초록 ▼

○ 연구결과
근권 토양에서 분리한 미생물의 IAA 생산능력, 질소고정능력 및 인산가용화능력을 실험한 결과 1차 선발된 400여개의 미생물 중 IAA를 생산하고, 질소고정능력을 동시에 보유하는 미생물은 47개였으며 IAA 생산능력은1.44-28.08ug/ml로 매우 다양하였다. 또한 아세틸렌환원력을 측정하여 질소고정능력을 측정한 결과는 1.72-14.28 nmole/mg-protein/h 로 나타났다. 이러한 IAA 생산 및 질소고정능을 대상으로 15개의 미생물을 대상으로 지방산 분석비교 방법(MIDI)을 이용하여 동정한 결과

○ 연구결과
근권 토양에서 분리한 미생물의 IAA 생산능력, 질소고정능력 및 인산가용화능력을 실험한 결과 1차 선발된 400여개의 미생물 중 IAA를 생산하고, 질소고정능력을 동시에 보유하는 미생물은 47개였으며 IAA 생산능력은1.44-28.08ug/ml로 매우 다양하였다. 또한 아세틸렌환원력을 측정하여 질소고정능력을 측정한 결과는 1.72-14.28 nmole/mg-protein/h 로 나타났다. 이러한 IAA 생산 및 질소고정능을 대상으로 15개의 미생물을 대상으로 지방산 분석비교 방법(MIDI)을 이용하여 동정한 결과 Psudomonas 및 Burkholderia가 많은 것으로 나타났다. 또한 이 15종의 균을 대상으로 인산가용화능을 측정한 결과 이 중 10개의 균이 인산가용화능을 나타내었다. 다양한 기능을 보유하고 있는 농업용 유용미생물을 경제적으로 대량생산하기 위해서는 동시에 다양한 미생물이 상호간에 길항관계를 갖지 않고 잘 생육할 수 있는 조합 및 배양방법이 필수적으로 요망된다. 질소고정균과 인산가용화균의 동시 배양기술을 이용하여 이러한 배양방법 및 길항작용 여부를 조사한 결과 yeast extract mannitol 변형배지를 이용하여 두 가지 상이한 균주의 접종시차를 적절하게 조절하면 하나의 배지에서 두 가지 이상의 상이한 균주를 동시에 배양하는 것이 가능하리라 판단되었다. 또한 인산 가용화능이 우수한 Burkholderia sp.strain CBPB-HIM를 대상으로 제조, 보관 및 운송이 편리한 입상 미생물 비료 개발을 목표로 경제적 담체인 황토 및 쌀겨를 이용하여 입상 미생물 제제화의 최적 조건을 선발하기 위하여 수행되었다. 황토:쌀겨(1:1) 를 이용하여 입상화 한 것이 황토:쌀겨(1:1)+10% 인광석을 이용하여 입상화 한 것에 비하여 생존 세포 수가 높았는데, 이는 인광석이 펠렛에 공극을 늘려 건조가 심해진 것을 주요인으로 생각된다. 탄소원으로서 glucose를 첨가한 것이 glycerol을 첨가한 것보다 생존 세포 수를 높여줬는데 이는 glycerol이 입자 표면으로 확산되어 균이 이용할 수 없기 때문으로 추정된다. 황토와 쌀겨(1:1)+10% 인광석을 이용하여 입상화한 제품의 저장 중 균의 생존률이 다른 조합을 이용하여 입상화한 제품보다 유의성 있게 높았다. 황토와 쌀겨(1:1)+10% 인광석을 이용하여 입상화시 탄소원 첨가의 효과는 1% glucose를 첨가한 것이 glycerol을 첨가한 경우와 탄소원을 화는 저장한지 5일 만에 기록했다.첨가하지 않은 경우보다 Burkholderia sp.의 생존 세포수가 높게 나타났다. 함유된 인광석의 인산 가용화 능력에 있어서 수용성 인은 황토와 쌀겨(1:1)+10% 인광석으로 이뤄진 입상 제제에 glucose 1%가 첨가된 경우 206 mgP kg^-1로서 가장 높았으며, 중조 가용성 인의 경우는 glycerol 1%가 첨가된 입상 제제가 206 mgP kg-1로서 가장 높았다. 두 경우 모두 최고의 가용화능을 보였다.
질소고정균(N)과 인산가용화균(P)의 종자처리는 무처리에 비하여 발아율 및 발아세에 유의성 있는 증가를 보였으며 각각의 단독처리에 비하여 복합 처리 시 그 증가율이 더욱 컸다. 또한 처리 방법[M(N+P)와 S(N+P)]간에는 유의성 있는 차이를 나타내지 않았다.
복합처리 방법[M(N+P)]과 단독처리 방법[S(N+P)]에 따른 식물체의 생육을 조사한 결과. 식물체의 건물량, 지상부 및 지하부 길이 모두 접종구에서 유의성 있는 증가를 나타내었다. 복합처리 방법 간에는 생육 초기에는 동시배양균처리가 건물량 증가에 더 큰 영향을 나타내었으며 중반기 이후에는 건물량, 지상부 및 지하부 길이가 단독 배양하여 복합처리 한 것에 비하여 우수 하였다.
Methylobacterium oryzae와 N fixing Azospirillum brasilense 와 P-solubilizing bacterium Burkholderia sp. strain CBPB-HOD 의 접종을 통해 토마토와 고추, 벼의 세 가지 다른 작물의 생장과 양분 흡수 효과를 평가하였다. 토마토에 대한 3종 균주(CW903, CBPB-HOD, CBMB20)의 단독 및 복합처리 효과는 무처리구와 비교했을때 뿌리와 근권에서 줄기 길이, 가지 둘레, nitrogenase 활성들의 증가를 나타내었다. 그러나 무처리구와 비교하여 세 가지 균주를 한 번에 접종시킨 경우에는 뿌리길이가 짧고 nitrogenase 활성도 현저히 낮았다. 고추에서 CBMB20의 접종은 다른 두 균주의 접종과 비교했을 때 줄기와 뿌리가 가장 컸음을 보였고, CBMB20과 CW903, CBPB-HOD와 CW903의 혼합 접종은 뿌리에서 가장 높은 nitrogenase 활성을 나타내었다. 벼에서 CBMB20와 CW903 또는 CBPB-HOD의 혼합접종은 지상부의 길이가 가장 크게 나타났으며 CW903와의 혼합접종이 뿌리의 생육이 우수하였다. 종합적으로 보면, 박테리아 균주의 단일접종이나 혼합접종 영향은 작물마다 다양하게 나타나며, 양분 흡수도 양분의 종류에 따라 다르게 나타났다. 그렇지만 M. oryzae CBM20의 접종은 단일접종을 하거나 다른 균주와 혼합접종을 하는 경우 모두 작물생장이 증가하였다.

Abstract ▼

ㆍ Plant growth in agricultural soils is influenced by a myriad of abiotic and biotic factors. While growers routinely use physical and chemical approaches to manage the soil environment to improve crop yields, the application of microbial products for this purpose is less common. The rhizosphere, th

ㆍ Plant growth in agricultural soils is influenced by a myriad of abiotic and biotic factors. While growers routinely use physical and chemical approaches to manage the soil environment to improve crop yields, the application of microbial products for this purpose is less common. The rhizosphere, the narrow zone of soil surrounding the root that is under the immediate influence of the root system, is relatively rich in nutrients, due to the loss of as much as 40% of plant photosynthates from the roots. Consequently, the rhizosphere supports large and active microbial populations that not only benefit from the nutrients secreted by the plant root but also beneficially influence the plant in a direct or indirect way, resulting in a stimulation of its growth. The importance of rhizosphere microbial populations for maintenance of root health, nutrient uptake, and tolerance of environmental stress is now recognized. Beneficial free-living soil bacteria are generally referred to as plant growth-promoting rhizobacteria (PGPR) and are found in association with the roots of many different plants. The bacteria that provide some benefit to plants are of two general types: those that form a symbiotic relationship, which involves formation of specialized structures of nodules on host plant roots, and those that are free-living in the soil; the latter are often found near, on or even within plant tissues.
The so called PGPR classified according to their beneficial effects, can be a significant component of management practices to achieve the attainable yield. Although numerous free-living soil bacteria are considered to be PGPR, not all bacterial strains of a particular genus and species have identical metabolic capabilities and interactions with plants. The large scale applications of PGPRs to crops as inoculants would be attractive leading to potential environmental benefits; reducing the use of agricultural chemicals. The prospect of manipulating crop rhizosphere microbial populations by inoculation of beneficial bacteria to increase plant growth has shown considerable promise in laboratory and greenhouse studies, but responses have been variable in the field. Recent progress in our understanding of the biological interactions that occur in the rhizosphere and of the practical requirements for inoculant formulation and delivery should increase the technology's reliability in the field and facilitate its commercial development.
This article gives an overview of the potential roles and different mechanisms of by which PGPR have been found to promote plant growth. Here we extend the potential for the PGPR to contribute as biofertilizers for field crops. We also advance the thesis that PGPR may promote crop yield increases by modifying soil-plant processes so that N and other nutrients are more completely retained in the plant0soil system.
ㆍ Nitrogen-fixing bacteria where isolated from the rhizosphere of different crops of Korea. A total of 16 isolates were selected and characterized. Thirteen of the isolates produced characteristics similar to those of the reference strains of Azospirillum, and the remaining 3 isolates were found to be Enterobacter spp. The isolates could be categorized into 3 groups based on their ARDRA patterns, and the first 2 groups comprised Azospirillum brasilense and Azospirillum lipoferum. The acetylene reduction activity (ARA) of these isolates was determined for free cultures and in association with wheat roots. There was no correlation between pure culture and plant-associated nitrogenase activity of the different strains. The isolates that showed higher nitrogenase activities in association with wheat roots in each group were selected and sequenced. Isolates of Azospirillum brasilense CW301, Azospirillum brasilense CW903, and Azospirillum lipoferum CW1503 were selected to study colonization in association with wheat roots. We observed higher expression of β-galactosidase activity in A. brasilense strains than in A, lipoferum strains, which could be attributed to their higher population in association with wheat roots. All strains tested colonized and exhibited the strongest β-galactosidase activity at the sites of lateral roots emergence.
ㆍ Mass culturing of two beneficial organi는 used as biofertilizers for crops would reduce the risks in production and minimize the capital involved and this demands appropriate media that supports both organism and also selection of organi는 that are not antagonistic to each other. A study was initiated to culture a nitrogen fixer (Rhizobium) and phosphate solubilizer (Bacillus megaterium) in a single medium and to study their growth patterns and shelf llife in carrier. The growth of Rhizobium and Bacillus megaterium was assessed in different media and a slight modification in the traditional yeast extract mannitol media promoted the growth of both the organisms. The growth of the individual organisms in the modified medium was assessed by estimating the population at regular intervals and compared to their original medium. Maximum population of Rhizobium and phosphobacteria was at 60 hr when the phosphiobacteria inoculation of later was after 48 hr of Rhizobium inoculation. The shelf life of the individual organisms inoculated in a sterilized carrier. The population of both organisms in carrier based mixed inoculant remained at 108 cells till 90 days.
ㆍ Inoculation of the carrier-based mixed bioinoculants of N-fixer (Azospirillum lipoferum strain Az204/Rhizobium strain BMBS P47) and phosphate -solubilizing bacterium(Bacillus megaterium var phosphaticum strain Pb1) promoted growth and yield of pearl millet and blackgram under potculture conditions. The mixed inoculant of Az204 and Pb1 enhanced germination, seedling vigor, plant height, and seed weight, and resulted in 6% increase in grain yield of pearl millet. Likewise, the mixed inoculant of BMBS P47 and Pb1 Pb1 increased growth, nodulation, and yield in blackgram. The rhizosphere soil enzyme activities, including nitrogenase, urease, and phosphatase, in in both pearl millet and blackgram were significantly increased by the inoculation of the mixed inoculant, compared to that of the individual inoculants. The results clearly indicate the beneficial effect of co-culturing the N-fixer and P-soubilizer in inoculants production.
ㆍ Penicillium oxalicum strain CBPS-3F-Tsa, an efficient phosphate solubilizing fungus, was evaluated for production of organic acid in vitro and effectof inoculation on the growth promotion of Maize under greenhouse conditions. The fungus solubilized 129.1, 118.8 and 54.1 mg P/l of tri-calcium phosphate [Ca3(PO4)2], aluminium phosphate (AlPO4) and ferric phosphate (FePO4), respectively, after 72 h of incubation. Malic acid, gluconic acid and oxalic acid were detected in the flasks supplemented with various phosphate sources together with large amount of malic acid [240, 146, 145 mM AlPO4, FePO4, and Ca3(PO4)2 respectively] followed by the other two. The effects of inoculation of P. oxalicum CBPS-3F-Tsa on maize plants were studied under pot culture conditions. P. oxalicum CBPS-3F-Tsa was inoculated to maize plants alone or together with inorganic phosphates in the form of fused phosphates (FP) and rock phosphates (RP). Inoculation of P. oxalicum CBPS-3F-Tsa increased the plant growth, and N and P accumulation in plants, compared to control plants, and also had positive effects when applied with RP. The results of this study show that the fungus P. oxalicum strain CBPS-3F-Tsa could solubilize different insoluble phosphates by producing organic acids, particularly malic acid, and also improved the efficiency of RP applied to maize plants.
ㆍ Five phosphate solubilizing bacteria (PSB)used in this study were screened based on their ability to solubilize tricalcium phosphate (TCP) in Pikovskaya's medium. Among tested bacterial strains Burkholderia sp. strain CBPB-HIM showed the highest solubilization (363 μg of soluble P ml-1) activity at 48 h of incubation. Further, this strain has been selected to assess its shelf life in nutrient amended and unamended clay, rice bran and rock phosphate (RP) pellet based granular formulation. The results showed that the maximum viability of bacterium was observed in clay and rice bran (1:1) + 10% RP pellets than clay-RP pellets, irrespective of testedstorage temperatures. Further, clay and rice bran (1:1) + 10% RP pellets amended with 1% glucose supported the higher number of cells compared to glycerol amended and nutrient unamended pellets. In this carrier solubilization of Morocco rock phosphate (MRP) by Burkholderia sp. strain CBPB-HIMwas also investigated. The maximum of water and bicarbonate extractable P (206 and 245 μg P g-1of pellet respectively) was recorded in clay and rice bran (1:1) + 10% RP pellets amended with 1% glucose and glycerol respectively on day 5 of incubation. Therefore,this study proved the possibility of developing granular inoculant technology combining clay, rice bran and RP as substrates with phosphate solubilizing Burkholderia.
ㆍ The composition of thebacterial community associated with plant roots is influenced by a variety of plant, environmental factors and also management practices. Our study aimed at detecting the root associated bacterial communities of Chinese cabbage under different fertilization regimes using cultivation dependent methods. The cultivable population was studied using plate countassay, fatty acid methyl ester (FAME) analysis and carbon substrate utilization using BIOLOG™plates. Taxonomical identification of the isolates by FAME resulted in about 83% identification and they represented 9 and 14 different known bacterial genera from the rhizosphere and root interior respectively from Proteobacteria (α, β, and γ ), firmicutes (actinobacteria and the Bacillus groups) and Bacteroidetes. Pseudomonas and Bacilluswere associated with the plants grown under all the fertilized conditions and actinobacteria could be observed only in rhizosphere of plants grown on unfertilized plots. FAME and BIOLOG profiles of the rhizosphere and endophytic isolates could separate them with reference to fertilization. Principal component analysis (PCA) on the BIOLOG substrate utilization revealed that the isolates were metabolically dissimilar. The diversity, as revealed by the diversity indices was greater among the isolates obtained from unfertilized samples than that of fertilized ones. The isolates analyzed for different traits related to plant growth promotion revealed differences between rhizosphere and endophytic isolates and also with reference to the treatments. The highest percentage of phosphate solubilizing bacteria (PSB) and 1-aminocyclopropane-1-carboxylic acid (ACC)utilizers was recorded in chemical fertilizer treated samples, followed by the organic fertilizer treated. The results from this study indicate that fertilizers have an effect on the root associated bacterial communities of Chinese cabbage and also on their physiological characteristics related to plant growth promotion.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 요약문 ... 3
• SUMMARY ... 14
• CONTENTS ... 19
• 목차 ... 20
• 제 1 장 연구개발과제의 개요 ... 21
• 제 2 장 국내외 기술개발 현황 ... 25
• 제 3 장 연구개발내용 및 결과 ... 27
• 제 1 절 연구개발 수행 내용 ... 27
• 제 2 절 연구개발 수행 결과 ... 39
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 86
• 제 5 장 연구 개발 결과의 활용계획 ... 94
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 95
• 제 7 장 참고문헌 ... 105
• 끝페이지 ... 130