독소원성 대장균(EC81, O148:H28)이 생산하는 이열성 장독소와 독소원성 C. perfringens A형(NCTC8238, Hobbs serotype 2)이 생산하는 장독소에 대하여 PCR기법의 감도를 검색한 결과, 독소원성 대장균은 100 ng/ul로부터 1pg 희석용액에서까지 417-bp의 LT DNA fragment가 확인되었으며 독소원성 C. perfringens A형은 100 ng/ul로부터 10 pg 희석용액에서까지 364-bp의 장독소 DNA fragment가 확인되어, 독소원성 대장균이 독소원성 C. perfringens A형보다 10배의 높은 감도를 나타내었다.

The studies were carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular cocytes and to determine the optimum thawing temperature and equilibration time on in vitro developmental rate of frozen bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TGM-199 medium containing 10 IU /ml의 PM SG, 10 IU /ml의 hCG, ip g/ml의 -estradiol and 10% FCS for 24~48 hrs in incubator with 5% in air at 38.5. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquld nitrogen and thawed in 3 water. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are sunanarized as followes :1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM499 medium were 75.0~76.8% and 17.3~27.6%, respect-ively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%)were significantly(p<0.05) higher than cumulus-denuded oocytes (23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with l l04cells /ml, 1 x l06cells /ml, lx l08cells /ml and 1 x l015cells /ml oviduct epithelial cells in TCM-199 medium were 74.5~77.8% and 15.7~21.20 respectively.3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes cocultured in '1CM-199 media containing PMSG, hCG, PMSG+hCG. PMSG+-estradiol, hCG+-estradiol 0 to 40 hrs after insemination were 74.0~77.4% and l8.9~23.l%, re-spectiv ely.4.The survival rates of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol,DMSO and propanediol were 23.5~31.4% and 20.6~34.l%, respectively. 5. The temperature thawed at 3 after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 2 and 35.6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20min.). (Key words : bovine embryos, co-culture, freezing, in vitro development)

호기성 미생물의 배양중 산소전달 및 소비를 계량적으로 표현하는 방법을 고찰하였다. 용존산소가 미생물에 이르기까지의 과정을 5단계로 모델화하였으며 이들 단계중 특히 film resistance에 대해 고찰하였다. 일단 균체에 전달된 산소는 균체의 표면에 형성된 film resistance를 통해 균에 이른다. 균이 pellet을 형성하였을 때 균사체내에서의 diffusion rate와 diffusion되면서 일어나는 산소의 소비속도와의 관계를 Lumped model 및 Distributed model을 도입하여 설명하였고, 계량화 하였다.

본 연구는 김치에서 분리되어 Leu. mesenteroides subsp. mesenteroides, Leu. mesenteroides subsp. dextranicum, Leu. lactis, Leu. paramesenleroides, Lac. bavaricus 및 Lac. homohiochii로 동정된 대표적인 저온성 젖산균 10균주에 대하여 발효과정에서의 동태와 역할을 예측하기 위하여 수행되었다. 이를 위하여 소금 2.5%를 함유하는 무균 배추즙에 각 젖산균의 starter를 0.01%를 접종하고 10℃에서 14일간 배양하였다. 모든 젖산균들은 왕성하게 증식하여 배양 4일에 정상기에 도달하였다. 사멸기에서 곡선의 기울기는 균주에 따라 크게 달랐다. 산도는 2일에서 4일 사이에 급격히 증가하였고, 5일 이후에는 매우 완만하게 증가하였다. pH는 2일과 3일 사이에 급격히 감소하였고, 4일 이후에는 매우 완만하게 감소하였다. 최종 배양액의 총산도는 0.52∼0.75%, 휘발성 산도는 0.04∼0.18%이었고, pH는 3.55∼3.85이었다. 관능검사 결과 Leuconostoc속 규주의 배양액이 Lactobacillus속의 배양액보다 flavor가 좋았다. 본 젖산균들을 김치 발효용 starter로 사용하고 저온에서 숙성 시키면 숙성 소요시간을 크게 단축시킬 수 있고, 과숙현상이 억제될 것으로 생각되었다.

The study was conducted to determine the optimal hormone and glucose levels during the in vitro culture of bovine oocytes matured and fertilized in vitro for blastocyst development. Oocytes matured in TCM 199 + 10% FCS + hormones and glucose were fertilized in vitro in a TALP medium with swim up separated and heparin-treated epididymal cauda spermatozoa. Oocytes were cultured for 2~5 days in synthetic oviduct fluid medium (SOFM) supplemented with 10% FGS and with different hormone and glucose levels, and further cultured 5 days same medium in SOFM. The results are summarized as follows : The in vitro maturation and penetration rates of porcine oocytes cultured in TCM 199 media containing PMSG, hCG, PMSG + hCG, hCG + estradiol, PMSG + estradiol 0 to20 hours after insemination were 88.0% and 81.8%, 82.6% and 68.4%, 80.0% and 75.0%, 80.0% and 65.0%, 77.3% and 64.7%, respectively. The in vitro maturation and penetration rates of porcine oocytes cultured in TCM 199 media containing PMSG, hCG, PMSG + hCG, hCG + estradiol, PMSG + estradiol 20 to 40 hours after insemination were 92.0% and 87.0%, 92.0% and 82.6%, 91.3% and 81.0%, 85.2% and 73.9%, 87.5% and 81.0%, respectively. The cleavage and in vitro developmental rates to blastocyst of porcine oocytes cultured in TCM 199 media containing 0.05 mM, 0.10 mM, 0.30 mM, 0.50 mM, 1.00 mM, and 3.00 mM glucose lelvels 0~3 days after insemination were 31.5~48.1% and 10.0~16.7%, respectively. The cleavage and in vitro developmental rates to blastocyst of porcine oocytes cultured in TCM 199 media containing 0.05 mM, 0.10 mM, 0.30 mM, 0.50 mM, 1.00 mM, and 3.00 mM glucose levels 4~8 days after insemination were 30.0~53.8% and 8.7~19.2%, respectively. The cleavage and in vitro developmental rates to blastocyst were higher in TCM 199 media containing various glucose levels 0~3 days after insemination than 4~8 days.

The studies on the carried out to investigate the effects of co-culture with uterine fluids and uterine epithelial cells on the in-vitro fertilization and developmental rate of porcine follicular oocytes. The ovaries were obtained from slaughtered swine. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluids from the visible follicles of diameter 3~5 mm. The follicular oocytes were cultured in TCM-199 medium containing hormones and 10% ECS for 46~48 hrs in a incubator with 5% in air at 38.5 and then matured oocytes were again cultured for 12~18 hrs with motile capacitated sperm by preincubation of heparin. The results obtained in these experiments were summarized as follows ; 1.The in-vitro maturation and fertilization rate of porcine oocytes co-cultured with uterine fluids in TCM-199 medium were 68.0% arid 55.7%, the rates were higher than of control, 56.5% arid 38.7%. 2. When the in-vitro fertilized oocytes were co-cultured with porcine uterine epithelial cells, the fertilization rate was 60.3%, the rates were higher than that of control, 35.7%. 3. When the in-vitro fertilized oocytes were co-cultured with porcine uterine epithelial cells, the development rate to be blastocyst was 12.4%, the rates were higher than that of control, 9.2%(p<0.05).

딸기 펄프를 Serum과 불용성 펄프로 분리하고 serum 만을 방향성분을 회수하여 55∼58℃, 30∼60mmHg의 조건에서 감압증축후 재조합하는 방식으로 농축 딸기 펄프를 조제하였다. 대조구와 농축 딸기 펄프를 -18℃에서 18주 동안 저장하였을 때 두 시료 모두 가용성 고형분과 환원당이 증가하는 경향을 나타내었으며, 관능평가에서 조직감은 농축딸기 펄프가 낮은 품질을 나타내었으나 향미·색의 강도·전체적인 선호도에서는 품질 차이가 없었다.