Scholarlink

<p>The filamentous cyanobacterium <i>Limnothrix</i> sp. strain SK1-2-1 is capable of producing pentadecane (a C15 alkane) and phycocyanin. The aim of this study was to develop a method for the production and recovery of extracellular substances (skECS), containing a novel acidic extracellular polysaccharide (skEPS) as a biopolymer, and to analyze the properties and functions of the obtained skECS. Analyses showed that skECS had a high molecular weight of 1.46 × 10<sup>6</sup>&#xa0;g/mol and comprised 28.2% (w/w) sugar and 30.2% (w/w) protein. By contrast, skEPS contained glucose (38.4&#xa0;mol%), mannose (35.3&#xa0;mol%), and rhamnose (14.8&#xa0;mol%). skECS was characterized using native PAGE and atomic force microscopy. Aqueous skECS solutions at concentrations ranging from 0.25 to 1.00&#xa0;mg&#xa0;mL<sup>−1</sup> showed antioxidant capacity. Additionally, blue-light irradiation of SK1-2-1 cells enhanced skEPS production and promoted simultaneous cell flocculation. The accumulation of candidate gene transcripts involved in skEPS biosynthesis in response to blue- and white-light irradiation showed that the expression of <i>sesA</i> (<i>sk0924</i>), which encodes the blue-light sensor substance cyclic-di-GMP, was induced by blue light. Furthermore, nine genes related to the Wzy-dependent pathway, which were inferred to act in an <i>sesA</i>-dependent manner, were non-uniformly induced under blue-light irradiation, with varying degrees of expression. These results reveal novel properties and functions of skECS, light-specific induction of production, and their potential as useful materials for biorefineries.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Novel biopolymer in extracellular substances from the filamentous cyanobacterium Limnothrix sp.

  • 期刊论文

  • 发表日期：

    2026年1月22日

查看全文
  • Kotaro Kido,
  • Runa Koshikawa,
  • Rise Katoh,
  • Nguyen Thi Thuy Quynh,
  • Yu Kanesaki,
  • Morifumi Hasegawa,
  • Akihiro Nakamura,
  • Munehiko Asayama

摘要

The filamentous cyanobacterium Limnothrix sp. strain SK1-2-1 is capable of producing pentadecane (a C15 alkane) and phycocyanin. The aim of this study was to develop a method for the production and recovery of extracellular substances (skECS), containing a novel acidic extracellular polysaccharide (skEPS) as a biopolymer, and to analyze the properties and functions of the obtained skECS. Analyses showed that skECS had a high molecular weight of 1.46 × 106 g/mol and comprised 28.2% (w/w) sugar and 30.2% (w/w) protein. By contrast, skEPS contained glucose (38.4 mol%), mannose (35.3 mol%), and rhamnose (14.8 mol%). skECS was characterized using native PAGE and atomic force microscopy. Aqueous skECS solutions at concentrations ranging from 0.25 to 1.00 mg mL−1 showed antioxidant capacity. Additionally, blue-light irradiation of SK1-2-1 cells enhanced skEPS production and promoted simultaneous cell flocculation. The accumulation of candidate gene transcripts involved in skEPS biosynthesis in response to blue- and white-light irradiation showed that the expression of sesA (sk0924), which encodes the blue-light sensor substance cyclic-di-GMP, was induced by blue light. Furthermore, nine genes related to the Wzy-dependent pathway, which were inferred to act in an sesA-dependent manner, were non-uniformly induced under blue-light irradiation, with varying degrees of expression. These results reveal novel properties and functions of skECS, light-specific induction of production, and their potential as useful materials for biorefineries.