RELATIONSHIP BETWEEN THE MORPHOLOGY OF BACTERIOPHAGES AND THEIR PERSISTENCE IN THE ENVIRONMENT

The aim of the present work waste observe the morphological difference s between bacteriophages from sewage, recent pollution and those from samples that contain microorganisms that have survived either natural inactivation or water treatment processes (persistent pollution). We s tudied the occurrence of bacteriophages infecting Bacteroides fragilis (HSP40 strain), F-specific coliphages (HS(pFamp)R strain) and somatic coliphages (CN13 strain). Phages isolated with B. fragilis in both wa stewater and samples with persistent pollution were in all cases membe rs of the Siphoviridae group with flexible tails. With E. coli strain HS(pFamp)R we detected F-specific coliphages in 97.7% wastewater. Howe ver, the percentage decreased to 76.9% in samples with persistent poll ution. In the case of somatic coliphages in wastewater, detected using E. coil CN13, 91% of the phages belonged to the Myoviridae family and a 6% to the Siphoviridae family. In contrast, in persistent pollution samples, an increase of Siphoviridae phages was observed (up to 26.4% ). (C) 1997 IAWQ. Published by Elsevier Science Ltd.