Puntillo Melisa, Gaggiotti Mónica, Oteiza Juan Martín, Binetti Ana, Massera Ariel, Vinderola Gabriel
Instituto de Lactología Industrial (CONICET-UNL), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santa Fe, Argentina.
Laboratorio de Calidad de Leche y Agroindustria, INTA EEA Rafaela, Santa Fe, Argentina.
Front Microbiol. 2020 Dec 8;11:586716. doi: 10.3389/fmicb.2020.586716. eCollection 2020.
We aimed at isolating lactic acid bacteria (LAB) from different plant materials to study their crossed-fermentation capacity in silos and to find strains able to confer enhanced aerobic stability to silage. A total of 129 LAB isolates were obtained from lucerne (alfalfa), maize, sorghum, ryegrass, rice, barley, canola, , , soy, white clover, wheat, sunflower, oat, and moha. Four subsp. strains (isolated from oat, lucerne, sorghum, or maize) were selected for their growth capacity. Identity (16S sequencing) and diversity (RAPD-PCR) were confirmed. Fermentative capacity (inoculated at 10, 10, 10, 10 CFU/g) was studied in maize silage and their cross-fermentation capacity was assessed in oat, lucerne, sorghum, and maize. Heterofermentative strains with the highest acetic acid production capacity conferred higher aerobic stability to maize silages. Regardless the source of isolation, strains, inoculated at a rate of 10 CFU/g, were effective to produce silage from different plant materials. From more than 100 isolates obtained, the application of a succession of experiments allowed us to narrow down the number of potential candidates of silage inoculants to two strains. Based on the studies made, LpM15 and LfM1 showed potential to be used as inoculants, however further studies are needed to determine their performance when inoculated together. The former because it positively influenced different quality parameters in oat, lucerne, sorghum, and maize silage, and the latter because of its capacity to confer enhanced aerobic stability to maize silage. The rest of the strains constitute a valuable collection of autochthonous strains that will be further studied in the future for new applications in animal or human foods.
我们旨在从不同植物材料中分离乳酸菌(LAB),以研究它们在青贮窖中的交叉发酵能力,并寻找能够提高青贮饲料有氧稳定性的菌株。总共从紫花苜蓿、玉米、高粱、黑麦草、水稻、大麦、油菜、大豆、白三叶草、小麦、向日葵、燕麦和莫哈草中获得了129株乳酸菌分离株。选择了4株亚种菌株(分别从燕麦、紫花苜蓿、高粱或玉米中分离),因其生长能力较强。通过16S测序确认了其身份,通过随机扩增多态性DNA聚合酶链反应(RAPD-PCR)确认了其多样性。在玉米青贮饲料中研究了发酵能力(接种量为10⁵、10⁶、10⁷、10⁸CFU/g),并在燕麦、紫花苜蓿、高粱和玉米中评估了它们的交叉发酵能力。产乙酸能力最高的异型发酵菌株赋予玉米青贮饲料更高的有氧稳定性。无论分离来源如何,接种量为10⁵CFU/g的菌株都能有效地从不同植物材料中生产青贮饲料。从获得的100多株分离株中,通过一系列实验,我们将青贮接种剂的潜在候选菌株数量缩小到了两株。基于已开展的研究,LpM15和LfM1显示出有潜力用作接种剂,然而,需要进一步研究以确定它们一起接种时效果如何。前者是因为它对燕麦、紫花苜蓿、高粱和玉米青贮饲料的不同质量参数有积极影响,后者是因为它能够提高玉米青贮饲料的有氧稳定性。其余菌株构成了宝贵的本土菌株库,未来将进一步研究其在动物或人类食品中的新应用。