Earticle

Distribution and in vitro growth characteristics of entomopathogenic Paecilomyces species were studied based on the specimens and isolates deposited in Entomopathogenic Fungal Culture Collection (EFCC), Kangwon National University, Chuncheon, Korea. Paecilomyces species were frequently collected from different mountains and valleys and were almost distributed uniformly. Collection period of Paecilomyces species ranged from July to September, with most of the collections at the end of September. P. tenuipes was mostly collected one among different Paecilomyces species. The optimum medium for mycelial growth of P. tenuipes was PDA, whereas in other media such as SDAY and HMA also produced similar growth. The optimum temperature and pH levels were 25C and 6.0~7.0, respectively. Best carbon and nitrogen sources were dextrose and tryptone, respectively, while KH2PO4 was the best mineral source for mycelial growth. Highest mycelial growth was observed when the C/N ratio was 20:1.

SCM415 alloy was implanted with nitrogen ions using plasma source ion implantation (PSII), at a dose range of $1{\times}10^{17}\;to\;6{\times}10^{17}\;N^+cm^{-2}$ Auger electron spectrometry (AES) was used to investigate the depth profile of the implanted layer. Friction and wear tests were carried out on a block-on-ring wear tester. Scanning electron microscopy (SEM) was used to observe the micro-morphology of the worn surface. The results revealed that after being implanted with nitrogen ions, the frictional coefficient of the surface layer decreased, and the wear resistance increased with the nitrogen dose. The tribological mechanism was mainly adhesive, and the adhesive wear tended to become weaker oxidative wear with the increase in the nitrogen dose. The effects were mainly attributed to the formation of a hard nitride precipitate and a supersaturated solid solution of nitrogen in the surface layer.

In this study, pH 5, 6, 7, 8, 9, 10 in each of two organic nitrogen source medium (Mushroom minimal medium + Yeast extract (YE), ST (mushroom minimal medium + Soytone) and MCM (mushroom complete medium) medium) 3 types of mycelium of 'Lepista nuda', WT (Wild type), LN96 (Lepista nuda 96), and LN103 (Lepista nuda 103), respectively, were inoculated and inoculated with a 3 day interval for 15 days. to investigate the mycelial growth length. As a result of checking the growth length of the mycelium on the 12th day, 3 days before the end of the experiment, it was confirmed that the mycelial growth rate was faster in YE pH8 medium for WT, MCM pH8 medium for LN96, and YE pH10 medium for LN103 compared to the untreated PDA. WT was confirmed to grow faster than PDA at pH 8, LN96 at pH 7, 8, 9, and LN103 at pH 6, 7, 8, 9, and 10. Based on this, it is judged that the mycelium of the spearmint mushroom has a faster growth rate in an organic nitrogen source medium than in PDA in basic rather than weakly acidic.

본 연구는 monosodium glutamate의 부산물인 condensed molasses solubles (CMS)가 반추가축의 질소 공급원으로서 반추위 미생물 단백질 합성에 미치는 영향을 in vitro 실험을 통하여 조사하였다. 실험 1에서는 반추위 미생물에 대한 질소 공급원으로서 CMS의 가치를 요소와 비교하였고, 실험 2는 미생물의 생성양이 최대가 되는 시간대를 조사하기 위하여 수행하였고, 실험 3에서는 실험 1과 2에서 배양 후 실시된 원심분리 (1000g×5분)에 의해 생성된 침전물이 총 질소의 공급양과 측정된 질소양에 차이를 발생시킴에 따라 침전물의 성분을 조사하고자 수행하였고, 실험 4는 배양 2시간대에서 CMS와 요소로부터 발생되는 암모니아의 발생양을 조사하기 위하여 수행하였다. 이상의 결과를 요약하면 다음과 같다. 1. 반추위 미생물태 질소 합성량은 CMS/당밀 처리구 (7.79mg/100ml)와 요소/당밀 (7.61mg/100ml)의 처리구간에 유의적인 차이는 없었지만 CMS/당밀의 처리구가 암모니아태 질소의 함량을 유의적으로 감소시켰다. 2. CMS/당밀 처리구의 암모니아태 질소 함량과 pH는 당밀/요소 처리구보다 유의적으로 감소하였다. 하지만 미생물태 질소의 양은 처리구간에 차이가 없었다. 최대 미생물의 성장률은 배양 후 10시간에서 발생하였다. 3. 당밀 대신 100% 수용성인 설탕을 이용하였을 경우에도 침전물이 발생하여 침전물이 당밀에 의한 것이 아님이 확인되었고, 또한 배양 시간이 짧았을 경우 (2시간) 질소의 손실양도 상대적으로 크게 감소하여, 총 질소의 공급양과 측정된 질소양의 차이는 침전물에 박테리아가 포함되었기 때문인 것으로 조사되었다. 4. 배양 2시간 동안 CMS로부터 발생되는 암모니아의 생성속도는 요소로부터 발생되는 속도보다 유의적으로 빠르게 나타났다. 본 실험의 결과 CMS는 반추위 미생물 단백질을 합성하는 데 있어 최소한 요소의 가치를 지니고 있음이 조사되었다.

A series of four in vitro experiments were conducted to evaluate condensed molasses solubles (CMS) as a source of nitrogen for ruminal microbes. In experiment 1, as compared with urea, the value of CMS as a nitrogen source was examined. In experiment 2, to determine the time needed for maximal response of microbial synthesis, the treatments were incubated for increasing times (from 6 h to 16 h). Because a sediment that was assumed to cause nitrogen loss was found after incubation in experiments 1 and 2, it was decided to avoid formation of sediment using sugar instead of molasses or a shorter time incubation (experiments 3 and 4). Furthermore, in experiment 4, because the extent to which ammonia nitrogen is released from CMS and urea before 6 h of incubation was uncertain, it was decided to examine the peaks of concentrations of ammonia nitrogen released from CMS and urea by sampling after 2 h incubation. There was no significant difference in the concentration of microbial-N between molasses/CMS and molasses/ urea treatments in experiment 1, although there were greater decreases in ammonia concentration with the molasses/CMS treatment. The microbial protein synthesis was increased progressively until 10 h for both treatments (experiment 2). Although ingredients that were completely soluble (sucrose, urea) were used in experiment 3, the sediment was still evident suggesting that the sediment was largely of microbial not feed origin. Ammonia release from CMS was much faster than from urea during 2 h incubation. In conclusion, the results of the present studies suggest that the feed value of CMS as a source of nitrogen for ruminal bacteria was similar to that of urea when it was estimated in vitro.

UDP-glucose는 β-1,3-glucan 합성의 중요한 전구체로 이를 측정함으로써 세포 내의 glucan synthesis 대사의 활성도를 추정할 수 있는 중요한 지표가 됨을 본 연구 결과를 통하여 알 수 있었다. UDP-glucose는 세포 성장기에 다량 생산되다가 β-1,3-glucan 합성하는 시기에 일정한 농도가 되며 β-1,3-Glucan 합성 메카니즘에서 glucose를 운반하는 중요한 역할을 하는 것으로 나타났다. 2단 연속 발효조를 이용하여 세포 성장 발효조와 β-1,3-glucan 생산 발효조에서 UDPglucose 변화를 관찰하여 β-1,3-glucan 생산시 농도가 높음을 관찰할 수 있었다. β-1,3-Glucan 생산 발효조의 pH를 5.5로 조절함으로써 UDP-glucose의 농도를 증가시킬 수 있을 뿐만 아니라 β-1,3-glucan의 생산 속도를 최적화할 수 있었다.

In this research, analysis of UDP-glucose a precursor of β-1,3-glucan by high performance liquid chromatography (HPLC) was established using a reversed phase system. One of key metabolite UDP-glucose was selected and its concentration changes was measured with the change of fermentation conditions. The effects of fermentation conditions with/without nitrogen source for cell growth on β-1,3-glucan production were dependent on the UDP-glucose concentration. The UDP-glucose was synthesized rapidly during cell exponential growth period and maintained high during β-1,3-glucan production period. The UDP-glucose concentration was higher for β-1,3-glucan production fermentor than that for cell growth fermentor. The β-1,3-glucan production was optimal at pH 5.5 and synthesis of β-1,3-glucan was greatest at pH 5.5.

탄소원과 질소원의 무게비가 Thraustochytrium aureum ATCC 34304의 성장 및 지방산 조성에 미치는 영향을 규명하였다. 초기 당농도에 관계없이 배양 5일 후의 균체농도는 C/N 값이 증가하면 증가하였다가 감소하였다. 각 초기 당농도에 따라서, 균체농도가 최대가 되는 C/N의 비는 각기 고유한 값을 나타내었다. 초기 당농도 5 g/L 내지 25 g/L 범위내에서 균체농도가 최대가 되는 C/N 값은 1 내지 4 사이에 분포하였다. C/N 비에 따른 균체수율 Yx/s의 값은 C/N의 값이 증가하면 감소하였으나 10 내지 20 사이의 범위에서는 0.35의 일정한 값을 유지하였다. T. aureum ATCC 34304가 생합성하는 포화지방산인 미리스트산의 조성은 C/N 비의 변화에 영향을 받지 않았으나 팔미트산의 조성은 C/N 값 4 이하에서는 20% 내외의 값을 나타내었고 C/N 값이 증가하면 15%까지 감소하였다. 탄소수사 18개인 C18:의 지방산 중 올레인산 (C18:1)과 리놀레인산 (C18:2)의 조성은 C/N 값이 증가하면 0%에서 각각 20% 및 7%까지 지속적으로 증가하였다. 반면 γ-리놀레인산 (C18:3)의 조성은 C/N 값의 증가에 따라 5%에서 2%까지 감소하였다. 탄소수가 20개 이상인 ω - 3 다중불포화 지방산 중 EPA (C20:5)와 DPA (C22:5)의 조성은 C/N 값의 증가에 따라 감소하는 경향을 나타내었으며, DHA (C22:6)조성은 C/N 값이 증가하더라도 40% 내외의 값을 유지하였다.

The effect of the weight ratio of carbon source to nitrogen source on the growth and the composition change of fatty acids of Thraustochytrium aureum ATCC 34304 was investigated. The cell concentration of 5 days' culture increased and then decreased according to the increase of C/N. The ratioes for the maximum biomass were unique respectively and distributed between 1 and 4 with the initial sugar concentration in the range of 5 g/L to 25 g/L. The biomass yield, Yx/s decreased along with the increase of C/N, but maintained a constant value 0.35 between 10 and 20. The composition of myristic acid (C14:0), one component of the lipid synthesized by T. aureum, was not affected with the change of C/N, but the composition of palmitic acid (C16:0) was around 20% below 4 of C/N and decreased to 15% according to C/N about 4. The compositions of oleic acid (C18:1) and linoleic acid (C18:2) increased from 0 to 20% and 7% respectively. The composition of γ-linoleic acid (C18:3), however, reduced from 5% to 2%. EPA (C20:5) and DPA (C22:5) showed a tendency of reduction in the weight composition according to the increase of C/N, but DHA (C22:6) had a trend maintaining an approximately constant value, around 40%, irrespective of the change of C/N.

Cellulose is the most abundant organic source of all plant materials. It is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Cellulase is applicable to enzymatic hydrolysis of the bonds and produced from microorganism such as fungi and bacteria. In this study, cellulase was produced by Penicillium sp. KL1 in a 5-L laboratory scale fermentor. The culture medium for fermentation were consisted of 10g/L rice straw, 0.5 g/L yeast extract, 1 g/L KH2PO4 and 0.5 g/L CaCl2. Also, the effects of additives on nitrogen source (5 g/L) were examined using L-asparagine and corn steep liquor (CSL). The fermentation was performed at 30oC, 300 rpm in 5 L vessel during 10 days. After fermentation, the enzyme activities were measured by using filter paper(FP) and ρ-nitrophenyl-β- Dglucopyranoside( ρ-NPG) as substrates and determined by DNS method at 540 nm. Protein concentration was determined at 595 nm according to Bradford method using bovine serum albumin (BSA) as the standard. The enzyme activities were 1.33 U/ml of filter paper unit (FPU) and 1.51 U/ml of β-glucosidase unit (CBU) in the containing L-asparagine. Also, 1.10 U/ml of FPU and 1.40 U/ml of CBU were shown in the media containing CSL. Finally, the specific activity in the media containing L-asparagine was 34 FPU/mg-protein.

Cellulose is the most abundant organic source of all plant materials. It is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Cellulase is applicable to enzymatic hydrolysis of the bonds and produced from microorganism such as fungi and bacteria. In this study, cellulase was produced by Penicillium sp. KL1 in a 5-L laboratory scale fermentor. The culture medium for fermentation were consisted of 10g/L rice straw, 0.5 g/L yeast extract, 1 g/L KH2PO4 and 0.5 g/L CaCl2. Also, the effects of additives on nitrogen source (5 g/L) were examined using L-asparagine and corn steep liquor (CSL). The fermentation was performed at 30oC, 300 rpm in 5 L vessel during 10 days. After fermentation, the enzyme activities were measured by using filter paper(FP) and ρ-nitrophenyl-β- Dglucopyranoside( ρ-NPG) as substrates and determined by DNS method at 540 nm. Protein concentration was determined at 595 nm according to Bradford method using bovine serum albumin (BSA) as the standard. The enzyme activities were 1.33 U/ml of filter paper unit (FPU) and 1.51 U/ml of β-glucosidase unit (CBU) in the containing L-asparagine. Also, 1.10 U/ml of FPU and 1.40 U/ml of CBU were shown in the media containing CSL. Finally, the specific activity in the media containing L-asparagine was 34 FPU/mg-protein.

Eschscholtzia californica has been known as one of a traditional medicinal plant1) and shown to contain benzo[c]phenanthridine alkaloid used in the treatment of dental plaque and gingivitis.2) Among culture medium composition, nitrogen which exists in inorganic form, such as nitrate or ammonium in culture medium strongly influences on cell growth and secondary metabolites production. In this study, the effect of nitrogen source on cell growth and benzo[c]phenanthridine alkaloids production in suspension culture of Eschscholtzia californica were investigated. Experiments were conducted by modifying NH4 +/NO3 - ratio and total amount of initial nitrogen concentration in Murashige & Skoog (MS) medium. The increase of NH4 +/NO3 - ratio at total nitrogen concentration of 60mM caused decrease on cell growth and alkaloids production. Total amount of initial nitrogen concentration also had influence on cell growth and benzo[c]phenanthridine alkaloids production. From this result, we found that ammonium inhibited cell growth and benzo[c]phenanthridine alkaloids production and then we conducted further study to verify ammonium function.

10 L 공기순환반응기에서 음식물쓰레기 당화액배지의 환원당 농도 70 g/L, 효모가 수분해액을 첨가하여 T-N농도를 2.5 g/L로 조절한 결과, BC생산 농도는 6.67 g/L이었으며, 질소원을 첨가하지 않은 SFW에서보다 생산량이 27% 증가하였다. 같은 조건으로 공기순환배양기에서 50 L 순산소를 첨가하여 확대배양한 결과 BC 생산농도는 7.37 g/L 이었으며, 이때 균의 OUR은 0.214 mg DO/L․min, q O 2은 0.257 mg DO/g cell․min이었다.

Bacterial cellulose(BC) was produced using saccharified food wastes(SFW) medium in air circulation bioreactor. When hydrolyzed yeast was supplied into the SFW medium to increase T-N concentration to 2.5 g/L, 6.67 g/L of BC was produced in 10 L air circulation bioreactor. Therefore, 27% of BC productivity was improved than that of culture with SFW medium. When the culture was scaled up to 50 L air circulation bioreactor, 7.37 g/L of BC was produced by supplement of pure oxygen. Oxygen uptake rate(OUR) and specific respiration rate ( q O 2) in the culture were 0.21 mg DO/L․min and 0.26 mg DO/g cell․min after 12 hours cultivation, respectively. In conclusion, addition of hydorlyzed yeast as nitrogen source into SFW medium considerably improved BC productivity.

본 연구에서는 효모가수분해액을 BC 생산배양의 질소원으로 첨가하여 BC 생산성을 제고시켰다. 효모가수분해액 15%을 첨가하여 BC 생산배지의 총 질소원의 농도(T-N)가 2.60 g/L 일때 BC 농도는 3.4 g/L로 가장 높은 생산성을 보였다. 그리고 50 L 공기순환배양기에서 당화액배지(환원당 농도 70 g/L)에 효모가수분해액을 15% 첨가하고, 공기 공급 시 순산소를 함께 주입하고, 한천분말 0.6%를 첨가하였 을 때, BC 농도는 8.84 g/L에 도달하였다. 이는 질소원을 첨가하지 않고 환원당 농도를 40 g/L로, agar의 농도를 0.4%, 공기만을 주입하여 얻은 BC 농도 6.79 g/L 보다 BC생산성이 30.2% 향상되었다.

To improve bacterial cellulose productivity, yeast hydrolyzed by culture broth of Bacillus alcalophilus, a protease production strain, was added to BC production medium. BC concentration was increased to 3.4 g/L at 100 mL flask when 15% of hydrolyzed yeast was added to BC production medium. At 50 L air circulation bioreactor, BC concentration was increased to 8.84 g/L when 15% of hydrolyzed yeast, 0.6% of agar and pure oxygen were supplemented to BC production medium. As a result, 30.2% of BC productivity was improved comparing to that of our previous study.

포도당의 초기농도 10, 20, 25, 30, 40, 50g/l와 NH4CI의 초기농도 0.33, 0.4, 0.5, 1.5, 3, 50g/l 의 조 합으로 형성된 발효배지를 사용하여 탄소원과 질소 원의 초기 조성비 C/N이 각종 발효 변수의 수율 및 PHB 축적량에 마치는 영향을 규명하여 보았다. 탄소원의 소비량에 대한 균체 수율 Yx/x는 C/N비가 증가함에 따라 대단히 완만하게 감소하였으며 C/N비 70 이상에서는 일정한 값 0.35( g cell biomassl g glucose)를 나타내였다. 잔여균체 수율 YRx/sC/N비가 증가하면 감소하며 C/N비 65 이상에서는 일정한 값 0.065( g residual biomassl g glucose)를 나타내였다. 그러나 PHB의 수율 YPHB/S는 C/N비의 증가에 따라 상승하여 C/N비 40 내지 60 사이에서 최대수율 0.35( g PHB/g glucose)를 나타내었다. 균체증가량에 대한 PHB의 생성수율 는 C/N비의 증가에 따라 증가하나 C/N비 70 이상에셔는 일정한 값 0.83( g PHB/g cell mass)을 유지하였다. 또한 잔여균체량에 대한 PHB의 생성수율도 C/N비 의 증가에 따라 증가하였으며 탄소원이 더이상 소모 되지 않는 상태에셔의 건조균체량에 대한 PHB 축 적률은 C/N비에 따라 상승하여 최대값 81%에 도 달하였다. 이 경우에 대한 C/N값은 67 근방이었으 며 이 이상의 C/N비에 대한 PHB의 축적률은 81% 로 일정하였다.

The effects of ratios of initial concentration of carbon source to the initial concentration of nitrogen source in the fermentation media on both the yields of PHB fermentation variables and the accumulation of poly-B-hydroxybutyric acid(PHB) were investigated. The fermentation media were composed of the combination of varing glucose concentrations, 10, 20, 25, 30, 40, 50g/l and the NH4Cl concentrations 0.33, 0.4, 0.5, 1.5, 3, 5g/l. The yield of biomass on glucos, Yx/s, decreased very slowly according to the increase of the ratio of C to N. And the yield became constant at 0.35(g biomass/g glucose) with the ratio higher than 70. The yield of residual biomass, Yx/s, also decreased with the ratio of C to N and finally showed a constant value of 0.065(g residual biomass/g glucose) when the ratio was higher than 65. In accordance with the augmentation of the ratio, the yield of PHB, YPHB/S, however, increased and showed the maximum value of 0.35 (g PHB/g glucose) between 40 and 60 of the ratio. The maximum yield of PHB to the change of biomass, YPHB/S, was 0.87(g PHB/g biomass), and the yie1d YPHB/RX, was 4.2(g PHB/g residual biomass). The maximum accumulation percent of PHB to the final biomass was 81% when the ratio was higher than 67.

Ammonium limitation did not promote ply(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) production of Azotobacter vinelandii UWD. In acid phase, ammonium limitation during utilization of propionic acid and butyric acid led to 35% decrease in product yield. In glucose phase, both biomass yield and polymer yield decreased about 22% under ammonium limitation. However, in nitrogen-fixing culture glucose was consumed 25% faster and the final PHBV wt% decreased slightly. Under nitrogen limitation a portion of the carbon sources was used fro nitrogen fixation rather than biomass and polymer formation, resulting in a decrease in biomass yield and polymer yield.

곰팡이인 Mortierella alpina DSA-12를 이용한 arachidonic acid의 생산을 위한 유기질소원의 선정과 배양 조건의 결정에 연구를 수행하였다. Corn steep powder (CSP)를 원료의 가격과 arachidonic acid의 생산을 기준으로 유기질소원으로 선정하였다. 탄소원으로 glucose와 질소원으로 CSP를 사용한 경우에 최적의 C/N ratio는 15〜17 범위이다. Arachidonic acid의 생산을 위한 최적의 배양조건은 25℃에서 500 rpm의 교반과 0.5 vvm의 통기이며, 이 때 50 g/L의 glucose와 18g/L의 CSP로부터 21.8 g/L의 균사체량에 10.2 g/L의 총 지질을 얻을 수 있었으며, arachidonic acid의 농도는 3.70 g/L이었다. 500 L의 발효조에서 0.5 vvm과 200 rpm의 교반으로 실험을 수행한 결과 19.8 g/L의 균사체량과 9.1 g/L의 총 지질 및 3.67 g/L의 arachidonic acid를 얻었다. 이러한 결과는 bench-scale의 발효조에서도 질소원으로 CSP를 이용하여 arachidonic acid의 생산이 가능함을 보여주었다.

Experiments were carried out to select an organic nitrogen source and optimize the culture conditions for the production of arachidonic acid by Mortierella alpina DSA-12. Corn steep powder(CSP) was selected as an organic nitrogen source based on arachidonic acid production and raw material price. The optimum C/N ratio was in the range of 15 to 17 with the medium containing glucose as carbon source and CSP as nitrogen source. The optimum culture conditions for arachidonic acid production showed 500 rpm agitation and 25℃ culture temperature at 0.5 vvm aeration. Under the optimum conditions, the concentration of cell, total lipid and arachidonic acid were 21.8 g/L, 10.2 g/L and 3.70 g/L, respectively, from 50 g/L glucose and 18 g/L CSP. In the 500 L fermenter with 0.5 vvm aeration and 200 rpm agitation, the concentration of cell, total lipid and arachidonic acid were 19.8 g/L, 9.1 g/L and 3.67 g/L, respectively, from 50 g/L glucose and 18 g/L CSP. This result showed that an arachidonic acid production could be possible with a bench-scale fermenter using corn steep powder as a nitrogen source.

The effect of concentration of yeast extract and NH4Cl in the mediun of alcohol fermentation of S. cerevisiae ATCC 24858 on the fermentation characteristics, specific growth rate, sugar conversion, alcohol productivity was experimentally investigated. Regardless of initial sugar concentrations, the values of the above three characteristics increased with augument of concentration of yeast extract. However, the increasing tendency ceased above a certain concentration. The concentration of NH4Cl had little effect on the change of the three characteristics. The functional relationships between the concentration of yeast extract and the characteristics were different according to the initial sugar concentrations, but those between the ratio of yeast extract concentration to initial sugar concentration and the characteristics could be expressed as same forms respectively regardless of initial sugar concentrations. Also the values of the three characteristics approached to the maximum values around 0.085 of the ratio, but did not increase any more above 0.1 of the ratio. We have come to conclusion that the optimum ratio of the yeast extract concentration to the initial sugar concentration was about 0.085 and the ratio should not be decided as greater than 0.1 in the medium of alcohol fermentation of S. cerevisiae ATCC 24858.

본 연구에서는 Eschscholtzia californica의 이차 대사산물인 benzo[c]phenanthridine alkaloids의 생산량을 향상시키기 위해 주요 영양성분인 질소원 농도를 조절하여 배지의 조성을 최적화하였다. 그 결과, 질산과 암모늄 이온의 초기 농도 비율은 세포 성장과 alkaloids 생산량 증대에 중요한 영향을 미치는 인자로서 작용함을 볼 수 있었다. 총 질소 농도를 standard MS배지의 총 질소원 농도와 동일하게 유지하고 (60 mM), 농도 비율 다양하게 조절했을 때, 세포 성장과 alkaloids 생산량은 질산과 암모늄 이온을 각각 단독으로 이용할 때 보다 효율적으로 증대함을 볼 수 있었다. 최대 성장 (9.84 g DCW/L)과 alkaloids 생산량(60.72 mg/L)은 50：10의 비율에서 나타났으며, 농도 비율의 감소는 세포 성장을 억제하고 alkaloids 생산량을 감소시켰다. 또한, 질산과 암모늄 이온이 세포 성장과 alkaloids 생산량에 미치는 영향력을 보다 명확히 확인하기 위해 질산이온과 암모늄 이온 농도를 각각 조절한 결과, 암모늄 이온이 증가할수록 alkaloids 생산량은 비슷하나, 세포 성장은 감소하였으며, 또한, 질산 이온의 농도를 증가시킬수록 세포 성장은 비슷한 값을 나타내었지만, alkaloids 생산량은 다양한 차이를 나타내었다. 본 실험에서 세포성장과 alkaloids 생산량에 적합한 농도는 50：25 (mol/mol) 비율에서 나타났으며, 본 실험을 통해 Eschscholtzia californica의 현탁 세포배양에서 질소원 농도의 조절을 통한 외부 환경조절은 세포 성장과 alkaloids 향상에 매우 효과적이며, 소량의 암모늄 이온의 첨가 시 질산 이온 농도조절은 세포 성장을 억제하지 않으면서 alkaloids 생산량을 유도하는데 적합한 이온임을 확인하였다.

The effect of nitrogen source on cell growth and benzo[c]phenanthridine alkaloids production by modifying NO3-:NH4+ ratio in cell suspension culture of Eschscholtzia californica was investigated. When total nitrogen concentration is maintained (60 mM), maximum benzo[c]phenanthridine alkaloids production is about 60.72 mg/L at 50:10 (mol/mol). This productivity was 3.8 times higher than that obtained when cells were grown instandard MS medium. The decrease of NO3 -:NH4+ ratio at 60 mM of total nitrogen caused the decline of both growth and benzo[c]phenanthridine alkaloids production. Under the same concentration of NO3- (50 mM), higher concentration of NH4+ inhibited cell growth strongly but induced alkaloids production slightly. Also, under the same concentration of NH4+ (25 mM), higher concentration of NO3 - induced alkaloids production strongly but high concentration of NO3- (≥100 mM) interfered alkaloids instead. Maximum benzo[c]phenanthridine alkaloids production is about 62.71 mg/L at 50:25 (mol/mol). These results suggest that higher biomass and higher alkaloids production could be obtained by optimizing each nitrogen concentration as well as NO3-:NH4+ ratio in the culture medium. Nitrate and ammonium in culture medium have distinct role in the regulation of growth and alkaloids production; ammonium had a strong influence on growth while nitrate had an influence on alkaloids production.

Xanthomonas Campestris에 의한 Xanthan gum 생산에서 질소원의 영향에 관한 연구 결과를 요약하면 아래와 같다. Sodium glutamate를 질소원으로 채용한 xanthan gum 생산발효에서 세포 생산량에 대한 생산물 생성량, 세포 생산량에 대한 탄소원 소비량은 초기질소농도에 독립적이었다. 0.4-1.0g/L의 So범위에서 B1와 B1는 상수를 보였고 sodium glutamate질소원과 peptone질소원 사이에서 질소원 차이에 따른 차이는 없었다. Xanthan gum생산수율은 탄소/질소농도가 10-16일 때 최대값을 보였다. Peptone질소원은 sodium glutamate질소원보다 세포 성장에 더 효율적이다. Peptone만을 질소원으로 사용한 발효와 혼합질소원을 질소원으로 사용한 발효가 생산물 생산수율 및 발효시간이 유사하므로 xanthan gum생산시 혼합질소원을 질소원으로 사용할 경우 xanthan생산원가를 절감할 수 있다

The effects of nitrogen sources(sodium glutamate and peptone) on the production of xanthan gum were investigated. The fermentation using sodium glutamate as a nitrogen source is longer than that of peptone. In the initial nitrogen concentration of 0.4-1.0g/L, Bs was about 2.0 and Bs was 1.2. The optimal yields were obtained when the carbon source/nitrogen concentration was 10-16. The fermentation time and product yields in the fermentation medium of mixed nitrogen source [sodium glutamate-N(0.75g/L)+peptone-N(0.25g/L)] were similar to those of peptone.