以反應曲面法提升 Komactobacter intermedius 之細菌纖維素產量

Abstract

細菌纖維素( Bacterial cellulose, BC ) 是一種具有優良物理性質，例如高抗壓強度、高保水性以及高生物相容性的生物聚合物，在許多應用領域的開發潛力。本實驗採用Komactobacter intermedius BCRC 910677作為纖維素生產的菌株 ，透過反應曲面法( Response surface methodlogy, RSM ) 優化培養基提升細菌纖維素產量。利用果糖和蛋白腖作為碳、氮源而得到相較於其他碳、氮源有著相對較佳的產量的結果。本實驗並利用Box-Behnken design (BBD) 作為反應曲面法 (RSM) 的實驗設計並分別以果糖濃度、蛋白腖濃度以及 pH 值作為參數優化培養基組成。依據 RSM 的理論最佳條件而設計最佳化培養基為果糖 41 g/L蛋白腖38 g/L 及 pH 5.2 促使最終產量相較於Hestrin-Schramm (HS) 培養基提升3.8 倍，證實利用統計方法透過 RSM 的評估設計調整培養基成分是提升細菌纖維素產量的有效方式。另外透過掃描式電子顯微鏡 (Scanning electron microscope, SEM) 觀察，使用優化培養基生成的纖維平均寬度 (38 nm) 以及纖維寬度分布 (14-70 nm) 皆低於HS 培養基 (50 nm 以及21-147 nm )。

Bacterial cellulose (BC) is a biopolymer with extraordinary material properties such as high tensile strength, high water holding capability and high bio-compatibility; thus possessing great potential for diverse applications. This study aims to enhance BC productivity of an indigenous cellulose producing bacteria Komactobacter intermedius BCRC 910677 via response surface methodology (RSM) optimized medium. Fructose and peptone were used as carbon and nitrogen sources respectively for this medium as they both showed good productivity compared to other carbon and nitrogen sources in the initial test. In RSM study, Box-Behnken design (BBD) is applied for experimental design as the three factors, fructose concentrations, peptone concentrations and pH values were tested in order to obtain optimal medium composition for BC production. The resulting optimized medium contains fructose 41 g/L, peptone 38 g/L at pH 5.2 and increased 3.8 fold production compared to Hestrin-Schramm (HS) medium. In this study it can be seen that RSM optimized composition is a promising apprpaoch to increase BC productivity. Inspection under scanning electron microscope (SEM) reveals that fiber diameter range from 14-70 nm, with an average diameter of 38 nm, while the range for fiber diameter of the HS medium was 21-147 nm with an average of 50 nm.