Presence of large virus-like particles in a eutrophic reservoir

The presence of large virus-like particles (LVLP) studies on morphological diversity of viruses in freshwithout tails was observed in the water of a severely eutrowater and marine environments, only phages have phied freshwater reservoir We used a transmission electron been found (Frank & Moebus 1987, Demuth et al. microscope coupled to a semiautomatic lmage analysing system to study the size distl-ibution of aquatic vlruses. The LVLP particles icosahedral shape had maximum head diameters between 195 and 210 nm. bling viruses have been described (Bergh et al. 1989, Although the affiliation and host of the LVLP are unknown, Klut & Stockner 1990). These particles, usually with similarities in size and shape were found with the African diameters between 60 and 120 nm, are assumed either swine fever virus. The diffuse organlc contamination from piggeries in the catchment area may explain the presence of to be phages that have lost their tails or viruses of these LVLP. The observed overlap In slze of the LVLP wlth the e u k a r ~o t i c hosts (Bergh et al. 1g89). The denomination smallest bacteria implies serious methodological problems in of virus-like particles indicates clearly the uncertainty distinguishing these communities under the ep~fluorescence of their affiliation, Bratbak et (1992) reported microscope. Therefore, although at present we do not know how common LVLP are in other aquatic systems, we discour-unusually large virus-like particles (LVLP) with head age the use of eplfluorescence microscopy for vlral abun-diameters between 340 and 400 nm present) from dance estimations durinq routine work.