Abstract
The growth of Clostridium 16-An and the collagen digestion activity during a mixed culture with aerobes were investigated in respect to the influence of temperature, NaCl concentration and nitrogenous components in the medium as well as the change in redox potential. The results are summarized as follows. 1) i6-An grew vitally at30-40°C, but below 20°C practically grew neither in the single culture of 16-An nor in the mixed culture. 2) During the mixed culture, Eh of the medium decreased gradually to the value of -0. 2 V with the growth of aerobes. This Eh decrease was accompanied by an increase in collagen digestion activity and 16-An count. Con-cerning collagen digestion, the activity of the mixed culture with aerobic 37-1 (Vibrionaceae) was stronger than that with aerobic C-24 (Pseudomonas). 3) The growth of 16-An was pre-vented by addition of NaCl from making 5% concentration in the medium, irrespective of the presence or absence of aerobes. 4) 16-An required a medium containing meat extract for growth and production of collagen digestion ability. However, a supplement of peptone or ge-latin to the medium accelerated the growth of 16-An and strengthened its collagenolytic ability. Particularly in respect to the effect of gelatin, it is notably suggested that a specific effect of ge-latin in the medium of mixed culture with 37-1 is responsible for the additional increase in col-lagen digestion activity in such a way that the effect varies depending on the kind of associat-ed aerobe.
