Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100, Jilin Gongzhuling, People's Republic of China.
Institute of Agro-food Technology, Jilin Academy of Agricultural Sciences, No. 1366 Cai Yu Street, Changchun, 130033, Jilin Province, People's Republic of China.
World J Microbiol Biotechnol. 2024 Jan 3;40(2):59. doi: 10.1007/s11274-023-03831-w.
Corn germ meal (CGM) is one of the major byproducts of corn starch extraction. Although CGM has rich fiber content, it lacks good protein content and amino acid balance, and therefore cannot be fully utilized as animal feed. In this study, we investigated the processing effect of cellulase synergized with Bacillus velezensis on the nutritional value of pretreated CGM (PCGM) in two-stage solid-state fermentation (SSF). High-throughput sequencing technology was used to explore the dynamic changes in microbial diversity. The results showed that compared with four combinations of B. velezensis + Lactiplantibacillus plantarum (PCGM-BL), cellulase + L. plantarum (PCGM-CL),control group (PCGM-CK), and cellulase + B. velezensis + L. plantarum (PCGM-BCL), the fourth combination of PCGM-BCL significantly improved the nutritional characteristics of PCGM. After two-stage SSF (48 h), viable bacterial count and contents of crude protein (CP) and trichloroacetic acid-soluble protein (TCA-SP) all were increased in PCGM-BCL (p < 0.05), while the pH was reduced to 4.38 ± 0.02. In addition, compared with PCGM-BL, the cellulose degradation rate increased from 5.02 to 50.74%, increasing the amounts of short-chain fatty acids (216.61 ± 2.74 to 1727.55 ± 23.00 µg/g) and total amino acids (18.60 to 21.02%) in PCGM-BCL. Furthermore, high-throughput sequencing analysis revealed significant dynamic changes in microbial diversity. In the first stage of PCGM-BCL fermentation, Bacillus was the dominant genus (99.87%), which after 24 h of anaerobic fermentation changed to lactobacillus (37.45%). Kyoto Encylopaedia of Genes and Genomes (KEGG) metabolic pathway analysis revealed that the pathways related to the metabolism of carbohydrates, amino acids, cofactors, and vitamins accounted for more than 10% of the enriched pathways throughout the fermentation period. Concisely, we show that cellulase can effectively improve the nutritional value of PCGM when synergized with B. velezensis in two-stage SSF.
玉米胚芽粕（CGM）是玉米淀粉提取的主要副产物之一。虽然 CGM 含有丰富的纤维含量，但缺乏良好的蛋白质含量和氨基酸平衡，因此不能作为动物饲料充分利用。在这项研究中，我们研究了纤维素酶协同地衣芽孢杆菌对预处理玉米胚芽粕（PCGM）在两段式固态发酵（SSF）中营养价值的处理效果。使用高通量测序技术来探索微生物多样性的动态变化。结果表明，与地衣芽孢杆菌+植物乳杆菌（PCGM-BL）、纤维素酶+植物乳杆菌（PCGM-CL）、对照组（PCGM-CK）和纤维素酶+地衣芽孢杆菌+植物乳杆菌（PCGM-BCL）这四种组合相比，第四种 PCGM-BCL 组合显著改善了 PCGM 的营养特性。经过两段式 SSF（48 小时）后，PCGM-BCL 中的活菌数和粗蛋白（CP）和三氯乙酸可溶性蛋白（TCA-SP）含量均有所增加（p<0.05），而 pH 值降低至 4.38±0.02。此外，与 PCGM-BL 相比，纤维素降解率从 5.02%增加到 50.74%，PCGM-BCL 中的短链脂肪酸（216.61±2.74 至 1727.55±23.00µg/g）和总氨基酸（18.60 至 21.02%）的含量也增加了。此外，高通量测序分析显示微生物多样性发生了显著的动态变化。在 PCGM-BCL 发酵的第一阶段，芽孢杆菌是优势属（99.87%），经过 24 小时的厌氧发酵后，变为乳酸杆菌（37.45%）。京都基因与基因组百科全书（KEGG）代谢途径分析显示，碳水化合物、氨基酸、辅因子和维生素代谢途径在整个发酵过程中占富集途径的 10%以上。简而言之，我们表明纤维素酶在两段式 SSF 中与地衣芽孢杆菌协同作用可以有效地提高 PCGM 的营养价值。
