Isolation and characterization of a lipid-degrading bacterium and its application to lipid-containing wastewater treatment.

To construct an efficient lipid-containing wastewater treatment system, microorganisms that degrade lipids efficiently were isolated from various environmental sources. Strain DW2-1 showed the highest rate of degradation of 1% (w/v) salad oil among the isolated strains. Strain DW2-1 was identified as Burkholderia sp. and designated Burkholderia sp. DW2-1. The rate of degradation of salad oil, olive oil, sesame oil, and beef tallow by strain DW2-1 were 96.7%, 92.3%, 90.1% and 77.4%, respectively, during a 48-h cultivation. Strain DW2-1 grew well in a synthetic wastewater medium (>1 x 10(10) colony forming unit [CFU]/ml) between 20 degrees C and 38 degrees C, and its rate of degradation of salad oil was above 90% after a 48-h cultivation. The lipase and biosurfactant (BSF) activities of strain DW2-1 after a 48-h cultivation were 1720 U/l and 480 U/ml, respectively. In continuous cultures for lipid-containing wastewater treatment, DW2-1 was stably maintained and degraded more than 90% of salad oil during a 7-d cultivation.

Isolation and characterization of a bluegill-degrading microorganism, and analysis of the root hair-promoting effect of the degraded products.

Bluegill-degrading bacteria were isolated from various environmental sources. Brevibacillus sp. BGM1 degraded bluegill efficiently at 50 degrees C, and its culture supernatant showed the highest peptide and amino acid concentrations as trichloroacetic acid (TCA) soluble fraction (ASF) (10.7 mg/ml) of all supernatants obtained with bluegill as a substrate. Strain BGM1 secreted a protease(s) into the medium, and the concentration of peptides and amino acids gradually increased. The fertile effect of the degraded bluegill products (DGP) on Brassica rapa was also investigated. The root hair density of B. rapa grown with DGP at a concentration of 30 mug peptides and amino acids/ml was about 1.7 times higher than when grown with the same concentration of undegraded bluegill. DGP was shown to increase root hair numbers and adventitious root formation. The results of this study suggest that a specific peptide(s) for promotion of root hair is produced from the order Perciformes with a protease(s) from BGM1.