Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
National Animal Husbandry Extension Service, Beijing 100125, People's Republic of China.
Food Chem. 2014 Nov 1;162:229-34. doi: 10.1016/j.foodchem.2014.04.069. Epub 2014 Apr 26.
A pectin methylesterase gene (pe8F46) was cloned from Penicillium chrysogenum F46 and successfully expressed in Pichia pastoris. The full-length cDNA consists of 969 bp and encodes a 322-residue polypeptide with the calculated molecular weight of 34.1 kDa. Deduced PE8F46 belongs to family 8 of carbohydrate esterases and shares 54% identity with a functionally characterised counterpart from Myceliophthora thermophile. Purified recombinant PE8F46 showed the optimal activity at pH 5.0 and 40°C, and remained 52% maximum activity even at 10°C. An orthogonal experiment was employed to determine the best conditions for firming pineapple dices. After incubation with 0.75% (w/v) PE8F46 and 0.4% calcium lactate (w/v) for 20 min, the firmness of pineapple dices was improved by 47.6%, 13.7% higher than that of a commercial pectinase complex. These results suggest that PE8F46 has application potential in the food industry.
从青霉 F46 中克隆了一个果胶甲酯酶基因（pe8F46），并成功在毕赤酵母中表达。全长 cDNA 由 969bp 组成，编码一个 322 个残基的多肽，计算分子量为 34.1kDa。推测 PE8F46 属于碳水化合物酯酶家族 8，与嗜热真菌 Mycelia thermophile 中功能已确定的对应物具有 54%的同一性。纯化的重组 PE8F46 在 pH5.0 和 40°C 下表现出最佳活性，即使在 10°C 下仍保持 52%的最大活性。采用正交实验确定了菠萝丁固化的最佳条件。用 0.75%（w/v）PE8F46 和 0.4%（w/v）乳酸钙处理 20min 后，菠萝丁的硬度提高了 47.6%，比商业果胶酶复合物高 13.7%。这些结果表明 PE8F46 在食品工业中有应用潜力。
