【摘要】：我國水產(chǎn)養(yǎng)殖向著集約化、高密度模式發(fā)展。大量的人工投餌,導(dǎo)致殘餌和糞便在養(yǎng)殖池底堆積,底部環(huán)境持續(xù)惡化,限制了水產(chǎn)養(yǎng)殖的可持續(xù)發(fā)展。光合細(xì)菌是微生態(tài)制劑的一種,可專門針對底部缺氧環(huán)境發(fā)揮作用,改良養(yǎng)殖環(huán)境。本論文通過富集、篩選適應(yīng)海洋環(huán)境的光合細(xì)菌,對其優(yōu)勢菌株進(jìn)行生長特性,底泥改良效果研究,并將其應(yīng)用于海參水產(chǎn)養(yǎng)殖,為光合細(xì)菌在水產(chǎn)養(yǎng)殖中的應(yīng)用提供一定的理論依據(jù)。本研究對實驗室已有的光合細(xì)菌混合液及采自威海海域養(yǎng)殖場附近的污泥中的光合細(xì)菌進(jìn)行了分離以及16S rDNA序列測定;選取2株優(yōu)勢菌株研究其對營養(yǎng)物質(zhì)的利用、生長條件及培養(yǎng)基優(yōu)化;模擬自然養(yǎng)殖環(huán)境下,池塘底泥堆積現(xiàn)象,分析比較兩株菌對底泥的改良效果;將底泥改良效果好的菌株應(yīng)用于海參養(yǎng)殖,探究其在海參養(yǎng)殖中的效果。試驗共獲得5株光合細(xì)菌,其中2株屬于Rhodopseudomonas sp.,2株屬于Rhodovulum sp.,1株為Rhodobacter sp.。營養(yǎng)物質(zhì)研究表明,PSB1、PSB2能夠利用大部分的碳源,都不能利用甲醇、甲酸鈉;PSB2可以利用丙酸鈉。PSB、PSB2均在2000 Lx,30℃條件下生長良好。正交試驗表明,三種因素對PSB1的影響為:碳源氮源硫化物;最優(yōu)組合為葡萄糖3 g/L、氯化銨0.5 g/L和硫化物2 g/L;對PSB2的影響為碳源硫化物氮源,最優(yōu)組合為葡萄糖1 g/L、氯化銨1.5 g/L和硫化物1 g/L。底泥改良試驗結(jié)果表明:PSB1和PSB2都可以穩(wěn)定水體pH,降解水中的硫化物、氨氮和CODMn。與PSB1相比,PSB2對硫化物的耐受性差,無亞硝酸鹽降解能力。PSB1處理底泥最佳效果為:添加1%的PSB1,pH在6.98-7.33范圍內(nèi)波動,CODMn、硫化物、氨氮和亞硝態(tài)氮降解率分別為92.91%、79.61%、97.00%和73.56%。將PSB1直接添加到海參養(yǎng)殖水體中,探究其對海參生長和養(yǎng)殖水體的效果。添加1‰PSB1,海參每周的增重率達(dá)到最高(3.12%),較對照組的1.20%,提高了1.92%;PSB1能夠穩(wěn)定水體pH,改善養(yǎng)殖水體的水質(zhì),養(yǎng)殖缸內(nèi)硫化物、亞硝態(tài)氮和CODMn含量均低于對照組。結(jié)果表明光合細(xì)菌可以促進(jìn)養(yǎng)殖生物的生長、改善水質(zhì)、維持下層水體的健康,在水產(chǎn)養(yǎng)殖中具有良好的應(yīng)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，

本文編號：2330111