Prof Okoh is the leader of the Applied and Environmental Microbiology Research Group (AEMREG). His research expertise falls within the aegis of Applied and Environmental Microbiology with particular emphasis on microbial water/wastewater quality, biodegradation of pollutants, reservoirs of antibiotic resistance, and bioactive compounds of health and biotechnological importance. He has been involved in various collaborations with eminent academics within and outside South Africa, and have reviewed for over 50 international journals. He has also been a recipient of such fellowships as the Postgraduate Fellowship Award, OAU, Ile–Ife, Nigeria, 1990–1992; United Nations University Fellowship (1998); UNESCO Biotechnology Action Council Fellowship (2000), as well as several grants from the NRF, MRC, WRC, ESKOM, RS-DFID, and ISRAR/APUA.