Desmutagenic effects of culture liquid

The culture liquid obtained in propionic acid fermentation displayed antimutagenic activity with respect to NQO-induced mutagenesis in S. typhimurium TAIOO (Table 2.12). 

Cultivation time, h Incubation time, h Number of revertants per plate mutagen alone mutagen + antimutagen Inhibition, % 

Plates of Salmonella typhimurium TA-100, containing the mutagen NQO at 0.125 pg/ 0.1 ml per plate, were incubated with or without 0.1 ml per plate of the culture liquid from P. shermanii grown for the indicated periods of time (cultivation time). From Vorobieva et al. (1993b). 

The culture liquid of P. shermanii taken after 48 h of cultivation was concentrated 6-fold by lyophilization. Increasing the culture liquid concentration led to a reduction in the number of revertants (Fig. 2.6). 

Chemical mutagens NQO, 2-(2-fiiryl)-3-(5-nitrO 2-furyl)acrylamide (AF-2) and others are inactivated when heated with cysteine or cysteamine. 

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