Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
J Biosci Bioeng. 2010 Sep;110(3):322-5. doi: 10.1016/j.jbiosc.2010.03.001. Epub 2010 Mar 25.
Old oil palm trunks that had been felled for replanting were found to contain large quantities of high glucose content sap. Notably, the sap in the inner part of the trunk accounted for more than 80% of the whole trunk weight. The glucose concentration of the sap from the inner part was 85.2g/L and decreased towards the outer part. Other sugars found in relatively low concentrations were sucrose, fructose, galactose, xylose, and rhamnose. In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Based on these findings, we fermented the sap to produce ethanol using the sake brewing yeast strain, Saccharomyces cerevisiae Kyokai no.7. Ethanol was produced from the sap without the addition of nutrients, at a comparable rate and yield to the reference fermentation on YPD medium with glucose as a carbon source. Likewise, we produced lactic acid, a promising material for bio-plastics, poly-lactate, from the sap using the homolactic acid bacterium Lactobacillus lactis ATCC19435. We confirmed that sugars contained in the sap were readily converted to lactic acid with almost the same efficiency as the reference fermentation on MSR medium with glucose as a substrate. These results indicate that oil palm trunks felled for replanting are a significant resource for the production of fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia.
被砍伐用于重新种植的旧油棕树干中发现含有大量高葡萄糖含量的树液。值得注意的是，树干内部的树液占整个树干重量的 80%以上。来自树干内部的树液的葡萄糖浓度为 85.2g/L，并向外部逐渐降低。其他浓度相对较低的糖是蔗糖、果糖、半乳糖、木糖和鼠李糖。此外，油棕树液还富含各种氨基酸、有机酸、矿物质和维生素。基于这些发现，我们使用清酒酿造酵母菌株 Saccharomyces cerevisiae Kyokai no.7 将树液发酵生产乙醇。在没有添加营养物质的情况下，从树液中生产乙醇的速度和产量与以葡萄糖为碳源的 YPD 培养基上的参考发酵相当。同样，我们使用同型乳酸细菌 Lactobacillus lactis ATCC19435 从树液中生产出了一种有前途的生物塑料原料——聚乳酸。我们证实，树液中所含的糖很容易转化为乳酸，其效率与以葡萄糖为底物的 MSR 培养基上的参考发酵几乎相同。这些结果表明，在马来西亚和印度尼西亚等棕榈油生产国，为了重新种植而砍伐的油棕树干是生产燃料乙醇和乳酸的重要资源。
