• Title/Summary/Keyword: aerobiosis

Search Result 3, Processing Time 0.039 seconds

Active role of oxygen on penicillin sensitivity and fromation of membrane protein in escherichia coli K12 (Escherichia coli K12의 막단백질 형성과 페니실린 민감성에 대한 산소의 능동적 역할)

  • 박현근;한홍의
    • Korean Journal of Microbiology
    • /
    • v.24 no.3
    • /
    • pp.263-269
    • /
    • 1986
  • Membrane proteins of facultatively anaerobic Escherichia coli K12 which was logarithmically grown in aerobiosis and anaerobiosis were compared on 5 to 10% liner gradient gel electrophoresis (Na Dod $SO_4 -PAGE$). Membrane proteins were formed as different patterns between aerobiosis and anaerobiosis. Among them, 91Kdal protein (pbp1a) was not synthesized in aerobiosis and 60Kdal protein (fts cluster), in anaerobiosis. Thereby cells cultured aerobically were differenciated as diversiform cell shape, comparing cells cultured anaerobically and the latter were resistant to penicillin G. Thus it is believed that in facultative anaerobes atmospheric oxygen regulated the synthesis of membrane proteins and even the expression of equivalent genes, and moreover alleviated the resistance to an antibiotic penicillin.

  • PDF

Effects of sodium diacetate or microbial inoculants on aerobic stability of wilted rye silage

  • Li, Yan Fen;Wang, Li Li;Jeong, Eun Chan;Kim, Hak Jin;Ahmadi, Farhad;Kim, Jong Geun
    • Animal Bioscience
    • /
    • v.35 no.12
    • /
    • pp.1871-1880
    • /
    • 2022
  • Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air. Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), Lactobacillus plantarum (LP), L. buchneri (LB), or their equal mixture (LP+LB) at 1×106 colony-forming unit/g fresh matter. Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest in vitro DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages. Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage.