• Journal of Marine Bioscience and Biotechnology
• /
• v.1 no.4
• /
• pp.292-297
• /
• 2006

Lab-scale and pilot-scale productions of photosynthetic bacteria, that were able to efficiently treat wastewater from aquacultural farm, were experimented for their highly-pure culture. The results of experiments in a gas pack reactor, an anaerobic flask and a flask using $N_2$ gas as N-source showed that only photosynthetic bacteria formed red colonies on agar plate and their purity was over 90% in a colony, observed under a microscope. It was found that the basal medium could most promote the growth of photosynthetic bacteria, confirmed by experiments of serial cultures on various media. Under the culture conditions, the specific growth rate was found to be $0.18h^{-1}$ from the culture in 5L bioreactor and the same value could be obtained in pilot-scale production.

• Microbiology and Biotechnology Letters
• /
• v.32 no.3
• /
• pp.243-248
• /
• 2004

Production of (R)-3-hydroxybutyric acid (R3HB) by fed-batch culture and continuous culture of metabolically engineered Escherichia coli harboring Ralstonia eutropha PHB biosynthesis and depolymerase genes was examined in a 30 1 pilot-scale fermentor. A new stable two-plasmid system, pBRRed containing the R. eutropha PHB depolymerase gene and pMCS 105 containing the R. eutropha PHB biosynthesis genes, was developed. Among a variety of E. coli strains harboring plasmids, recombinant E. coli XL-10 Gold (pBRRed, pMCS105) was able to produce R3HB with the highest efficiency in a batch culture. By the fed-batch culture of recombinant E. coli XL-10 Gold(pBRRed, pMCS 105) in a 30 1 fer-mentor, the final R3HB concentration was 22.4 g/l giving a productivity of 0.97 g/l-h. To produce R3HB to a high concentration with high productivity, a new strategy of fed-batch culture followed by a continuous culture was investigated. The maximum productivity and R3HB concentration were 5.06 g/l-h and 25.3 g/l, respectively. These results show that economical production of R3HB is possible by recombinant E. coli in large scale.

• Microbiology and Biotechnology Letters
• /
• v.21 no.6
• /
• pp.609-614
• /
• 1993

The optimum conditions for the submerged mycelial culture of Lentinus edodes SR-1 were elucidated to be incubation temperature of 25C, initial pH 4.0, agitation of 300 rpm, inoculation of 10.0%(v/v), and aeration of 1.0 v/v/m in TGY medium. The optimum c/n ratio and economic yield coeffcient for the submerged mycelial culture were 13.1:1 and 0.45 respectively. As the plant growth hormones test, SCM medium containing 0.5ppm of 2,4-dicholorophenoxyacetic acid increased mycelial yield in 1.1%, but 6-benzylaminopurine was not effective.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.6
• /
• pp.371-374
• /
• 2002

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)［P(3HB/V)］, by fed-batch culture of recombinant Escherichia coli harboring a plasmid containing the Alcaligenes latus polyhy-droxyalkanoate (PHA) biosynthesis genes, was examined in two pilot-scale fermentors with air supply only, In a 30 L fermentor having a XLa value of 0.11 S­$^1$, the final P(3HB/V) concentration and the P(3HB/V) content obtained were 29.6 g/L and 70.1 wt%, respectively giving a productivity of 1.37 g P(3HB/V)/L-h. In a 300 L fermentor having a XLa of 0.03 S­$^1$, the P(3HB/V) concentration and the P(3HB/V) content were 20.4 g/L and 69 wt%, respectively giving a productivity of 1.06g P(3HB/V)/L-h. These results suggest that economical production of P(3HB/V) is possible by fed-batch culture of recombinant E. coli in a large-scale fermentor having low KLa value.

• KSBB Journal
• /
• v.30 no.6
• /
• pp.345-349
• /
• 2015

Antifreeze proteins (AFP) inhibit growth and recrystallization of ice, and permit organisms to survive in cold environments. The AFP from an Antarctic bacterium, Flavobacterium frigoris PS1, FfIBP (Flavobacterium frigoris icebinding protein), was produced in E. coli using a cold shock induction system. The culture temperature was shifted from $37^{\circ}C$ to $15^{\circ}C$ and a 20 L culture scale was used. The final weights of dried cell and FfIBP were estimated to be 126 g and 8.4 g, respectively. The thermal hysteresis (TH) activity ($1.53^{\circ}C$) of the produced FfIBP was 3.6-fold higher than that of the LeIBP (Leucosporidium ice-binding protein) produced in Picha. The current study demonstrates that large-scale production of FfIBP was successful and the result could be extended to further application studies using recombinant AFPs.

• Journal of Korean Academy of Nursing
• /
• v.43 no.3
• /
• pp.379-388
• /
• 2013

Purpose: The purpose of this study was to develop a tool to evaluate patient safety culture in nursing homes and to test its validity and reliability. Methods: A preliminary tool was developed through interviews with focus group, content validity tests, and a pilot study. A nationwide survey was conducted from February to April, 2011, using self-report questionnaires. Participants were 982 employees in nursing homes. Data were analyzed using Cronbach's alpha, item analysis, factor analysis, and multitrait/multi-Item analysis. Results: From the results of the analysis, 27 final items were selected from 49 items on the preliminary tool. Items with low correlation with total scale were excluded. The 4 factors sorted by factor analysis contributed 63.4% of the variance in the total scale. The factors were labeled as leadership, organizational system, working attitude, management practice. Cronbach's alpha for internal consistency was .95 and the range for the 4 factors was from .86 to .93. Conclusion: The results of this study indicate that the Korean Patient Safety Culture Scale has reliability and validity and is suitable for evaluation of patient safety culture in Korean nursing homes.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.3
• /
• pp.609-614
• /
• 2010

The effluent from anaerobic digestion contains organic nitrogen and phosphorus, which are both required for growth of Spirulina platensis. Effluent (20%) from the upflow anaerobic sludge blanket (UASB) from a pig farm, supplemented with 4.5 g/l sodium bicarbonate ($NaHCO_3$) and 0.2 g/l urea fertilizer (46:0:0, N:P:K), was found to be not only a suitable medium for the growth of Spirulina platensis but also a low-cost alternative. Cost calculation showed that this medium is 4.4 times cheaper than modifized Zarrouk's medium. The average productivities of a semi-continuous culture grown under outdoor conditions in a 6-1 scale and a 100-1 pilot scale were 19.9 $g/m^2/d$ and 12 $g/m^2/d$, respectively. In addition, the biomass of organisms grown in UASB effluent contained approximately 57.9% protein, 1.12% $\gamma$-linolenic acid, and 19.5% phycocyanin. The average rates of bicarbonate, total nitrogen, and phosphorus removal were 380 mg/l/d, 34 mg/l/d, and 4 mg/l/d, respectively.

• International Journal of Advanced Culture Technology
• /
• v.3 no.2
• /
• pp.100-109
• /
• 2015

Environmental problems from petroleum-based plastic wastes have been rapidly increasing in recent years. The alternative solution is focus on the development of environmental friendly plastic derived from renewable resource. Poly(lactic acid) (PLA) is a biodegradable polymer synthesized from biomass having potential to replace the petroleum-based non-degradable polymers utilizations. PLA can be synthesized by two methods: (1) ring-opening of lactide intermediate and (2) direct polycondensation of lactic acid processes. The latter process has advantages on high yields and high purity of polymer products, materials handling and ease of process treatments. The polymerization process of PLA synthesis has been widely studied in a laboratory scale. However, the mass scale production using direct polycondensation of lactic acid has not been reported. We have investigated the kinetics and scale-up process of direct polycondensation method to produce PLA in a pilot scale. The order of reaction is 2 and activation energy of lactic acid to lactic acid oligomers is 61.58 kJ/mol. The pre-polymer was further polymerized in a solid state polymerization (SSP) process. The synthesized PLA from both the laboratory and pilot scales show the comparable properties such as melting temperature and molecular weight. The appearance of synthesized PLA is yellow-white solid powder.

• Journal of Korean Academy of Nursing
• /
• v.49 no.5
• /
• pp.613-630
• /
• 2019

Purpose: This study aimed to develop a scale measuring the Patient-Centered Nursing Culture (PCNC) and provide a basic tool to improve PCNC in Korea. Methods: A conceptual framework and construct factors were extracted through extensive literature review and in-depth interviews with nursing professionals. In total, 59 items were derived based on the pilot survey. Data were collected from 357 nurses working at general hospitals and analyzed for verifying the reliability and validity of the scale. Results: Nine factors containing 54 items were extracted from the exploratory factor analysis to verify the construct validity. The nine factors were top management leadership, policy and procedure, education and training, middle management leadership, supportive teamwork, nursing workplace environment, professional competence, patient-centered nursing activity, and nurses' values. These items were verified by convergent, discriminant, and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach's ${\alpha}=.96$). Conclusion: The developed PCNC scale is expected to be used as the tool for the development of theory and improvement of PCNC, the empirical testing for cause and effect of PCNC, the development of interventions, education and training programs for improving PCNC, and indicators for evaluation or accreditation of hospital service quality.

• KSBB Journal
• /
• v.22 no.2
• /
• pp.91-96
• /
• 2007

The saccharogenic liquid (SFW) obtained by the enzymatic saccharification of food wastes was used as a medium for production of bacterial cellulose (BC). The enzymatic saccharification of food wastes was carried out by the cultivation supernatant of Tricoderma inhamatum KSJ1 culture. Acetobacter xylinum KJ1 was employed for the BC production culture. Under the scaled-up aeration condition of 1.0 vvm, 5.64 g/L of BC was produced in 3 days cultivation in 50 L air circulation bioreactor using SFW medium with addition of 0.4% agar. The productivity was similar to that of 10 L air circulation bioreactor (5.84 g/L). This cultivation method with 50 L air circulation bioreactor decreasing shear stress and increasing oxygen transfer coefficient ($k_La$) was very useful in BC mass production. The physical properties, such as morphology, molecular weight, crystallinity, and tensile strength of BC produced by the static culture (A), the air circulation culture using 10 L bioreactor (B) and 50 L bioreactor (C) were investigated. The number average molecular weight of BCs produced under the different culture conditions (A-C) showed 2,578,000, 1,975,000, and 1,809,000, respectively. Tensile strength was 1.72 $kg/mm^2$, 1.19 $kg/mm^2$, and 1.18 $kg/mm^2$, respectively. All of the BCs had a form of cellulose I representing pure cellulose. The relative degree of crystallinity showed the range of 86.2$\sim$87.8%. BC production by the air circulation culture mode brought more favorable results in terms of the physical properties and its ease of scale-up. Therefore, it is expected that the new BC production method, the air circulation culture using SFW, would contribute greatly to BC-related manufacturing.