Ke. Ashelford et al., PLASMID TRANSFER BETWEEN STRAINS OF PSEUDOMONAS-PUTIDA, AND THEIR SURVIVAL, WITHIN A PILOT-SCALE PERCOLATING-FILTER SEWAGE-TREATMENT SYSTEM, FEMS microbiology, ecology, 18(1), 1995, pp. 15-25
The ability of non-indigenous bacteria to survive and conjugate within
a fully functioning pilot-scale percolating filter bed, with a substa
ntial biofilm and a diverse invertebrate community, was investigated.
Pseudomonas putida UWC8, harbouring the conjugative plasmid pQKH6, iso
lated from river epilithon, and P. putida UWC9 were introduced and sur
vived in a culturable state for up to 145 days. During this time plasm
id transfer, with transfer frequencies of up to 6.54 X 10(-5) cfu per
recipient, could be detected. The macro-invertebrate community was als
o investigated. The invertebrate grazers had no detectable effect upon
the densities of the introduced bacteria.