• 생명과학회지
• /
• 제10권2호
• /
• pp.125-130
• /
• 2000

To overproduce endoxylanase from a recombinant Bacillus subtilis harboring the pJHKJ4 plasmid, the effects of carbon and nitrogen sources on the cell growth and expression level of endoxylanase were investigated in the flask cultures. Among the various carbon and nitrogen sources tested, glucose and maltose as carbon source and yeast extract as nitrogen source were found to be the most effective for the cell growth and the endoxylanase expression. When the concentration of glucose was increased from 0.5% to 5%, the highest activity of extracellular endoxylanse, 166 unit/$m\ell$, was observed at 2% glucose. In case of maltose, the endoxylanase was stably produced at the level of 180 unit/$m\ell$, regardless of the concentration of maltose. The higher the concentration of yeast extract, the greater cell growth and endoxylanase expression were obtained. However, the highest endoxylanase activity per unit cell mass was observed with 1% yeast extract. With the optimized medium (2% glucose, 1% yeast extract, etc), about 630 unit/$m\ell$ of endoxylanse was expressed through the batch fermentation in a fermentor, which expression level corresponded to about 0.7 g-endoxylanase protein /$\ell$. It was also found that the plasmid was stably maintained above 70% level, and more than 90% of endoxylanase activity was detected in the extracellular medium.

• 미생물학회지
• /
• 제16권3호
• /
• pp.93-102
• /
• 1978

Saccharomyces cerevisiae strain M was cultured in a molasses-containing media with repeated transplantations of the yeasts from one culture to another to adapt to molasses. After that only different amounts of phosphorous and nitrogen sources were added to the media. And then some variations during the culture time and the effects of consituents of cell mass on the functional activity and sensitivity of the cell were investigated. The results obtained were summarized as follows : 1. In the same culture condition of yeasts, the carbohydrates and trehaloses contents were more remarkably increased when small amounts of phosphate and nitrogen sources were added, then when alrge amounts were added, but yield percentage on assimilated sugars was lower. 2. The content of trehalose in yeast cells was reduced remarkably at the early stage in the culture, but this increased remarkably at later stage. When small amounts of nitrogen and phosphate were added to the culture medium, the amount of thehalose in the cells increased greasly. 3. The more protein content was present in the yeast cells, the smaller the carbohydrate and trehalose content, but more amino-N, RNA and moisture content were present in the cells. And in this case fermentability of the cells was stronger, but sugar tolerance was lower. 4. During the preservation period of compressed yeast cells at different temperature, the higher the temperature was, the more rapidly the amount of trehalose in the cells decreased. And in the cell where the amount of trehalose in the cells decreased. And in the cell where the amount of trehalose(carbohydrate) was large and the amount of protein was small, the amount of trehalose decreased at a slower rate during the preservation period.

• 식물병연구
• /
• 제27권3호
• /
• pp.99-106
• /
• 2021

The fungal isolate Isaria javanica pf185 has potential as a mycopesticide because it demonstrates insecticidal activity against the green peach aphid and antifungal activity against Colletotrichum gloeosporioides. For commercialization of this isolate, determination of the optimal and least expensive culture conditions is required; however, these data are not currently available. This study describes the conditions for optimal development of conidia and production of metabolites for the biocontrol of the fungal pathogen. The optimal culture conditions were examined using cultures on solid agar and liquid media. High growth temperature enhanced spore formation but reduced antifungal activity in both solid and liquid media. The highest spore yield was obtained in a medium containing glucose as a carbon source and yeast extract as a nitrogen source. Soybean powder and wheat bran were effective nitrogen sources that promoted spore production and antifungal activity of the isolate. These results revealed the basic, cost-effective growth media for commercial production of a biopesticide with insecticidal and antifungal properties for use in integrated pest management.

• 한국미생물·생명공학회지
• /
• 제17권5호
• /
• pp.519-523
• /
• 1989

Aspergillus sp.로부터 glucoamylase를 생성키 위한 조건을 검토하였다. 곰팡이는 탄소원으로 soluble starch, 질소원으로 yeast extract를 사용했을 때 최대 효소생성을 얻을 수 있었다. 그리고, 탄소원 및 질소원의 농도에 따른 효소생성은 soluble starch를 5%, yeast extract를 1% 수준으로 사용했을 때 효소생성은 극대화하였다. 또한 배지의 초기 pH를 6.0, 그리고 배양온도를 28$^{\circ}C$로 유지했을 때 효소생성이 높았다. 고체배지를 사용했을 때에는, 밀기울 배지가 glucoamylase 생성을 위해서 가장 효과가 좋았다.

• Journal of Microbiology and Biotechnology
• /
• 제7권4호
• /
• pp.262-266
• /
• 1997

To increase the high production of 1-deoxynojirimycin (DNJ) from Streptomyces sp. SID9135, the effect of various carbon sources, nitrogen sources, cationic metal ions, the initial pH of the medium, and agitation speed were investigated. The most effective carbon and nitrogen sources were found to be lactose 2.5% (w/v) and soybean meal 2.0% (w/v), respectively. None of the cationic metal ions examined had any detectable stimulating effect on DNJ production except $Fe^{+2}$ ion. The initial optimum pH for DNJ production ranged from 6-8 and agitation speed was most effective at 400 rpm. In the jar fermentor experiments under optimal culture conditions, the accumulation of DNJ reached about $640{\mu}g$/ml after 5 days of cultivation and the level remained the same for a further two days.

• 한국축산식품학회지
• /
• 제30권3호
• /
• pp.359-364
• /
• 2010

Lactobacillus acidophilus A12 was isolated from chicken feces for use as an immunostimulating livestock probiotic. The purpose of this study was to optimize the production of L. acidophilus A12 using response surface methodology (RSM). Initially, the influence of growth medium was studied in terms of carbon sources (glucose, fructose, lactose, glycerol, sucrose, ethanol, and mannitol), nitrogen sources (beef extract, yeast extract, malt extract, and tryptone), and inorganic salts ($CaCl_2$, $MgSO_4$, $KH_2PO_4$, $(NH_4)_2SO_4$, $FeSO_4$, and NaCl). Through one factor-at-a time experiment, lactose, yeast extract, and $CaCl_2$ were determined to be the best sources of carbon, nitrogen, and inorganic salt, respectively. The optimum composition was found to be 17.7 g/L lactose, 18.6 g/L yeast extract, and 0.9 g/L $CaCl_2$. Under these conditions, a maximum cell density of 9.33 Log CFU/mL was produced, similar to the predicted value.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제27권2호
• /
• pp.87-98
• /
• 2022

This study aims to prepare a technical protocol for identifying the source of nitrate in water using nitrogen (δ¹⁵N) and oxygen (δ¹⁸O) stable isotope ratios. The technical processes for nitrate sources identification are composed of site investigation, sample collection and analysis, isotope analysis, source identification using isotope characteristics, and source apportionment for multiple potential sources with the Bayesian isotope mixing model. Characteristics of various nitrate potential sources are reviewed, and their typical ranges of δ¹⁵N and δ¹⁸O are comparatively analyzed and summarized. This study also summarizes the current knowledge on the dual-isotope approach and how to correlate the field-relevant information such as land use and hydrochemical data to the nitrate source identification.

• Journal of Nutrition and Health
• /
• 제27권7호
• /
• pp.699-708
• /
• 1994

This study aimed to verify the nutritional and curative effects of protein hydrolysate in rats with cysteamine-induced duodenal uncer. Duodenal ulcer rat model was established by intraperitoneal injections of cysteamine. Sprague-Dawley, female rats weighing approximately 200g were intraperitoneally injected twice cysteamine(13mg/100g BW) at intervals of 3h per day. This procedure was repeated 3$\times$at intervals of 3d. Animals fed on 10% casein diet for infection periods. After last injection, 4 kinds of diets(10% casein, 20% casein, 10% casein hydrolysate, 20% casein hydrolysate) were given. Gastric montility, trypsin activity in gastrointestinal content, retention rate of nitrogen, plasma total protein, albumin, amino-N, urinary urea nitrogen, creatinine and hydroxyproline were analyzed for nutritional effects of dietary nitrogen levels(10%, 20%) and sources(casein, casein hydrolysate). In duodenal ulcer rat model, there was no differences between 20% casein diet and 20% casein hydrolysate in the view of severeness of ulcer, gastric emptying rate, serum total protein, serum albumin, plasma $\alpha$-amino-N, UUN, creatinine excretion, GFR, nitrogen retention. On the other hand, rats on 10% casein hydrolysate diet group had more curative effect of the ulcer, higher plasma albumin concentration and nitrogen retention than 10% casein diet group. The casein hydrolysate diet group was lower trypsin activity in small intestinal content than the casein diet group, at both nitrogen levels(10%, 20%). The results suggest that protein hydrolysate be applied in diet therapy for the patients with gastrointestinal ulcer.

• Environmental Engineering Research
• /
• 제15권2호
• /
• pp.111-115
• /
• 2010

To study the relationship between the concentrations of nitrogen in mountain streams, and anthropologic and natural factors, the water chemistry of the mountain streams in the entire Hyogo Prefecture, Japan, were investigated. A thousand mountain streams were investigated between 1998 and 2001. The concentrations of nitrate nitrogen ranged from 2.92 to 0.1 mg/L, with an arithmetic mean value of 0.45 mg/L. A number of streams showing more than 1.0 mg/L of nitrate nitrogen accounted for 8% of the mountain streams investigated. These results indicated that the concentrations of nitrate nitrogen in the mountain streams were low in the entire Hyogo Prefecture. In general, the mountain stream water in Hyogo Prefecture appears to not have been affected by wet and dry deposition originating from anthropologic sources in mountain streams and Japan. On the other hand, sites with more than 0.8 mg/L nitrate nitrogen were distributed over the entire Hyogo Prefecture, which were classified into five groups. Each group showed unique geographical, geological and anthropological characteristics. No common characteristic among five groups were discover. These results suggest that the cause of high concentrations of nitrogen in mountain streams is not from a uniform set of conditions.

• 한국균학회지
• /
• 제4권1호
• /
• pp.31-44
• /
• 1976

팽이버섯[Flammulina velutipes(Curt. ex Fr.) Sing.] 톱밥 재배(栽培)에 있어서 배지(培地)의 각종(各種) 영양급원(營養給源)의 첨가효과(添加效果) 및 배지(培地)의 물리적(物理的) 향상(向上)을 위(爲)한 방법(方法)을 구명(究明)하는 한편 재배과정중(栽培過程中) 일어나는 배지(培地)의 화학적(化學的) 성분(成分) 변화(變化)를 조사(調査)하여 팽이버섯의 영양요구(營養要求)에 대(對)한 기초자료(基礎資料)를 얻고자 일련(一連)의 시험(試驗)을 수행(遂行)한 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 포플러 톱밥에 미강(米糠), 밀기울 및 우분(牛糞)을 첨가비(添加比)를 달리하여 혼합(混合)한 배지(培地)에서 팽이버섯을 병재배(栽培)한 결과(結果), 포플러 톱밥 10에 미강(米糠) 3을 혼합한 처리구(處理區)에서 자실체(子實體) 수량(收量)이 84.4g/병(배지(培地)280g)으로서 가장 높았고 비교적(比較的) 수량(收量)이 높았던 포플러 톱밥 10에 미강(米糠) 3, 2 및 밀기울 3을 혼합한 처리구(處理區)에서 배지(培地)의 전질소(全窒素), 당류(糖類)와 가량(加量)의 함량이 높았다. 2. 톱밥 배지(培地)의 추출액(抽出液) 배지(培地)에서의 균사생장(菌絲生長)은 탄소(炭素) 및 질소(窒素) 등(等) 영양요소(營養要素)가 부족(不足)한 톱밥 단용구(單用區)나 우분첨가구(牛糞添加區)에서 극(極)히 저조(低調)하였으며, 톱밥 배지상(培地上)에서는 이들 처리구(處理區)에서 균사생장(菌絲生長) 속도(速度)는 빨랐으나 균사밀도(菌絲密度)는 현저(顯著)히 떨어졌다. 3. 가비중(假比重) 및 수분함량(水分含量)을 달리한 포플러 톱밥10+미강(米糠) 3 혼합배지(混合培地)에서 균사생장(菌絲生長)은 수분함량(水分含量) 72%, 가비중(假比重) 0.2에서 촉진(促進)되었으나 자실체(子實體) 수량(收量)은 가비중(假比重) 0.3, 수분함량(水分含量) 67%에서 가장 높았다. 4. 포플러 톱밥에 첨가(添加)되는 미강량(米糠量)이 증가(增加)됨에 따라 배지(培地)의 무게 감소율(減少率)은 커지며, 회분함량(灰分含量)도 증가(增加)하는 경향(傾向)을 보였고 종균(種菌) 접종(接種) 75일(日) 후(後) 무게 감소율(減少率)은 $17.8{\sim}28.8%$ 범위(範圍)였으며 회분(灰分)은 $10.1{\sim}13.2%$가 증가(增加)되었다. 5. 전재배기간중(全栽培期間中) cellulose는 $11{\sim}14%$, lignin은 $3{\sim}4%$의 절대량(絶對量)의 감소(減少)를 보여 포플러 톱밥에 첨가(添加)되는 미강량(米糠量)에 따른 큰 차이(差異)가 없었으며 가용성(可溶性) 당(糖)의 함량(含量)은 증가(增加)하는 경향(傾向)을 보였다. 6. 재배기간중(栽培期間中) 전질소(全窒素)는 시료(試料)에 대(對)한 함량(含量)은 증가(增加)하며 절대량(絶對量)은 감소(減少)하였으나 극(極)히 미소(微小)한 함량변화(含量變化)를 보였으며 유기태(有機態) 질소(窒素), 아미노태(態) 질소(窒素) 및 acid hydrolysable는 균사생장(菌絲生長) 및 자실체(字實體) 발생기간중(發生期間中)에 현저(顯著)히 감소(減少)되었다. 7. 질소원(窒素源)을 달리하는 배지(培地)를 사용(使用)한 액체배양(液體培養)에서 peptone, yeast extracts 등(等)의 유기태(有機態)가 첨가(添加)된 배지(培地)에서는 균사생장(菌絲生長)이 촉진(促進)된 반면(反面) 무기태(無機態) 질소원(窒素源)이 첨가(添加)된 Richard' solution과 Czapek-dox solution에서는 균사생장(菌絲生長)이 저조(低調)하였다. 또한 유기태(有機態) 질소원(窒素源)의 함량(含量)이 높은 배지(培地)에서 균사생장(菌絲生長)이 더욱 양호(良好)하였다.