서지주요정보
Bacillus thuringiensis 의 세포성장과 포자 형성에 관한 연구 = Cell groeth and sporulation of bacillus thuringiensis
서명 / 저자 Bacillus thuringiensis 의 세포성장과 포자 형성에 관한 연구 = Cell groeth and sporulation of bacillus thuringiensis / 강병철.
저자명 강병철 ; Kang, Byung-Chul
발행사항 [대전 : 한국과학기술원, 1992].
Online Access 제한공개(로그인 후 원문보기 가능)원문

소장정보

등록번호

8003149

소장위치/청구기호

학술문화관(문화관) 보존서고

DCE 92030

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

초록정보

The cell growth and sporulation of Bacillus thuringiensis var. kurstaki were investigated under various culture modes: batch culture, fed-batch culture, total cell retention culture (TCRC) and two-stage continuous culture. In latter two culture modes, TCRC and two-stage continuous culture, an internal ceramic filter was used to improve spore concentration and volumetric productivities. In batch culture, culture media based on semidefined GYS medium were optimized to increase cell mass and spore concentration. Acetic acid produced from glucose during exponential growth was further catabolized in the early stationary phase of growth. As concentration of glucose was increased from 1 to 16 g/L, pH was sharply decreased and poor sporulation occurred. When 8 g/L of yeast extract was added, $6.6\times10^8$ of spore was obtained and pH drop was prevented. Spore concentration measured at the time when complete sporulation had occurred linearly increased from $1.1\times10^9$ to $7.6\times10^9$ spores/mL as the concentration of glucose was increased form 10 to 50 g/L. However, further increase of concentration of glucose strongly inhibited cell growth and sporulation. Fed-batch culture was carried out for increasing the production of spore of B. thuringiensis. Constant fed-batch culture (CFBC) and intermittent fed-batch culture (IFBC) were employed in this study. In CFBC, the production of spore decreased with an increase of the feeding glucose concentration. In IFBC, during which fast growth rate was maintained, spore concentration of $1.25\times10^{10}$ spores/mL was obtained with maximum cell mass of 72.6 g/L, and was about three times higher than that of constant fed-batch culture when total glucose concentration of 100 g/L was consumed. It was found that the maintenance of fast growth rate was important in order to obtain the high concentration and volumetric productivity of spore and IFBC was more suitable than CFBC from the viewpoint of the higher spore concentration. The production of spore of B. thuringiensis was investigated in a bioreactor incorporating a ceramic membrane filter to improve spore concentration and volumetric productivity. Two cultivation methods were used in this study: a total cell retention culture (TCRC) and a two-stage continuous culture with partial cell bleeding. In the TCRC fed by 50 g/L of glucose a spore concentration of $1.6\times10^{10}$ CFU/mL was obtained with a spore percentage greater than 95% and a maximum cell mass of 82.2 g/L. The volumetric productivity was four times higher than for batch cultivation. In the two-stage continuous culture with partial cell bleeding spore concentration was strongly dependent on the bleed ratio. The spore concentration of $1.8\times10^9$ CFU/mL was obtained at the second stage with a bleed ratio of 0.33, a dilution rate of 0.23 $h^{-1}$ and a spore percentage of 70%. Growth and sporulation kinetics of B. thuringiensis in batch and fed-batch culture are mathematically modelled and the model was compared with experiments. The processes of growth and sporulation have been assumed to compete with each other in the vegetative organism. In batch culture, the conventional unstructured model based on Monod kinetics was in good agreement with the experiment because the formation of sporulated cells did not appear during exponential growth. In glucose-limited fed batch culture the modified unstructured model presented can be applicable to the case of the feeding of low glucose concentration, while the conventional unstructured model describes the behavior of the system fairly well in the case of the feeding of high glucose concentration.

서지기타정보

서지기타정보
청구기호 {DCE 92030
형태사항 xii, 168 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Byung-Chul Kang
지도교수의 한글표기 : 장호남
지도교수의 영문표기 : Ho-Nam Chang
학위논문 학위논문(박사) - 한국과학기술원 : 화학공학과,
서지주기 참고문헌 : p. 156-168
주제 Ceramics.
cell culture.
Bacillus thuringiensis.
세라믹. --과학기술용어시소러스
세포 배양. --과학기술용어시소러스
Bacteria, Sporeforming.
QR CODE qr code