The effect of storage in liquid nitrogen on the recovery of human dental plaque bacteria.
Centrifuged deposits of various individual bacteria from type-culture collections and dental plaque samples were immersed in liquid nitrogen for periods of up to 2 years. All the organisms were recovered after storage in liquid nitrogen but Fusobacterium nucleatum (ATCC 10953) and Campylobacter fetus (NCTC 10354) consistently showed a reduction in the number of colony-forming units after freezing. The main effect on bacterial proportions in plaque samples was a reduction in aerobic Gram-negative cocci. Thus, storage in liquid nitrogen may be useful for comparative studies of dental plaque and as a means of storing individual organisms.
D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000302:isolation & purification*; D002168:Campylobacter fetus / Q000302:isolation & purification; D002648:Child; D003773:Dental Plaque / Q000382:microbiology*; D005673:Fusobacterium / Q000302:isolation & purification; D006801:Humans; D009584:Nitrogen; D013997:Time Factors; D014021:Tissue Preservation
D009584:Nitrogen