Elucidation of algal morphogen biosynthetic machinery from an epiphytic marine bacterium and its heterologous reconstitution.

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K05724
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 37020:Chemistry and chemical methodology of biomolecules-related
• Research Institution: Tokushima Bunri University
• Principal Investigator: KENMOKU HIROMICHI 徳島文理大学, 香川薬学部, 准教授 (10399438)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: サルーシン / 藻類共生細菌 / テルペノイド / 生合成 / 分化誘導 / ヒトエグサ / 変異株 / 抗生物質

Outline of Final Research Achievements

We were able to present a candidate enzyme gene cluster involved in the biosynthesis of thallusin, a thallus differentiation inducer produced by symbiotic bacteria of marine algae of the Ulva class. In addition, the mutation sites of the high thallusin-producing mutants obtained by screening antibiotic-resistant mutants were concentrated in two types of genes that are common to the mutation sites that show high productivity of secondary metabolites in other bacteria. In addition, we studied the composition of the culture medium in this context and were able to find a combination of mutant strain and culture medium that showed several hundred times higher productivity. On the other hand, for the purification of thallusin from bacterial culture broth, we investigated adsorption resins and derivatization methods and were able to establish a pretreatment method that is simpler and more robust than conventional purification and analysis methods.

Free Research Field

天然物化学、生物分子科学

Academic Significance and Societal Importance of the Research Achievements

本細菌のサルーシンの生合成酵素遺伝子クラスター候補に着目して、比較ゲノム解析を行ったところ、細菌バイオフィルムの生合成遺伝子クラスターとの関連性が示唆されたことや、サルーシンの生産が単一の協調的発現によらない一次代謝的なものであることが示唆されたことから、アオサ藻綱海産藻類の葉状体分化を中心とした細菌共生システムが、進化的にバイオフィルム内での共生的相互作用に由来する可能性を指摘出来た。また、研究開始当初から数百倍の生産性を示す複数の変異株と培地の組み合わせと簡便かつ効率的な大量抽出・精製法を確立するに至り、光学活性サルーシンの発酵生産を現実的なものとすることができた。