Enzymes  are  the protein substances produced  by  the  living cells which catalyzes a  biochemical reaction.  They accelerate  a  specific chemical reaction.

Enzymes, which are known  as biocatalysts, are very useful in the manufacturing of several products  of commercial  value.  The enzymes are  widely used  for  the manufacture of alcoholic  beverages  etc.  The  enzyme  w-amylase  used in  bread- making,  is commercially prepared from Aspergillus  olyzae. The amylogluccsidase, used  as a substitute for malt  in  the production  of beer  and  spirits,  is commercially

prepared from Aspergillus  niger. Pectolytic enzymes are produced  from  a number of  fungi  for use  in  fruit processing.  Cellulase enzyme used for removing cellulose cloud  and  clarifying juices  is  produced from  the  mould  Trichoderma viride  and proteases  used  in  cheese-making from Aspergillus niger.