Jornal de Bacteriologia e Parasitologia

Abstrato

Time-Temperature Model for Bacterial and Parasitic Annihilation from Cow Dung and Human Faecal Sludge: A Forthcoming Bio-Fertilizer

Zahid Hayat Mahmud, Pankoj Kumar Das, Hamida Khanum, Muhammad Riadul Haque Hossainey, Ehteshamul Islam, Hafij Al Mahmud, Md Shafiqul Islam, Khan Mohammad Imran, Digbijoy Dey and Md Sirajul Islam

The present study investigated the optimum time and temperature for inactivation of bacteria and parasites in cow dung and pit faecal sludge, a forthcoming fertilizer. Samples were collected from different areas of Bangladesh and were examined through modified centrifugal flotation and conventional culture techniques to isolate parasites and bacteria respectively. A cow dung sample from Gopalganj and a pit sample from Dohar that were found to be the most contaminated among the samples tested were heated to annihilate the pathogens present there. After 30 min of exposure at 60°C, all bacteria lost their ability to grow on culture media except enterococci. Among the parasites found in the pit sample, Entamoeba histolytica was the least heat resistant, which was killed at 60°C within 30 min followed by Ancylostoma duodenale larva, Strongyloides stercoralis larva, Trichuris trichiura, Ancylostoma duodenale eggs and Strongyloides stercoralis egg. Ascaris lumbricoides and Hymenolepis nana were the most resistant to heat, inactivated at 75°C within 15 min. In cow dung, Paramphistomum was the most resistant, became inactivated at 65°C within 60 min whereas Haemonchus at 65°C within 30 min. The study findings showed the best time dependent temperature to deactivate the pathogens present in faecal sludge in Bangladesh context.