The present invention provides a process for the preparation of stable and reusable biosensing granules useful in the assessment of biodegradability of effluents. The biosensing granules are prepared by culturing active aerobic microbial consortia in synthetic medium, separating the active aerobic microbial consortia, immobilizing the microbial consortia using natural polymer to form biosensing granules, and dehydrating the immobilized biosensing granules to obtain stable biosensing granules having a moisture content of 5-30%.