Oil production of bloom forming algae in conjunction with fish aquaculture in Mekong delta

• Project/Area Number: 15H05252
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Aquatic bioproduction science
• Research Institution: Nagasaki University
• Principal Investigator: WADA Minoru 長崎大学, 水産・環境科学総合研究科(水産), 教授 (70292860)
• Co-Investigator(Kenkyū-buntansha): 岩滝 光儀 東京大学, アジア生物資源環境研究センター, 准教授 (50423645) ; 横内 一樹 国立研究開発法人水産研究・教育機構, 中央水産研究所, 研究員 (50723839) ; 菅 向志郎 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (60569185) ; 平坂 勝也 長崎大学, 海洋未来イノベーション機構, 准教授 (70432747)
• Research Collaborator: ISHIMATSU Atsushi ; TAKAHASHI Kazuya ; SAKAKURA Yoshitaka
• Project Period (FY): 2015-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥15,860,000 (Direct Cost: ¥12,200,000、Indirect Cost: ¥3,660,000); Fiscal Year 2018: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2017: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2016: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2015: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
• Keywords: ホコハゼ / 養殖池 / メコンデルタ / 緑藻 / 脂質蓄積 / 微細藻類 / 油脂生産 / 魚類養殖 / 脂質生産 / トビハゼ養殖

Outline of Final Research Achievements

In search of potential microbial resources for the production of valuable oil, we examined the green algal strains that had been isolated from aquaculture ponds of the mudskipper, Pseuddapocryptes elongates in Mekong Delta. The 18S-rRNA gene sequences revealed most of the algae were affiliated with Oocystaceae, had better growth　characteristics (specific growth rates and maximum growth yield). A couple of the algal strains even showed greater extent of oil accumulation and fatty acid diversity per cell than that of Chlorella vulgaris. We also examined bacteria associated with the non-axenic strains of Oocystis based on the bacterial 16SrRNA amplicon sequencing. The　predominant bacteria in the late log phase of the algal growth included those affiliated with Rhizobiaceae, Brevundimonas, and Sphingomonas, all of which had been known for their ability to promote algal growth. Predominant bacteria varied sensitively in response to the change in salt condition of algal culture.

Academic Significance and Societal Importance of the Research Achievements

本研究は南ベトナム・メコンデルタのホコハゼ養殖池における常在緑藻に注目して、その種類（分子系統）、増殖特性、脂質蓄積能および、共存細菌との相互作用の観点から緑藻の特徴を初めて明らかにしたものである。その成果は、医薬・食品分野への応用が期待されるω３脂肪酸を含む油脂生産において、これまで未知の微生物資源であった水産養殖環境に由来する緑藻の潜在的な有用性を明らかにするとともに、「魚を育てながら、意図的に赤潮藻類を増やして高付加価値産物を得る」という、新たな養殖事業の可能性を示した点で社会的な意義をもつ。

Research Products

• [Int'l Joint Research] Can Tho University(ベトナム)
• [Int'l Joint Research] Can Tho University(ベトナム)
• [Journal Article] Dactylodinium pterobelotum gen et sp. nov., a new marine woloszynskioid dinoflagellate positioned between the two families Borghiellaceae and Suessiaceae (2017)
  • Author(s): K. Takahashi, O. Moestrup, M. Wada, A. Ishimatsu, Nguyen V.N., Y. Fukuyo and M. Iwataki
  • Journal Title: Journal of Phycology Volume: 53 Issue: 6 Pages: 1223-1240
  • DOI: 10.1111/jpy.12575
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Comparison of planktonic microbial abundance and dissolved oxygen consumption between the aquaculture ponds of mudskippers and shrimps in the Mekong Delta, Southern Vietnam (2016)
  • Author(s): M. Wada, F. Mori, K. Yokouchi, M. Yagi, T. Takita, A. Ishimatsu, M. Iwataki, K. Takahashi, H.V. Mai, T.T. Vo, H.P. Ha, D.D. Tran
  • Journal Title: Fisheries Science Volume: 82 Issue: 5 Pages: 787-797
  • DOI: 10.1007/s12562-016-1000-1
  • NAID: 40020941552
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] メコンデルタのホコハゼ養殖池で優占する緑藻類： 分子系統・増殖・脂質蓄積および共存細菌からみた特徴 (2019)
  • Author(s): 和田実, 迫田亮, 皆川真行, 平坂勝也, 高橋和也, 岩滝光儀, Tran Dac Dinh, 石松惇
  • Organizer: 平成31年度日本水産学会春季大会
• [Presentation] Harmful algal blooms, fish kills, and economic impact: A case study of Lampung Bay, Indonesia. (2017)
  • Author(s): K. Wakita, Muawanah, M. Iwataki, T. Komatsu, K. Takahashi, M. Wada, Y. Fukuyo
  • Organizer: JSPS-CCore-RENSEA First Joint Seminar on Coastal Ecosystems in Southeast Asia,
  • Place of Presentation: Phoenix Hotel, Johor Bharu, Malaysia
  • Year and Date: 2017-03-12
  • Int'l Joint Research
• [Presentation] Molecular phylogenies and growth characteristics of green microalgae isolated from aquaculture pond in southern Vietnam (2017)
  • Author(s): Sakoda R, Minakawa M, Takahashi K, Iwataki M, Hirasaka K, Wada M
  • Organizer: The 11th International Workshop on the Oceanography and Fisheries Science of the East China Sea (2017 ECS Workshop, Nagasaki)
  • Int'l Joint Research
• [Presentation] Growth characteristics and molecular phylogenies of bacteria associated with a green alga derived from an aquaculture pond in Mekong Delta, southern Vietnam (2017)
  • Author(s): Minakawa M, Sakoda R, Takahashi K, Iwataki M, Wada M
  • Organizer: The 11th International Workshop on the Oceanography and Fisheries Science of the East China Sea (2017 ECS Workshop, Nagasaki)
  • Int'l Joint Research
• [Presentation] Ultrastructure and molecular phylogeny on an undescribed woloszynskioid dinoflagellate showing characters intermediate between the two families Borghiellaceae and Suessiaceae. (2016)
  • Author(s): K. Takahashi, Φ. Moestrup, M. Wada, A. Ishimatsu, M. Iwataki
  • Organizer: 17th International Conference on Harmful Algae, Centrosul, Florianopolis, Brazil, Oct 2016
  • Place of Presentation: CentroSul Convention, Center Centrosul, Florianopolis, Brazil
  • Year and Date: 2016-10-09
  • Int'l Joint Research
• [Presentation] Ultrastructure and phylogeny of an undescribed woloszynskioid Vietnamese coast. (2015)
  • Author(s): Kazuya Takahashi, Minoru Wada, Atsushi Ishimatsu, Mitsunori Iwataki
  • Organizer: 9th International EASTHAB Symposium
  • Place of Presentation: Jinan University, Guangzhou, China
  • Year and Date: 2015-12-13
  • Int'l Joint Research