• Title/Summary/Keyword: continuous culture

Search Result 968, Processing Time 0.04 seconds

The Impact of Shared Leadership on Organizational Commitment and Career Development in Startups

  • Chanuk Park;Sin-Bok Lee
    • International Journal of Advanced Culture Technology
    • /
    • v.12 no.1
    • /
    • pp.60-74
    • /
    • 2024
  • Due to the relative lack of concerns and research on organizational career development in startups, we study aimed to reveal the impact of shared leadership in startups on organizational career development through organizational commitment. The research method was an online survey targeting 200 startup members from April 11 to April 28, 2023, and a total of 195 copies were used in the final analysis. As a result of the study, first, among the shared leadership of startups, development and mentoring were found to have a positive impact on emotional commitment. Second, among the shared leadership of startups, planning and organizing, support and empathy were found to have a positive impact on continuous commitment. Third, planning and organizing, support and empathy had a positive impact on normative commitment. Third, among startups' shared leadership, planning and organizing, support and empthy had a positive impact on normative commitment. Fourth, emotional and continuous commitment were found to have a positive impact on improving career goals in organizational career growth. Fifth, emotional and continuous and normative commitment were each found to have a positive influence on the development of professional abilities in organizational career development. Lastly, emotional, continuous and normative commitment were all found to have a positive influence on the speed of promotion in organizational career growth. As a result, it is expected that the results of this study will be able to suggest shared leadership policy directions and goals for startups.

Insertional mutations exhibiting high cell-culture density HCD phenotypes are enriched through continuous subcultures in Chlamydomonas reinhardtii

  • Thung, Leena;He, Jing;Zhu, Qingling;Xu, Zhenyu;Liu, Jianhua;Chow, Yvonne
    • ALGAE
    • /
    • v.33 no.1
    • /
    • pp.127-141
    • /
    • 2018
  • Low efficiency in microalgal biomass production was largely attributed to the low density of algal cell cultures. Though mutations that reduced the level of chlorophyll or pigment content increased efficiency of photon usage and thus the cell-culture density under high-illumination growth conditions (e.g., >$500{\mu}mol\;photon\;m^{-2}\;s^{-1}$), it was unclear whether algae could increase cell-culture density under low-illumination conditions (e.g., ${\sim}50{\mu}mol\;photon\;m^{-2}\;s^{-1}$). To address this question, we performed forward genetic screening in Chlamydomonas reinhardtii. A pool of >1,000 insertional mutants was constructed and subjected to continuous subcultures in shaking flasks under low-illumination conditions. Complexity of restriction fragment length polymorphism (RFLP) pattern in cultures indicated the degree of heterogeneity of mutant populations. We showed that the levels of RFLP complexity decreased when cycles of subculture increased, suggesting that cultures were gradually populated by high cell-culture density (HCD) strains. Analysis of the 3 isolated HCD mutants after 30 cycles of subcultures confirmed that their maximal biomass production was 50-100% higher than that of wild type under low-illumination. Furthermore, levels of chlorophyll content in HCD mutant strains were similar to that of wild type. Inverse polymerase chain reaction analysis identified the locus of insertion in two of three HCD strains. Molecular and transcriptomic analyses suggested that two HCD mutants were a result of the gain-of-function phenotype, both linking to the abnormality of mitochondrial functions. Taken together, our results demonstrate that HCD strains can be obtained through continuous subcultures under low illumination conditions.

Development of Continuous Clean Bioprocess for Kasugamycin Production (Kasugamycin 생산을 위한 연속 청정생물공정 개발)

  • Kim, Chang Joon;Park, Sun Ok;Chang, Yong Keun;Chun, Gie-Taek;Lee, Jong-Dae;Kim, Sangyong
    • Clean Technology
    • /
    • v.4 no.1
    • /
    • pp.45-59
    • /
    • 1998
  • Continuous immobilized-cell culture was carried out for the production of kasugamycin, a secondary metabolite by a filamentous bacteria, Streptomyces kasugaensis, with an intention of reducing waste generation. A sporulation medium was developed for production of bulk amounts of spores, and the spores were entrapped into celite biosupports for immobilization. It was possible to effectively keep the immobilized-cells inside the reactor during the continuous culture by an efficient immobilized cell separator of decantor type on the outlet of the fermentor. Using this continuous immobilized-cell fermentor system, we investigated the effects of feed substrate and phosphate concentrations on kasugamycin production and chemical oxygen demand(COD). Comparing with the conventional suspended-cell batch culture, the kasugamycin productivity was observed to increase by 2.5 times, whereas COD per unit kasugamycin production decreased by 2.3 times in the continuous immobilized-cell culture. Based on these results, the continuous immobilized-cell system was considered to be a cleaner bioprocess than the conventional batch suspended-cell system.

  • PDF

Gellan-type Microbial Polysaccharide Production in Continuous Fermentation (Gellan형 미생물 다당류의 연속생산)

  • 정봉우;이은미장광엽김춘영
    • KSBB Journal
    • /
    • v.9 no.1
    • /
    • pp.85-90
    • /
    • 1994
  • The Gellan-type polysaccharide produced by Pseudomonas elodea(ATCC 31461) is one of the new heteropolysaccharides, having useful properties as gelling, suspending, stabilizing, emulsifying and binding agents in aqueous systems. Medium compositions for growth stage and production stage are improved. The problems of low cell concentration and poor productivity in highly viscous fermentation were attributed to inadequate mixing accompanied by insufficient oxygen transfer. During continuous culture, cell growth and polysaccharide production were greatly affected by the apparent viscosity, and they showed oscillation behavior, i.e. as the product concentration increases, cell concentration decreases. With improved culture conditions, the productivity of continuous culture increased up to 0.6g/$\ell$/hr(6-fold that of batch culture ) at dilution rate, D=$0.14hr^{-1}$.

  • PDF

Biopolyrner Production of Zoogloea ramigera in Batch, Fed-Batch and Continuous Culture Processes (Zoogloea ramigera의 회분식, 유가배양, 연속배양에 의한 생물고분자 생산)

  • 안대희;정윤철
    • Microbiology and Biotechnology Letters
    • /
    • v.20 no.2
    • /
    • pp.196-202
    • /
    • 1992
  • Zoogloea ramigera 115 was selected for the production of viscous microbial polysaccharide for bioflocculants usage. Batch, fed-batch, and continuous culture processes were examined with regard to the high biopolymer production. Several carbon sources were tested, including glucose, lactose, molasses, and cheese whey. The C/N ratio of 90 was most effective for biopolymer production from glucose, while the C/N ratios of 30 for lactose and 60 for both molasses and cheese whey substrate gave a maximum production. Fed batch culture proved more effective to increase final biopolymer concentration than batch culture. Continuous fermentation with two stages modifying C/N ratio increased the productivity. The production rates were a maximum at dilution rate of 0.048 $hr^{-1}$ for molasses and at 0.096 $hr^{-1}$for cheese whey.

  • PDF

A study on the Relationship between Leadership and Agile Culture: focusing on the mediating effect of Perceived Organizational Support(POS) (리더십과 애자일 문화간의 관계에 관한 연구: 조직지원인식의 매개 효과를 중심으로)

  • Kim, Tae-Wan;You, Yen-Yoo;Hong, Jung-Wan
    • Journal of Convergence for Information Technology
    • /
    • v.11 no.6
    • /
    • pp.226-242
    • /
    • 2021
  • The purpose of this study was to examine the characteristics of Agile Culture, which is attracting attention as an organizational culture suitable for responding to changes in the recent corporate management environment, and to reveal the roles and relationships of leadership, Perceived Organizational Support(POS), and Agile Culture. The research was conducted on the employees of the National Agricultural Cooperative Federation and its subsidiaries, and SmartPLS 3.3.2 was mainly used for the research model test. As a result of the study, both Servant Leadership and Authentic Leadership had a positive effect on POS, and POS had a significant effect on all sub-dimensions of Agile Culture(Empowerment, Collective Intelligence and Continuous Learning). In addition, POS mediated the effects of the above two leaderships on Collective Intelligence and Empowerment, but there was no mediating effect in the relationship with Continuous Learning. These results suggest that leadership and Employees' perceptions of organizational support are important to build an Agile Culture.

Adaptive On-line Optimization of Cellular Productivity of Continuous Methylotroph Culture (메타놀자화균의 연속배양에 의한 균체생산의 온-라인 적응최적화)

  • 이형춘;박정오
    • The Korean Journal of Food And Nutrition
    • /
    • v.1 no.2
    • /
    • pp.31-36
    • /
    • 1988
  • An adaptive on-line optimization method has been applied to test the ability to maximize the cellular productivity of a continuous methylotroph culture system which was simulated by a variable yield Monod-type model. Optimum dilution rate and productivity were successively obtained and maintained at all times by the algorithm that utilizes steepest descent technique as optimization method and recursive least-square method with forgetting factor as dynamic model identification.

  • PDF

Production of Lactococcal Bacteriocin using Repeated-Batch and Continuous Cultures

  • Yoo, Jin-Young
    • Journal of Microbiology and Biotechnology
    • /
    • v.2 no.4
    • /
    • pp.284-287
    • /
    • 1992
  • Repeated-batch and continuous cultures of Lactococcus sp. 1112-1 were carried out for bacteriocin production using a glucose-casein medium. Repeated-batch culture did not efficiently enhanced the bacteriocin production. Continuous production was possible at the dilution rate of 0.4 $h^{-1}$. Maximum specific production rate ($Q^p$), bacteriocin production and biomass at the dilution rate were 347, 136 IU/g/h, 2, 121 IU/ml and 2.45 g/L, respectively.

  • PDF

Evaluation of L-Lactic Acid Production in Batch, Fed-batch, and Continuous Cultures of Rhizopus sp. MK-96-1196 Using an Airlift Bioreactor

  • Liu, Tiejun;Miura, Shigenobu;Arimura, Tomohiro;Tei, Min-Yi;Park, Enoch Y.;Okabe, Mitsuyasu
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.10 no.6
    • /
    • pp.522-527
    • /
    • 2005
  • Various processes which produce L-lactic acid using ammonia-tolerant mutant strain, Rhizopus sp. MK-96-1196, in a 3L airlift bioreactor were evaluated. When the fed-batch culture was carried out by keeping the glucose concentration at 30g/L, more than 140 g/L of L-lactic acid was produced with a product yield of 83%. In the case of the batch culture with 200g/L of initial glucose concentration, 121g/L of L-lactic acid was obtained but the low product yield based on the amount of glucose consumed. In the case of a continuous culture, 1.5g/L/h of the volumetric productivity with a product yield of 71% was achieved at dilution rate of $0.024\;h^{-1}$. Basis on these results three processes were evaluated by simple variable cost estimation including carbon source, steam, and waste treatment costs. The total variable costs of the fed-batch and continuous cultures were 88% and 140%, respectively, compared to that of batch culture. The fed-batch culture with high L-lactic acid concentration and high product yield decreased variable costs, and was the best-suited for the industrial production of L-lactic acid.