• 한국양식학회지
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• 제10권3호
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• pp.327-334
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• 1997

카제인과 알파전분으로 구성된 표준사료 70%와 실험코자하는 원료사료 30%를 함유하는 시험사료를 제조하여 평균 어체중 55 g의 이스라엘 잉어에 의한 원료사료의 단백질, 지방, 회분, 칼슘, 인 및 에너지 소화율을 측정하였다. 소화율의 측정은 27일간의 성장실험과 병행하여 수행되었는데, 분채집은 성장실험의 최종 10일간 행하였다. 실험기간 동안의 수온은 26-$30^\circC$로 유지되었으며 사료는 일일 5회씩 급여하였다. 본 실험에서 얻어진 결과는 다음과 같다. 일인산칼슘(MCP) 함유구를 섭취한 어류의 증체량, 사료요구율 및 단백질 이용효율이 처리구중 가장 우수하였으며, 어분 함유구가 공히 그 다음으로 우수한 성장 및 단백질 이용효율을 나타내었다. 식물성 원료사료중에서는 맥주효모 및 콘글루텐 함유구가 성장과 단백질 이용효율이 우수하였다. 전반적으로 실험어류는 실험사료를 잘 섭취하였으며, 정상적인 성장을 보였다. 단백질 소화율은 대두박(SBM)이 91.9%로 시험원료중 가장 높았으며, 호마박(SSM)이 77.6%로 가장 낮았다. 어분(간접식 백색어분 : WFM-S : 직접식 백색어분 : WFM-F : 갈색어분 : BFM)의 경우 85.8% (BFM)에서 87.8% (WFM-F)로 86.6%의 소화율을 나타낸 소맥분 (WFL)과 유의적인 차이가 없었다. 어분의 지방 소화율은 83.5% (BFM)에서 85.8% (WFM-S와 WFM-F)로 유사하였으며, 호마박(SSM)이나 맥주효모(BY)의 소화율과 유의적인 차이를 보이지 않았다. 한편, 시험원료중 지방함량이 가장 낮았던 SBM과 콘글루텐(CGM)의 소화율은 각각 88.3% 및 74%로 처리구중 각각 가장 높은 수치와 가장 낮은 수치를 보였다. 회분의 소화율은 MCP가 77.1%로 가장 우수하였으며, BY가 62.5%로 그 다음이었다. WFM-F은 4.8%인데 비해 WFM-S와 BFM은 각각 10.7% 및 10.6%로 유사하였다. CGM은 1.5%로 처리구중 가장 낮았다. 칼슘의 소화율은 회분 소화율과 동일한 경향을 보였으며, 인 소화율의 경우 WFM-S가 13.6%로 WFM-F (6.6%)와 BFM (8.5%)에 비해 높았다. BY 및 MCP의 인 소화율은 각각 57.2% 및 80.6%로 높게 나타났다. 에너지 소화율은 어분이 77.4-81.3%로 식물성 원료사료에 비해 높게 나타났으며, 식물성 원료사료중에서는 BY가 70.6%로 SBM, SSM 및 WFL과 유의적인 차이를 보이지 않았으나 CGM (64.5%)은 이들중 가장 낮았다(P<0.05). 본 실험의 결과 자료는 이스라엘 잉어에 의한 관행 원료사료내 영양소 및 에너지의 이용율의 수준을 보여주고 있으며, 사료배합시 또는 배합된 사료내 가소화 단백질 및 이용가능 인 함량을 예견하는데 유용하게 사용될 수 있을 것이다. 그러나 가소화 에너지 소화율 자료는 대부분의 시판잉어사료가 잎스트루젼 공정을 거쳐 제조된다는 점을 고려할 때 이용가능한 에너지 함량계산에 직접 활용될 수는 없을 것이다.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.118-126
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• 2020

Silicon and phosphorus are elements that are beneficial for plant growth. Despite the abundant availability of silicate and phosphate in the Earth's crust, crop nutritional requirements for silicon and phosphorus are normally met through the application of fertilizer. However, fertilizers are one of the major causes of heavy metal pollution. In our study, we aimed to assess silicate and phosphate solubilization by the bacteria Enterobacter ludwigii GAK2, in the presence and absence of phosphate [Ca₃(PO₄)₂] or silicate (Mg₂O₈Si₃), to counteract cadmium stress in rice (Oryza sativa L). Our results showed that the GAK2-treated rice plants, grown in soil amended with phosphate [Ca₃(PO₄)₂] or silicate (Mg₂O₈Si₃), had significantly reduced cadmium content, and enhanced plant growth promoting characteristics including fresh shoot and root weight, plant height, and chlorophyll content. These plants showed significant downregulation of the cadmium transporter gene, OsHMA2, and upregulation of the silicon carrier gene, OsLsi1. Moreover, jasmonic acid levels were significantly reduced in the GAK2-inoculated plants, and this was further supported by the downregulation of the jasmonic acid related gene, OsJAZ1. These results indicate that Enterobacter ludwigii GAK2 can be used as a silicon and phosphorus bio-fertilizer, which solubilizes insoluble silicate and phosphate, and mitigates heavy metal toxicity in crops.

• Journal of Ecology and Environment
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• 제39권1호
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• pp.31-42
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• 2016

The object of this study was to determine long-term temporal and spatial patterns of nutrients (nitrogen and phosphorus), suspended solids, and chlorophyll (Chl) in Chungju Reservoir, based on the dataset of 1992 - 2013, and then to develop the empirical models of nutrient-Chl for predicting the eutrophication of the reservoir. Concentrations of total nitrogen (TN) and total phosphorus (TP) were largely affected by an intensity of Asian monsoon and the longitudinal structure of riverine (Rz), transition (Tz), and lacustrine zone (Lz). This system was nitrogen-rich system and phosphorus contents in the water were relatively low, implying a P-limiting system. Regression analysis for empirical model, however, showed that Chl had a weak linear relation with TP or TN, and this was mainly associated with turbid, and nutrient-rich inflows in the system. The weak relation was associated with non-algal light attenuation coefficients (Kna), which is inversely related water residence time. Thus, values of Chl had negative functional relation (R² = 0.25, p < 0.001) with nonalgal light attenuation. Thus, the low chlorophyll at a given TP indicated a light-limiting for phytoplankton growth and total suspended solids (TSS) was highly correlated (R² = 0.94, p < 0.001) with non-algal light attenuation. The relations of Trophic State Index (TSI) indicated that phosphorus limitation was weak [TSI (Chl) - TSI (TP) < 0; TSI (SD) - TSI (Chl) > 0] and the effects of zooplankton grazing were also minor [TSI (Chl) - TSI (TP) > 0; TSI (SD) - TSI (Chl) > 0].

• 한국산림과학회지
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• 제98권2호
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• pp.170-177
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• 2009

There are remarkable differences in growth and morphological characters of roots between mountain and field cultivated Panax ginseng. Growth of root in mountain cultivated ginseng was much slower than that of field cultivated ginseng. However, the factor affecting the retarded growth in mountain ginseng was not known. Soil analysis revealed that phosphorus (P) content of mountain soil was exceptionally low at least ten-fold lower compared to that of field soil. Thus, we suggest that low availability of P in mountain soil may be one of the limiting factors for growth of ginseng in mountain soil environment. We had monitored the growth of ginseng plants after one and three years of phosphate fertilizer application. Three kinds of phosphate fertilizers: fused magnesium phosphate, fused superphosphate, and single superphosphate were applied to mountain soil. Application of phosphate fertilizers increased the fresh-, dry weight, and diameter of ginseng roots and resulted in increased P accumulation in roots. These results demonstrate that slow growth of ginseng in mountain soil environment might be attributed to the low P content in mountain soil. Thus, analysis of P amount in mountain soil will be a good indicator for the selection of suitable site the ginseng cultivation in forest.

• 한국작물학회지
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• 제26권3호
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• pp.226-232
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• 1981

냉온하(7~9월)에서 생육한 수도에 대한 재배수건별(표고별, 품종별) 냉해와 도체경엽중 유효규산 및 인산함량과의 관계를 밝히고져 경남북 일도에 걸처 냉해실태를 조사하여 분석해 본 결과는 다음과 같다. 1. 임실비율은 표고가 높아질수록 떨어졌으며 통일계품종에서 더욱 현저하였다. 2. 임실비율 증가에 따라 토양중 $SiO_2/P_2 O_5$ 함량비는 낮아졌고 도체경엽중에서는 높아졌다. 3. 규산이 인산함량에 비하여 도체의 경엽중에서는 10.5\sim20.5배 정도 토양중에는 0.28~0.78배로 함유되어 있었다. 4. 임실비율과 도체경엽중 $SiO_2/P_2 O_5$함량비와는 정의 유의상관이 인정되었다. 5. 식물체중 규산함량 증가에 따른 임실비율 증가는 일반계품종보다 통일계정종에서 현저하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.824-829
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• 2000

A five wk feeding experiment was conducted with day-old one thousand broiler chicks (Arbor Acres) to determine the effects of microbial phytase (Natuphos$^{(R)}$) supplemented to low nonphytate P (NPP) corn-soy diets. Five pens of 50 mixed sex birds each were randomly assigned to each of the four dietary treatments: T1, control diet containing normal NPP level; T2, T1-0.1% NPP+600 U of phytase/kg diet; T3, T1 - 0.2% NPP+600 U of phytase/kg diet; and T4, T1 - 0.3% NPP+600 U of phytase/kg diet. T1, T2, and T3 showed similar growth rate, feed intake, and feed efficiency, indicating that NPP level in broiler diets could be reduced by approximately 0.2% by the microbial phytase supplementation. But T4 showed significantly (p<0.05) lower weight gain than others. The phytase supplementation improved P availability resulting in low P excretion. Weight and girth of metatarsal bone were increased by phytase supplementation at low NPP diet treatments but ash contents were not significantly different. It can be concluded that NPP level of corn-soy broiler diets can be safely lowered by approximately 0.2 % by supplementing 600 U of microbial phytase/kg diet. With the adjusted level of NPP and phytase supplementation, P excretion could be reduced by 50%.

• Journal of Ecology and Environment
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• 제40권1호
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• pp.5-11
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• 2016

Background: As the decomposition of lignocellulosic compounds is a rate-limiting stage in the nutrient mineralization from organic matters, elucidation of the changes in soil enzyme activity can provide insight into the nutrient dynamics and ecosystem functioning. The current study aimed to assess the effect of thinning intensities on soil conditions. Un-thinned control, 20 % thinning, and 30 % thinning treatments were applied to a Larix kaempferi forest, and total carbon and nitrogen, total carbon to total nitrogen ratio, extractable nutrients (inorganic nitrogen, phosphorus, calcium, magnesium, potassium), and enzyme activities (acid phosphatase, ${\beta}$-glucosidase, ${\beta}$-xylosidase, ${\beta}$-glucosaminidase) were investigated. Results: Total carbon and nitrogen concentrations were significantly increased in the 30 % thinning treatment, whereas both the 20 and 30 % thinning treatments did not change total carbon to total nitrogen ratio. Inorganic nitrogen and extractable calcium and magnesium concentrations were significantly increased in the 20 % thinning treatment; however, no significant changes were found for extractable phosphorus and potassium concentrations either in the 20 or the 30 % thinning treatment. However, the applied thinning intensities had no significant influences on acid phosphatase, ${\beta}$-glucosidase, ${\beta}$-xylosidase, and ${\beta}$-glucosaminidase activities. Conclusions: These results indicated that thinning can elevate soil organic matter quantity and nutrient availability, and different thinning intensities may affect extractable soil nutrients inconsistently. The results also demonstrated that such inconsistent patterns in extractable nutrient concentrations after thinning might not be fully explained by the shifts in the enzyme-mediated nutrient mineralization.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.673-680
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• 2000

An experiment was conducted with day-old 300 commercial male broiler chicks (Arbor Acres$^{(R)}$) to evaluate the efficacy of crude phytase preparerations produced from a culture of Aspergillus ficcum. The experiment consisted of five dietary treatments; T1, com-soy control diet with 0.45% non-phytate phosphorus (NPP) for starter period and 0.35% NPP for grower period; T2, control - 0.1% NPP; T3, control 0.2% NPP; T4, T3+600 U of crude phytase (broth+cell); and T5, T3+600 U of crude phytase (broth). The body weight gain, feed intake, and feed/gain of chickens fed T1 diet was highest (p<0.01) among treatments. BW gain and feed intake of T4 and T5 were greater than those of T3 but were less than those of T1 and T2. T3 was highest in mortality among treatments. Decreasing the NPP level lowered availability of DM, crude ash, ether extract, crude fiber, Zn, and Fe but supplementation of crude phytase preparations improved the availability of these nutrients as well as those of Ca, P and Cu. Excretion of P and Cu significantly decreased as the NPP level in the diet decreased. Further reduction of P and Cu excretion and reduction of Ca, Mg and Fe excretion were achieved by supplementation of crude phytase preparations. The serum concentrations of Ca, P, Mg, Zn, Fe, and Cu were significantly increased by crude phytase supplementation. The weight and length of tibia, and contents of crude ash, Ca, P, Mg, and Zn were adversely affected by lowering NPP level but partially recovered by supplementation of crude phytase preparations. In conclusion, lowering NPP level in the broiler diet significantly depressed the performance. Supplementation of crude phytase preparations produced from Aspergillus ficuum could partially recover the depression.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.125-130
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• 2005

The growth and phosphatase (phosphomonoesterase) activity of Chroococcidiopsis culture isolated from the cryptoendoliths of the Antarctic were compared with a similar isolate from the Arizona hot desert. Such cyanobacteria living inside rocks share several features with the immobilized cells produced in the laboratory. This study has relevance because the availability of phosphorus is a key factor influencing the growth of these cyanobacteria in nature, in such unique ecological niches as the hot and cold deserts. Phosphatase activity therefore is of particular importance for these organisms if they are to survive without any other source of phosphorus availability. Also, there is paucity of knowledge regarding this aspect of study in cyanobacterial cultures from these extreme environments. The salient feature of this study shows the importance of specific pH and temperatures for growth and phosphatase activity of both cultures, although there were marked differences between the two isolates. The pH and temperature optima for growth and phosphatase activity (PMEase) of Chroococcidiopsis 1 and 2 were 9.5, $240^{\circ}C$ and 8.5, $40^{\circ}C$ respectively. The $K_m and V_max$ values of cultured Chroococcidiopsis 1 showed lower affinity of PMEase for the substrate compared to the enzyme affinity of the same organism when found within the rocks; Chroococcidiopsis 2 and Arizona rocks containing the same alga however showed similar affinity of PMEase for the substrate. An interesting observation was the similarity in response of immobilized Chroococcidiopsis 1 culture and the same organism in the Antarctic rocks to low light and low temperature stimulation of PMEase. This thermal response seems to be related to the ability of the immobilized Antarctic isolate and the rocks to either cryoprotect the PMEase or undergo a change to save the enzyme from becoming nonfunctional under low temperatures. The free cells of Chroococcidiopsis 1 culture however did not show such responses.

• 한국토양비료학회지
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• 제10권1호
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• pp.13-22
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• 1977

우리나라 주요토양(主要土壤)에 있어서 인산(燐酸)이 어떠한 형태(形態)로 분포(分布)하고 있으며, 그 토양인산(土壤燐酸)의 특성(特性)이 어떠한지를 밝히고 나아가 인산질자원(燐酸質資源)을 합리적(合理的)으로 사용(使用)하기 위한 기본적(基本的)인 정보(情報)를 얻고저 본시험(本試驗)을 실시(實施)했든바, 그 중(中)에서 무기태인산(無機態燐酸)에 관(關)한 연구결과(硏究結果)는 다음과 같다. 1. 일반적(一般的)으로 대부분(大部分)의 인산(燐酸)은 무기태(無機態)로 존재(存在)하며, 경작지(耕作地)는 미경지(未耕地)에 비(比)해 무기태(無機態)로 존재(存在)하는 인산비율(燐酸比率)이 더 높은 것으로 나타났다. 유기인산(有機燐酸)의 비율(比率)은 미경지(未耕地)보다 경지(耕地), 전(田)보다 답(畓)에서 더 높았다. C/P율(率)은 경지(耕地)보다 미경지(未耕地)에서 매우 크며, 그 비율(比率)과 인산지력(燐酸地力)과의 관계(關係)를 추측(推測)되었다. 2. 무기태인산(無機態燐酸)의 일반적(一般的)인 분포(分布)는 Fe-P>Al-P>Apatire-P>Ca-P의 순(順)이었다. 미경지(未耕地)에서는 모암(母岩)의 영향(影響)이 잘 반영(反影)돼 있으며, 이 경향(傾向)은 전(田)으로 이용(利用)되고 있는 토양(土壤)에 까지 다소(多少) 나타났으나, 답(畓)에서는 거의 똑같은 분포상태(分布狀態)가 나타났다. 3. 일반적(一般的)으로는 미경지(未耕地) 및 전토양(田土壤)에서 Lancaster법(法)으로 침출(浸出)된 인산(燐酸)이, 답(畓)에서는 Olsen법(法)에 의(依)한 침출인산(浸出燐酸)이 가장 높았다. Ca-P, Al-P는 Truog법(法), Lancoster법(法), Olsen법(法)에 의(依)한 유효인산(有効燐酸)과, Fe-P는 Olsen법(法)에 의(依)한 유효인산(有効燐酸)과 깊은 상관관계(相關關係)를 보였다. 4. 인산흡수계수(燐酸吸收係數)와 무기태인산(無機態燐酸) 및 유효인산(有効燐酸) 사이에 깊은 상관관계(相關關係)가 인정(認定)되었다.