Online First Article Effcient Sulphate Reduction by Cellulolytic and Sulphate-Reducing Bacterial Co-Culture Using Different Agro-Industrial Wastes as Growth Substrates Muhammad Muneeb 1 , Ali Hussain 2 *, Qurat-ul-Ain Ahmad 3 , Arshad Javid 1 and Jibran Hussain 3 1 Applied and Environmental Microbiology Laboratory, Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan 2 Applied and Environmental Microbiology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan 3 Department of Zoology, Division of Science and Technology, University of Education, Lahore, Pakistan 4 Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan Article Information Received 24 November 2022 Revised 18 January 2023 Accepted 28 February 2023 Available online 29 April 2023 (early access) Authors’ Contribution MM performed all experiments. QA co-supervised the work. AJ worked on collecting and arranging data. JH helped in statistical analysis and compilation of data. AH supervised the work and drafted manuscript. Key words Aquatic pollution, Economical bioremediation, Microbial consortium, Organic wastes, Sulphate-reducing bacteria Aquatic resources are being devastating rapidly due to the continuous intrusion of untreated wastes into the environment due to rapid industrialization and causing severe problems to aquatic life. Different physicochemical methods have been used to reduce these pollutants but all have their own limitations including production of secondary pollutants. The current study was designed to show the effect of cellulolytic and sulphate-reducing bacterial species in the form of a co-culture to treat an in-vitro prepared sulphate-rich wastewater while employing various agro-industrial organic waste as economical growth substrates. A combination of sulphate-reducing and cellulolytic bacteria in a ratio of 1:1 (v/v) was proved to be effcient for the reduction of sulphate in controlled as well as in the experimental conditions. The implicated microbial co-culture reduced 96 and 93 % of the added sulphate (5 gL −1 ) while using rice straw and animal manure, respectively in a 60-day trial of anaerobic incubation. Mixture of industrial and agricultural waste reduced about 90 % of the total added sulphate. A trend of decrease in pH with time was observed in all the incubated cultures. Our fndings will be helpful for devising sustainable waste management strategies. INTRODUCTION I n addition to many positive aspects of modern industrialized life, its eco-destructive aspects cannot be ignored (Idris et al., 2007). There is a close relationship between health hazards and anthropogenic sources of generation of different metallic pollutants (Campbell, 2006; Scragg, 2006; Becker et al., 2010; Paithankar et al., 2021; * Corresponding author: ali.zool@pu.edu.pk 0030-9923/2023/0001-0001 $ 9.00/0 Copyright 2023 by the authors. Licensee Zoological Society of Pakistan. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Karunanidhi et al., 2022). Different industries including food processing, potato starch, edible oil production, pulp manufacturing, petroleum refneries, textile, tanneries and solid waste process plants are adding different metallic and non-metallic pollutants in the environment constantly. Among these pollutants, various compound forms of sulphates are considered as the major culprits of environmental pollution (Wang, 2002; Boshoff et al., 2004; Vaiopoulou et al., 2005; Huang et al., 2006). These forms of sulphates have been causing some severe health hazards including pulmonary oedema, renal failure, hepatotoxicity, loss of consciousness and nervous disorders (Christia- Lotter et al., 2006; Kucukatay et al., 2007; Mortazavi and Jafari-Javid, 2009). A number of physicochemical methods to treat industrial wastewaters including but not limited to solvent removal, electro-dialysis, adsorption, reverse osmosis, electrochemical extraction and coagulation ABSTRACT Pakistan J. Zool., pp 1-8, 2023. DOI: https://dx.doi.org/10.17582/journal.pjz/20221124101150