2009 Volume 24 Issue 4 Pages 322-329
Aliivibrio fischeri NCIMB1281T (basonym, Vibrio fischeri) spontaneously started broad-host range vector particle (AfVP) production by budding from the logarithmic phase, and stabilised at around 7.0×1010-7.4×1011 particles mL-1 without any accompanying change in the host population. AfVPs had a spherical shape and varied in diameter from 18.1 to 159.2 nm [median±SD, 58.4±11.9 nm, n=528], with 95.1% between 30.2 and 84.6 nm in diameter exhibiting a normal distribution. Their buoyant density and DNA content ranged from 1.3607 to 1.3980 g cm-3, and 17.3 to 95.3 kbp, respectively. Regardless of UV treatment, AfVPs enhanced the efficiency of plating 116-136% at a multiplicity of infection of ca. 140 in Escherichia coli AB1157. Generalised transduction was observed with a frequency of between 10-4 and 10-6 cells per AfVP without UV treatment. Upon infection, the particle membrane remained outside the recipient cell, and a string-like structure coated with a fibrous proteinaceous-like material was present. The growth of the E. coli transductant (AfV-E-trans) reached a maximum of ca. 415% that of the parental E. coli recipient. AfV-E-trans acquired the ability to produce budding particles.