微囊藻群體形成的環(huán)境影響因素及其對(duì)磷利用的生理響應(yīng)
發(fā)布時(shí)間:2018-05-14 19:29
本文選題:銅綠微囊藻 + 環(huán)境因素 ; 參考:《重慶大學(xué)》2015年碩士論文
【摘要】:水華是富營(yíng)養(yǎng)化湖泊中浮游植物異常增殖聚集,并引起水質(zhì)下降等水環(huán)境問(wèn)題的現(xiàn)象。藻類水華是最為常見的一種。在國(guó)內(nèi)外富營(yíng)養(yǎng)化的湖泊中,藍(lán)藻水華是最為常見的水環(huán)境問(wèn)題。其中,銅綠微囊藻是危害性最大的藍(lán)藻水華藻類。為了給藍(lán)藻水華的有效治理提供一定的理論依據(jù),本實(shí)驗(yàn)選取藍(lán)藻的代表藻屬銅綠微囊藻為研究對(duì)象,通過(guò)單因素及正交實(shí)驗(yàn)研究了N、P等營(yíng)養(yǎng)鹽、Ca2+濃度、光強(qiáng)、溫度等環(huán)境因素對(duì)銅綠微囊藻生長(zhǎng)以及群體形成的影響,實(shí)現(xiàn)了在實(shí)驗(yàn)室條件下對(duì)群體微囊藻的培養(yǎng);通過(guò)對(duì)熒光倒置顯微鏡、掃描電子顯微鏡、激光共聚焦顯微鏡下群體微囊藻形態(tài)的觀察,從微觀角度解釋了群體形成的生物學(xué)原因;通過(guò)在磷脅迫條件下,進(jìn)行單細(xì)胞和群體兩種表型的微囊藻的堿性磷酸酶(AKP)、抗氧化酶(SOD、CAT)活力的對(duì)比分析,從酶學(xué)水平解釋了群體微囊藻成為優(yōu)勢(shì)藻種的原因以及群體形成對(duì)微囊藻水華的生物學(xué)意義。1)在單因素實(shí)驗(yàn)中,得出的主要結(jié)論有:銅綠微囊藻必須能夠保持正常生長(zhǎng)才能形成多而密集的群體,高Ca2+水平、高光強(qiáng)、適宜的溫度有利于微囊藻群體的形成。利于銅綠微囊藻群體形成的N、P濃度水平是N=10mg/L、P=0.5mg/L,N=50mg/L、P=2.5mg/L,N=100mg/L、P=5mg/L;Ca2+濃度水平為Ca2+=130mg/L、Ca2+=260mg/L、Ca2+=520mg/L;光強(qiáng)水平為4000 lux、8000 lux、12000 lux;溫度水平為15℃、20℃、25℃。2)在正交實(shí)驗(yàn)中,得出的結(jié)論是:與單環(huán)境因素條件相比,多環(huán)境因素的共同作用更能促進(jìn)微囊藻群體的形成;群體形成的環(huán)境條件最佳組合是初始濃度N=100mg/L、P=5mg/L、Ca2+=260mg/L,光強(qiáng)為4000 lux,溫度保持在25℃。3)在對(duì)單細(xì)胞和群體兩種表型的微囊藻進(jìn)行了形態(tài)上的比較后,可以推斷出:微囊藻形成群體的方式有兩種,一是將單細(xì)胞聚集起來(lái)集結(jié)成群體,二是進(jìn)行分裂增殖積累細(xì)胞數(shù)目形成群體。這兩種方式存在一個(gè)遞進(jìn)的關(guān)系,即單細(xì)胞聚集起來(lái)形成的小群體通過(guò)細(xì)胞分裂增殖形成大群體。但也不絕對(duì),在微囊藻生長(zhǎng)的復(fù)雜的生態(tài)系統(tǒng)中,這兩種方式通常是并存的。群體在形成的過(guò)程中,多糖(EPS)膠鞘起著粘結(jié)細(xì)胞、保護(hù)細(xì)胞、提供營(yíng)養(yǎng)物質(zhì)、輔助調(diào)節(jié)浮力等的作用,Ca2+的存在更是加強(qiáng)了細(xì)胞聚集的穩(wěn)定性。4)在缺磷脅迫下對(duì)單細(xì)胞和群體兩種表型的微囊藻進(jìn)行了AKP、SOD、CAT活力對(duì)比后可以知道:缺磷脅迫條件下,單細(xì)胞的AKP活力顯著上升,而群體的較低AKP活力則證明了在營(yíng)養(yǎng)波動(dòng)較大的環(huán)境中,群體能競(jìng)爭(zhēng)營(yíng)養(yǎng)物質(zhì)(如磷)保持優(yōu)勢(shì)生長(zhǎng);群體較高的抗氧化酶(SOD、CAT)活力也保證了其及時(shí)去除體內(nèi)多余的活性氧,增強(qiáng)抵抗逆境脅迫傷害的能力。
[Abstract]:Shui Hua is a phenomenon that phytoplankton abnormally proliferates and accumulates in eutrophic lakes and causes water environmental problems such as water quality decline. Algae Shui Hua is the most common species. Cyanobacteria Shui Hua is the most common water environmental problem in eutrophication lakes at home and abroad. Among them, microcystis aeruginosa is the most harmful cyanobacteria Shui Hua algae. In order to provide some theoretical basis for the effective control of cyanobacteria Shui Hua, the representative alga of cyanobacteria, Microcystis aeruginosa, was selected as the research object. The effects of temperature and other environmental factors on the growth and population formation of microcystis aeruginosa were studied. The morphology of microcystis was observed under confocal laser microscope, and the biological reasons of colony formation were explained from the microcosmic point of view. The activity of alkaline phosphatase (AKP) and antioxidant enzyme (SOD CAT) of microcystis with single cell and population phenotypes were compared and analyzed. The reason why microcystis became dominant algae species and the biological significance of colony formation to microcystis Shui Hua were explained from the level of enzyme. The main conclusions are as follows: microcystis aeruginosa must be able to maintain normal growth in order to form a large and dense population, high Ca2 level, high light intensity, the appropriate temperature is conducive to the formation of microcystis. The concentration of NNP in microcystis aeruginosa population is 10 mg / L, 0.5 mg / L, 50 mg / L, 2.5 mg / L, 5 mg 路L ~ (-1) of Ca ~ (2 2), which is Ca2 130 mg / L Ca ~ (2 2) 260 mg 路L ~ (2 +), 4000 luxlux8000 ~ (12) mg / L, light intensity, 15 鈩,
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