Screening of High 1,2-Propanediol Production by Lactobacillus buchneri Strains and Their Effects on Fermentation Characteristics and Aerobic Stability of Whole-Plant Corn Silage

The study was conducted to screen high 1,2-propanediol produced by Lactobacillus buchneri strains, isolated from baled silages stored for 1 or 2 years, and to evaluate their effects on fermentation quality and aerobic stability of whole-plant corn silage. In total, 31 L. buchneri strains were isolated from alfalfa, whole-plant corn and oat silages. Based on growth performance and 1,2-propanediol and acetic acid production, two strains, L. buchneri 9-2 and L. buchneri 10-1, from alfalfa silage, were further assessed in an ensiling trial on whole-plant corn. The corn silage inoculated with L. buchneri 9-2 or L. buchneri 10-1 had a higher concentration of 1,2-propanediol (34.7 or 34.6 g/kg dry matter (DM)) and acetic acid (47.2 or 45.9 g/kg DM) in comparison with L. buchneri 40788 (reference strain) treated silage (19.5 and 35.9 g/kg DM) after 90 d of fermentation. In addition, these two strains performed better in improving silage aerobic stability relative to control and L. buchneri 40788. The results above indicated that L. buchneri 9-2 and L. buchneri 10-1 could be candidate strains to increase 1,2-propanediol and acetic acid concentrations and improve the aerobic stability of whole-plant corn silage.