Aerobic mineralization of sorbed biphenyl by a microbial consortium

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1994

OSTI ID:39163

Calvillo, Y M

Sorption of organic pollutants is believed to limit their biodegradability and thus their removal from contaminated soils and sediments by microorganisms. A study was conducted of three possible mechanisms by which a microbial consortium might mineralize biphenyl that was hydrophobically sorbed to porous beads, specifically, spontaneous desorption, surfactant production, and cell adherence. The rates of desorption and biphenyl mineralization were compared to determine if the compound was acquired following spontaneous desorption. The culture was tested for extracellular surfactants and tests were conducted of the effect of 10 synthetic surfactants and 1 bacterial surfactant on the ability of two bacteria, which were isolated because of their capacity to use biphenyl in solution, to metabolize sorbed biphenyl. The possible role of sorbed cells was tested by replacement of the cell suspension with fresh salts solutions. This study showed that more biphenyl was mineralized than was present in solution from abiotic desorption. The rate of mineralization of sorbed biphenyl was at least 14 times greater than the rate of spontaneous desorption, showing that spontaneous desorption was not a mechanism by which the consortium acquired sorbed biphenyl. The surface tension of the culture medium did not decrease, the culture medium did not desorb biphenyl, and addition of 11 surfactants to bacterial cultures capable of using biphenyl in solution did not stimulate degradation of sorbed biphenyl, suggesting that extracellular surfactants were not important as a mechanism for acquiring the sorbed compound. However, combinations of some isolates mineralized sorbed biphenyl. Sorbed biphenyl was mineralized after the beads were washed to remove cells in suspension, suggesting attachment as a mechanism of microbial acquisition of the sorbed compound.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• OSTI ID: 39163
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROBIC CONDITIONS
BIODEGRADATION
BIPHENYL
CONTAMINATION
MINERALIZATION
SOILS