An isolated, synthetic or recombinant nucleic acid comprising (a) a nucleic acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more or complete (100%) sequence identity to SEQ ID NO:521, wherein the nucleic acid encodes a polypeptide having a beta-glucosidase activity, and optionally the sequence identities are determined by analysis with a sequence comparison algorithm or by a visual inspection; or (b) a nucleic acid sequence that hybridizes under stringent conditions to a nucleic acid comprising SEQ ID NO:521, wherein the nucleic acid encodes a polypeptide having a beta-glucosidase activity and has at least 80% identity to SEQ ID NO: 521, and the stringent conditions include a wash step comprising a wash in 0.2X SSC at a temperature of about 65°C for about 15 minutes; (c) a nucleic acid sequence encoding a polypeptide having at least 80% sequence identity to the sequence of SEQ ID NO:522, wherein the polypeptide has a beta-glucosidase activity; (d) the nucleic acid of (a), (b) or (c) encoding a polypeptide having a beta-glucosidase activity but lacking a signal sequence or a carbohydrate binding module; (e) the nucleic acid of (a), (b), (c) or (d) encoding a polypeptide having a beta-glucosidase activity but having a heterologous sequence, wherein optionally the heterologous sequence comprises a heterologous signal sequence, carbohydrate binding module, catalytic domain, or a combination thereof, and optionally the heterologous signal sequence, carbohydrate binding module or catalytic domain is derived from an oligomerase, cellulase or cellulolytic enzyme, or a non-oligomerase, cellulase or cellulolytic enzyme; or (f) a nucleic acid sequence fully complementary to (a), (b), (c), (d) or (e). (a) a nucleic acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more or complete (100%) sequence identity to SEQ ID NO:521, wherein the nucleic acid encodes a polypeptide having a beta-glucosidase activity, and optionally the sequence identities are determined by analysis with a sequence comparison algorithm or by a visual inspection; or (b) a nucleic acid sequence that hybridizes under stringent conditions to a nucleic acid comprising SEQ ID NO:521, wherein the nucleic acid encodes a polypeptide having a beta-glucosidase activity and has at least 80% identity to SEQ ID NO: 521, and the stringent conditions include a wash step comprising a wash in 0.2X SSC at a temperature of about 65°C for about 15 minutes; (c) a nucleic acid sequence encoding a polypeptide having at least 80% sequence identity to the sequence of SEQ ID NO:522, wherein the polypeptide has a beta-glucosidase activity; (d) the nucleic acid of (a), (b) or (c) encoding a polypeptide having a beta-glucosidase activity but lacking a signal sequence or a carbohydrate binding module; (e) the nucleic acid of (a), (b), (c) or (d) encoding a polypeptide having a beta-glucosidase activity but having a heterologous sequence, wherein optionally the heterologous sequence comprises a heterologous signal sequence, carbohydrate binding module, catalytic domain, or a combination thereof, and optionally the heterologous signal sequence, carbohydrate binding module or catalytic domain is derived from an oligomerase, cellulase or cellulolytic enzyme, or a non-oligomerase, cellulase or cellulolytic enzyme; or (f) a nucleic acid sequence fully complementary to (a), (b), (c), (d) or (e).