Fusion of Biotechnology and Craftsmanship: Bacterial Treatment to Improve Bashofu Fiber Extraction

ABSTRACT

Bashofu is a traditional Okinawan textile made from thin banana fibers. The raw materials derived from banana leaf sheaths are composed of plant fibers and unwanted constituents such as the plant cuticle layer. The unwanted constituents are hand-scraped by the traditional way that follows boiling the raw materials in a mild alkali solution. However, even after this mild degumming, the plant cuticle layer of current materials can still be too hard to be hand-scraped from the fibers. For smooth fiber separation, the unwanted constituents should be specifically degraded before hand-scraping. Fatty acid polyesters are the main components of plant cuticle layer and are not present in fibers. We attempted to specifically degrade the materials by Stenotrophomonas sp. with the ability to degrade Tween-20, as a result, the treated materials became softer and thinner with uniform thickness. Such changes in the morphology of the material allowed the plant cuticle layer to be easily separated from the banana fibers during hand-scraping, and the cross section of the extracted fibers was not affected by this bacterial treatment. This treatment would be used as a minimal improvement of the traditional Bashofu making in the future and would reduce the hard work for elderly artisans.

摘要

芭蕉芙是冲绳传统的纺织品，由薄香蕉纤维制成. 香蕉叶鞘的原料由植物纤维和植物角质层等不需要的成分组成. 不需要的成分是用传统的方法手工刮除的，即在弱碱溶液中煮沸原料. 然而，即使经过这种温和的脱胶，目前材料的植物角质层仍然太硬，无法用手从纤维上刮下来. 为了使纤维顺利分离，不需要的成分应在手动刮擦前进行专门降解. 脂肪酸聚酯是植物角质层的主要成分，不存在于纤维中. 我们试图通过狭窄单胞菌（Stenotrophomonas sp.）对材料进行特异性降解. 通过降解Tween-20的能力，处理后的材料变得更软、更薄、厚度均匀. 这种材料形态的变化使植物角质层在手工刮擦过程中很容易与香蕉纤维分离，并且提取纤维的横截面不受这种细菌处理的影响. 这种处理将在未来作为对传统巴绍夫制作的最小改进，并将减少老年工匠的辛勤工作.

KEYWORDS:

• Bashofu
• banana fiber
• plant cuticle layer
• Stenotrophomonas sp.
• fatty acid ester
• cultural property

关键词:

• 芭蕉布
• 香蕉纤维
• 植物角质层
• 狭窄单胞菌属
• 脂肪酸酯
• 文化财产

Research highlights

• To attempt to adapt bio-retting to the traditional fiber extraction, Stenotrophomonas sp. was isolated from a local banana plant field.

• Treatment using this strain made hard materials soft and allowed easy separation of fibers.

• Our bacterial treatment was considered as an acceptably minimal change to the old Bashofu production process preserved as an Important Intangible Cultural Property.

Acknowledgments

We would like to thank the Bashofu Textile Studio (Okinawa, Japan) and Hitomi Shinzato (OIST) for sample preparation, Takako Kai (a former OIST member) and Mayumi Suzuki (a former OIST member) for Sanger sequencing experiments, Tropical Technology Plus (Okinawa, Japan) for the creepmeter experiments, and Ryohei Yoshida (OIST) for valuable discussion on the experiment of autoclaving sample with the bacterial treatment. We would also like to express our deep gratitude to Yayoi Maehara (OIST) for significant contributions to fiber extractions and mechanical characterization experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15440478.2024.2351166

Additional information

Funding

This research was supported by Okinawa Institute of Science and Technology (OIST) Graduate University research fund and Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number [20K02354].