|| Bioinfo Publications || 472 International Journal of Microbiology Research ISSN: 0975-5276 & E-ISSN: 0975-9174, Volume 5, Issue 5, 2013, pp.- 472-475. Available online at http://www.bioinfopublication.org/jouarchive.php?opt=&jouid=BPJ0000234 MAREI E.M. 1 , ELBAZ R.M. 2 * AND HAMMAD A.M.M. 3 1 Virology Laboratory, Microbiology Department, Faculty of Agriculture, Ain Shams University- 11241, Egypt. 2 Botany and Microbiology Department, Faculty of Science, Helwan University, Ain Helwan- 11790, Egypt. 3 Microbiology Department, Faculty of Agriculture. Minia University, Minia- 61111, Egypt. *Corresponding Author: Email- d.reham@hotmail.com Received: August 18, 2013; Accepted: September 15, 2013 Introduction The lysogeny was found to be common in the marine environment, when a series of diverse marine environment were examined for prophage induction using mitomycin-C [1,2]. Moreover, Okhi [3] reported that mitomycin C-stimulated prophage induction in cultured and natural samples of the filamentous cyanobacterium Trichodes- mium sp. Using UV-radiation, up to 38% of the bacterial population were found to contain inducible prophage [1,4]. The lysogenic Anacystis nidulans was treated with different concen- trations of heavy metals-copper sulfate for induction of temperate phages. The temperate phage As-1 was induced by copper sulfate at concentrations from 3.1x10 -6 to 3.1x10 -4 M. Maximal phage in- duction occurred at 6 th hour after addition of copper sulfate at con- centration of 3.1x10 -6 M. Titer of the induced phages was calculated as plaque forming units (pfu ) by a direct plating method [5]. Lysogenic cells of Anabeana sp.1 were treated with mitomycin C and examined by transmission electron microscopy. Thickness of the algal cell wall, coagulation of cytoplasm, appearance of vacu- oles of different sizes and shapes, compact of the thylakoid and lysis of the cells were observed by Marei [2]. This work aims to induction of temperate cyanophages by using heavy metal-copper. In addition, cytopathic effect and alteration of cell structure due to induction of the temperate phages were also studied. Materials and Methods Source of Cyanobacteria Anabaena sp.1, sp.2 and sp.3, Nostoc muscorum and Oscillatoria sp. were obtained from the Virology Lab., Microbiology Department, Faculty of Agriculture - Ain Shams University. Anabaena cylindrica was kindly provided by Plant Physiology and Phycology Lab., Bota- ny and Microbiology Department, Faculty of Science - Helwan Uni- versity. Induction of Temperate Cyanophage Erlenmeyer flasks each containing 95ml of Watanabe medium [6] were prepared. Five ml liquid culture (10 7 cfu/ml) of each cyanobac- terial isolate were transferred separately into an individual flask. The flasks were incubated at 30°C under continuous illumination of fluorescence 5500-6500 lux for 10 days to reach exponential growth stage. Copper sulfate (CuSO4) was then added to the cultures of each isolate at concentrations of 3.1x 10 -3 -10 -6 M. A culture with no Citation: Marei E.M., Elbaz R.M. and Hammad A.M.M. (2013) Induction of Temperate Cyanophages Using Heavy Metal - Copper. International Journal of Microbiology Research, ISSN: 0975-5276 & E-ISSN: 0975-9174, Volume 5, Issue 5, pp.- 472-475. Copyright: Copyright©2013 Marei E.M., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited. International Journal of Microbiology Research ISSN: 0975-5276 & E-ISSN: 0975-9174, Volume 5, Issue 5, 2013 Abstract- Presence of prophages in cells of three isolates of Anabaena sp. (Anabaena sp.1, sp.2 and sp.3), Anabaena cylindrica, Nostoc muscorum and Oscillatoria sp. was investigated. Copper sulfate at concentration of 3.1x10 -4 M was successfully used for induction of temper- ate cyanophages. Among the cyanobacterial isolates tested Anabaena cylindrica was found to contain a prophage. A temperate phage was induced from Anabaena cylindrica by copper sulfate treatment and designated Ac-1. The induced phage isolate formed hazy circular plaques of 5 mm in diameter. The thermal inactivation point and longevity in vitro of the induced phage isolate (Ac-1) were found to be 70°C and 36 hrs., respectively. The induced cyanophage particles were examined by transmission electron microscopy. The phage particles were of head and tail type. The head diameter, tail length and tail width were found to be 50 nm, 116.6 nm and 8.3 nm, respectively. Ultrathin sections of infected A. cylindrica cells with temperate cyanophage and healthy ones were examined by electron microscopy. Marked changes in protoplasm and cell membrane, i.e. coagulation of protoplasm, formation of vesicles and vacuoles were observed in the infected cells as compared to the healthy ones. Phage particles were detected inside the infected A. cylindrica cells. Moreover, lysis of cell wall and release of the induced phage particles were also observed. Keywords- Temperate cyanophage, Heavy metal, Cytopathic effect INDUCTION OF TEMPERATE CYANOPHAGES USING HEAVY METAL - COPPER