초록
<P>We evaluated the production of holocellulases from the cellulolytic microorganisms <I>Cellulomonas flavigena</I> PR-22 and <I>Trichoderma reesei</I> MCG 80 using as substrates the organic fraction of municipal solid waste (OFMSW) and digestates from a hydrogenogenic-methanogenic bioenergy production process. The first set of experiments (E1) used the mutant actinobacteria <I>C. flavigena</I> PR-22 whereas another set (E2) used the mutant filamentous fungi <I>T. reesei</I> MCG 80. In E1 with OFMSW as substrate, xylanolytic activities ranged from 1800 to 3900 international units g<SUB>holocellulose</SUB> <SUP>−1</SUP> (IU g<SUB>hol</SUB> <SUP>−1</SUP>), whereas the cellulolytic activities ranged from 220 to 420 IU g<SUB>hol</SUB> <SUP>−1</SUP>. The variation of agitation speed did not have a significant effect on enzyme activity, whereas the increase of substrate concentration had a significant negative effect on both xylanolytic and cellulolytic activities on a holocellulose feed basis. Regarding E2, the OFMSW was evaluated at 1, 2 and 3 % volatile solids (VS). At 2 % VS the best filter paper activities were 1200 filter paper units (FPU) l<SUP>−1</SUP>; however, in a holocellulase basis the best result was 67 FPU g<SUB>hol</SUB> <SUP>−1</SUP>, corresponding to 1 % VS. Next, OFMSW was compared with OFMSW supplemented with lactose, digested solids from hydrogenogenic fermentation (D1) and digested solids from a two-stage process (D2). Against expectations, no positive effect was found in OFMSW due to lactose. The best enzymatic titres were in the order D1 > OFMSW ≈ OFMSW + lactose > D2. The use of digestates from hydrogenogenic fermentation for enzyme production holds promise for waste management. It promotes energy and added-value bioproduct generation—a green alternative to common practice of management and disposal of organic wastes.</P>