Purification and characterization of microbial protease produced extracellularly from Bacillus subtilis FBL-1

An ammonium sulfate precipitation of fermentation broth produced by Bacillus subtilis FBL-1 resulted in 2.9-fold increase of specific protease activity. An eluted protein fraction from the column chromatographies using DEAE-Cellulose and Sephadex G-75 had 94.2- and 94.9-fold higher specific protease activity, respectively. An SDS-PAGE revealed a band of purified protease at approximately 37.6 kDa. Although purified protease showed the highest activity at 45°C and pH 9.0, the activity remained stable in temperature range from 30 to 50°C and pH range from 7.0 to 9.0. Protease activity was activated by metal ions such as Ca2+, Mg2+, Mn2+, Fe2+, Ca2+ and K+, but 10 mM Fe3+ significantly inhibited enzyme activity (53%). Protease activity was inhibited by 2 mM EDTA as a metalloprotease inhibitor, but it showed good stability against surfactants and organic solvents. The preferred substrates for protease activity were found to be casein (100%) and soybean flour (71.6%)

Biotechnological Production of Lactic Acid and Its Recent Applications

Mliječna se kiselina upotrebljava u prehrambenoj, kozmetičkoj, farmaceutskoj i kemijskoj industriji te sve više i kao monomer za proizvodnju biorazgradljive (poli)mliječne kiseline. Mliječna se kiselina može proizvesti biotehnološkim procesom ili kemijskom sintezom. U novije se vrijeme sve više koristi biotehnološki postupak zbog zaštite okoliša i ograničene količine petrokemijskih izvora. Na različite načine pokušala se proizvesti mliječna kiselina iz jeftinih sirovina. U ovom su radu prikazani mikroorganizmi i sirovine za proizvodnju mliječne kiseline, njezina biotehnološka proizvodnja te načini primjene, a osobito najnovija istraživanja. Također se raspravlja o mogućnosti i ekonomskoj važnosti primjene mliječne kiseline u budućnosti.Lactic acid is widely used in the food, cosmetic, pharmaceutical, and chemical industries and has received increased attention for use as a monomer for the production of biodegradable poly(lactic acid). It can be produced by either biotechnological fermentation or chemical synthesis, but the former route has received considerable interest recently, due to environmental concerns and the limited nature of petrochemical feedstocks. There have been various attempts to produce lactic acid efficiently from inexpensive raw materials. We present a review of lactic acid-producing microorganisms, raw materials for lactic acid production, fermentation approaches for lactic acid production, and various applications of lactic acid, with a particular focus on recent investigations. In addition, the future potentials and economic impacts of lactic acid are discussed

Pilot-Scale Lactic Acid Production via Batch Culturing of Lactobacillus sp. RKY2 Using Corn Steep Liquor As a Nitrogen Source

U ovom se istraživanju pokušala odrediti učinkovitost proizvodnje mliječne kiseline uzgojem soja Lactobacillus sp. RKY2 u pilot-postrojenju uporabom kukuruznog ekstrakta kao izvora dušika. Količina mliječne kiseline nakon fermentacije, rast stanica, prinos i produktivnost nisu se bitno promijenili dodatkom čiste glukoze pri povećanju obujma procesa s 2,5 na 30 i 300 L. U svim pokusima udio mliječne kiseline linearno se povećavao s porastom početne koncentracije glukoze. U pokusu s hidrolizatom drva smanjili su se produktivnost mliječne kiseline i rast stanica s povećanjem obujma procesne opreme, zbog toksičnih kemikalija iz hidrolizata. Međutim, u svim je pokusima prinos mliječne kiseline bio veci od 90 % bez obzira na utrošak glukoze. Zaključeno je da je mliječna kiselina uspješno proizvedena u pilot-postrojenju upotrijebljenom u ovom istraživanju.In this study, the determination of the efficiency of a pilot-scale fermentation process using corn steep liquor as a nitrogen source was attempted in order to produce lactic acid via batch culturing of Lactobacillus sp. RKY2. Using pure glucose, fermentation efficiency characteristics, such as final lactic acid, cell growth, yield, and productivity were not substantially influenced by the scale-up of the laboratory-scale fermentation from 2.5- to 30- and 300-litre scale fermentations. In all experiments, the content of lactic acid produced increased in a linear fashion with increases in the initial glucose concentration. In the experiments using wood hydrolyzate, both lactic acid productivity and cell growth were decreased as a result of the scaling-up of the fermentation. This might be attributed to the toxic chemicals contained in the wood hydrolyzates. However, in all experiments, lactic acid yields remained higher than 90 % with regard to the amount of glucose consumed. Therefore, lactic acid was successfully produced by the pilot-scale bioreactor scheme adopted in this study

Pilot-Scale Lactic Acid Production via Batch Culturing of Lactobacillus sp. RKY2 Using Corn Steep Liquor As a Nitrogen Source

U ovom se istraživanju pokušala odrediti učinkovitost proizvodnje mliječne kiseline uzgojem soja Lactobacillus sp. RKY2 u pilot-postrojenju uporabom kukuruznog ekstrakta kao izvora dušika. Količina mliječne kiseline nakon fermentacije, rast stanica, prinos i produktivnost nisu se bitno promijenili dodatkom čiste glukoze pri povećanju obujma procesa s 2,5 na 30 i 300 L. U svim pokusima udio mliječne kiseline linearno se povećavao s porastom početne koncentracije glukoze. U pokusu s hidrolizatom drva smanjili su se produktivnost mliječne kiseline i rast stanica s povećanjem obujma procesne opreme, zbog toksičnih kemikalija iz hidrolizata. Međutim, u svim je pokusima prinos mliječne kiseline bio veci od 90 % bez obzira na utrošak glukoze. Zaključeno je da je mliječna kiselina uspješno proizvedena u pilot-postrojenju upotrijebljenom u ovom istraživanju.In this study, the determination of the efficiency of a pilot-scale fermentation process using corn steep liquor as a nitrogen source was attempted in order to produce lactic acid via batch culturing of Lactobacillus sp. RKY2. Using pure glucose, fermentation efficiency characteristics, such as final lactic acid, cell growth, yield, and productivity were not substantially influenced by the scale-up of the laboratory-scale fermentation from 2.5- to 30- and 300-litre scale fermentations. In all experiments, the content of lactic acid produced increased in a linear fashion with increases in the initial glucose concentration. In the experiments using wood hydrolyzate, both lactic acid productivity and cell growth were decreased as a result of the scaling-up of the fermentation. This might be attributed to the toxic chemicals contained in the wood hydrolyzates. However, in all experiments, lactic acid yields remained higher than 90 % with regard to the amount of glucose consumed. Therefore, lactic acid was successfully produced by the pilot-scale bioreactor scheme adopted in this study

Burden and future projection of revision Total hip Arthroplasty in South Korea

Background The annual number of hip arthroplasties is increasing combined with the aging population worldwide. In accordance with the increasing number of primary hip arthroplasties, the number of revision total hip arthroplasties (THAs) is expected to increase. The incidence and burden of revision THAs in the United States and have been reported by registry studies. To identify potential differences according to ethnics and regional practice, it is important to obtain data from East Asia. Nevertheless, there has been a lack of studies on the burden and future projection of revision THA based on a large-scale database in East Asia. The purpose of this study was to evaluate annual incidence and burden of revision THAs and to project the future burden in South Korea. Methods We identified primary THAs, primary hemiarthroplasties (HAs) and revision THAs, which were performed from 2010 to 2018, using database of Health Insurance and Review and Assessment (HIRA); nation-wide medical claim system of South Korea. The annual incidence rates (per 100,000) of primary THA, primary HA and revision THA, and the annual burden of revision THA; the number of revision THAs divided by the sum of primary hip arthroplasties and revision THAs, were calculated. The future burden of revision THAs were projected through 2030 using generalized linear model with Quasi-poisson regression. Results During the 9-year period, the annual incidences of primary THA, primary HA and revision THA increased by 47, 29 and 3%, respectively, while the revision burden decreased from 0.13 to 0.10. Compared to 2018, the annual incidences of primary THA, HA, and revision THA were projected to increase by 7.2, 2.3 and 1.1% per year, respectively, whereas the burden of revision THA was projected to decrease to 0.07 in 2030. Conclusion Trends of revision THA in South Korea were similar with those of national registry studies from the United States. The annual incidence of revision THA has steadily increased, whereas its burden has decreased. Findings of our study could be used for epidemiological comparison between Western countries and East Asia as well as for the establishment of medical policies of revision THA in East Asian countries.This study was funded by a grant of the Korea Health Technology R&D funded by the Ministry of Health & Welfare, Republic of Korea [grant number: HI18C0284]. The role of the funding by grant was in the access to and the analysis of the database

Reference values for respiratory system impedance using impulse oscillometry in healthy preschool children

PurposeThe normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children.MethodsA total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses.ResultsThe IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009×Height, R2=12.1%; Xrs5=0.774+0.006×Height-0.002×Age, R2=20.2% and for girls (Rrs5=2.201-0.012×Height, R2=18.2%; Xrs5=-0.674+0.004×Height, R2=10.5%).ConclusionThis study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases

Enzymatic synthesis of chlorogenic acid glucoside using dextransucrase and its physical and functional properties

Chlorogenic acid, a major polyphenol in edible plants, possesses strong antioxidant activity, anti-lipid peroxidation and anticancer effects. It used for industrial applications; however, this is limited by its instability to heat or light. In this study, we, for the first time synthesized chlorogenic acid glucoside (CHG) via transglycosylation using dextransucrase from Leuconostoc mesenteroides and sucrose. CHG was purified and its structure determined by nuclear magnetic resonance and matrix-associated laser desorption ionization–time-of-flight mass spectroscopy. The production yield of CHG was 44.0% or 141 mM, as determined by response surface methodology. CHG possessed a 65% increase in water solubility and a 2-fold browning resistance and it displayed stronger inhibition of lipid peroxidation and of colon cancer cell growth by MTT assay, compared to chlorogenic acid. Therefore, this study may expand the industrial applications of chlorogenic acid as water-soluble or browning resistant compound (CHG) through enzymatic glycosylation

Risk factors for subsequent vertebral fractures following a previous hip fracture

Introduction The purpose of our study was to evaluate the incidence and to identify risk factors of subsequent vertebral fractures after hip fractures, and to determine whether the subsequent vertebral fracture increases the mortality rate of elderly hip fracture patients. Materials and methods From January 2009 to July 2016, 1,554 patients were diagnosed as having a hip fracture and were treated surgically at our institution. Among them, 1121 patients age > 50 years at the time of injury and were followed up for 1 year or longer after the hip fracture surgery. In these patients, radiographs of the hip and spine were taken at each follow-up. We reviewed medical records and radiographs of these patients. Among the 1121 patients, 107 patients (9.5%) had subsequent vertebral fractures after the hip fracture during entire follow-up periods. Results In multivariable analysis, previous history of vertebral fracture [odds ratio (OR), 2.62;p < 0.001], medication possession rate (MPR) of osteoporosis treatment < 80% (OR, 1.92;p = 0.014), and a lower lumbar bone mineral density (BMD) (OR, 2.58;p = 0.001) appeared as risk factors for subsequent vertebral fractures. Conclusion However, the subsequent vertebral fractures did not affect the mortality after the hip fractures. Age >= 70 years [hazard ration (HR) 2.70;p = .039], body mass index < 18.5 kg/m(2)(HR, 2.57;p =0 .048), and Charlson comorbidity index >= 2 (HR, 2.04;p =0.036) were risk factors of the death. Timely management is warranted to prevent subsequent vertebral fractures in hip fracture patients with risk factors.N

A Case of Successful Selective Abortion Using Radio-frequency Ablation in Twin Pregnancy Suffering from Severe Twin to Twin Transfusion Syndrome

Twin to twin transfusion syndrome (TTTS) is one of the major complication of monochorionic twin pregnancy which is mainly understood by placental vascular anastomosis. Perinatal mortality and morbidity is high as 80-100% if untreated and even higher if the disease is developed at early stage. Variety of methods of isolating or intercepting placental vascular anastomosis are introduced, but they are only available in centers where all the required equipments are prepared. We report here a case of TTTS complicated with severe polyhydroamnios during the second trimester. The blood supply to donor twin was interrupted successfully at 19+2 weeks of gestation by minimally invasive radio-frequency cord ablation, under ultrasound guidance. The normal recipient twin was delivered successfully at 35 weeks of gestation and had no eventful neonatal course