalinocytes were observed after treatment with 0.027 µg/ml lead compared to untreated slugs. On the other hand, all the oxidative stress parameters were significantly increased in the treated slugs compared with the control. Concerning the histopathological studies, lead caused a rupture, vacuolation, or degeneration in the digestive cells of treated slugs. Finally, it can be concluded that the land slugs were sensitive to lead which was reflected by endocrine disruption, immunotoxicity, and increased oxidative stress parameters with histopathological damages. Hence, Laevicaulis stuhlmanni can be used as a metal accumulation bio-indicator to reflect the metal pollution in the soil.

Associations of the PPARα and Lipoprotein Lipase Enzyme Gene Polymorphisms with Dyslipidemia in Obese and Non-obese Males.

Background: Peroxisome proliferator-activated receptor α (PPARα) is a nuclear transcription factor responsible for gene expression, particularly those associated with lipid metabolism. The lipoprotein lipase enzyme (LPL) is considered a key enzyme in lipid metabolism and transport. The link between dyslipidemia and obesity is well understood. Dyslipidemia is also an established risk feature for cardiovascular disease. Thus, it becomes progressively essential to identify the role of genetic factors as risk markers for the development of dyslipidemia among obese males. Methods: A case-control study was performed including 469 males. Anthropometric characteristics and serum lipid profiles such as triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were evaluated. Genomic DNA extraction and purification were performed using whole blood samples. Restriction enzyme fragment length polymorphism was used to genotype PPARα and LPL single nucleotide polymorphisms. The associations between these polymorphisms and dyslipidemia were examined. Results: The CC and CG genotypes of PPARα gene polymorphisms were significantly associated with higher TC and LDL-C levels (P<0.05). The TT genotype of the LPL gene polymorphism was significantly associated with higher TG levels and lower HDL-C levels (P<0.05). In contrast, the GG genotype may have a protective action against dyslipidemia. Conclusion: The study reaches the interesting conclusion that there was a significant association between PPARα as well as LPL gene polymorphisms and dyslipidemia among obese and non-obese males.

A novel sandwich electrochemical immunosensor utilizing customized template and phosphotungstate catalytic amplification for CD44 detection.

A sandwich-type electrochemical immunosensor was proposed for the ultra-sensitive detection of CD44, a potential biomarker for breast cancer. In this design, a customized template-based ionic liquid (1-butyl-2,3-dimethylimidazolium tetrafluoroborate) carbon paste electrode (CILE) served as the sensing platform, and thionine/Au nanoparticles/covalent-organic frameworks (THI/Au/COF) were used as the signal label. Moreover, an enzyme-free signal amplification strategy was introduced by involving H2O2 and phosphotungstate (PW12) with peroxidase-like activity. Under optimized conditions, the linear range is as wide as six orders of magnitude, and the detection limit is as low as 0.71 pg mL-1 (estimated based on S/N = 3). Average recoveries range from 98.16 %-100.1 %, with a relative standard deviation (RSD) of 1.42-8.27 % in mouse serum, and from 98.44 %-99.06 %, with an RSD of 1.14-4.84 % (n = 3) in artificial saliva. Furthermore, the immunosensor exhibits excellent specificity toward CD44, good stability, and low cost, indicating great potential for application in clinical trials.

A sensitive fluorescence assay of serum dipeptidyl peptidase IV activity to predict the suitability of its inhibitors in patients with type 2 diabetes mellitus.

DPP-IV inhibitors, which are close to the natural hypoglycemic pathway of human physiology and have few side effects, have been extensively employed in the management of type 2 diabetes mellitus (T2DM). However, there are currently no specific blood indicators that can indicate or predict a patient's suitability for DPP-IV inhibitors. In this study, based on the self-developed high-specificity fluorescent substrate glycyl-prolyl-N-butyl-4-amino-1, 8-naphthimide (GP-BAN), a detection method of human serum DPP-IV activity was established and optimized. The method demonstrates a favorable lower limit of detection (LOD) at 0.32 ng/mL and a satisfactory lower limit of quantification (LOQ) of 1.12 ng/mL, and can be used for the detection of DPP-IV activity in trace serum (2 µL). In addition, Vitalliptin and Sitagliptin showed similar IC50 values when human recombinant DPP-IV and human serum were used as enzyme sources, and the intra-day and inter-day precision obtained by the microplate analyzer were less than 15 %. These results indicate that the microplate reader based detection technique has good accuracy, repeatability and reproducibility. A total of 700 volunteers were recruited, and 646 serum samples were tested for DPP-IV activity. The results showed that serum DPP-IV activity was higher in patients with T2DM than in controls (P < 0.01). However, the statistical data of family history of diabetes, gender and age of diabetic patients showed no statistical significance, and there was no contrast difference. The DPP-IV activity of serum in T2DM patients ranged from 2.4 µmol/min/L to 78.6 µmol/min/L, with a huge difference of up to 32-fold. These results suggest that it is necessary to test DPP-IV activity in patients with T2DM when taking DPP-IV inhibitors to determine the applicability of DPP-IV inhibitors in T2DM patients. These results suggest that it is necessary to detect the activity of DPP-IV in blood before taking DPP-IV inhibitors in patients with T2DM to judge the applicability of DPP-IV inhibitors in patients with T2DM.

S. aureus Eap is a polyvalent inhibitor of neutrophil serine proteases.

Staphylococcus aureus expresses three high-affinity neutrophil serine protease (NSP) inhibitors known as the extracellular adherence protein domain (EAPs) proteins. Whereas EapH1 and EapH2 are comprised of a single EAP domain, the modular extracellular adherence protein (Eap) from S. aureus strain Mu50 consists of four EAP domains. We recently reported that EapH2 can simultaneously bind and inhibit cathepsin-G (CG) and neutrophil elastase (NE), which are the two most abundant NSPs. This unusual property of EapH2 arises from independent CG and NE-binding sites that lie on opposing faces of its EAP domain. Here we used X-ray crystallography and enzyme assays to show that all four individual domains of Eap (i.e. Eap1, Eap2, Eap3, and Eap4) exhibit an EapH2-like ability to form ternary complexes with CG and NE that inhibit both enzymes simultaneously. We found that Eap1, Eap2, and Eap3 have similar functional profiles insofar as NSP inhibition is concerned, but that Eap4 displays an unexpected ability to inhibit two NE enzymes simultaneously. Using X-ray crystallography, we determined that this second NE-binding site in Eap4 arises through the same region of its EAP domain that also comprises its CG-binding site. Interestingly, small angle X-ray scattering data showed that stable tail-to-tail dimers of the NE/Eap4/NE ternary complex exist in solution. This arrangement is compatible with NSP-binding at all available sites in a two-domain fragment of Eap. Together, our work implies that Eap is a polyvalent inhibitor of NSPs. It also raises the possibility that higher-order structures of NSP-bound Eap may have unique functional properties.

Association between angiotensin-converting enzyme gene insertion/deletion polymorphism and cognition impairment in patients with schizophrenia.

RATIONALE: Several lines of evidence indicate that an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene (ACE) gene may be involved in the pathogenesis of schizophrenia and cognitive impairment. However, the relationship between ACE I/D polymorphism and cognitive impairment in patients with schizophrenia remains unclear. OBJECTIVES: The aim of this study was to examine whether ACE gene I/D polymorphism contributed to cognitive impairment in Chinese patients with schizophrenia, and whether the association between clinical symptoms and cognitive impairment depended on different ACE genotypes. METHODS: The ACE I/D polymorphism was genotyped in 928 schizophrenia patients and 325 healthy controls using a case-control design. The severity of psychopathological symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). Cognitive functioning was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). RESULTS: There were significant differences in genotype and allele frequencies of the ACE I/D polymorphism between patients and healthy controls (both P < 0.01). After controlling for demographic characteristics, patients who are homozygous carriers of D and I performed worse on the RBANS attention index than heterozygous carriers (P = 0.009). In addition, attention index score was negatively correlated with PANSS negative symptom score in patients of all genotypes (all P < 0.05), and positively correlated with positive symptom score only in the I/I genotype (P = 0.005). CONCLUSIONS: These findings suggest that ACE I/D gene variants play a role in susceptibility to schizophrenia, specific cognitive impairment and the association between clinical symptoms and cognitive impairment in schizophrenia patients.

[Research progress in biosynthesis-related enzymes of coumarin compounds and their bioactivities].

Coumarins are natural products with benzopyran ring as the parent nucleus. Numerous coumarin derivatives exhibit a variety of pharmacological activities, including antibacterial, anti-inflammatory, antitumor, anti-coagulant, anti-osteoporotic, and insecticidal activities. Therefore, they play an important role in both medicine and agriculture. The development and utilization of coumarin derivatives have attracted increasing attention. The advancement of gene sequencing technology and the rapid progress in synthetic bio-logy have led to significant advancement in the biosynthesis of coumarin derivatives, and has received increasing attention from global researchers. This paper presents a comprehensive overview of the key biosynthesis-related enzymes of coumarin derivatives, such as cytochrome P450 enzyme(CYP450), prenyltransferase(PT), UDP-glucosyltransferase(UGT). Additionally, the pharmacological activities of these enzymes, including anti-tumor, anti-inflammatory, antioxidant, and antibacterial activities, are systematically summarized. This review aims to provide a valuable reference for the biosynthesis of coumarin derivatives and further exploration of their medicinal potential.

Adsorption of extracellular lipase in a packed-bed reactor: an alternative immobilization approach.

In light of the growing demand for novel biocatalysts and enzyme production methods, this study aimed to evaluate the potential of Aspergillus tubingensis for producing lipase under submerged culture investigating the influence of culture time and inducer treatment. Moreover, this study also investigated conditions for the immobilization of A. tubingensis lipase by physical adsorption on styrene-divinylbenzene beads (Diaion HP-20), for these conditions to be applied to an alternative immobilization system with a packed-bed reactor. Furthermore, A. tubingensis lipase and its immobilized derivative were characterized in terms of their optimal ranges of pH and temperature. A. tubingensis was shown to be a good producer of lipase, obviating the need for inducer addition. The enzyme extract had a hydrolytic activity of 23 U mL-1 and achieved better performance in the pH range of 7.5 to 9.0 and in the temperature range of 20 to 50 °C. The proposed immobilization system was effective, yielding an immobilized derivative with enhanced hydrolytic activity (35 U g-1), optimum activity over a broader pH range (5.6 to 8.4), and increased tolerance to high temperatures (40 to 60 ℃). This research represents a first step toward lipase production from A. tubingensis under a submerged culture and the development of an alternative immobilization system with a packed-bed reactor. The proposed system holds promise for saving time and resources in future industrial applications.

Integrated analysis of gut microbiome and its metabolites in ACE2-knockout and ACE2-overexpressed mice.

Background: Aberrant activation of the classic renin-angiotensin system (RAS) and intestinal micro dysbiosis adversely affect insulin resistance (IR), dyslipidemia, and other metabolic syndrome markers. However, the action of angiotensin-converting enzyme 2 (ACE2) and gut health in systemic homeostasis vary, and their interaction is not completely understood. Methods: We adopted a combinatory approach of metabolomics and fecal 16S rRNA analysis to investigate gut microbiota and metabolite in two different mouse models, ACE2 knockout (ACE2 KO) mice and the ACE2-overexpressing obese mice. Results: 16S rRNA gene sequencing revealed that ACE2 influences microbial community composition and function, and ACE2 KO mice had increased Deferribacteres, Alcaligenaceae, Parasutterella, Catenibacterium, and Anaerotruncus, with decreased short-chain fatty acid (SCFA)-producing bacteria (Marvinbryantia and Alistipes). In contrast, ACE2-overexpressed mice exhibited increased anti-inflammatory probiotic (Oscillospiraceae, Marinifilaceae, and Bifidobacteriaceae) and SCFA-producing microbes (Rikenellaceae, Muribaculaceae, Ruminococcaceae, Odoribacter, and Alistipes) and decreased Firmicutes/Bacteroidetes, Lactobacillaceae, Erysipelotrichaceae, and Lachnospiraceae. Metabolome analysis indicated differential metabolites in ACE2 KO and ACE2-overexpression mice, especially the glucolipid metabolism-related compounds. Furthermore, correlation analysis between gut microbiota and metabolites showed a dynamic mutual influence affecting host health. Conclusion: Our study confirms for the first time a significant association between ACE2 status and gut microbiome and metabolome profiles, providing a novel mechanism for the positive effect of ACE2 on energy homeostasis.

Microbial carbohydrate active enzyme (CAZyme) genes and diversity from Menagesha Suba natural forest soils of Ethiopia as revealed by shotgun metagenomic sequencing.

BACKGROUND: The global over-reliance on non-renewable fossil fuels has led to the emission of greenhouse gases, creating a critical global environmental challenge. There is an urgent need for alternative solutions like biofuels. Advanced biofuel is a renewable sustainable energy generated from lignocellulosic plant materials, which can significantly contribute to mitigating CO2 emissions. Microbial Carbohydrate Active Enzymes (CAZymes) are the most crucial enzymes for the generation of sustainable biofuel energy. The present study designed shotgun metagenomics approaches to assemble, predict, and annotate, aiming to gain an insight into the taxonomic diversity, annotate CAZymes, and identify carbohydrate hydrolyzing CAZymes from microbiomes in Menagesha suba forest soil for the first time. RESULTS: The microbial diversity based on small subunit (SSU) rRNA analysis revealed the dominance of the bacterial domain representing 81.82% and 92.31% in the studied samples. Furthermore, the phylum composition result indicated the dominance of the phyla Proteobacteria (23.08%, 27.27%), Actinobacteria (11.36%, 20.51%), and Acidobacteria (10.26%, 15.91%). The study also identified unassigned bacteria which might have a unique potential for biopolymer hydrolysis. The metagenomic study revealed that 100,244 and 65,356 genes were predicted from the two distinct samples. A total number of 1806 CAZyme genes were identified, among annotated CAZymes, 758 had a known enzyme assigned to CAZymes. Glycoside hydrolases (GHs) CAZyme family contained most of the CAZyme genes with known enzymes such as ß-glucosidase, endo-ß-1,4-mannanase, exo-ß-1,4-glucanase, α-L-arabinofuranosidase and oligoxyloglucan reducing end-specific cellobiohydrolase. On the other hand, 1048 of the identified CAZyme genes were putative CAZyme genes with unknown enzymatical activity and the majority of which belong to the GHs family. CONCLUSIONS: In general, the identified putative CAZymes genes open up an opportunity for the discovery of new enzymes responsible for hydrolyzing biopolymers utilized for biofuel energy generation. This finding is used as a first-hand piece of evidence to serve as a benchmark for further and comprehensive studies to unveil novel classes of bio-economically valuable genes and their encoded products.

Carbonic anhydrase encapsulation using bamboo cellulose scaffolds for efficient CO2 capture and conversion.

Utilizing carbonic anhydrase (CA) to catalyze CO2 hydration offers a sustainable and potent approach for carbon capture and utilization. To enhance CA's reusability and stability for successful industrial applications, enzyme immobilization is essential. In this study, delignified bamboo cellulose served as a renewable porous scaffold for immobilizing CA through oxidation-induced cellulose aldehydation followed by Schiff base linkage. The catalytic performance of the resulting immobilized CA was evaluated using both p-NPA hydrolysis and CO2 hydration models. Compared to free CA, immobilization onto the bamboo scaffold increased CA's optimal temperature and pH to approximately 45 °C and 9.0, respectively. Post-immobilization, CA activity demonstrated effective retention (>60 %), with larger scaffold sizes (i.e., 8 mm diameter and 5 mm height) positively impacting this aspect, even surpassing the activity of free CA. Furthermore, immobilized CA exhibited sustained reusability and high stability under thermal treatment and pH fluctuation, retaining >80 % activity even after 5 catalytic cycles. When introduced to microalgae culture, the immobilized CA improved biomass production by ~16 %, accompanied by enhanced synthesis of essential biomolecules in microalgae. Collectively, the facile and green construction of immobilized CA onto bamboo cellulose block demonstrates great potential for the development of various CA-catalyzed CO2 conversion and utilization technologies.

Bacterial surface display of PETase mutants and MHETase for an efficient dual-enzyme cascade catalysis.

Biological degradation of PET plastic holds great potential for plastic recycling. However, the high costs associated with preparing free enzymes for degrading PET make it unfeasible for industrial applications. Hence, we developed various cell catalysts by surface-displaying PETase mutants and MHETase using autotransporters in E. coli and P. putida. The efficiency of surface display was enhanced through modifying the host, co-expressing molecular chaperones, and evoluting the autotransporter. In strain EC9F, PET degradation rate was boosted to 3.85 mM/d, 51-fold and 23-fold increase compared to free enzyme and initial strain ED1, respectively. The reusability of cell catalyst EC9F was demonstrated with over 38 % and 30 % of its initial activity retained after 22 cycles of BHET degradation and 3 cycles of PET degradation. The highest reported PET degradation rate of 4.95 mM/d was achieved by the dual-enzyme cascade catalytic system EC9F+EM2 + R, a mixture of cell catalyst EC9F and EM2 with surfactant rhamnolipid.

Impact of protein and small molecule interactions on kinase conformations.

Protein kinases act as central molecular switches in the control of cellular functions. Alterations in the regulation and function of protein kinases may provoke diseases including cancer. In this study we investigate the conformational states of such disease-associated kinases using the high sensitivity of the kinase conformation (KinCon) reporter system. We first track BRAF kinase activity conformational changes upon melanoma drug binding. Second, we also use the KinCon reporter technology to examine the impact of regulatory protein interactions on LKB1 kinase tumor suppressor functions. Third, we explore the conformational dynamics of RIP kinases in response to TNF pathway activation and small molecule interactions. Finally, we show that CDK4/6 interactions with regulatory proteins alter conformations which remain unaffected in the presence of clinically applied inhibitors. Apart from its predictive value, the KinCon technology helps to identify cellular factors that impact drug efficacies. The understanding of the structural dynamics of full-length protein kinases when interacting with small molecule inhibitors or regulatory proteins is crucial for designing more effective therapeutic strategies.

Structure and function of rhizosphere soil microbial communities associated with root rot of Knoxia roxburghii.

The microbial communities in rhizosphere soil play important roles in plant health and crop productivity. However, the microbial community structure of rhizosphere soil still remains unclear. In this study, the composition, diversity and function of the microbial communities in the rhizosphere soil of healthy and diseased plants were compared using Illumina MiSeq high-throughput sequencing. The Sobs (richness) and Shannon (diversity) indices of the soil microbial communities were higher in the rhizospheres of 2- and 3-year-old susceptible plants than in those of the healthy plants. With the increase in planting time, the numbers of fungi tended to decrease, while those of the bacteria tended to increase. Fungal diversity could be used as a biological indicator to measure the health of Knoxia roxburghii. The microbial composition and differential analyses revealed that the rhizosphere soil infested with fungi had a higher relative abundance at the phylum level in Ascomycota and Basidiomycota, while the bacteria had a higher relative abundance of Chloroflexi and a lower relative abundance of Actinobacteriota. At the genus level, the rhizosphere soil infested with fungi had relatively more abundant unclassified_f__Didymellaceae and Solicoccozyma and relatively less abundant Saitozyma and Penicillium. The bacterial genus norank_f__Gemmatimonadaceae was the most abundant, while Arthrobacter was less abundant. In addition, the abundance of Fusarium in the fungal community varied (p = 0.001). It tended to increase in parallel with the planting years. Therefore, it was hypothesized that the change in the community composition of Fusarium may be the primary reason for the occurrence of root rot in K. roxburghii, and the change in the abundance of Fusarium OTU1450 may be an indication of the occurrence of root rot in this species. The community function and prediction analyses showed that the pathogenic fungi increased with the increase in planting years. In general, soil fungi can be roughly divided into three types, including pathotrophs, symbiotrophs, and saprotrophs. An analysis of the differences in the prediction of different rhizosphere functions showed that D and L were significantly different in the COG enrichment pathway of the K. roxburghii rhizosphere bacteria (p < 0.05). The soil physical and chemical properties, including the pH, AK, total potassium (TK), and catalase (S_CAT), had the most significant effect on the soil fungal community, and most of the soil physical and chemical properties significantly correlated with the bacterial community. This study demonstrated that the occurrence of root rot had an important effect on the diversity, structure and composition of microbial communities. In addition, the results will provide a theoretical basis to prevent and control root rot in K. roxburghii.