Characterization and Enumeration of Microorganisms Associated with Anaerobic Digestion of Tomato-Processing Waste

Different physiological groups of microorganisms; cellulolytics,
xylanolytics, pectinolytics, proteolytics, lipolytics
and methanogens were enumerated and monitored
during the anaerobic digestion of tomato-processing
waste (TPW). In the batch digestion lasting 110 days, the
numbers of cellulolytics, xylanolytics, pectinolytics, proteolytics
and lipolytics showed a steady increase up to 40
days, but declined thereafter. In the semicontinuous
digestion, the numbers of cellulolytics, proteolytics and
lipolytics were found to be greater at 24 and 32 days
hydraulic retention times (HRT) than at 8 and 16 days
HRT. On the other hand, the numbers of xylanolytics
and pectinolytics varied very little at different HRT. At
the higher HR T, there were more methanogens than at
the lower HRT. Differences in the types of bacteria isolated
from digesters in the batch and semicontinuous
processes were found. Bacteria belonging to Bacteroides,
Eubacteria, Fusobacteria, Lactobacillus, Propionibacteria
and Selenomonas were isolated. Two
apparently novel isolates of cellulolytic bacteria belonging
to the genus Eubacteria were also found.