• 환경위생공학
• /
• 제4권2호
• /
• pp.91-99
• /
• 1989

An anaerobic acidogenic fermentation experiment was carried out in order to investigate the distribution of volatile acid products and gas generations with varing temperatures and pH values. The experiment was carried out using $1\%$ glucose as substrate and a pair of 3.5 liter vessle as bench scale batch reactors. The reactors were operated for 7 days at 25, 30 and $35^{\circ}C$ and at pH values of 4.0, 4.5, 5.0, 5.5 and 6.0 at each temperature conditions. Major products at all experiment pH's at $35^{\circ}C$ were acetic acids and butyric acids which together composed around $90^{\circ}F$ of total product acids. At higher pH values at $35^{\circ}C$, propionic acid reached around $10\%$. At all experiment conditions, 52 to $55\%$ of generated gases comprised of hydrogen gas and 45 to $48\%$ of carbon dioxide. With temperature increase from 25 to $35^{\circ}C$, the production rate of acetic acid increased 2.9 fold, butyric acid 22 fold, hydrogen gas 2.0 fold and carbon dioxide gas 2.3 fold. Optimum reaction conditions for highest production of acetic acid and hydrogen gas was determined to be pH 5.5 at $35^{\circ}C$.

• KSBB Journal
• /
• 제20권6호
• /
• pp.401-407
• /
• 2005

본 연구는 C. beijerinckii KCTC 1785의 배양배지(RCM)에서 수소생산을 위한 최적화 조건을 탐색하고 수소생산을 위한 배지성분을 최적화하였다. 수소생산을 위한 최적 초기 pH와 발효온도는 각각 7.0과 $35^{\circ}C$이었고, 교반은 수소생산을 가속화 시켰다. C. beijerinckii KCTC 1785는 6%(w/v)의 glucose 농도까지 성장할 수 있지만 4%의 glucose 농도에서 가장 많은 수소를 생산하였으며, 이 때 바이오가스 중 수소 함량은 37%(v/v)이었다. 그러나 배지내 잔여 glucose 양을 고려할 때 수소생산을 위한 최적 glucose 농도는 1%이었다. 발효가 진행되는 동안 수소가 생산됨과 동시에 acetic acid와 butyric acid가 동시에 생성되었으며, acetic acid와 butyric acid가 각각 5,000 mg/L과 3,000 mg/L 이상의 농도에서 수소생산을 저해하였다. 또한 발효조의 pH를 5.5로 계속 유지하였을 경우 15시간 동안 0.5% glucose로부터 1,728 mL의 수소를 생산하였으며 이 때 수소의 생산수율은 1.23 mol $H_2/mol$ glucose이었다. C. beijerinckii KCTC 1785의 성장에 있어서 yeast extract 또는 tryptose는 반드시 필요한 배지의 성분이었다.

• KSBB Journal
• /
• 제11권3호
• /
• pp.380-387
• /
• 1996

재조합 대장균의 성장과 그 부산물 생성 관계를 알기위하여 탄소원인 포도당의 놓도 변화와 액아당 의 농도 변화에 따른 각각의 영향들을 검토하였다. 포도당 감소 시간은 초기 포도당 농도 5gjL에서 배양 실시후 8시간 전후이었고 나머지는 배양 실시후 16시간부터 20시간이면 거의 흡수되었다. 이 결과로서 탄소원의 농도는 배양 초기에 많이 흡수되고 세 포가 짧은 시간에 성장됨을 알 수 있다. 포도당 농도변화와 맥아당 농도 변화에서 보면 세 포 최대비생산속도값이 초기 탄소원 농도가 감소됨 에 따라 반대로 높은 값으로 증가되었다. 세포 생성 최대 농도치는 탄소원 초기 농도 10.0g / jL에서 포도당은 3.33gjL이고, 맥아당은 4.06gjL 임을 볼때 비슷한 값이고 탄소원 초기농도 5.00gjL 에 서 포도당은 3.05gjL이고, 맥아당은 2.l0gjL 임 을 보면 탄소원 저농도에서는 탄소원이 포도탕 일때 더 양호하게 세포가 성장되었다. 탄소원 종류에 따른 부산물 생성으로서는 포도당 과 맥아당이 마찬가지로 lactic acid와 acetic acid 가 많이 생성되었고 propionic acid, methanol은 적 은 양으로 생성되었다. 특이하게 ethanol의 경우는 초기 포도탕 농도가 40.0g/L 일때 11.25g/L이 생 성되었고, 초기 액아당 농도가 20.0g/L 일때 4.90g / /L까지 얻어짐을 보였는데 이 현상은 균주의 활성및 대사적 특성에서 형성된 것으로 이상 발효라 할 수 있다. 그리고 탄소원 두 가지 다 그 초기 농도가 높을 때 부산물 생성이 많이 생생되었고 탄소원 농도가 낮요면 적은 양이 생성되었다. Lactic acid는 포도 당에서 더 많이 생성되었고 acetic acid는 맥아당에 서 더 많이 생성되었다. 이 현상은 균주의 대사적 특 성으로 생각되고 이 반응 기작은 더욱 연구되어야 할 것으로 사료된다.

• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.461-468
• /
• 2016

One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.

• 한국미생물·생명공학회지
• /
• 제50권1호
• /
• pp.81-88
• /
• 2022

Acetic acid bacteria (AAB) are versatile organisms involved in the production of variety of fermented foods, such as vinegar and kombucha, and products of biotechnological relevance, such as bacterial cellulose. In the present study, Malatya apricot, a variety with protected designation of origin (PDO), and vinegar samples produced using various fruits were used to isolate AAB. The 19 AAB isolates obtained were typed using (GTG)5 fingerprinting, and the ones selected were identified by sequencing either 16S rDNA alone or in combination with 16S-23S rRNA internal transcribed spacer region or ligA gene. While all apricot isolates (n = 10) were Gluconobacter cerinus, vinegar isolates (n = 9) were composed of Komagataeibacter saccharivorans, Acetobacter syzygii, and possible two new species of AAB, Komagataeibacter sp., and Gluconobacter sp. (GTG)5 fingerprinting showed the presence of several genotypes of G. cerinus in the apricot samples. Screening for some technologically relevant properties, including thermotolerance, ethanol tolerance, and cellulose production capability, showed that all Komagataeibacter and some Gluconobacter isolates could tolerate the temperature of 35℃, and that vinegar isolates could tolerate up to 8% ethanol. One isolate, Komagataeibacter sp. GUS3 produced bacterial cellulose (1 g/l) and has the potential to be used for cellulose production.

• 한국미생물·생명공학회지
• /
• 제18권4호
• /
• pp.327-330
• /
• 1990

Thalictrum rugosum 세포배양에서 여러 가지 식물생장 조절물질이 세포증식 및 berberine 생산에 미치는 영향을 조사하였다. 조사된 식물생장 조절물질들 중에서 indole-3-acetic acid(IAA)가 berberine 생산에 가장 적합함을 알 수 있었고 그 최적농도는 1$\mu \textrm m$ 이었다. 비교 기준인 2,4-D의 사용결과에 비할 때 60이상의 생산량 상승효과가 있었으며, cytokinin인 6-benzylaminopurine(BA)를 동시에 사용하는 것보다 IAA만을 단독으로 사용하는 것이 더 효과적이다.

• The Plant Pathology Journal
• /
• 제36권5호
• /
• pp.476-490
• /
• 2020

The parasitic weed, Orobanche crenata, is one of the most devastating constraint for faba bean production in Mediterranean regions. Plant host defense induction was reported as one of the most appropriate control methods in many crops. The aim of this study was to elucidate the effect of salicylic acid (SA) and indole acetic acid (IAA) on the induction of faba bean resistance to O. crenata under the field and controlled experimental conditions. Both hormones were tested on two contrasting faba bean genotypes: Giza 843 (partially resistant to O. crenata) and Lobab (susceptible) at three different application methods (seed soaking, foliar spray, and the combination of both seed soaking and foliar spray). Soaking seeds in SA or IAA provided the highest protection levels reaching ~75% compared to the untreated control plants. Both elicitors limited the chlorophyll content decrease caused by O. crenata infestation and increased phenolic compound production in host plants. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were stimulated in the host plant roots especially in the susceptible genotype Lobab. The magnitude of induction was more obvious in infested than in non-infested plants. Histological study revealed that both SA and IAA decreased the number of attached O. crenata spikes which could be related to specific defense responses in the host plant roots.

• 미생물학회지
• /
• 제38권2호
• /
• pp.144-151
• /
• 2002

Rhodopseudomonas sp. KCTC1437균주를 이용하여 Polyhydroxyalkanoate (PHA)와 5-aminolevulinic acid (ALA)를 생산하기 위한 배양조건과 이들 생합성 조건의 상호관련성에 대하여 조사하였다. PHA생합성을 위한 탄소원으로는 acetic acid가 가장 효과적이었으나, succinic acid를 보조 탄소원으로 사용하였을 때의 세포건체량은 2.5g/ι, PHA함량은 건체량의 73%로서 주 탄소원만을 사용할 때에 비하여 크게 증가하였다. 조사된 탄소원으로부터 생합성된 PHA는 모두 polyhydroxybutyrate 단일중합체 이었으나, valeric acid로부터는 3-hydroxybutyrate와 3-hydroxyvalerate로 구성된 공중합체가 생산되었다. ALA의 생합성을 위하여서는 환원제 인 sodium thioglycolate를 첨가하여 혐기적 조건을 만들고, 탄소원인 acetic acid와 propionic acid 이외에 전구물질인 levulinic acid, succinic acid와 glycine을 반복적으로 공급해주었을 때 가장 좋았으며, 약 400 mg/ι의 ALA를 생산할 수 있었다. 그러나 ALA 생합성의 필수물질인 glycine, levulinic acid와 환원제는 세포생장과 PHA의 생합성을 저해하는 것으로 나타났다. 이러한 실험 결과, Rhodopseudomonas sp. KCTC1437균주로부터 PHA와 ALA를 동시에 생산할 수 있으나, 두 가지 유용산물을 효율적으로 생합성하기 위한 각각의 배양조건이 상호 배타적임을 확인하였다.

• 한국미생물·생명공학회지
• /
• 제22권2호
• /
• pp.120-125
• /
• 1994

By using a synthetic medium simulated on the amino acid composition of soybeam, the effect of salt concentrations on the production of volatile organic acid by the strains of Zygosaccharomyces rouxii So-3101, a soy sauce yeast, was studied at the concentrations of 12.5, 18.0, 22.0 and 28.5% NaCl. The growth, consumption of glucose, and production of alcohol, total acid and volatile organic acid, showed the highest values at a concentration of 12.5% NaCl, and those values were decreased with an increase in the salt concentration. The ratio of volatile organic acid to total organic acid was remained at approximately the same level within the range of salt concentrations between 12.5~22.0%, whereas the ratio was decreased at a salt concentration of 28.5%. After incubation for 16 days, 8 volatile organic acids, i.e. acetic, propionic, n-butyric, isobutyric, isovaleric, isocaproic, n-caproic, and heptanoic acids, were detected by gas chromatography. Among the volatile organic acids, acetic acid was produced in the appreciable amiunt and its ratio to the other volatile acids was increased with an increase in the salt concentration.A small amount of isocaproic, propionic, isobutyric and isovaleric acids were produced, and n-caproic, n-butyric and heptanoic acids were detected only at the lower salt concentration.

• 한국미생물·생명공학회지
• /
• 제27권1호
• /
• pp.75-79
• /
• 1999

Various conditions for onion-juice production, and for alcohol and acetic acid fermemtations were investigated to produce a vinegar from onion. In the production of the onion juice, treatments with enzymes such as 0.6% Celluclast 1.5L and 0.2% Viscozyme L increased the yields significantly from 45.0% to 54.5% and 72.5%, respectively. Alcohol and acetic acid fermentations from the onion juice were effectively improved by using the onion juice heated at 80$^{\circ}C$ for 10 minutes, and by adding 0.3% yeast extract, 0.3% $MgSO_4$ and 0.3% $K_3PO_4$ as nutrients to the onion juice. At the optimum condition, 5.8% alcohol was produced after five days of fermentation at $30^{\circ}C$ from the 14 Brix onion juice, which was adjusted by adding sugar. A vinegar with 6.7% acetic acid content was produced after 20 days of fermentation of $30^{\circ}C$ from 4% alcohol that was adjusted by adding onion juice.