Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.
J Sci Food Agric. 2013 Oct;93(13):3345-51. doi: 10.1002/jsfa.6183. Epub 2013 May 29.
Mannan is a hemicellulose constituent commonly found in plant-derived feed ingredients. The gum-like property of mannan can obstruct digestive enzymes and bile acids, resulting in impaired nutrient utilisation. In this study, β-mannanase production by Aspergillus niger strain BCC4525 was investigated using several agricultural residues under solid state condition. The biochemical properties of the target enzyme and the effects of enzyme supplementation on broiler performance and energy utilisation were assessed.
Among five carbon sources tested, copra meal was found to be the best carbon source for β-mannanase production with the maximum yield of 1837.5 U g(-1) . The crude β-mannanase exhibited maximum activity at 80 °C within a broad range of pH from 2 to 6. In vitro digestibility assay, which simulates the gastrointestinal tract system of broilers, showed that β-mannanase could liberate reducing sugars from corn/soybean diet. Surprisingly, β-mannanase supplementation had no significant effect on broiler feed intake, feed conversion rate or energy utilisation.
A high level of β-mannanase was produced by A. niger BCC4525 under solid state condition using copra meal as carbon source. Although the enzyme has the desired properties of an enzyme additive for improving broiler performance, it does not appear to be beneficial.
甘露聚糖是一种常见于植物源性饲料成分的半纤维素成分。甘露聚糖的胶状特性可以阻碍消化酶和胆汁酸，从而导致营养物质利用受损。在这项研究中，研究了黑曲霉 BCC4525 菌株在固态条件下使用几种农业废弃物生产β-甘露聚糖酶。评估了目标酶的生化特性以及酶补充对肉鸡性能和能量利用的影响。
在所测试的五种碳源中，发现椰子粕是生产β-甘露聚糖酶的最佳碳源，最大产量为 1837.5 U g(-1)。粗β-甘露聚糖酶在 80°C 下表现出最大活性，pH 值范围从 2 到 6 很宽。体外消化率测定，模拟肉鸡胃肠道系统，表明β-甘露聚糖酶可以从玉米/大豆日粮中释放还原糖。令人惊讶的是，β-甘露聚糖酶补充对肉鸡采食量、饲料转化率或能量利用没有显著影响。
黑曲霉 BCC4525 在固态条件下使用椰子粕作为碳源可以产生高水平的β-甘露聚糖酶。尽管该酶具有改善肉鸡性能的酶添加剂的理想特性，但似乎没有益处。
