Isolation and characterization of algicidal marine bacteria against harmful algal blooms
- Alternative Title
- 유해적조에 대한 해양 살조세균의 분리 및 특성
- Abstract
- 유해적조에 대한 유용한 생물학적 제재로 새로운 살조세균을 개발하기 위해 해양세균을 분리하고, 유해적조생물의 생장에 대한 억제효과를 실험하였다. 분리된 세 균주는 Alexandrium catenella와 Cochlodinium polykrikoides 그리고 Chattonella marina 등 유해적조생물 3종에 대해 뚜렷한 살조활성 (algicidal activity)을 나타내었다. 이들 균주는 각각 Arthrobacter sp., Brachybacterium sp. 그리고 Bacillus sp.로 동정되었다. 이 균주들은 살조물질분비형 살조세균으로 살조물질을 분비하여 유해적조종을 죽이며, 테스트된 대부분의 유해적조생물에 대해 살조효과를 나타내었다. 그러나 규조류와 다른 먹이생물에 대해서는 성장저해효과를 발견할 수 없었다. 이와 같은 결과들은 Arthrobacter sp., Brachybacterium sp. 및 Bacillus sp. 3균주의 살조활성이 유해적조를 제어하는데 있어 잠재적으로 유용함을 시사해 준다. 살조세균이 적조생물을 어떤 물질을 생성하여 제어하는지를 보다 잘 이해하기 위해 분비된 살조물질을 동정하였다. Brachybacterium sp. AB-3가 생성한 살조물질을 분리하였고, NMR 구조분석을 실시한 결과 살조물질은 β-carboline으로 동정되었다. β-carboline은 Alexandrium catenella에 대해 1 ㎍/㎖의 LC50 (반수치사농도) 값을 가졌다. β-carboline은 이외에도 다른 유해적조 생물종들에 대해서도 넓은 범위의 뛰어난 살조활성을 나타내었다. β-carboline은 열에 비교적 안정하였고, pH 3, 4, 5를 제외한 다양한 pH에서 안정하였다. 이 결과들은 Brachybacterium sp. AB-3가 생산한 β-carboline이 유해적조 생물을 죽이거나 억제하는데 있어서 매우 효과적이라는 사실을 시사해준다.
In order to exploit the novel algicidal bacteria as a useful biological agent against harmful algal blooms (HABs), marine bacterial strains were isolated and their inhibitory effects for the growth of HAB species was examined. The isolated three strains exhibited significant algicidal activity against HAB species Alexandrium catenella, Chattonella marina, and Cochlodinium polykrikoides. The isolated algicidal bacteria were identified as Arthrobacter sp., Brachybacterium sp. and Bacillus sp., respectively. The strains killed HAB species as an indirect attacker and showed apparent algicidal effects against most HAB species tested. However, no inhibitory effects were found vis-a-vis the growth bacillariophyceae or livefood organisms cultures. These result indicate that the algicidal activities of Arthrobacter sp., Brachybacterium sp. and Bacillus sp. are potentially useful in controlling HABs. The released algicides were identified to understand better how algicidal bacteria killed their prey. The algicidal compounds produced by Brachybacterium sp. AB-3 was purified and led to reveal the structure of a β-carboline through NMR (nuclear magnetic resonance) analyses. β-carboline showed a significant algicidal activity against Alexandrium catenella at a LC50 (lethal concentration) of 1 ㎍/㎖. In addition, β-carboline represented algicidal activities against a wide range of other HAB species. β-carboline was heat-tolerant and stable in pH variations except pH 3, 4 and 5. These result demonstrated that β-carboline from Brachybacterium sp. AB-3 were very effective at killing or inhibiting of HAB species.
- Issued Date
- 2009
- Awarded Date
- 2009. 2
- Type
- Dissertation
- Keyword
- 유해적조
- Publisher
- 부경대학교 대학원
- Alternative Author(s)
- Kim, Yun Sook
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 미생물학과
- Advisor
- 이원재
- Table Of Contents
- PART Ⅰ General introduction of harmful algae blooms (HABs) and algicidal bacteria = 1
1. Definition of the term 'harmful algal blooms (HABs)' = 2
2. The diversity of HAB species = 2
3. Negative effects caused by HABs = 3
4. Complex life cycle of HAB species = 5
5. Control of HABs = 6
6. Algicidal bacteria = 8
7. Purpose of this study = 9
PART Ⅱ Isolation and characterization of marine algicidal bacteria against harmful algal species = 11
1. Introduction = 12
2. Materials and Methods = 14
2.1. Algal cultures = 14
2.2. Isolation and screening of algicidal bacteria = 14
2.3. Identification and characterization of bacteria by morphological, biochemical, and hylogenetic analysis = 15
2.4. Determination of mode of algicidal action = 16
2.5. Relationship of algicidal activity and bacterial growth = 16
2.6. Impact and algicidal activity of algicidal bacteria culture supernatants on algal cultures = 17
2.7. Algicidal range of algicidal bacteria culture supernatants = 19
2.8. Properties of culture filtrate = 19
3. Results = 20
3.1. Screening of algicidal bacteria = 20
3.2. Identification and characterization of strain AB-1 = 20
3.2.1. Identification and culture condition of strain AB-1 = 20
3.2.2. Relationship of algicidal activity and bacterial growth = 25
3.2.3. Determination of mode of algicidal action = 25
3.2.4. Impact and algicidal activity of bacterial culture supernatants on Alexandrium catenella cultures = 25
3.2.5. Algicidal range of Arthrobacter sp. AB-1 culture supernatants = 29
3.2.6. Properties of culture filtrate = 29
3.3. Identification and characterization of strain AB-3 = 34
3.3.1. Identification and culture condition of strain AB-3 = 34
3.3.2. Relationship of algicidal activity and bacterial growth = 34
3.3.3. Determination of mode of algicidal action = 40
3.3.4. Impact and algicidal activity of bacterial culture supernatants on Alexandrium catenella cultures = 40
3.3.5. Impact and algicidal activity of bacterial culture supernatants on Cochlodinium polykrikoides cultures = 40
3.3.6. Algicidal range of Brachybacterium sp. AB-3 culture supernatants = 44
3.3.7. Properties of culture filtrate = 44
3.4. Identification and characterization of strain AB-4 = 44
3.4.1. Identification and culture condition of strain AB-4 = 44
3.4.2. Relationship of algicidal activity and bacterial growth = 49
3.4.3. Determination of mode of algicidal action = 49
3.4.4. Impact and algicidal activity of bacterial culture supernatants on Chattonella marina cultures = 55
3.4.5. Algicidal range of Bacillus sp. AB-4 culture supernatants = 55
3.4.6. Properties of culture filtrate = 60
4. Discussion = 62
5. Summary = 65
PART Ⅲ Purification and characterization of an algicide from Brachybacterium sp. AB-3 = 66
1. Introduction = 67
2. Materials and Methods = 69
2.1. Preparation of crude algicides = 69
2.2. Purification and identification of algicides = 69
2.2.1 Preparation of cell-free ethyl acetate extracts = 69
2.2.2. Purification of algicides = 69
2.2.3. Instrumental analyses = 70
2.3. Bioassay for algicidal activity = 70
2.4. Bioassay for algicidal range = 71
2.5. Properties of β-carboline = 71
3. Results = 72
3.1. Isolation of algicidal compound = 72
3.2. Structure determination of the purified algicidal compound = 72
3.3. Bioassay for algicidal activity = 72
3.4. Bioassay for algicidal range = 80
3.5. Properties of β-carboline = 80
4. Discussion = 85
5. Summary = 87
References = 88
요약 = 105
Acknowledgment (감사의 글) = 107
- Degree
- Doctor
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