Biodegradation of dissolved jet fuel in chemostat by a mixed bacterial culture isolated from a heavily polluted site.

A mixed bacterial culture capable of biodegrading of jet fuel was isolated from a heavily polluted site in Tapa, Estonia. Residual concentrations of pollutants in the chemostat culture were determined. The total residual concentrations of dissolved jet fuel in culture medium were 0.42 and 2.1 microg l(-1) at the dilution rates 0.1 and 0.17 h(-1) respectively. Benzene, toluene, ethylbenzene, and xylenes were completely degraded and thus not detected in culture broth (detection limit 0.1 microg l(-1)) at the dilution rates 0.1 and 0.17 h(-1). The values of apparent substrate saturation constant (KSapp) in multisubstrate growth conditions were estimated from the experimental data. The residual concentrations satisfy the regulations in the Republic of Estonia for petroleum hydrocarbons (0.00 mg l(-1)--'very good'). Results obtained indicate that use of the biodegradation could be sufficient for the treatment of polluted with kerosene-type jet fuel groundwater up to the acceptable quality.

Scar formation after breast-conserving surgery for cancer. Sir Charles Gairdner Hospital Breast Cancer Group.

A study of surgery for breast cancer was performed to examine the influence of haematoma formation and radiotherapy on the development of mammographically detected scars. Fifty-nine women undergoing lumpectomy and radiotherapy were studied. Sixteen had mammographic scars 12 months after surgery. There was a correlation between postoperative haematoma formation and scarring (P = 0.03) but not between tumour size and scarring. The type of radiation therapy did not influence scar formation.