School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Rd, 212013, Zhenjiang, Jiangsu, China.
Appl Microbiol Biotechnol. 2013 Aug;97(15):6725-37. doi: 10.1007/s00253-013-5002-y. Epub 2013 Jun 5.
The industrial solid wastes generated during the production of silymarin from the fruits of milk thistle Silybum marianum was used as the substrate. Preparation and evaluation of the feeds produced by solid-state fermentation (SSF) of the industrial solid wastes was carried out. The protein content of the fermented feed (FF) from a combination of Aspergillus niger and Candida tropicalis was the highest among the examined strains. The optimal process parameters for protein enrichment with SSF using A. niger and C. tropicalis included incubation temperature of 30.8 °C, fermentation time of 87.0 h, and initial moisture content of 59.7 %. Under these conditions, the value additions of FF occurred. The fiber of FF was decreased by 25.07 %, while the digestibility of protein, protein content, and the ratio of total essential amino acids to total amino acids were increased by 79.85, 16.22, and 8.21 %, respectively. The analysis indicated that FF contained 1.44 mg/kg flavonoids and 0.5 mg/kg silybin, which significantly increased by 2.42 and 1.63 times, respectively than those in unfermented substrates. FF recorded reduced molecular weight of proteins from 20.1 to 44.3 kDa to below 14.3 kDa. The results of feeding trial of FF replacement with soybean meal in broilers diets for 8 weeks showed that FF significantly improved carcass characteristics including abdominal fat rate, serum biochemical parameters including aspartate transaminase, blood urea nitrogen and high density lipoprotein cholesterol, and immune responses of broilers. A potential feed quality improvement was achieved through mixed strains SSF of industrial solid wastes of S. marianum fruits.
利用奶蓟草（Silybum marianum）果实工业固体废物作为基质，进行固态发酵（SSF）生产饲料的方法。通过对黑曲霉（Aspergillus niger）和热带假丝酵母（Candida tropicalis）混合菌株固态发酵生产的发酵饲料（FF）进行了检测。结果表明，黑曲霉和热带假丝酵母组合发酵饲料的蛋白含量最高。采用黑曲霉和热带假丝酵母进行 SSF 蛋白富集的最佳工艺参数为：培养温度 30.8℃、发酵时间 87.0 h、初始含水量 59.7%。在此条件下，FF 的附加值最高。FF 的纤维含量降低了 25.07%，而蛋白质消化率、蛋白含量和必需氨基酸总量与总氨基酸比值分别提高了 79.85%、16.22%和 8.21%。分析表明，FF 含有 1.44 mg/kg 类黄酮和 0.5 mg/kg 的水飞蓟宾，分别比未发酵底物提高了 2.42 倍和 1.63 倍。FF 记录的蛋白质分子量从 20.1 到 44.3 kDa 降低到 14.3 kDa 以下。FF 替代豆粕在肉鸡日粮中喂养 8 周的喂养试验结果表明，FF 显著改善了肉鸡的胴体特性，包括腹脂率、血清生化参数，如天冬氨酸转氨酶、血尿素氮和高密度脂蛋白胆固醇，以及免疫反应。通过混合菌株 SSF 处理奶蓟草果实工业固体废物，实现了潜在的饲料质量改善。
