• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.291-294
• /
• 2000

The production of polyhydroxybutrate(PHB) by Alcaligenes eutrophus NCIB 11599 was studied in a synthetic medium from whey as a sole carbon source. Especially pH-effect was treated and compared in this study. At the end of fermentation (A) unadjusted to pH, the dry cell weight, PHB concentration, and PHB conversion rate were 10.3g/L, 3.1g/L, and 30%, respectively. At the end of fermentation (B) adjusted to $pH(7.0{\sim}7.5)$, the dry cell weight, PHB concentration, and PHB conversion rate were 12.5g/L, 4.8g/L, and 41%, respectively. PHB conversion rate was about 10% higher on the fermentation (B) than on the fermentation (A).

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.245-246
• /
• 2000

Agrobacterium sp.에 의해 생산되는 커들란은 2차 부산물이기 때문에 이의 생산을 증대시키기 위해서는 고농도 세포배양이 필요하다. 본 연구에서는 고농도 세포배양을 실현하기 위하여 탄소원 과 질소원을 제어 공급하는 방법을 이용하였다. 초기 탄소원의 농도가 20g/L일 때 24시간 내에 모두 소모되었으며 생산된 세포의 농도는 6g/L였다. 고농도의 탄소원을 이용하여 배양조내의 설탕의 농도가 10g/L 이상이 되도록 제어하는 방법을 사용하였다.

• 대한간호학회지
• /
• 제5권1호
• /
• pp.87-92
• /
• 1975

This study was performed from July to December 1974 to investigate the rates of contamination of distilled water for injection and local anesthetics. 222 vials were sampled from 7 different places of St. Mary's Hospital The samples were cultured for isolation of microorganisms. The results were as follows; 1. Of 222 vials, 11 were Contaminated by 6 types: Staphylococcus epidermis, Bacillus subtilis, Mima polymorph a, Alcaligenes faecalis, Herellea vaginicala and pepto- streptococcus. 2. 5(9.1 %) of 55 vials from surgical wards, 2 (4.2 %) of 48 vials from surgical OPD, and 4 (12,l %) of 33 vials from pediatric wards were contaminated 3. Between rates of contamination of distilled water for injection and local anesthetics and the number of punctures, there was no significant relationship. (CR=1.42 P〉0.1) 4. There was no significant relationship (CR=1.02 P〉0.1) between the rates of contamination of vials and the duration of the first and the last punctures. 5. The ratios of contamination between 75% alcohol and 2% phenol used for disinfection of rubber lids of vials did not show significant difference.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권6호
• /
• pp.546-551
• /
• 2005

[ ${\beta}-1,3-Glucan$ ] (curdlan) is a water-insoluble polysaccharide composed exclusively of ${\beta}-1,3\;linked$ glucose residues. Extracellular curdlan was mostly synthesized by Agrobacterium species and Alcaligenes faecalis under nitrogen-limiting conditions. In this study, we screened the microorganisms capable of producing extracellular curdlan from soil samples. For the first time, we reported Gram-positive bacterium Bacillus sp. SNC 107 capable of producing extracellular curdlan in appreciable amounts. The effect of different carbon sources on curdlan production was studied and found that the yield of curdlan was more when glucose was used as carbon source. It was also found that maximum production was achieved when the initial concentration of ammonium and phosphate in the medium was 0.5 and 1.9 g/L respectively. In this study the curdlan production was increased from 3 to 7g/L in shake flask cultures.

• 한국환경과학회지
• /
• 제11권12호
• /
• pp.1315-1320
• /
• 2002

Since the enzymatic degradation of microbial poly[(R)-3-hydroxybutyrate-co-3-hydroxyvalerate] (P(3HB-co-3HV)) initially occurs by a surface erosion process, a degradation behavior could be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma gas discharge and blending techniques were used to modify the surface of microbial P(3HB-co-3HV). The surface hydrophobic property of P(3HB-co-3HV) film was introduced by CF$_3$H plasma exposure. Also, the addition of small amount of polystyrene as a non-degradable polymer with lower surface energy to P(3HB-co-3HV) has been studied. The enzymatic degradation was carried out at 37 $^{\circ}C$ in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. Both results showed the significant retardation of enzymatic erosion due to the hydrophobicity and the enzyme inactivity of the fluorinated- and PS-enriched surface layers.

• Journal of Microbiology and Biotechnology
• /
• 제5권4호
• /
• pp.238-240
• /
• 1995

A novel and simple purification method for microbial $poly-{\beta}-hydroxybutyrate$ (PHS) was developed. Sodium hydroxide was found to be efficient for digesting cell materials. Initial biomass concentration, NaOH concentation, digestion time, and incubation temperature were optimized. When 40 g/l of biomass was incubated in 0.1 N NaOH at $30^{\circ}C$ for 1 h, PHB purity of 88.4% with a weight average molecular weight ($M_w$) of 770,000 and a polydispersity index (PI) of 2.4 was recovered with a yield of 90.8% from the biomass which initially contained PHB of a $M_w$ of 780,000 and a PI of 2.3.

• 대한수의학회지
• /
• 제20권1호
• /
• pp.53-58
• /
• 1980

Antimicrobial susceptibility of 157 Gram-negative bacilli (90 Escherichia coli. 30 Enterobacter aerogenes, 18 Klebsiella pneumoniae, 12 Proteus spp., 3 Pseudomonas aeruginosa and 4 Alcaligenes faecalis) isolated from infected bovine udders was determined by the plate dilution method. Gentamicin and oxolinic acid at a concentration of $12.5{\mu}g/ml$ were very active to all of 157 Gram-negative bacilli tested, and 98% of these strains were susceptible to nalidixic acid at a concentration of $25{\mu}g/ml$. Most of the 90 Escherichia coli strains were inhibited by chloramphenicol, ampicillin and carbenicillin and carbenicillin at a concentration of $12.5{\mu}g/ml$. None of the Klebsiella pneumoniae strains were inhibited at a concentration of $50{\mu}g/ml$ of ampicillin and carbenillin, whereas all the species of Proteus resisted a concentration of $50{\mu}g/ml$ or higher tetracycline. All the 3 strains of Pseudomonas aeruginosa were highly resistant to streptomycin, kanamycin, Ampicillin, chloramphenicol, tetracycline and nalidixic acid.

• 미생물학회지
• /
• 제29권3호
• /
• pp.155-159
• /
• 1991

Four strains of Pseudomonas putida (NAH), Pseudomonas sp.(TOL), Achromobacter xylosoxidans, and Alcaligenes sp. were compared with their degradative capability of aromatic compounds. All of the bacterial strains were utilized catechol as a sole carbon source for growth, but signigicantly different in degradative properties for 5 other aromatic compounds. Catechol 2, 3-dioxygenase gene from P. putida (NAH) has been cloned and expressed in E. coli. The DNA clone designated pCNU101 contains NAH-derived 6 Kb insert and its physical map was characterized. A subclone (pCNU106) for the catechol dioxygenase gene in pCNU101 contained 2.0kb-DNA insery fragmented by HpaI and ClaI.

• Journal of Microbiology
• /
• 제43권6호
• /
• pp.572-576
• /
• 2005

This study focused on detecting catabolic genes for polycyclic aromatic hydrocarbons (PAHs) distributed in the reed rhizosphere of Sunchon Bay, Korea. These marsh and mud environments were severely affected by human activities, including agriculture and fisheries. Our previous study on microbial roles in natural decontamination displayed the possibility that PAH-degrading bacteria, such as Achromobacter sp., Alcaligenes sp., Burkholderia sp. and Pseudomonas sp. play an important decontamination role in a reed rhizosphere. In order to gain further fundamental knowledge on the natural decontamination process, catabolic genes for PAH metabolism were investigated through PCR amplification of dioxygenase genes using soil genomic DNA and sequencing. Comparative analysis of predicted amino acid sequences from 50 randomly selected dioxygenase clones capable of hydroxylating inactivated aromatic nuclei indicated that these were divided into three groups, two of which might be originated from PAH-degrading bacteria. Amino acid sequences of each dioxygenase clone were a part of the genes encoding enzymes for initial catabolism of naphthalene, phenanthrene, or pyrene that might be originated from bacteria in the reed rhizosphere of Sunchon Bay.

• 한국환경과학회지
• /
• 제10권2호
• /
• pp.105-111
• /
• 2001

Improvement of water quality and Investigation of bacterial characteristics have been conducted in a pilot plant using biological activated carbon (BAC) in water treatment process at the downstream of the Nakdong River. Most of water control parameters were highly improved after passing through BAC. Approximately 54% of dissolved organic carbon was removed in coal-based BAC process. Bacterial biomass and bacterial production appeared $9.8{\times}10^8 CFU/g and 7.1mg-C/m^3$.hr in coal-based BAC, respectively. Predominant bacteria species grown in BAC were identified as Pseudomonas, Flavobacterium, Alcaligenes, Acinetobacter and Aeromonas species. Particularly Pseudomonas vesicularis was dominant in both coal-based and coconut-based BACs, while Pseudomonas cepacia was dominant in wood-based BAC.