Due to the advantages of polymer micelles and the anticancer activity of doxorubicin (DOX), the polymer micelle of DOX is expected to be used for drug delivery in anticancer applications. As a biocompatible and biodegradable polymer, amphiphilic copolymer heparosan-adipic dihydrazide-vitamin E succinate (KV) can be self-assembled to form micelles with core-shell structure in aqueous phase. In this article, KV conjugates with two different degrees of substitution (DS) were synthesized to load DOX and were characterized by ¹H NMR. The size distribution, morphology, zeta potential and release behavior in vitro of the DOX-loaded micelles were studied. In vitro cytotoxicity was investigated by MTT assay against MGC80-3 and COS7 cells. The cellular uptake of the DOX-loaded micelles was observed by fluorescence microscopy and flow cytometry. The ¹H NMR spectra results confirmed the KV polymers were successfully conjugated and the degree of VES grafted on heparosan polysaccharide were 12% and 25%. Briefly, the micelles with two different DS were expressed as KV₁₂ and KV₂₅. The DOX-loaded micelles could resist serum adsorption because of the negative charge on the surface. The average particle size measured by dynamic light scattering (DLS) method was 140-150 nm and the TEM results indicated that the morphology of DOX-loaded micelles were spherical. The encapsulation efficiency and drug loading were 80% and 10%-15%, respectively. The DOX-loaded micelles had sustained release behavior and the cumulative release of DOX/KV₁₂ was slightly higher than DOX/KV₂₅. Moreover, the viabilities of cells which were co-incubated with blank micelles were greater than 90%. It is clear that the blank micelles almost non-toxic to both cells. The IC₅₀ of drug-loaded micelles against COS7 cells was much higher than that of MGC80-3 cells and the DOX/KV₁₂ exhibited greater cytotoxicity. The cellular uptake of DOX/KV on MGC80-3 was greater than COS7 cells. In this study, KV polymer micelles have a sustained drug release activity and have a good selectivity to tumor cells, so it would be a potential carrier in drug delivery.

Heme peroxidase EfeB in E. coli belongs to the dye-decolorizing peroxidase (DyP) superfamily. Peroxidases in this superfamily have a good ability in degradation of synthetic dyes, but their physiological functions in organisms are unclear. In order to further understand the physiological function of EfeB, the mutant strain EcoΔefeB was constructed by homologous recombination. The differences between parental strain E. coli BL21 and EcoΔefeB at genome transcription level as well as cell growth under different conditions were compared. The response of efeB to iron ion was also investigated. The results showed that the deletion of efeB gene caused the differential expression of 1 765 genes, which were mainly related to cell metabolic pathway, cell membrane synthesis and flagellum movement. There was no significant difference in cell growth between BL21 and EcoΔefeB at pH 7. 0, but the growth of BL21 was much better than that of EcoΔefeB at pH 4. 5. The functional expression of efeB may support the survival of E. coli at low pH. EfeB was significantly up-regulated when Fe

As a typical food safety industrial model strain, Bacillus subtilis has been widely used in the field of metabolic engineering due to its non-pathogenicity, strong ability of extracellular protein secretion and no obvious codon preference. In recent years, with the rapid development of molecular biology and genetic engineering technology, a variety of research strategies and tools have been used to construct B. subtilis chassis cells for efficient synthesis of biological products. This review introduces the research progress of B. subtilis from the aspects of promoter engineering, gene editing, genetic circuit, cofactor engineering and pathway enzyme assembly. Then, we also summarized the application of B. subtilis in the production of biological products. Finally, the future research directions of B. subtilis are prospected.
Bacillus subtilis/genetics* ; Bacterial Proteins/genetics* ; Gene Editing ; Metabolic Engineering ; Promoter Regions, Genetic

Microbial oils are potential resources of fuels and food oils in the future. In recent years, with the rapid development of systems biology technology, understanding the physiological metabolism and lipid accumulation characteristics of oleaginous microorganisms from a global perspective has become a research focus. As an important tool for systems biology research, omics technology has been widely used to reveal the mechanism of high-efficiency production of oils by oleaginous microorganisms. This provides a basis for rational genetic modification and fermentation process control of oleaginous microorganisms. In this article, we summarize the application of omics technology in oleaginous microorganisms, introduced the commonly used sample pre-processing and data analysis methods for omics analysis of oleaginous microorganisms, reviewe the researches for revealing the mechanism of efficient lipid production by oleaginous microorganisms based on omics technologies including genomics, transcriptomics, proteomics (modification) and metabolomics (lipidomics), as well as mathematical models based on omics data. The future development and application of omics technology for microbial oil production are also proposed.
Fermentation ; Lipids ; Metabolomics ; Proteomics ; Technology

AIM: To explore the clinical features, diagnosis and treatment experience and the distribution characteristics of pathogenic microorganisms of primary canaliculitis, and provide reference for its diagnosis and treatment. METHODS: Retrospective clinical study. A total of 119 cases(120 eyes)diagnosed as primary canaliculitis in the department of ophthalmology of Wuxi No.2 People's Hospital from June 2019 to February 2023 were included. The treatment methods were mainly divided into conservative treatment(removing canaliculus stones through lacrimal punctum combined with injecting antibiotic eye ointment into the tube)and surgical treatment. The inspection methods of pathogenic microorganisms included secretion smear microscopy and microbial culture.RESULTS: Primary canaliculitis was more common in middle-aged and older female, mainly manifested by long-term red eye and increased secretion; however, the majority was not accompanied by tearing. Totally, 118 cases(99.2%)had monocular disease, while 63 cases(63 eyes; 52.5%)had inferior lacrimal canaliculus disease. Laboratory examination: Among 119 cases(120 eyes), 4 cases(4 eyes)did not undergo laboratory examination, and the other 115 cases(116 eyes)were as follows: Gram staining microscopy of secretion smear showed that Actinomyces were detected in 102 cases(103 eyes; 88.8%), while no fungus was detected; Microbial culture: 85 cases(86 eyes; 74.1%)were positive for bacterial culture. A total of 111 bacterial strains were cultured, which contained 26 types of bacteria. Among them, 32 strains were aerobic(28.8%); 26 strains were anaerobic(23.4%); and 53 strains were facultative anaerobic(47.7%). The most common bacteria were streptococcus(20 strains), staphylococcus(13 strains), Propionibacterium(10 strains), and capnocytophaga(10 strains). Only 4 cases(4 eyes; 3.4%)of microbial cultures were positive for Actinomyces. Fungus was negative in all microbial cultures. Treatment: Of the 119 cases(120 eyes), 114 cases(115 eyes; 95.8%)were cured by conservative treatment of removing lacrimal canaliculus stones through lacrimal punctum and intracanalicular ointment infiltration(IOI), while 5 cases(5 eyes)were not effective in conservative treatment; however, all of them were cured after surgical treatment, and the cure rate for primary canaliculitis was 100.0%.CONCLUSION: The incidence of primary canaliculitis is low, and it is prevalent in middle-aged and older female. Single lacrimal canaliculus is more common, which could be missed and misdiagnosed in clinic. Actinomyces is the major pathogen observed mostly in mixed infections, with heterogeneous strains, mainly anaerobic or facultative anaerobic bacteria. Streptococcus and Staphylococcus are the most common whereas fungal canaliculitis is rare. The cure rate of primary canaliculitis is high after diagnosis, and IOI method is recommended as the initial treatment of canaliculitis.

Sus scrofa lysozyme (SSL) was digested by different proteases to find peptides with enhanced antibacterial activity against gram-negative bacteria. Hydrolysate with the highest anti-bacterial activity was loaded onto a gel filtration chromatography column followed by a reversed-phase one. The obtained substance was identified by liquid chromatography-mass spectrometry, synthesized to test its antibacterial spectrum and analyzed for bioinformatics. The hydrolysate of trypsin showed the highest antibacterial activity. By purification and identification, the functional peptide with sequence of A-W-V-A-W-K was obtained. The peptide was synthesized and proved to retain partial function of SSL and had activity against gram-negative bacteria. By bioinformatics analysis, the peptide was found to locate in a helix-loop-helix structure, suggesting that the peptide may kill cells by penetrating cell membrane and cause the outflow of cell contents. The discovery of the peptide could lay the foundation for improving the antibacterial activity of SSL.

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.
Alcoholic Beverages ; microbiology ; Bacteria ; classification ; metabolism ; Clostridium ; physiology ; Fatty Acids, Volatile ; metabolism ; Fermentation ; Food Microbiology

To illustrate the complex fermentation process of submerged culture of Antrodia camphorata ATCC 200183, we observed the morphology change of this filamentous fungus. Then we used two optimization models namely response surface methodology (RSM) and artificial neural network (ANN) to model the fermentation process of Antrodia camphorata. By genetic algorithm (GA), we optimized the inoculum size and medium components for Antrodia camphorata production. The results show that fitness and prediction accuracy of ANN model was higher when compared to those of RSM model. Using GA, we optimized the input space of ANN model, and obtained maximum biomass of 6.2 g/L at the GA-optimized concentrations of spore (1.76x 10(5) /mL) and medium components (glucose, 29.1 g/L; peptone, 9.3 g/L; and soybean flour, 2.8 g/L). The biomass obtained using the ANN-GA designed medium was (6.1+/-0.2) g/L which was in good agreement with the predicted value. The same optimization process may be used to improve the production of mycelia and bioactive metabolites from potent medicinal fungi by changing the fermentation parameters.
Algorithms ; Antrodia ; genetics ; metabolism ; Culture Media ; chemistry ; metabolism ; Fermentation ; Mycelium ; metabolism ; Neural Networks (Computer)

Diosgenin is an important raw material in steroid hormone and widely used in pharmaceutical industry. The traditional method for diosgenin production is acidolysis, which causes serious pollution. In order to obtain a cleaner and more efficient approach of diosgenin production, a strain of Gibberella intermedia WX12 (the sexual stage of Fusarium proliferatum) was screened from the strains deposited in our laboratory. This strain converted saponins in Dioscorea zingiberensis C.H. Wright (DZW) into diosgenin. The conversion medium was optimized by statistical experimental design. The optimized conversion medium was as follows (g/L): glucose 20.6, yeast extract 5.0, NaCl 1, K2PO4 3, ZnSO4 x 7H2O 1.5 and saponins 3. Under the optimal conditions, the yield of diosgenin achieved to (31 +/- 0.3) mg/g DZW, which was 3 times higher than that of the original medium.
Biotransformation ; Culture Media ; Dioscorea ; chemistry ; Diosgenin ; metabolism ; Gibberella ; growth & development ; metabolism ; Saponins ; metabolism

Glycerol from oil hydrolysis industry is being considered as one of the abundent raw materials for fermentation industry. In present study, the aerobic and anaerobic metabolism and growth properties on glycerol by Esherichia coli CICIM B0013-070, a D-lactate over-producing strain constructed previously, at different temperatures were investigated, followed by a novel fermentation process, named temperature-switched process, was established for D-lactate production from glycerol. Under the optimal condition, lactate yield was increased from 64.0% to 82.6%. Subsequently, the yield of D-lactate from glycerol was reached up to 88.9% while a thermo-inducible promoter was used to regulate D-lactate dehydrogenase transcription.
Aerobiosis ; Anaerobiosis ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Glycerol ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lactic Acid ; biosynthesis ; Promoter Regions, Genetic ; genetics ; Temperature