Effect of Cassava Processing Effluent on Microbial Diversity and Physicochemical Constituents of Soils

Abstract

This paper examines the effect of cassava processing effluent on the microbiological and physicochemical constituents of soils at Luyor Gwara in Khana, River State, Nigeria. The parameters of concern were investigated using standard analytical techniques. Bacterial and fungal counts were reported as colony forming units (CFU) and spore forming units (SFU) respectively. Mean values of total heterotrophic bacterial and fungal count of the polluted soils ranged from 1.18 × 107CFU/g to 1.90 × 107CFU/g and from 1.4 × 106 SFU/g to 7.0 × 106 SFU/g respectively. While bacterial and fungal counts in the control soil ranged from 3.0 × 106CFU/g to 4.0 × 106CFU/g and 1.0 × 106 SFU/g to 3.0 × 106 SFU/g respectively. Except for station C that had lower fungal counts, the bacterial and fungal counts were higher in polluted soils than in control soils. There was statistical significant difference in the total heterotrophic bacterial and fungal count at p≤0.05. The bacteria frequencies were Staphylococcus aureus (20.58%), Bacillus spp (17.64%), Escherichia coli (14.7%), Corynebacterium spp (11.8%), Lactobacillus spp (8.82%), Pseudomonas spp (8.82%), Alcaligenes faecalis (8.82%), Klebsiella spp (5.88%), and Kurthia spp (2.94%). While fungi were Aspergillus niger (30%), Penicillium spp (20%), Microsporium canis (15%), Fusarium spp (10%), Mucor spp (10%), Saccharomyces cerevisiae (10%), and Epidermophyton floccosum (5%). The soil temperatures ranged from 27.8 to 25.4ºC, pH from 6.99 to 7.84, Electrical conductivity from 172 to 60μs/cm, Sulphate ranged from 184 to 34.5mg/kg, Nitrate from 61.77 to 31.10mg/kg, Phosphate from 10.5 to 2.1mg/kg, and total Organic Carbon ranged from 0.51 to 0.045%. Generally, physicochemical constituents were higher in the cassava effluent polluted soils than in the control. The cassava effluent however impacted negatively on the soil microbial populations and diversity which will sure affect the soil ecology and fertility. The presence of potential pathogens poses serious health hazard by disease associated with these organisms.