碩士 / 東吳大學 / 微生物學系 / 106 / Malachite green (MG) is a chemical synthetic dye that is often added to aquaculture water to inhibit the growth of microorganisms and to enter the environment easily as wastewater discharges. Malachite green in the body will be rapidly metabolized into leucomalachite green (LMG), and retained in the organism, because of its toxicity has been banned from many countries banned addition and use in aquaculture. The purpose of this experiment was to use biodegradation to remove malachite green in marine aquaculture.
The results of the experiments showed that the best was B3 anaerobic sediment: more than 90% of 20 mg / L malachite green could be degraded within 4 days under anaerobic acclimation. Then the degradation of malachite green effect of B3 anaerobic sediment added to different concentrations (20, 50 and 100 mg / L) of malachite green, respectively, placed at 25 ℃ and 30 ℃, the experiment showed that as the concentration increases and Changes in malachite green temperature caused by changes in ability: the same concentration, 30 ℃ better than 25 ℃, 20 mg / L at 30 ℃ within 5 days can be degraded more than 90% malachite green, and 25 ℃ need 32 days. At 30 ℃, 20 mg / L could degrade more than 90% of malachite green in 5 days and 100 mg / L to achieve the same effect in 12 days at the same temperature. After confirming that B3 anaerobic sediment can degrade malachite green, the anaerobic strain that is screened therefrom is Vibrio alginolyticus which can degrade 90% of malachite green with a starting concentration of 20 mg / L within 1 day. Shewanella decolorationis NTOU1 and sieved Vibrio alginolyticus were added back to the sediment, respectively, and 90% of the malachite green with a starting concentration of 20 mg / L could be resolved within 5 days respectively. The anaerobic groups in the reactor were At the beginning of the experiment there was no significant difference, over 90% of the malachite green was degraded in two weeks, and over time, after the addition of 2 mg / L of malachite green, the group without degrading bacteria remained There was a certain concentration of malachite green, whereas samples with degrading bacteria retained their degradability even after increasing the malachite green concentration to 20 mg / L.
The best performing aerobic batch experiments were also B3 adapted sediment, with 20 mg / L for 10 days. B3 groups were then added to malachite green at different concentrations (20, 50 and 100 mg / L) and placed at 25 ° C and 30 ° C respectively. B3 aerobic sediments did not show any change in temperature and concentration Differences in the degradation of malachite green at the end of the experiment still retained a certain concentration of malachite green. Subsequent aerobic strains that degrade malachite green, from the aerobic acclimation sediment of B3: Tenacibaculum mesophilum and Enterobacter cloacae, require 90% malachite green for 5 and 8 days, respectively. Pure bacteria were additionally added to the culture pond sediment samples to compare the degradation effect of the culture medium containing pure bacteria, Laccase and mushrooms. In the aerobic state, the pure bacteria group also reached the same degradation effect for 5 days. In the experiment of adding Lacasse, Lacasse, which is a mixture of two kinds of mushrooms (Pleurotus eryngii and Apricot shiitake mushroom), is the best, Degradation of most of the malachite green within 5 days. In the aerobic reactor, all groups were able to degrade more than 90% of malachite green in two weeks at the beginning of the experiment. After several repeated additions of malachite green, an additional addition of pure bacteria and mushroom culture The substrate to the reactor at the end of the experiment to maintain the ability of microorganisms on the degradation of malachite green, can be degraded more than 90% of the malachite green in two weeks, no additional additive samples observed decreased degradation of malachite green At the end of the experiment, the concentration of malachite green remained.
However, applying the optimum conditions obtained during the experiment to the miniaturized in-situ cell showed different results. On the first day after the addition of 2 mg / L malachite green, the malachite green measured in the water had only 0.4 mg / L, while about 0.7 mg / kg in the sediment. On the sixth day after the start of the experiment, the malachite green concentration in the pond water and sediment was lower than the detection limit of the instrument. From the seventh day to the end of the experiment, malachite green was measured at different points in the sediment of a small pond, After 118 days, the concentration distribution ranged from below the lowest detection limit of the instrument up to nearly 5 mg / kg, indicating uneven distribution of malachite green in small pond sediments.
This experiment proved that microorganisms have the ability to degrade malachite green, and the main metabolite is LMG. However, the adsorption and distribution of malachite green in small pond sediments need further study.
| Identifer | oai:union.ndltd.org:TW/106SCU00381001 |
| Date | January 2017 |
| Creators | HSIEH, CHI-YEN, 謝濟彥 |
| Contributors | 張碧芬 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 102 |
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