黑麴菌固態發酵生產β-甘露聚醣酶水解棕櫚油渣產生甘露寡醣

泰國、馬來西亞及印尼及其它東南亞國家是生產棕櫚油主要國家，棕櫚油渣是棕櫚油萃取過程的廢棄物，其非澱粉多醣中包含70%以上的甘露聚醣，是生產甘露寡醣的低成本良好受質來源。甘露寡醣可被動物腸道中的益生菌利用，改善菌群組成，且能刺激巨噬細胞分泌細胞激素及趨化激素，以提升免疫反應。在東南亞地區經常添加棕櫚油渣於飼料中，提高飼料品質及營養價值，但尚未有文獻探討利用酵素作用棕櫚油渣，生產甘露寡醣之作用條件，故本研究利用黑麴菌進行固態發酵生產β-甘露聚醣酶建立最佳酵素生產條件，並水解棕櫚油渣中之甘露聚醣，分析產物甘露寡醣組成。棕櫚油渣之基本成分分析，顯示含碳水化合物68.69±0.08%、粗蛋白15.43±0.18%、水分10.03±0.05%、粗灰份4.54±0.11%及粗脂肪1.31±0.24%；選取六株Aspergillus niger 菌株進行實驗，發現A. niger NPUST-M05生產β-甘露聚醣酶活性最佳，在第7天達最高產量172.02±15.14 U/g，故選擇該菌株探討添加關華豆膠及刺槐豆膠之碳源輔因子對酵素含量之影響，結果顯示兩組輔因子於1.5%之添加量時，有較高之酵素含量；利用未添加輔因子之粗酵素液水解棕櫚油渣30分鐘，可獲得總醣 53.38±3.24 mg/g、還原糖 34.58±0.17 mg/g及甘露寡醣26.51±0.18 mg/g，水解產物之甘露寡醣以甘露二醣及甘露三醣分佈最多。經上述結果顯示，使用β-甘露聚醣酶水解棕櫚油渣，可生產甘露寡醣，增加廢棄物之利用性。

關鍵字

棕櫚油渣； β-甘露聚醣酶；甘露寡醣

並列摘要

Thailand, Malaysia, Indonesia and other Southeast Asian countries are the main production areas of palm oil. Palm kernel cake (PKC), a waste product of the palm kernel oil extraction process contains more than 70% mannan of non-starch polysaccharides and therefore can serve as an excellent low-cost substrate for mannan oligosaccharide production. Mannan oligosaccharide can be used by probiotics in animal intestine to improve the composition of flora, and can stimulate the secretion of cytokines and chemokines from macrophages to enhance the immune response. In Southeast Asia, PKC is usually added into feed to increase the quality and nutritional value, but there is no reference demonstrated the application of enzyme on PKC for mannan oligosaccharide production. The objective of this study is to produce mannan oligosaccharide using β-mannanase produced by Aspergillus niger on PKC in solid state fermentation. The proximate analysis of PKC showed it contained 68.69±0.08% of carbohydrate, 15.43±0.18% of crude protein, 10.03±0.05% of moisture, 4.54±0.11% of crude ash and 1.31±0.24% effect of enzyme content by adding guar gum and locust bean gum as co-factor. The highest enzyme activity was shown when adding 1.5% of both carbon source co-factors. After PKC was hydrolyzed by crude enzyme solution for 30 minutes, 53.38±3.24 mg/g of total sugar, 34.58±0.17 mg/g of reducing sugar and 26.51±0.18 mg/g of mannan oligosaccharide were obtained. Mannobiose and mannotriose were the main contents of mannan oligosaccharides in the hydrolyzed product. The utilization of PKC could be enhanced by production of mannan oligosaccharide using β-mannanase.