Effects of organic compounds on the degradation ofp-nitrophenol in lake and industrial wastewater by inoculated bacteria
- 68 Downloads
Many microorganisms fail to degrade pollutants when introduced in different natural environments. This is a problem in selecting inocula for bioremediation of polluted sites. Thus, a study was conducted to determine the success of four inoculants to degradep-nitrophenol (PNP) in lake and industrial wastewater and the effects of organic compounds on the degradation of high and low concentrations of PNP in these environments.Corynebacterium strain Z4 when inoculated into the lake and wastewater samples containing 20 µg/ml of PNP degraded 90% of PNP in one day. Addition of 100 µg/ml of glucose as a second substrate did not enhance the degradation of PNP and the bacterium utilized the two substrates simultaneously. Glucose used at the same concentration (100 µg/ml), inhibited degradation of 20 µg of PNP in wastewater byPseudomonas strain MS. However, glucose increased the extent of degradation of PNP byPseudomonas strain GR. Phenol also enhanced the degradation of PNP in wastewater byPseudomonas strain GR, but had no effect on the degradation of PNP byCorynebacterium strain Z4.
Addition of 100 µg/ml of glucose as a second substrate into the lake water samples containing low concentration of PNP (26 ng/ml) enhanced the degradation of PNP and the growth ofCorynebacterium strain Z4. In the presence of glucose, it grew from 2×104 to 4×104 cells/ml in 3 days and degraded 70% of PNP as compared to samples without glucose in which the bacterium declined in cell number from 2×104 to 8×103 cells/ml and degraded only 30% PNP. The results suggest that in inoculation to enhance biodegradation, depending on the inoculant, second organic substrate many play an important role in controlling the rate and extent of biodegradation of organic compounds.
Key wordsbiodegradation p-nitrophenol Pseudomonas Corynebacterium
Unable to display preview. Download preview PDF.
- Alexander M (1985) Biodegradation of organic chemicals. Environ. Sci. Technol. 19: 106–111Google Scholar
- Goldstein RM, Mallory LM & Alexander M (1985) Reasons for possible failure of inoculations to enhance biodegradation. Appl. Environ. Microbiol. 50: 977–983Google Scholar
- Hess TF, Schmidt SK, Silverstein J & Howe B (1990) Supplemental substrate enhancement of 2,4-dinitrophenol mineralization by a bacterial consortium. Appl. Environ. Microbiol. 56: 1551–1558Google Scholar
- Hoben HJ & Somasegaran P (1982) Comparison of pour, spread, and drop plate methods for enumeration ofRhizobium sp. in inoculants made from pre-sterilized peat. Appl. Environ. Microbiol. 44: 1246–1247Google Scholar
- LaPat-Polasko LT, McCarty PL & Zehnder A (1984) Secondary substrate utilization methylene chloride by an isolated strain ofPseudomonas sp. Appl. Environ. Microbiol. 47: 825–830Google Scholar
- Papanastasiou AC & Maier WJ (1982) Kinetics of biodegradation of 2,4-dichlorophenoxyacetate in the presence of glucose. Biotech. Bioeng. 24: 2001–2011Google Scholar
- Rozich AF & Colvin RJ (1986) Effects of glucose on phenol biodegradation by heterogeneous populations. Biotech. Bioeng. 28: 965–971Google Scholar
- Schmidt SK & Alexander M (1985) Effects of dissolved organic carbon and the second substrate on the biodegradation of organic compounds at low concentrations. Appl. Environ. Microbiol. 49: 822–827Google Scholar
- Schmidt SK, Scow KM & Alexander M (1987) Kinetics ofP-nitrophenol mineralization byPseudomonas sp.: Effects of second substrate. Appl. Environ. Microbiol. 53: 2617–2523Google Scholar
- Scow KM, Schmidt SK & Alexander M (1989) Kinetics of biodegradation of mixture of substrates in soil. Soil. Biol. Biochem. 21: 703–708Google Scholar
- Zaidi BR, Stucki G & Alexander M (1988) Low chemical concentration and pH as factors limiting success of inoculation to enhance biodegradation. Environ. Toxicol. Chem. 7: 143–151Google Scholar
- Zaidi BR, Murakami Y & Alexander M (1988) Factors limiting success of inoculation to enhance biodegradation of low concentrations of organic chemicals. Environ. Sci. Technol. 22: 1419–1425Google Scholar
- —— (1989) Predation and inhibitors in lake water affect the success of inoculation to enhance biodegradation of organic chemicals. Environ. Sci. Technol. 23: 859–863Google Scholar