Isolation and identification of humicola sp. andits application for wastewater treatment

Abstract

A fast growing filamentous organism was isolated from the water of a polluted stream through the edge of Seoul city and triedto utilize in treating waste-water. The organism was identified as a species belonging to genus $\mbox{\underline{HUMICOLA}}$ which is a member of Imperfect Fungi. The newly isolated $\mbox{\underline{Humicola}}$ sp. could grow in an artificial sewage formulated with minerals and sucrose as a sole organic nutrient with specific growth rate of 0.18 per hour which is much higher than that of average filamentous bacteria naturally growing in sewage. The organism could utilize starch and cellulosic materials also. When the culture was agitated by passing air through the bottom of a fermentor the mycelia flocculated into small balls and showed tendency to settle down when the flow stopped. Furthermore, the mycelia of the organism contained high level of protein which occupied about 60% of the dry cell weight. The high growth rate on diversified carbon sources, automatic settlement, and the high protein content, qualified the $\mbox{\underline{Humicola}}$ sp. as an organism to be used in treating wastewaters. A specially designed continuous reactor of tower type having 9.4 liters of working capacity was constructed and trials to treat an artificial sewage in it were made. The organism could remove 92% of original COD of the aritficial sewage when the tower reactor operated with dilution rate of 0.18 per hour at 24℃. Under this condition the system could operate stably even under non-aseptical conditions. With a bench scale reactor of the conventional activated sludge process, a dilution rate of 0.06 per hour was needed for the 92% removal of COD of the same artificial sewage. The retention time for the two systems to obtain the 92% removal of COD were thus to be 5.5 and 16.6 hours, respectively. The fact indicated that the wastewater treatment efficiency of the newly constructed tower reactor with $\mbox{\underline{Humicola}}$ sp. was about ...