李凌
摘 要:建立以主要餌料微藻的可持續(xù)育種技術(shù)體系和育種群體,培育高產(chǎn)、抗逆新品系,突破微藻培養(yǎng)廣鑒技術(shù),構(gòu)建成熟的微藻餌料工程化生產(chǎn)技術(shù)與工藝為目標(biāo)。通過(guò)對(duì)18S rDNA、rbcL基因和ITS區(qū)序列的測(cè)定及系統(tǒng)進(jìn)化分析,建立了微藻種間及株系間分子鑒別技術(shù);對(duì)多株餌料微藻的生長(zhǎng)及適應(yīng)性進(jìn)行了比較研究,篩選出了適應(yīng)不同光強(qiáng)的雨生紅球藻藻株,抗逆性強(qiáng)的小球藻、三角褐指藻,耐高溫的纖細(xì)角毛藻藻株及鹽藻、扁藻等多株優(yōu)良餌料微藻,為規(guī)?;囵B(yǎng)提供了良好材料。研究了微藻高密度培養(yǎng)中的生長(zhǎng)指標(biāo)和適應(yīng)機(jī)制,并在此基礎(chǔ)上針對(duì)雨生紅球藻、微擬球藻、三角褐指藻、小球藻等多種餌料微藻研究了不同培養(yǎng)條件及添加物對(duì)其生長(zhǎng)及營(yíng)養(yǎng)物質(zhì)積累的影響,建立了多種餌料微藻的高密度培養(yǎng)技術(shù),其中微擬球藻在氣升式螺旋管道(光徑1.2 cm)光生物反應(yīng)器中培養(yǎng)時(shí),最高密度可達(dá)15 g/m2,比目前常規(guī)技術(shù)提高了3~4倍。針對(duì)餌料微藻的特點(diǎn),設(shè)計(jì)了規(guī)模大小遞增的光生物反應(yīng)器,建立了敵害生物綜合防御的方法和技術(shù)體系,有效降低污染幾率;克服了傳統(tǒng)封閉培養(yǎng)中氧氣解析、二氧化碳補(bǔ)償、光線分布、物料均質(zhì)、細(xì)胞貼壁等難題,實(shí)現(xiàn)了主要參數(shù)溫度、pH值和溶解氧等
數(shù)據(jù)的在線檢測(cè)和自動(dòng)控制。通過(guò)實(shí)驗(yàn)室100mL-500mL-,戶外200L-多組并聯(lián)柱狀光生物反應(yīng)器逐級(jí)擴(kuò)大培養(yǎng),建立了多種餌料微藻工程化生產(chǎn)工藝,建設(shè)了2個(gè)產(chǎn)業(yè)化基地,實(shí)現(xiàn)300 t體積的規(guī)模培養(yǎng)。以三角褐指藻、小球藻和牟氏角毛藻3種餌料型微藻為對(duì)象,通過(guò)在現(xiàn)有液固分離的小型設(shè)備上進(jìn)行濃縮效果實(shí)驗(yàn),確定了生產(chǎn)型的濃縮設(shè)備并針對(duì)以上3種不同微藻的特性,進(jìn)行了微藻濃縮工藝的研究,建立了不同微藻的濃縮工藝。優(yōu)化了微藻產(chǎn)品(藻膏)低溫保存技術(shù),形成微藻產(chǎn)品濃縮與保存技術(shù)規(guī)模和規(guī)范。
關(guān)鍵詞:餌料型微藻 篩選 高效培養(yǎng) 光生物反應(yīng)器
Abstract:The aim of the program is to establish sustainable breeding technological system and group of the main bait microalgae, cultivate high-yielding, resistant strains, break through the identification technology, and build large-scale production technology of bait microalgae. The molecular identification technology of microalgae was established by phylogenetic analysis of 18S rDNA, rbcL gene and ITS sequences. Based on the comparison of growth and adaptability of multiple microalgae strains, Haematococcus pluvialis adapted to different light intensities, Chlorella sp. and Phaeodactylum tricornutum with strong stress resistance,Chaetoceros gracilis resistant to high temperature, and other good strains (e.g. Dunaliella salina and Tetraselmis sp.) were selected to provide materials for large-scale culture. The growth index and adaptation mechanism of microalgae in high density cultivation were studied, and through researching the effect of culture conditions and additives on the growth and nutrient accumulation of several microalgae (e.g. H. pluvialis, Nannochloropsis sp.,P.tricornutum,Chlorella sp.),a high-density cultivation technology were established, by which the biomass of Nannochloropsis sp.increased 3~4 times,and reached up to 15 g/m2 in airlift helical pipes photobioreactors (diameter 1.2 cm). Based on the characteristics of bait microalgae,photobioreactors with different sizes were designed, pollution risk was efficiently reduced by establishing technology for predators extermination, the traditional problem in closed culture, such as oxygen release,carbon dioxide compensation, light distribution, material homogenization, and cells attachment were overcome, and the main parameters,such as temperature, pH and dissolved oxygen data were detected online and controlled automatically.A large-scale production technology of microalgae was established through enlargement culture step by step using 100 mL to 500 mL and 200 L column photobioreactor,and two industrialization bases were built to meet the cultivation scale of 300 tons. Based on the characteristics of P.tricornutum,Chlorella sp. and Chaetoceros muelleri, concentration technology for different microalgae was established through experiment on small liquid-solid separation equipment. Cryopreservation technology of microalgae products (algae paste) was optimized, and the technical specification for concentration and preservation of microalgae products was formed.
Key Words:Bait microalgae;Screen;Efficient culture;Photobioreactor
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