Disease relevance of Tetronasin

• The determinant tnrB (ptetR51) but not tnrA (ptetR11), also conferred resistance to tetronasin when cloned into Streptomyces albus [1].
• The exception was the cellulolytic Ruminococcus flavefaciens, which adapted during successive cultivation on media with increasing ionophore concentrations to grow at 100-fold higher concentrations of tetronasin than were initially lethal to the organism [2].
• Lactobacillus casei was 55 times more sensitive to tetronasin than to monensin, indicating a potential role for tetronasin in reversing lactic acidosis [2].
• The addition of tetronasin to cultures of the ruminal bacteria Ruminobacter amylophilus and Bacteroides ruminicola had no influence on their protease, deaminase or dipeptidase activities [3].

High impact information on Tetronasin

• A genomic library of S. longisporoflavus DNA was cloned in Streptomyces lividans and screened to identify tetronasin-resistance determinants [1].
• Analysis of a gene cluster from S. longisporoflavus potentially involved in tetronasin biosynthesis [4].
• When tetronasin was added in vitro to ruminal fluid from sheep not receiving the ionophore, proteolytic activity (14C-labeled casein hydrolysis) was unaffected, but the rate of ammonia production from amino acids was decreased by 87% (P less than .01) [3].
• However, when the bacteria were adapted to grow in the presence of tetronasin, deamination of amino acids was severely inhibited (87 to 100%, P less than .01), even when tetronasin was absent from the incubation mixture [3].

Associations of Tetronasin with other chemical compounds

• The hydrolysis of Ala(2) and Ala(3) by whole cells was not affected by protonophores, ionophores or dicyclohexylcarbodiimide, but Ala(2) hydrolysis by EDTA-treated cells was inhibited by the Ca(2+)/H(+) ionophore, tetronasin [5].

References