This research aims to optimize the conditions for improvement of pineapple leaf fiber quality using pectinase from selected bacterial strains compared with the commercial ones. First, Bacillus subtilis subsp. inaquosorum P4-1 was selected for its highest capability of pectinase production (19.59±0.47 U/ml) obtained from natural sources in Thailand. After that, the response surface methodology was applied for the optimization of cultivation condition to reach highest pectinase production. Highest pectinase activity at 59.86 U/ml was obtained when B. subtilis P4-1 was cultivated at 150 rpm, 35 °C in the liquid media containing 18.65 g/l citrus pectin, 4.12 g/l Monosodium-L-glutamate, 2.4 g/l KH₂PO₄, 0.5 g/l MgSO₄·7H₂O, 0.8 g/l Na₂HPO₄, 3 g/l (NH₄)₂SO₄, 0.2 g/l CaCl₂. To improve the pineapple leaf fiber quality, the pineapple leaves were first fed into the fiber extraction machine to obtain pineapple leaf fiber as raw materials to be used in this experiment. The 3 commercially available pectinase in Thailand: Pectinex Ultra Tropical, Pectinex Ultra SP-L and Scourzyme L, were compared and the results showed that Pectinex Ultra SP-L produced pineapple leaf fiber with the best quality at enzyme:fiber ratio of 1:10 in combination with 0.75 % tergitol surfactant after 1 day of soaking period. The same conditions were then applied for the improvement of pineapple leaf fiber quality using pectinase from selected bacterial B. subtilis P4-1. The resulting fibers showed no significant difference with that from the commercial pectinase after the sensory test.

本研究旨在优化使用来自选定菌株的果胶酶与商业菌株相比改善菠萝叶纤维质量的条件。首先，枯草芽孢杆菌亚种。选择inaquosorum P4-1 是因为其从泰国天然来源获得的果胶酶生产能力最高 (19.59±0.47 U/ ml )。之后，应用响应面方法优化培养条件，以达到最高的果胶酶产量。在59.86 U /米最高果胶酶活性升时获得的枯草芽孢杆菌P4-1以150rpm，在含有18.65克液体培养基35℃/中培养升柑橘果胶，4.12克/升L-谷氨酸一钠, 2.4 g/ l KH ₂ PO ₄ , 0.5 g/ l MgSO ₄ ·7H ₂ O, 0.8 g/ l Na ₂ HPO ₄ , 3 g/ l (NH ₄ ) ₂ SO ₄ , 0.2 g/升的CaCl ₂. 为提高菠萝叶纤维质量，首先将菠萝叶送入纤维提取机中，得到菠萝叶纤维作为本实验所用的原料。比较了泰国市售的 3 种果胶酶：Pectinex Ultra Tropical、Pectinex Ultra SP-L 和 Scourzyme L，结果表明，Pectinex Ultra SP-L 在酶：纤维比为 1:10 时生产的菠萝叶纤维质量最好浸泡 1 天后，与 0.75% tergitol 表面活性剂结合使用。然后使用来自选定细菌枯草芽孢杆菌P4-1 的果胶酶，将相同的条件应用于改善菠萝叶纤维质量。感官测试后，所得纤维与市售果胶酶的纤维无显着差异。