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The lipase from Serratia marcescence ECU1010 (Sml) was capable of enantioselectively catalyzing the synthesis of many chiral drug precursors. This paper investigated the immobilization of Sml on appropriate supporting materials and its performance in bioreactor. Chitosan, Celite 545, and DEAE-cellulose were found to be the ideal supports among 8 carriers tested with respect to enzyme load and activity recovery of lipase. When Sml was immobilized, significant improvements of stability against pH, thermal, and operational deactivation were observed with all the 3 better supports, and the best stability was observed when the lipase was immobilized on glutaraldehyde activated chitosan. As for the effect of organic solvent in the biphasic reaction system, the hydrolytic activity of the immobilized lipase on trans-3-(4′-methoxyphenyl)glycidic acid methyl ester ((±)-MPGM) observed in isopropyl ether was 6 and 3 times higher than those in toluene and methyl tert-butyl ether. The lipasecatalyzed production of (−)-MPGM by enzymatic resolution of (±)-MPGM with chitosan-Sml in isopropyl etherwater biphasic system was carried out in a 2 L stirred-tank reactor. The batch operation was more efficient operation mode for the enantioselective hydrolysis of (±)-MPGM, affording enantiopure (−)-MPGM in 44.3% overall yield, in contrast to 29.3% in a continuous reactor.

For the enhancement of lipase stability in organic solvent containing reaction, live immobilization method, using Bacillus subtilis spore as a display vehicle was attempted. Bacillus subtilis coat protein cotE was used as an anchoring motif for the display of lipA and lipB of Bacillus subtilis. Using this motif, lipolytic enzyme Lipase A and Lipase B were functionally displayed on the surface of Bacillus subtilis spore. Purified spore displaying CotE-LipB fusion protein showed higher lipolytic activity compared to that of CotE-LipA fusion protein. The surface localization of Lipase B was verified with flow cytometry and protease accessibility experiment. Spore displayed lipase retained its activity against acetone and benzene which completely deactivated free soluble lipase in the same reaction condition.

This study focused on the effects of different mineral supplements on the ability of Corynebacterium glutamicum to degrade phenol in contaminated soil and convert the phenol into useful amino acids. Three types of minerals including FeSO4, MgSO4, and MnSO4 were added at several concentrations to C. glutamicum culture media containing 1% yeast extract prior to treating the soil samples with 4.24 mM phenol. The reactor was incubated at 30°C and 150 rpm for 3 days, and the treated soil was sampled daily and analyzed using gas chromatography for residual phenol and the amino acids produced. Additionally, a plant toxicity assay was employed to examine the fertilization of the phenol-contaminated soil after C. glutamicum treatment supplemented with the three minerals. Our results suggested that among various tested concentrations, 72 μM of iron showed a significant effect on the utilization of phenol by C. glutamicum for conversion to amino acids, therefore enhancing fertilization of the phenol-contaminated soil.

Anaerobic oxidation of volatile fatty acids (VFAs) as the key intermediates is restricted thermodynamically. Presently, enriched acetogenic and methanogenic cultures were used for syntrophic anaerobic digestion of VFAs in an upflow anaerobic sludge bed reactor fed with acetic, propionic, and butyric acids at maximum concentrations of 5.0, 3.0, and 4.0 g/L, respectively. Interactive effects of propionate, butyrate and acetate were analyzed. Hydraulic retention time (HRT) and acetate oxidizing syntrophs and methanogen (hydrogenotrophs) to syntrophic bacteria (propionate- and butyrate-oxidizing bacteria) population ratio (M/A) were investigated as key microbiological and operating variables of VFA anaerobic degradations. M/A did not affect the size distribution and had little effect on extracellular polymer contents of the granules. Granular sludge with close spatial microbial proximity enhanced syntrophic degradation of VFAs compared to other cultures, such as suspended cultures. Optimum conditions were found to be propionate = 1.93 g/L, butyrate = 2.15 g/L, acetate = 2.50 g/L, HRT = 22 h, and M/A = 2.5 corresponding to maximum VFA removal and biogas production rate. Results of verification experiments and predicted values from fitted correlations were in close agreement at the 95% confidence interval. Granules seemed to be smaller particles and less stable in construction with an irregular fractured surface compared to the original granules.

Folate-decorated monoolein (MO) cubosomes containing poly(ethyleneimine) (PEI), cinnamic acid (CA), and doxorubicin (DOX) were prepared to deliver the anticancer drug specifically to cancer cells (KB cells) and boost the anti-cancer efficacy without causing an acute toxicity. Hydrophobically modified (Hm) gelatin (Gel)-folate (FA) conjugate (HmGel-FA) was prepared through amidation reaction among Gel, decanoyl chloride, and FA. HmGel-FA and Pluronic F127 were used as stabilizers for the cubosomal particles. According to the measurement of air/water interfacial tension, the surface activity was greater in the order of HmGel > HmGel-FA > Gel. Since it was reported that PEI and CA formed a self-assembly in the water channel of cubosomes and the dissolving property of the self-assembly was dependent on the pH value of medium, they were included in the water channel as a controller for DOX release. On the TEM micrographs of the cubosomes, water channels were surrounded by MO bilayers, and the payload (i.e. PEI, CA, DOX) had little effect on the structure. The in vitro anti-cancer efficacy of folate-decorated cubosomes containing PEI, CA, and DOX was higher than that of folate-free ones. According to flow cytometric analysis and confocal laser scanning microscopy, DOX fluorescence intensity was greater in the order of KB cells treated with folate-decorated cubosomes containing PEI, CA, and DOX > folate-free ones > free DOX. The folate-decorated cubosomes would be able to target the cancer cells and subsequently the receptor-mediated endocytosis would take place.

Sự sản xuất heterologous iso-migrastatin (iso-MGS) đã được chứng minh thành công trong một chủng S. lividans SB11002 được thiết kế, được phát triển từ S. lividans K4-114, sau khi đưa vào pBS11001, chứa toàn bộ cụm gen sinh tổng hợp mgs. Tuy nhiên, dưới các điều kiện lên men tương tự, nồng độ iso-MGS trong chủng đã được thiết kế thấp hơn đáng kể so với ở nhà sản xuất bản địa — Streptomyces platensis NRRL 18993. Để khắc phục vấn đề nồng độ iso-MGS thấp và mở rộng tính hữu dụng của hệ thống heterologous này cho việc sinh tổng hợp và kỹ thuật iso-MGS, việc tối ưu hóa hệ thống môi trường lên men đã được thực hiện một cách hệ thống. Ảnh hưởng của các thành phần chính trong môi trường nuôi cấy, bao gồm carbon, nguồn nitơ hữu cơ và vô cơ, đã được nghiên cứu thông qua phương pháp tối ưu hóa từng yếu tố. Kết quả cho thấy, sucrose và chiết xuất men là các nguồn carbon và nitơ hữu cơ tốt nhất, dẫn đến sản xuất iso-MGS được tối ưu hóa. Ngược lại, tất cả các nguồn nitơ vô cơ khác được đánh giá đều tạo ra các mức độ ức chế khác nhau đối với sản xuất iso-MGS. Cuối cùng, môi trường sản xuất R2YE được tối ưu hóa đã sản xuất iso-MGS với nồng độ 86.5 mg/L, cao gấp khoảng 3.6 lần so với môi trường R2YE ban đầu và cao gấp 1.5 lần so với nồng độ tìm thấy trong nhà sản xuất S. platensis NRRL 18993 bản địa.

Tissue-engineered cartilage has provided a promising method in the treatment of physeal growth arrest. This study was designed to investigate transplantation of microencapsulated allogeneic chondrocytes to treat the injured growth plate. Allogeneic chondrocytes were encapsulated within alginate-polylysinealginate semipermeable membranes. Microencapsulated chondrocytes co-cultured with Bone Mesenchymal Stem Cells (BMSCs) were evaluated whether it could promote chondrogenesis of BMSCs. An experiment model of an injured growth plate was made by resecting the lateral half of the right distal femur physis in rabbits. Microencapsulated allogeneic chondrocytes, allogeneic chondrocytes as well as empty microcapsules were grafted into growth plate defects of 6-week-old rabbits. Histological and radiographic examinations were examined after transplantation up to 16 weeks. The histological study showed that BMSCs co-cultured with microencapsulated chondrocytes could produce GAG and II collagen similarly with chondrocytes. Angular deformity and length discrepancy in the group with microencapsulated allogeneic chondrocytes were less than those in other groups (p < 0.001). The histological study confirmed the viability of microencapsulated chondrocytes at 16 weeks postoperatively. The neogenetic chondrocytes of columnar arrangement have been found in the growth plate defect to prevent early ossification and closure of the growth plate. The histological study confirmed the viability of microencapsulated chondrocytes at 16 weeks postoperatively. The neogenetic chondrocytes of columnar arrangement have been found in the growth plate defect to prevent early ossification and closure of the growth plate.