INFLUENCE OF SURFACE-ACTIVE AGENT CONCENTRATION ON THE SPECTROPHOTOMETRIC BIOMASS ESTIMATION DURING SUBMERGED GROWTH OF Mycobacterium bovis

Influence of initial L-asparagine and glycerol concentrations on the batch growth kinetics of Mycobacterium bovis BCG

“…The CFU productivity was based on the minimum dissolved oxygen value (P CFU ) because at this point it was the maximum viable count (8,16,17). Such behavior was also confirmed in this work, as it can be seen in figure 4: the maximum value of CFU corresponds to the minimum value of oxygen concentration in the medium since the population of viables is responsible for the oxygen uptake.…”

“…However, it must be considered that this detergent exerts two distinct and antagonistic effects: it stimulates bacterial growth by allowing higher access of the microorganisms to the nutrients through reduction of the bacterial clump size and consequent increase of the specific area; on the other hand, it inhibits bacterial growth, probably through the oleic acid action, which is toxic for the bacilli. The inhibition depends on the relation between the concentrations of Tween-80 and the cells (8). Curiously, in the paper cited previously (28), the authors affirm that in their process conditions the optimal dissociation of the bacilli was achieved at 0.3% Tween-80.…”

“…For the assays carried out in the bioreactor (5 to 13) the cultivation media were sterilized inside the vessel at 121ºC for 30 min. Besides the fact that the sterilization by wet heat is easier than filtration, it was verified that heating the medium did not cause alterations in the growth kinetics (8).…”