HUBEI AGRICULTURAL SCIENCES ›› 2022, Vol. 61 ›› Issue (14): 92-101.doi: 10.14088/j.cnki.issn0439-8114.2022.14.016

• Animal Husbandry & Veterinary Medicine • Previous Articles     Next Articles

Isolation and characterization of lactic acid-producing bacteria from naturally fermented silages and vegetables

DONG Ke1, LI Xia1, WEI Zhen-wu2, ZHU Dao-chen1, JIANG Jian-xiong1   

  1. 1. Biofuels Institute/School of Environment & Safety Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China;
    2. College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
  • Received:2021-03-29 Online:2022-07-25 Published:2022-08-25

Abstract: The lactic acid producing bacteria were isolated from the naturally fermented silages of Broussonetia papyrifera leaves and whole-crop oat as well as from the traditional fermented and salted vegetables, and their growth and acid-producing characteristics were unveiled to study their effects on fermentation quality of corn stalk silage. Single clones of acid-producing bacteria were obtained through plate streaking method and their taxa were identified based on 16S rDNA sequences. Growth curves and pH tolerance abilities of bacteria were studied using spectrophotometric method, and acid-producing curves of bacteria were measured with a portable pH meter. The organic acid kinds and concentrations produced by bacteria were determined using HPLC. Drying method for determination of DM, Kjeldahl method for determination of CP, paradigm method for determination of CF, ADF and ADL, anthrone colorimetry for determination of WSC, ashing method for determination of Ash. Results showed that a total of 96 strains were isolated and identified, including 6 strains of Lactobacillus plantarum, 6 strains of Lactobacillus brevis, 27 strains of Lactobacillus curvatus, 35 strains of Lactobacillus buchneri, 1 strain of Staphylococcus cohnii, 1 strain of Pediococcus pentosaceus, 19 strains of Bacillus sp., and 1 strain of Enterococcus sp. Among them, L. curvatus G3, L. plantarum G17 and Y17, L. brevis Y4, L. buchneri PC-C1, and Bacillus YC1-1-4 possessed a higher growth rate as well as organic acid producing rate. L. plantarum had the highest tolerant ability to initial low pH in culture medium, followed by L. buchneri, L. brevis, and P. pentosaceus, and the lowest was L. curvatus. HPLC analysis indicated that the strains of G3, G17, Y4, YC1-1-4, PC-C1, YC2-6, and G18 produced the highest yield of beneficial organic acids including lactic acid, acetic acid, and propionic acid. These acid-producing bacteria were used for producing corn stalk silage, in which the content of crude protein was significantly increased and the contents of acid detergent fiber and acid detergent lignin were reduced.

Key words: organic acid-producing bacteria, 16S rDNA, growth characteristics, corn stalk silage, fermentation quality

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