• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권4호
• /
• pp.367-371
• /
• 2005

About 3,000 bacterial colonies with esterase activities were isolated from soil samples by enrichment culture and halo-size on Luria broth-tributyrin (LT) plates. The colonies were assayed for esterase activity in microtiter plates using enantiomerically pure (R)- and (S)-2-phenylbutyric acid resorufin ester (2PB-O-res) as substrates. Two enantioselective strains (JH2 and JH13) were selected by the ratio of initial rate of hydrolysis of enantiomerically pure (R)- and (S)-2-PB-O-res. When cell pellets were used, both strains showed high apparent enantioselectivity ($E_{app}>100$) for (R)-2PB-O-res and were identified as Exiguobacterium acetylicum. The JH13 strain showed high esterase activity on p-nitrophenyl acetate (pNPA), but showed low lipase activity on p-nitrophenyl palmitate (pNPP). The esterase was located in the soluble fraction of the cell extract. The crude intracellular enzyme preparation was stable at a pH range from 6.0 to 11.0.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.398-401
• /
• 2003

Bacillus species predominantly outgrown in a night soil treatment system were isolated and characterized. Cell interactions took place among them and cell population changed under various culture conditions. Maximum removal of $NH_4\;^+-N$ and cell production occurred under the conditions of 30% DO and C/N ratio of 8. Additions of 0.8% peptone and 0.3% yeast extract to a basal medium influenced the growth of isolates and the removal of $NH_4\;^+-N$ in flask culture, and metal ions such as Ca, Fe and Mg also did. During the flask experiment of nitrogen removal under an aerobic condition, active nitrification by the isolates occurred largely in 1 h with the decrease of COD and alkalinity destructed was only 74.6% of theoretical value. From the nitrogen balance, the percentage of nitrogen lost in the flask culture was estimated to be 29.0%. This conversion of ammonia to $N_2$ under an aerobic condition was confirmed by GC analysis. The B3 process using the Bacillus species seemed to have some economic advantage.

• KSBB Journal
• /
• 제29권2호
• /
• pp.106-111
• /
• 2014

Wheat sprout (Triticum aestivum) shows excellent nutritional and health effects due to the contents in amino acids, minerals, and other nutrients rich in chlorophyll and vitamins. In this study, spent coffee grounds were used to cultivate the wheat sprout for 12 day. An amount of 0%, 20%, 40%, 60%, 80%, and 100% (w/w, based on commercial sterile soil media) spent coffee grounds were used under the same conditions. Total length and weight of wheat sprout, aboveand below-ground length and weight, and the chloropyll contents were compared. Soil media were analyzed before and after wheat cultivation, showing that 40% and 60% (w/w) coffee media promoted wheat growth in view of length and weight. Chlorophyll contents in each group showed almost constant values, while 100% (w/w) coffee media led to a slight decrease. In conclusion, spent coffee grounds stimulated wheat growth, showing nearly stable contents of chlorophyll.

• KSBB Journal
• /
• 제30권3호
• /
• pp.97-102
• /
• 2015

This study aimed to evaluate the potential plantgrowth promoting effects of potassium polyacrylate, a superabsorbent polymer, and Bacillus sp. SH1RP8, a family of plant-growth-promoting bacteria. Potassium polyacrylate was selected as the polymer for use due to its high molecular weight and its ability to retain and continuously supply moisture. Plant-growth-promoting rhizobacteria (PGPR) were isolated from the soil and applied to plants growing in dry environments, such as saline conditions. The moisture absorption and retention abilities of potassium polyacrylate were evaluated at a high temperature ($50^{\circ}C$) and in a dry condition, during which time the polymer showed a water retention potential of 19606.07% after 29 days. To overcome the reaming problem in the soil environment, natural polymers (such as cellulose) were mixed with the potassium acrylate. The shoot growths of Peucedanum japonicum Thunb and Arundo donax were significantly enhanced when treated with the mixture of the isolated rhizosphere bacterium SH1RP8 and potassium polyacrylate (63.5 and 124.3%, respectively).

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제5권1호
• /
• pp.57-60
• /
• 2000

$(R)-\beta-acetylmercaptoisobutyric$ acid (RAM), a chiral compound, is an important intermediate for the chemical synthesis of various antihypertensive and congestive heart failure drugs. Microorganisms capable of converting $(R,S)-\beta-acetylmercaptoisobutyric$ acid ((R,S)-ester) to RAM were screened from soil microorganisms. A strain of Pseudomonas sp. 1001 screened from a soil sample was selected to be the best. Cells showed an activity of 540 U/mL from culture broth and the enzyme was thermostable up to $70^{\circ}C$. This strain could produce RAM asymmetrically from (R,S)-ester.

• KSBB Journal
• /
• 제8권3호
• /
• pp.230-236
• /
• 1993

Chitin과 cellulose를 dimethylacetamide/LiCl 용매에 용해시켜 유리판 위에서 Chitulose film을 제조 하였다. 이 film은 토양속에서 20일 후에 거의 분해 되었고, 토양 미생물을 16-26hr 후에 투과시켰다. 한편, 필름의 투과도를 검토해 본 결과 물의 투과도는 Chitulose film에서 chitin, cellulose의 혼합 비율에 따라 0~187,500ml/$m^2$/day로 cellulose 함량이 높을 수록 투과도가 낮게 나타났으며, 풍건보다는 중탕에 의한 필름건조방법으로 제조된 것이 우수하였다. 각종 유기물의 최대, 최소투과도는 Chitulose film 의 종류에 따라 달리 나타나 chitin과 cellulose의 조성에 따라 선택적 투과성을 나타내였다. $Na^+$ 이온에 대한 투과도도 달리 나타나 보였고, 산소 투과도도 역시 Chitulose film의 조성에 따라 14-17,850 c $cm^3/m_2$/day로 큰 차이를 보였다. 2~3도 화상을 입힌 쥐에다 Chitulose film을 인조피부로 사용한 결과 염증없이 14일 후에 딱지가 떨어졌고, 31일 후에 완치되는 것이 관찰되었다.

• Journal of Species Research
• /
• 제12권1호
• /
• pp.68-89
• /
• 2023

This is the second catalog listing unrecorded invertebrates discovered during the research project 'Discovery of Korean Indigenous Species'. The data to compile the catalog were primarily gathered from the final reports of the project, between 2013 and 2021. We present 38 previously undocumented species, belonging to four phyla (Platyhelminthes, Annelida, Rotifera and Arthropoda). Samples were collected from intertidal coastal waters, soil, freshwater ponds, reservoirs and hosts in South Korea. In this study, we provide brief taxonomic information, including collection site (GPS), diagnosis, specimen vouchers, figures of representative individuals and the Korean name newly assigned, for each species. All data were reviewed and updated by experts working on the respective taxonomic group. The aim of the present study is to publish species that have been previously reported through the project. Upon publication, these species will be added to the 'National Species List of Korea', curated by the National Institute of Biological Resources(NIBR).

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 춘계학술발표대회
• /
• pp.89-91
• /
• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권6호
• /
• pp.435-439
• /
• 2004

Three Bacillus strains were isolated from soil samples. Morphological and physiologi­cal characterization indicated that the isolated strains were B. mycoides, B. licheniformis and B. brevis. White pepper was produced from black pepper by the fermentative method using the isolates in shake flaks as well as in a large-scale fermenter. Volatile oil and piperine contents of the product were $3.2\%$ (v/w) and $4\%$ (v/w) respectively. The moisture content was $15\%$. The mi­crobial contamination was less than 10 per 100 g. The product also exhibited excellent storage stability.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 춘계학술발표대회
• /
• pp.497-500
• /
• 2000

유류오염토양에서 분리한 유류분해균주 중 계면장력 저하능이 우수한 균주를 분리하여 동정한 결과 Pseudomonas aeruginosa D2D2로 판명되었다. 탄소원으로 glucose와 olive oil을 각 1.5%씩 첨가하였을 때 표면장력이 27.9 dyne/cm로 표면장력 저하능력이 가장 우수한 것으로 나타냈다. 생산된 biosurfactant로 ethly acetate 추출하여 crude biosurfactant를 얻었으며, TLC 분석한 결과 glycolipid계열의 biosurfactant임을 확인하였다.