| In this paper, we studied the biological characteristics of several organic pollutants degradation strains isolated from sea cucumber aquaculture ponds and their identification. Meanwhile, according to the benthic habits of sea cucumber, the immobilization methods of some organic pollutants degradation strains was studied and optimized and the purification efficiency by different immobilization methods were compared. The main results are detailed as follows:1 The basic characterization and identification of four bacteria for organic-pollutants degradationBy the means of morphological, physiological and biochemical tests, and 16S rDNA sequence analysis, four bacterial strains (CD,304, S2 and S3) isolated from sea cucumber culture pond were identified. The bacterial strain CD was identified as Bacillus cereus, the strains S2 and S3 were identified was Bacillus subtilis and the strain 304 was identified was Bacillus infantis. The antagonism between the strains and the effect of temperature, pH and salinity on growth of strains were tested. The results show that, there were no antagonism between the strain CD,304 and S2 and the growth of the strain 301 was inhibited by the strain S3. The suitable growth temperature of the strain CD was 21～39℃and the optimum growth temperature was 24℃; the suitable growth temperature of the strain 301 was 21～39℃, the optimum growth temperature was 27℃; the suitable growth temperature of the strains S2 and S3 was 27～39℃and the optimum temperature was 27℃. The suitable growth salinity range of the strain CD was 0～35, the suitable growth salinity range of the strain 301 was 0-15 and the optimum growth salinity was 5. The salinity tolerance of the strains S2 and S3 was the widest and the suitable salinity range was 0～40.The suitable growth pH value range of the strains CD,301 and S2 was 6.0-9.0 and the suitable growth pH value range of the strain S3 was 6.5～8.5.2 Study on technology of adsorption immobilization of bacteria for organic-pollutants degradation of sea cucumber culture environmentUsing zolite as carrier, the preliminary study of immobilization of the low-temperature bacteria(Paracoccus marcusii, strain NO. DB11) isolated from sea cucumber culturing ponds was carried out. Their degradation effects on artificial aquaculture sewage water were compared. In this paper, the factors influencing the immobilization and the degradation of waste water in aquaculture by the stain DB11 were studied. The results show that, the adsorption time, pH, temperature and rotations can significantly influenced the effect of immobilization(P<0.05). In this study, the optimum immobilization conditions for the immobilization were adsorption time 90min, temperature 16℃, pH value 5.8 and shaker rotations 180rpm/min. The purification efficiency by immobilized strain DB11 is much higher than that by free bacteria. The removal rate of COD, NH4+-N and NO2--N reached 56.2%,51.0%, 78.3% and the degradation rate were increased by 11.2%,10.4% and 5.29% respectively. The removal rate of COD reached 65.3% by the normal temperature bacillus bacteria combination and the degradation rate were increased by 22.4%. In view of this, the zeolite powder as a carrier for immobilized Paracoccus marcusii technology may have greater value in sea cucumber culture pond water quality and sediment environmental restoration practice.3 Study on technology of entrapment immobilization of bacteria for organic-pollutants degradation of sea cucumber culture environmentIn this paper, using polyvinyl alcohol (PVA) and sodium alginate (SA) as the embedding carrier, the preliminary study of entrapment immobilization of the two organic-pollutants degradation strains (strain numbers CD and DB11) isolated from sea cucumber culturing ponds was carried out. Some zeolite and carbon were added to the microsphere. The degradation effects of microsphere and different kinds of probiotics on artificial aquaculture sewage water were compared. The results show that, the immobilized can significantly influenced the effect of (P<0.05). The purification efficiency by immobilized microsphere added carbon was much higher than that by free bacteria(P<0.05). In this study, the optimum proportion of the starch, the population of bacteria and zeolite in the microsphere was 12.5%,109cfu/g,1.5% respectively for the best removal of ammonia. The purification efficiency by immobilized complex microsphere is much higher than that by free bacteria. The removal rate of COD, NH4+-N and NO2--N reached 62.4%,65.5%,62.2% and the degradation rate was increased by 17.5%,13.0% and 12.8% respectively. The degradation rate of COD, NH4+-N and N02--N was increased by 1.03%,8.89%, 17.5% respectively after adding zeolite immobilized bacteria probiotics to the aquaculture wastewater and The degradation rate of COD, NH4+-N and NO2--N was increased by 14.92%,18.54%,16.53% respectively after adding microsphere probiotics. Therefore, Using the PVA and SA as the carrier and adding zeolite and carbon source for immobilizing bacteria may have greater value in sea cucumber culture pond water quality and sediment environmental restoration practice. |
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