There are a variety of microorganisms in nature will produce tiny fibers after metabolizing nutrient. It is mainly by the polymerization of beta-1,4-glucan.Bacterial fiber is composed of high density microfibrils. It is the smallest natural fibers in nature. The diameter of natural fibers is around 20~100nm and mesh pore size of the structure is about 0.5~1.0um. 自然界中有多種微生物其養分代謝後會產生微小的纖維，主要是由 beta-1、4-glucan所聚合而成。微生物纖維為自然界中最小的天然纖維。微生物纖維的直徑約20~100nm，是高密度微纖維（microfibrils）所組成，其網狀孔隙結構大小約為0.5～1.0um。