Enhancement of transglutaminase production in Streptomyces mobaraensis DSM 40587 by non-nutritional stress conditions: Effects of heat shock, alcohols, and salt treatments

Lili Zhang,Lanwei Zhang,Huaxi Yi,Ming Du,Yingchun Zhang,Xue Han,Zhen Feng,Jingyan Li,Yuehua Jiao,Yanhe Zhang,Chunfeng Guo 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.7

Stress-mediated bioprocess is a strategy designed to enhance biological target productivity. In this study,an attempt was made to enhance transglutaminase (TGase) production by Streptomyces mobaraensis by using different stress conditions including heat shock, alcohols and salt stress. Results showed that the effects of stress on TGase production depended on the type applied. For heat shock, TGase production (1.32 U/ml) was recorded maximum in the culture treated at 48 h post inoculation in water bath at 60 oC for 1 min. For alcohols treatment, the maximum activity of TGase (1.77 and 1.75 U/ml) was obtained when 3% methanol was added into the medium at 0 or 24 h of fermentation. However, a 3.5-fold increased production of TGase (3.8 U/ml) was observed in the medium supplemented with 0.2mol/l MgCl2 compared with the basic medium at the beginning of fermentation. In conclusion, TGase production from S. mobaraensis was improved by heat shock, methanol and salt stress treatments, MgCl2 stress was the most effective.

Novel Organic/Inorganic Hybrid Star Polymer Surface-Crosslinked with Polyhedral Oligomeric Silsesquioxane

Jingyan Zhang,Dong Si,Shifeng Wang,Hao Liu,Xiaoming Chen,Haiou Zhou,Mingdi Yang,Guoying Zhang 한국고분자학회 2020 Macromolecular Research Vol.28 No.2

Novel organic/inorganic hybrid star polymer was prepared dually crosslinked within inner-core via divinylbenzene (DVB) and outer-surface via octafunctional polyhedral oligomeric silsesquioxane (POSS). Core cross-linked star polymers bearing dialkynyl-terminated polystyrene arms, (dialkynyl-PS)n-CCL, were synthesized at first by the atom transfer radical polymerization (ATRP) of DVB using α,α-dialkynyl-terminated PS macroinitiator, followed by the subsequent fractionation. Under high dilution conditions, (dialkynyl-PS)n-CCL was subjected to surface cross-linking with octa(3- azidopropyl) polyhedral oligomeric silsesquioxane, POSS-(N3)8, via click reaction, affording POSS-functionalized hybrid polymer doubly cross-linked within core and surface regions, SCL-(PS)n-CCL. FT-IR, 1H NMR, GPC, and elemental analysis results revealed that on average, the obtained hybrid polymer possesses a cross-linked PDVB inner core, ~14 linear PS arms (the MW per arm of 5.1 kDa), and ~4-5 POSS moieties at outer surface. Differential scanning calorimetry (DSC) thermograms and thermogravimetric analysis (TGA) revealed that after surface cross-linking the thermal stability of SCL-(PS)n-CCL is considerably improved. This work provides a proof-of-concept example for the preparation of dually cross-linked hybrid star polymer, which represents a novel category of organic/inorganic composite materials with unique chain architectures.

An In situ Forming Hydrogel Based on Photo-Induced Hydrogen Bonding

Jingyan Zhang,Shifeng Wang,Zeren Zhao,Dong Si,Haiou Zhou,Mingdi Yang,Xianbiao Wang 한국고분자학회 2020 Macromolecular Research Vol.28 No.12

Stimulus-induced in situ forming hydrogels possess the characteristics of easy management and minimal invasiveness via simple injection at target sites with a liquid and easy forming bulk gels. In the present study, a photoreactive monomer, N'-(2-nitrobenzyl)-N-acryloyl glycinamide (NBNAGA) was introduced to modify polyacrylamide (PAM) hydrogel preparation with stimuli responsiveness. Firstly, poly(acrylamide-co-N'-(2-nitrobenzyl)-N-acryloyl glycinamide), P(AM-co-NBNAGA), copolymer solution was prepared via reversible addition fragmentation chain transfer (RAFT) polymerization using the monomers mixture of AM, NBNAGA, and N,N'- methylene bis-acrylamide (BIS). The obtained polymer solution with viscous, transparent, and flowable appearance contained weak single hydrogen bonding and slight chemical crosslinking in a microscopic perspective. Secondly, without further purification, after irradiation using UV light at 365 nm, poly(acrylamide-co-N-acryloyl glycinamide) (P(AM-co-NAGA)) hydrogel conveniently in situ formed due to the cleavage of o-nitrobenzyl groups and the corresponding emergency of dual hydrogen bonding among “uncaged” dual amide moieties. P(AM-co-NAGA) hydrogel depicted both favorable temperature sensitivity and self-healing properties, then the heating induced in vitro release profiles of doxorubicin (DOX) was analyzed.

A Hybrid Path Planning Method for Partly Unknown Environment

Tao Zhang,Yi Zhu,Jingyan Song 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

For efficiently solving path planning problem in partly unknown environment and making full use of the prior known knowledge of the environment and the sensor based information, a hybrid method consisting of both global and local path planning is proposed in this paper. In this hybrid method, a new approach for generating the sequence ofsub-goal is proposed. Most importantly, comparing with some related works, the proposed method pays more attentionto the capability of local planning layer instead of global planning layer, which results in more reliable ability to escapefrom trap in partly known environment without expensive computation. The simulation results verified the effectiveness of the proposed method.

Isolation and Applied Potential of Lactic Acid Bacteria from Chinese Traditional Fermented Food in Specific Ecological Localities

Huaxi Yi,Lanwei Zhang,Xue Han,Ming Du,Yingchun Zhang,Jingyan Li,Kai Sun,Yawen Hou 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.6

The isolation and screening of lactic acid bacteria (LAB) from natural sources have been one of the powerful means to obtain strains for the food industry. A total of 275 indigenous isolates were obtained from 43samples of traditional fermented foods in specific ecological niches throughout the northwestern China, and among which 13 strains of LAB were selected for their potential in food preservation and production. Among the 13 isolates, Lactobacillus (10) was dominant over Lactococcus (3). The distribution of the isolates was as follows: Lactobacillus paracasei ssp. paracasei (J23, M10,M20, M22), Lactobacillus rhamnosus (J20, M18),Lactococcus lactis ssp. lactis (X20, Q7), Lactobacillus casei (Q1, Q12), Lactobacillus plantarum (J11),Lactococcus lactis ssp. cremoris (X8), Lactobacillus delbrueckii ssp. bulgaricus (Q5). All 13 isolates produced bacteriocin with a broad inhibitory spectrum against selected Gram-positive as well as Gram-negative pathogenic and spoilage species. Biochemical analysis revealed that they possessed high acidification and coagulation activity. Several strains possessed the high activity of 2 or 3technological characteristics, related to novel starters and food preservatives.

The miR-145-5p/CD36 pathway mediates PCB2-induced apoptosis in MCF-7 cells

Yuan Yuan,Caihua Xue,Qiang Wu,Mengjie Wang,Jiahua Liu,Longfei Zhang,Qianwen Xing,Jingyan Liang,Hua Wu,Zhi Chen 한국유전학회 2021 Genes & Genomics Vol.43 No.2

Background Procyanidin B2 (PCB2) can increase the levels of anti-infammatory and immune mediators. Objectives However, its molecular mechanism in human breast cancer remains unclear. This study aimed to investigate the antitumor efect of PCB2 on MCF-7 cells and to examine the underlying mechanism. Methods The fow cytometry and EdU incorporation assays were measured the PCB2-induced BMECs. The expression levels of infammatory factors and immune response genes were upregulated in MCF-7 cells, high-throughput sequencing was used to detect diferentially expressed genes in blank and PCB2-treated MCF-7 cells. Results The results showed that PCB2 induced the apoptosis of MCF-7 cells. CD36 profles were afected in MCF-7 cells. Additionally, prediction software identifed a miR-145-5p binding site in the CD36 sequence. Luciferase reporter assays and Western blot analysis were used to verify the regulatory relationships between the diferentially expressed miRNA miR145-5p and CD36. MiR-145-5p and its key target (CD36) constitute a potential miRNA-mRNA regulatory pair. Functional studies in MCF-7 cells revealed that CD36 promotes but miR-145-5p inhibits apoptosis. Conclusion Overall, these data suggest that miR-145-5p inhibits the enhancing efect of PCB2 on CD36 expression by binding CD36 and subsequently regulating apoptosis, the immune response and anti-infammatory pathways. These results provide theoretical and experimental support for the treatment of breast cancer.