MYCODEGRADATION OF DRILL MUDS BY AXENIC AND MIXED FUNGAL ISOLATES FROM DRILL CUTTINGS AT OLOGBO, EDO STATE, NIGERIA

Abstract

Drilling produces large volumes of drilling waste, which can pose significant threats to soil, water quality and development. Fungi are known to degrade a wide variety of materials and compounds. This study examined the mycodegradation potentials of axenic and mixed fungal isolates associated with drill cuttings emanating from onshore well located at Ologbo, Edo State. Aerobic mycodegradation was determined using shake flask experiment (assessing the total viable counts (cfu/ml), pH, turbidity, Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD)were also determined for a period of 28 days. Results of shake flask experiment revealed the highest total viable count (9.1 x 102 cfu/ ml) for the broth cultures containing consortium of isolates on day 16. Generally, the pH and turbidity were in the range of 7.16 to 8.37and 33 to 63 respectively. The reduction in COD ( from 88 mg/ l at day 1 to 60 mg/ l at day 28) and BOD5 (from 20.9 mg/ l at day 1 to 0.14 mg/ l at day 28) were evidence of the oxidation of the substrates. The growth profile showed that Aspergillus and Penicillium strived better in the water based mud than in synthetic based mud, with Penicillium sp. having the highest fungal count of (0.57x103 cfu/ml) and attained its peak at day 4.There was no significant difference in the degradation of the drilling muds by the isolates (p > 0.05). It was therefore shown that these selected isolates have potential applications in the bioremediation of sites polluted with mud waste