دانلود رایگان مقاله روش کشت بافت برای گیاه پالایی رنگ در صنعت آبزی پروری

ABSTRACT

Brilliant green has been used as an effective compound to control external fungal and protozoan infections of fish though is carcinogenic and teratogenic. Present study focuses on the efficient degradation of brilliant green using callus cultures of the plant, Tecoma stans var. angustata, showing a peroxidase activity of 3.07 IU g−1. Callus cultures retained 86% activity after immobilization in calcium alginate. Dye degradation parameters were initially optimized using batch cultures. A packed bed reactor was constructed using the immobilized beads and different concentrations of the dye from 8.5 to 45 mg l−1 along with H2O2 were given in an up-flow mode. Km and Vmax for the dye degradation were 0.01924 g l−1 and 0.035 g l−1 h−1. The bioreactor could degrade 94% of the dye (concentration–35 mg l−1) at a residence time of 42.0 × 10−3 h. Percentage of degradation varied depending on the flow rate, residence time and dilution rate. TLC and reverse phase HPLC analysis showed that the dye was completely degraded to minor non toxic metabolites via complete degradation of the aromatic rings and by cleavage of functional groups. The current study is a preliminary work that can be used for application in Aquaculture and allied Industries where biodegradation of brilliant green is required.

4. Conclusion

Biological effluent and dye treatment methods are much better than physicochemical dye removal methods like adsorption, chemical precipitation and flocculation, oxidation by ozone, chlorine and hydrogen peroxide, reduction, electrochemicaltreatments and ion-pair extraction etc. Though a large number of works are going on regarding bioremediation of wastewater using enzymes, only a few reports are there on enzyme mediated degradation of organic pollutants [25]. Most of such works are based on decolourization rather than degradation which results in the formation of more dangerous aromatic intermediates [26]. One of the major challenges associated with peroxidase catalyzed removal of phenols and other aromatic compounds is the susceptibility of the enzyme to inactivation by various side reactions of the treatment [27]. Though there are a few numbers of reports on the peroxidase enzymes from plants for their ability to catalyze the removal of aromatic compounds from wastewaters, the studies mainly focus on commercial horseradish peroxidase, soybean peroxidase (SBP)[25] etc. that are very costly. In our study, we used the callus cultures of an easily available plant that uses only very low concentration of 2,4-D as plant growth regulator for callus proliferation. We have also optimized the degradation parameters that will be very much useful for carrying out the scale-up studies. Hydrogen Peroxide is a chemical widely used in aquaria as an antibacterial and anti-algal agent. Use of required quantity of peroxidase enzyme in the aquaria can nullify the adverse effects of Brilliant Green considering it as a reducing substrate for the enzyme in the presence of Hydrogen Peroxide. The present study throws light on the potential application of a cheap source of peroxidase enzyme for use in aquaria to deactivate the adverse effect of the dye.