海洋光合细菌在水产养殖中的应用基础研究

发布时间：2018-11-13 18:44

【摘要】：我国水产养殖向着集约化、高密度模式发展。大量的人工投饵,导致残饵和粪便在养殖池底堆积,底部环境持续恶化,限制了水产养殖的可持续发展。光合细菌是微生态制剂的一种,可专门针对底部缺氧环境发挥作用,改良养殖环境。本论文通过富集、筛选适应海洋环境的光合细菌,对其优势菌株进行生长特性,底泥改良效果研究,并将其应用于海参水产养殖,为光合细菌在水产养殖中的应用提供一定的理论依据。本研究对实验室已有的光合细菌混合液及采自威海海域养殖场附近的污泥中的光合细菌进行了分离以及16S rDNA序列测定;选取2株优势菌株研究其对营养物质的利用、生长条件及培养基优化;模拟自然养殖环境下,池塘底泥堆积现象,分析比较两株菌对底泥的改良效果;将底泥改良效果好的菌株应用于海参养殖,探究其在海参养殖中的效果。试验共获得5株光合细菌,其中2株属于Rhodopseudomonas sp.,2株属于Rhodovulum sp.,1株为Rhodobacter sp.。营养物质研究表明,PSB1、PSB2能够利用大部分的碳源,都不能利用甲醇、甲酸钠;PSB2可以利用丙酸钠。PSB、PSB2均在2000 Lx,30℃条件下生长良好。正交试验表明,三种因素对PSB1的影响为:碳源氮源硫化物;最优组合为葡萄糖3 g/L、氯化铵0.5 g/L和硫化物2 g/L;对PSB2的影响为碳源硫化物氮源,最优组合为葡萄糖1 g/L、氯化铵1.5 g/L和硫化物1 g/L。底泥改良试验结果表明:PSB1和PSB2都可以稳定水体pH,降解水中的硫化物、氨氮和CODMn。与PSB1相比,PSB2对硫化物的耐受性差,无亚硝酸盐降解能力。PSB1处理底泥最佳效果为:添加1%的PSB1,pH在6.98-7.33范围内波动,CODMn、硫化物、氨氮和亚硝态氮降解率分别为92.91%、79.61%、97.00%和73.56%。将PSB1直接添加到海参养殖水体中,探究其对海参生长和养殖水体的效果。添加1‰PSB1,海参每周的增重率达到最高(3.12%),较对照组的1.20%,提高了1.92%;PSB1能够稳定水体pH,改善养殖水体的水质,养殖缸内硫化物、亚硝态氮和CODMn含量均低于对照组。结果表明光合细菌可以促进养殖生物的生长、改善水质、维持下层水体的健康,在水产养殖中具有良好的应用前景。
[Abstract]:Aquaculture in China is developing towards intensive and high density model. A large number of artificial baits lead to the accumulation of residual bait and feces in the bottom of the pond and the deterioration of the environment at the bottom which limits the sustainable development of aquaculture. Photosynthetic bacteria (PSB) are one of the microecological agents, which can play a role in improving the culture environment. In this paper, photosynthetic bacteria adapted to marine environment were screened through enrichment, growth characteristics of dominant strains were studied, and the effects of sediment improvement were studied, and applied to aquaculture of sea cucumber. To provide some theoretical basis for the application of photosynthetic bacteria in aquaculture. In this study, we isolated the photosynthetic bacteria from the mixed liquid of photosynthetic bacteria and the sludge collected from the breeding farm in Weihai sea area, and determined the 16s rDNA sequence. Two dominant strains were selected to study the utilization of nutrients, growth conditions and optimization of culture medium, and simulated the accumulation of sediment in ponds under natural culture environment, and analyzed and compared the improvement effect of two strains on sediment. The strain with good effect of sediment improvement was applied to sea cucumber culture to explore its effect in sea cucumber culture. Five strains of photosynthetic bacteria were obtained in the experiment, of which 2 belong to Rhodopseudomonas sp.,2 strain, belong to Rhodovulum sp.,1 strain and belong to Rhodobacter sp.. strain. Studies on nutrients showed that PSB1,PSB2 could utilize most carbon sources, but could not use methanol and sodium formate, while PSB2 could utilize sodium propionate. PSB,PSB2 grew well at 2000 Lx,30 鈩，

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