昆明优质本土乳酸菌的筛选及其对全株玉米青贮品质的影响

Screening of High-quality Native Lactic Acid Bacteria in Kunming and Its Effect on the Quality of Whole-plant Maize Silage

为筛选出适用昆明地区全株玉米青贮发酵的优质乳酸菌菌株,探求其青贮效果,本研究以自然发酵60 d的全株玉米(Zea mays)、紫花苜蓿(Medicago sativa)、鸭茅(Dactylis glomerata)为试验材料,将继代培养、菌株分离和形态及基因序列鉴定等方式筛选的3株优质菌株制成菌液,单独或2种菌液按1∶1配比添加到全株玉米中,检测其对全株玉米发酵品质、营养品质及有氧稳定性的提升效果。结果表明:短乳杆菌B10、植物乳杆菌B16及戊糖片球菌C23是昆明地区3种青贮饲料中的优质本土乳酸菌;与自然发酵相比,同型发酵乳酸菌B16,C23单独添加或与异型发酵乳酸菌B10配合添加可显著提高青贮饲料中乳酸菌的数量(P<0.05);与商用复合乳酸菌相比,优质本土乳酸菌单一菌液或复合菌液的添加可更好的保存青贮饲料的DM及CP含量,但对青贮饲料有氧稳定性的提升效果相对较差。因此,添加本土优质乳酸菌可改善全株玉米青贮品质。

The aim of this study was to screen out the high-quality lactic acid bacteria strains suitable for whole corn silage fermentation in Kunming area,and to explore the silage effect.The research chose whole-plant corn(Zea mays),alfalfa(Medicago sativa),and orchardgrass(Dactylis glomerata) that were naturally fermented for 60 days as materials.Three high-quality strains screened by subculture,strain isolation,morphology and gene sequence identification were prepared as bacterial solution,which were added to whole corn alone or as a mixture of two kinds of bacterial at a ratio of 1∶1,and their effects on the fermentation quality,nutritional quality and aerobic stability of the whole corn were measured.The results showed that Lactobacillus brevis B10,Lactobacillus plantarum B16 and Pediococcus pentosaceus C23 were the high-quality native lactic acid bacteria in the three kinds of silages in Kunming.Compared with natural fermentation,the addition of homofermentative lactic acid bacteria B16 and C23 alone or in combination with heterofermentative lactic acid bacteria B10 could significantly increase the number of lactic acid bacteria in silage(P<0.05).Compared with commercial compound lactic acid bacteria,the addition of high-quality native lactic acid bacteria alone or a compound bacterial solution can better preserve the DM and CP content of silage,but the effects of high-quality native lactic acid bacteria on improving the aerobic stability of silage is relatively poor.Therefore,the quality of whole corn silage can be improved by adding local high-quality lactic acid bacteria.