Degradation of Purines and Pyrimidines by Microorganisms

INTRODUCTION ............................................................ 404 Purine Degradation in Animals .............................................. 404 Purine Metabolism in Plants ............................................... 405 Degradation of Purines and Pyrimidines by Microorganisms ........ ........... 405 AEROBIC DEGRADATION OF PURINES: ENZYMATIC STEPS .............. 406 Methylpurines ............................................................. 406 Adenine .............................................................. 406 Xanthine Dehydrogenase .................................................... 407 Cofactors ............................................................. 408 Specificity .............................................................. 408 Other enzymes oxidizing purines ................... ........................ 409 Uricase ............................................................. 409 Properties .............................................................. 409 Specificity ............................................................. 411 Mechanism of action ...................................................... 411 Uricase-like processes ...................................................... 412 Allantoin ............................................................. 413 Allantoin racemase ........................................................ 413 Allantoinase ............................................................. 413 Allantoate Amidohydrolase and Allantoicase .................................. 414 Ureidoglycolase ............................................................. 415 Urea Degradation ........................................................... 416 Glyoxylate Degradation ..................................................... 416 AEROBIC DEGRADATION OF PURINES BY VARIOUS MICROORGANISMS . 416 Protozoa ............................................................ 416 Algae....................................................................... 417 Fungi ............................ ................................ 417 Basidiomycetes ........................................................... 417 Phycomycetes ............................................................ 417 Ascomycetes ............................................................ 417 Fungi imperfecti .......................................................... 419 Yeasts.................................................................... 419 Bacteria ............................................................ 425 Cyanobacteria .......................................................... 420 Pseudomonas ............................................................. 420 Alcaligenes ............................................................ 421 Arthrobacter and Brevibacterium ............. ............................. 421 Bacius ............................................................. 421 Mycobacteria ............................................................ 422 Actinomycetales .......................................................... 422 Various bacteria .......................................................... 422 DEGRADATION BY ENTEROBACTERIACEAE AND STREPTOCOCCI ........ 423 Enterobacteriaceae .......................................................... 423 Streptococcus allantoicus .................................................... 425 Catabolic Pathway of S. allantoicus and Enterobacteriaceae ....... ............ 425 Conversion of allantoin to ureidoglycolate ......... ......................... 426 Reductive degradation of glyoxylate ............ ............................ 426 Tartronate-semialdehyde reductase ............ ............................. 426 Oxidative production of oxalurate ............. ............................. 426 Oxamate formation ....................................................... 427 Concluding remarks ....................................................... 428 Purine Degradation by Other Streptococci ................ .................... 429 ANAEROBIC DEGRADATION OF PURINES ................................. 429 Clostridium acidiurici and C. cylindrosporum .............. ................... 429 Degradation ofpurines......430 Degradation~ ~ ~ rn ..................................................43 Conversion of xanthine to formiminoglycine ........ ........................ 430 Utilization of formiminoglycine and glycine by whole cells ...... ............ 433 Conversion of formiminoglycine .............. ............................. 433