High efficiency degradation of tetrahydrofuran (THF) using a membrane bioreactor: identification of THF-degrading cultures of Pseudonocardia sp. strain M1 and Rhodococcus ruber isolate M2

• Published in: Journal of industrial microbiology & biotechnology Vol. 30; no. 12; pp. 705 - 714
• Main Authors: Daye, K J, Groff, J C, Kirpekar, A C, Mazumder, R
• Format: Journal Article
• Language: English
• Published: Germany Oxford University Press 01-12-2003
• Subjects: Biomass; Bioreactors; Bioreactors - microbiology; Carbon - metabolism; Chemical oxygen demand; Energy sources; Furans - metabolism; Pseudonocardia; Reactors; Retention; Retention time; Rhodococcus - classification; Rhodococcus - metabolism; Rhodococcus ruber; Sewage - microbiology; Total suspended solids; Wastewater treatment; Water treatment
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-003-0103-8

A mixed microbial culture capable of growing aerobically on tetrahydrofuran (THF) as a sole carbon and energy source was used as the inoculum in a 10 l working volume membrane bioreactor. Following start-up, the reactor was operated in batch mode for 24 h and then switched to continuous feed with 100% biomass recycle. On average, greater than 96% of THF fed to the reactor was removed during the 8-month study. THF loading rates ranged from 0.62 to 9.07 g l(-1) day(-1) with a hydraulic retention time of 24 h. THF concentrations as high as 800 mg/l were tolerated by the culture. Biomass production averaged 0.28 kg total suspended solids/kg chemical oxygen demand removed, i.e., comparable to a conventional wastewater treatment process. Periodic batch wasting resulted in a solids retention time of 7-14 days. Reactor biomass typically ranged from 4 to 10 g/l volatile suspended solids and the effluent contained no solids. Pure THF-degrading cultures were isolated from the mixed culture based on morphological characteristics, Gram-staining and THF degradation. Based on 16S rDNA analysis the isolates were identified as Pseudonocardia sp. M1 and Rhodococcus ruber M2.