Isolation of an Endophytic Cyanide resistant fungus Cunninghamella bertholletiae from (Manihot esculenta) and Cassava cultivated soil for Environmental Engineering Applications

Abstract

An endophytic cyanide resistant fungus Cunninghamella bertholletiae was isolated from cassava (Manihot esculenta) and cassava attached silt. The Cunninghamella sp. was sub-cultured into nutrient broth containing KCN (4mg/40mL) as a source of free cyanide. Samples were placed in an orbital (incubator) shaker at 30°C and 130rpm for 120 h. The cyanide resistant isolate was then successfully sub-cultured on PDA for 168 h at room temperature to determine if it can be regenerated after exposure to free cyanide. The fungus identification was based on; plate morphology, microscopic structure observation, nucleotide sequences and phylogenetic analysis. The identification revealed the fungus was Cunninghamella bertholletiae species from the Cunninghamella genus. The fungus has potential to be used as a free cyanide and total nitrogen degrader for environmental engineering applications. Cyanide, ammonium nitrogen and nitrate-nitrogen removal achieved were; 80%, 77.5% and 72.5%, within 120 h respectively.