Purification and properties of a milk-clotting enzyme produced by Bacillus amyloliquefaciens D4

Xiaoling He,Bozhong Gan,Fazheng Ren,Huiyuan Guo,Weibing Zhang,Xi Song 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.1

The milk-clotting enzyme from Bacillus amyloliquefaciens D4 was purified to 17.2-fold with 20% recovery by precipitation in ammonium sulfate and ion-exchange chromatography. The molecular mass of the enzyme was 58.2kDa as determined by SDS-PAGE, and it was proved to be a metalloprotease by EDTA inhibition. The enzyme was active in the pH range 5.5-7.0 and was inactivated completely by heating at 55℃ for 20 min. The highest level of enzyme activity was obtained at 65 ℃, pH 5.5, in the presence of 25mM CaCl_2. The milk-clotting activity was inhibited only slightly by Na^+ and K^+ and significantly by Cu^(2+), Zn^(2+) and Sn^(2+). The Km value of this enzyme was 0.471 mg/mL. The high level of milk-clotting activity coupled with a low level of thermal stability suggested that the milk-clotting enzyme from B. amyloliquefaciens D4 should be considered as a potential substitute for calf rennet.

The Production of Bioflocculants by Bacillus licheniformis Using Molasses and Its Application in the Sugarcane Industry

Xiaoling Zhuang,Yuanpeng Wang,Qingbiao Li,Shan Yan,Ning He 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.5

A bioflocculant produced by B. licheniformis was investigated with regard to a low-cost culture medium and its industrial application. Molasses replaced sucrose as the sole carbon source in bioflocculant fermentation. The optimum low-cost culture medium was determined to be composed of 20 g/L molasses, 0.4 g/L urea, 0.4 g/L NaCl,0.2 g/L KH2PO4, 1.6 g/L K2HPO4, and 0.2 g/L MgSO4. The bioflocculant from B. licheniformis was then applied to treat sugarcane-neutralizing juice to remove colloids,suspended particles, and coloring matters in a sugar refinery factory. The optimal operation conditions were a bioflocculant dosage of 21 U/mL, pH 7.3 and a heating temperature of 100oC. The color and turbidity of the sugarcane juice reached IU 1267 and IU 206, respectively,after clarification with the bioflocculant; these values were almost the same as those acquired following treatment with polyacrylamide (PAM), the most widely applied flocculant in sugar industries. These results suggest the great potential for use of bioflocculants in the sugar refinery process. A bioflocculant produced by B. licheniformis was investigated with regard to a low-cost culture medium and its industrial application. Molasses replaced sucrose as the sole carbon source in bioflocculant fermentation. The optimum low-cost culture medium was determined to be composed of 20 g/L molasses, 0.4 g/L urea, 0.4 g/L NaCl,0.2 g/L KH2PO4, 1.6 g/L K2HPO4, and 0.2 g/L MgSO4. The bioflocculant from B. licheniformis was then applied to treat sugarcane-neutralizing juice to remove colloids,suspended particles, and coloring matters in a sugar refinery factory. The optimal operation conditions were a bioflocculant dosage of 21 U/mL, pH 7.3 and a heating temperature of 100oC. The color and turbidity of the sugarcane juice reached IU 1267 and IU 206, respectively,after clarification with the bioflocculant; these values were almost the same as those acquired following treatment with polyacrylamide (PAM), the most widely applied flocculant in sugar industries. These results suggest the great potential for use of bioflocculants in the sugar refinery process.

Maternal undernutrition alters the skeletal muscle development and methylation of myogenic factors in goat offspring

Zhou Xiaoling,Yan Qiongxian,Liu Liling,Chen Genyuan,Tang Shaoxun,He Zhixiong,Tan Zhiliang 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.6

Objective: The effects of maternal undernutrition during midgestation on muscle fiber histology, myosin heavy chain (MyHC) expression, methylation modification of myogenic factors, and the mammalian target of rapamycin (mTOR) signaling pathway in the skeletal muscles of prenatal and postnatal goats were examined. Methods: Twenty-four pregnant goats were assigned to a control (100% of the nutrients requirement, n = 12) or a restricted group (60% of the nutrients requirement, n = 12) between 45 and 100 days of gestation. Descendants were harvested at day 100 of gestation and at day 90 after birth to collect the femoris muscle tissue. Results: Maternal undernutrition increased (p<0.05) the fiber area of the vastus muscle in the fetuses and enhanced (p<0.01) the proportions of MyHCI and MyHCIIA fibers in offspring, while the proportion of MyHCIIX fibers was decreased (p<0.01). DNA methylation at the +530 cytosine-guanine dinucleotide (CpG) site of the myogenic factor 5 (MYF5) promoter in restricted fetuses was increased (p<0.05), but the methylation of the MYF5 gene at the +274,280 CpG site and of the myogenic differentiation (MYOD) gene at the +252 CpG site in restricted kids was reduced (p<0.05). mTOR protein signals were downregulated (p<0.05) in the restricted offspring. Conclusion: Maternal undernutrition altered the muscle fiber type in offspring, but its relationship with methylation in the promoter regions of myogenic genes needs to be elucidated. Objective: The effects of maternal undernutrition during midgestation on muscle fiber histology, myosin heavy chain (MyHC) expression, methylation modification of myogenic factors, and the mammalian target of rapamycin (mTOR) signaling pathway in the skeletal muscles of prenatal and postnatal goats were examined.Methods: Twenty-four pregnant goats were assigned to a control (100% of the nutrients requirement, n = 12) or a restricted group (60% of the nutrients requirement, n = 12) between 45 and 100 days of gestation. Descendants were harvested at day 100 of gestation and at day 90 after birth to collect the femoris muscle tissue.Results: Maternal undernutrition increased (p<0.05) the fiber area of the vastus muscle in the fetuses and enhanced (p<0.01) the proportions of MyHCI and MyHCIIA fibers in offspring, while the proportion of MyHCIIX fibers was decreased (p<0.01). DNA methylation at the +530 cytosine-guanine dinucleotide (CpG) site of the myogenic factor 5 (MYF5) promoter in restricted fetuses was increased (p<0.05), but the methylation of the MYF5 gene at the +274,280 CpG site and of the myogenic differentiation (MYOD) gene at the +252 CpG site in restricted kids was reduced (p<0.05). mTOR protein signals were downregulated (p<0.05) in the restricted offspring.Conclusion: Maternal undernutrition altered the muscle fiber type in offspring, but its relationship with methylation in the promoter regions of myogenic genes needs to be elucidated.

Understanding Residential Relocation Satisfaction and Intention in Guangzhou, China

Shenjing He,Xiaoling Zhang 한국주거학회 2015 한국주거학회 국제학술대회논문집 Vol.2015 No.4

Phenyl VOCs catalytic combustion on supported CoMn/AC oxide catalyst

Guilin Zhou,Xiaoling He,Sheng Liu,Hongmei Xie,Min Fu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Supported CoMn/AC composite oxide catalysts were prepared by a typical impregnation methodat different calcination temperatures. The prepared CoMn/AC catalysts were characterized, and thecatalytic activity of the prepared supported CoMn/AC oxide catalysts was also investigated by thecatalytic combustion of phenyl volatile organic compounds (VOCs) (benzene, toluene, andethylbenzene). XRD and XPS results indicated that MnCo2O4 and CoMn2O4 were the main crystalphase species in the prepared supported CoMn/AC oxide catalysts. The active components wereobserved to be highly dispersed and had small crystal sizes. The toluene catalytic combustion resultsdemonstrated that the CAT350 catalyst had higher toluene catalytic combustion activity than theCTA250, CAT300, and CAT400 catalysts. The toluene catalytic combustion conversion of the CAT350catalyst exceeded 93.5% at 235 8C, with a decreased toluene concentration in air of less than 130 ppm at250 8C. The order of toluene catalytic activity of the supported CoMn/AC oxide catalystswas as follows:CAT250 < CAT300 CAT400 < CAT350. The catalytic combustion activity and stability of the CAT350catalyst also increased with the increase in reaction temperature. The catalytic activity of the CAT350catalyst was investigated to bring about the complete oxidation of benzene, ethylbenzene, and toluene. The combustibility of phenyl VOCs on the CAT350 catalyst was observed to follow the orderbenzene < ethylbenzene < toluene. Therefore, the differences in the phenyl VOC catalytic combustionperformances of the supported CoMn/AC composite oxide catalysts can be attributed to the differentphysical chemistry properties of the phenyl VOC molecules and the catalyst.

Nitric Oxide Alleviates Deterioration and Preserves Antioxidant Properties in ‘Tainong’ Mango Fruit During Ripening

Yanfang Ren,Junyu He,Houyu Liu,Guoqing Liu,Xiaoling Ren 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.1

We investigated the effects of nitric oxide (NO) on quality, membrane lipid peroxidation, and antioxidantenzymes in mango (Mangifera indica L. cv ‘Tainong’) fruit during ripening. Fruits were treated with 0.25 mmol·L-1sodium nitroprusside (SNP) by the immersion method and stored at 23°C for 20 days. SNP treatment significantlysuppressed the respiration rate, enhanced fruit firmness, and decreased the rot index, peel color index, and weightloss in the fruit. This treatment also slowed the increase in soluble solids content (SSC) while maintaining highlevels of titratable acidity (TA), ascorbic acid (AsA), and phenolic compounds. Furthermore, SNP treatment enhancedthe antioxidant activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and reduced theactivities of lipoxygenase (LOX) and polyphenol oxidase (PPO) in mango fruit, which was associated with the reducedaccumulation of malondialdehyde (MDA), superoxide anion radical (O2•-), and hydrogen peroxide (H2O2) comparedwith the control. Therefore, the addition of exogenous SNP has the potential for improving quality and prolongingthe shelf life of mango fruits by protecting them against oxidative damage caused by ROS during ripening.

The impact of lymph node dissection on survival in patients with clinical early-stage ovarian cancer

Ting Deng,Qidan Huang,Ting Wan,Xiaoling Luo,Yanling Feng,He Huang,Jihong Liu 대한부인종양학회 2021 Journal of Gynecologic Oncology Vol.32 No.3

Objective: To estimate the impact of lymph node dissection on survival in patients withapparent early-stage epithelial ovarian cancer (EOC). Methods: We conducted a retrospective review of patients with clinical stage I–II EOC. Allpatients underwent primary surgery at Sun Yat-sen University Cancer Center between January2003 and December 2015. Demographic features and clinicopathological information as wellas perioperative adverse events were investigated, and survival analyses were performed. Results: A total of 400 ovarian cancer patients were enrolled, and patients were divided into2 groups: 81 patients did not undergo lymph node resection (group A), and 319 patientsunderwent lymph node dissection (group B). In group B, the median number of removednodes per patient was 25 (21 pelvic and 4 para-aortic nodes). In groups A and B, respectively,the 5-year progression-free survival (PFS) rates were 83.3% and 82.1% (p=0.305), and the5-year overall survival (OS) rates were 93.1% and 90.9% (p=0.645). The recurrence rate inthe retroperitoneal lymph nodes was not associated with lymph node dissection (p=0.121). The median operating time was markedly longer in group B than in group A (220 minutesvs. 155 minutes, p<0.001), and group B had a significantly higher incidence of lymph cysts atdischarge (32.9% vs. 0.0%, p<0.001). Conclusion: In patients with early-stage ovarian cancer, lymph node dissection was notassociated with a gain in OS or PFS and was associated with an increased incidence ofperioperative adverse events.