Comparative Microbial Analysis of Earthworm Casts Collected From Ikenne, Ogun State, Nigeria
A comparative assessment of the physicochemical parameters and microbial profile of three types of earthworm casts (Pellet, Mass and Turret) were determined. The total viable count (TVC), coliform counts, yeast and mould counts were determined using standard procedures. The pH ranged from 7.8 for Mass cast to 8.6 for Pellet cast. Moisture content of the casts ranged from 29.43% for pellet casts to 47.10% for turret casts. Organic matter was 1.05%, 0.72% and 0.63% for pellet, turret and mass casts respectively. TVC was 4.8 x 107cfu/g, 6.1 x 107cfu/g and 1.2 x 108cfu/g for Mass, Turret and Pellet casts respectively. Pellet cast recorded the highest coliform count (1.5 x 107) while Turret cast the least (7.3 x 106 cfu/g). Mould counts was 8.3 x 106 cfu/g for turret cast and 1.2 x 107cfu/g for pellet and mass casts. The lowest yeasts count was 1.2 x 107cfu/g in mass cast while the highest was 3.8 x 107cfu/g for pellet cast. Microbial distribution in the three casts types showed that Staphylococcus aureus is common to all Cast-types. Citrobacter spp, Pseudomonas fluorescens, Penicillium chrysogenum and S. rosei were isolated from Pellet cast only. Aspergillus fumigatus, Fusarium oxisporum, Pseudomonas aeruginosa and Penicillium oxalicum were isolated from only Turret Cast while Aspergillus terreus, Fusarium compacticum, Klebsiella aerogenes and Streptococcus feacalis were isolated from Mass Cast only. The presence of Bacillus licheniformis in Pellet Cast is an advantage plus for Pellet cast usage since this bacteria contributes to nutrient cycling and displays antifungal activities.
Keywords: Pellet cast, Turret cast, Mass cast, Microbial Count,