ISOLATION, PURIFICATION AND SOME PROPERTIES - Biochemistry and Biotechnology: Research and Development - page 11

different carbon sources: glucose, starch or sucrose (media 2, 3). But LO biosynthesis was
detected only in the media containing wheat bran (medium 3). The highest LO activity was
also found when Trichoderma sp . 6 was used. The enzyme biosynthesis depended gradually
from the presence of nitrogen sources, The best results were obtained in the presence of 6%
NH 4 NO 3 : LO activity in the medium reached 8.5 U/ml (120 U/g - wheat bran (Figure 1). It
was twice higher than LO level reached using solid-phase cultivation method. The
dependence of LO biosynthesis from the conditions of cultivation was noticed for the first
time by the Japanese scientists for the Trichoderma viride Y-244 strain: the addition of
NaNO 3 during solid-phase fermentation increased LO yield 3 times, but in bulk conditions
this strain was not able to produce LO [3]. Strain T. harzianum Rifai was able to synthesize
LO during surface and bulk cultivation, but the enzyme levels were rather low [7].

Figure 2. Microphotographs (magnification x 63) of Trichodеrma sp.6, producing L-lysine -oxidase.

Figure 3. Influence of aeration on LO synthesis by Trichoderma sp . 6 in bioreactors. Temperature -28 о
С, рН - without adjustment. 1. - рО 2 80%; 2.- рО 2 55%; 3.- рО 2 30%.