Choudhury, Tanmoy GonMaiti, BiswajitMnvenugopalKarunasagar, Indrani2020-11-182020-11-182019-03Choudhury Tanmoy Gon, Maiti Biswajit, Mnvenugopal, Karunasagar Indrani. Influence of some environmental variables and addition of r-lysozyme on efficacy of Vibrio harveyi phage for therapy. Journal of Biosciences. 2019 Mar; 44(1): 1-90250-59910973-7138http://imsear.searo.who.int/handle/123456789/214413Bacteriophage therapy is a viable proposition for controlling luminous vibriosis caused by Vibrio harveyi in shrimpaquaculture. However, environmental factors influence the growth and activity of phage and affect its efficiency incontrolling bacterial diseases. An essential problem in the use of vibrio phage as a therapeutic agent was the development ofresistance to phage attachment, rendering them resistant to the lytic action of phage. This problem could be overcome byapplying a cocktail of phages. This study aimed to evaluate the effect of salinity and pH on the phage activity and also tostudy the role of recombinant shrimp lysozyme on the performance of the V. harveyi phage. Out of three different levels ofsalinity (20, 25 and 30 ppt) and pH (6, 7 and 8) tested, optimum phage activity was observed at a salinity of 25 ppt and atneutral pH. Application of recombinant shrimp lysozyme in combination with V. harveyi phage significantly improved theactivity of phage in in vitro assay as well as in microcosm study using seawater. The application of phage along withlysozyme can be a useful approach to overcome the inability of phage to enter the bacteria and thus eliminate or reduce fish/shrimp pathogenic bacteria in aquaculture.LysozymepHPhage therapySalinityVibrio harveyiJournal ArticleIndiaDepartment of Fishery Microbiology, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore 575 002, India Department of Aquatic Health and Environment, College of Fisheries, Central Agricultural University (Imphal), Lembucherra, Tripura 799 210, IndiaDepartment of Fishery Microbiology, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore 575 002, India UNESCO MIRCEN for Medical and Marine Biotechnology, Nitte University Centre for Science Education and Research, Nitte (Deemed to be University), Paneer Campus, Deralakatte, Mangalore 57018, IndiaDepartment of Fishery Microbiology, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore 575 002, IndiaDepartment of Fishery Microbiology, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore 575 002, India UNESCO MIRCEN for Medical and Marine Biotechnology, Nitte University Centre for Science Edu cation and Research, Nitte (Deemed to be University), Paneer Campus, Deralakatte, Mangalore 57018, India