|关键词||绿藻 氢化酶氧耐受性 低光强产氢 绿藻污水产氢|
对5种不同的绿藻氢化酶的氧耐受性进行了测定，结果表明：不同绿藻氢化酶氧耐受性有较大差别，其中蛋白核小球藻（Chlorella pyrenoidosa）氢化酶体内、体外氧耐受性分别比莱茵衣藻（Chlamydomonas reinhardtii CC124）高139%和61%，且在光照条件下，由于蛋白核小球藻氢化酶的氧耐受性较强，因此导致其产氢持续时间较莱茵衣藻的产氢持续时间长。
对蛋白核小球藻在污水（生活污水和沼液）中的生长及产氢特性进行了研究，表明蛋白核小球藻在污水和沼液中均有良好的适应性。蛋白核小球藻对25%沼液的COD、氨态氮和总磷的去除率分别达到67%、97%和98%。研究发现，蛋白核小球藻可以在沼液中添加乙酸钠直接产氢，最高产氢量达到70 mL·L-1，而在未添加乙酸钠的条件下，产氢量仅为16 mL·L-1。另外在添加乙酸钠培养1 d的条件下蛋白核小球藻的产氢量可大幅提高，最高产氢量达150 mL·L-1。对不同培养条件下的蛋白核小球藻的产氢进行了比较研究，发现蛋白核小球藻在沼液中以CO2辅助培养条件下的产氢量显著高于同条件下的生活污水培养的蛋白核小球藻，产氢量达到130.9 mL·g-1藻干重，说明利用沼液培养蛋白核小球藻并产氢具有可行性。;
The hydrogenase O2 tolerance of five different green algae was investigated; it was found that the hydrogenase O2 tolerance was different for different green algae. C. pyrenoidosa hydrogenase O2 tolerance (vivo and vitro) was 139% and 61% higher than that of C. reinhardtii, respectively; furthermore, this feature can benefit the photo H2 production. The duration of H2 production of C. pyrenoidosa was longer than C. reinhardtii.
H2 production of C. reinhardtii and C. pyrenoidosa was comparatively investigated under different condition; it was found that H2 production was inhibited by photosynthetic O2 evolution under normal light condition. For H2 production under light/dark cyclic condition, the hydrogenase activity could be recovered during dark condition, but it was inactivated by photosynthetic O2 evolution under illumination, which leading to a short period H2 evolution. Under sulfur-deprived condition, the duration of H2 evolution of C. reinhardtii could sustain 96 h; however, C. pyrenoidosa could not release H2.
The respiratory and photosynthetic O2 evolution rate of C. pyrenoidosa under different acetate concentrations and light intensities was investigated. It was found that the respiratory rates increased with the increasing of acetic acid concentrations, and photosynthetic O2 evolution rates decreased with the decreasing of light intensities. The anaerobic environment could be obtained through optimizing the acetate acid concentrations and light intensities in sulfur replete medium. Thus, C. pyrenoidosa could sustain releasing H2 gas under this condition.
The repeated H2 production of C. pyrenoidosa was investigated, it was found that C. pyrenoidosa could re-produce H2 under sulfur replete and sulfur-deprived condition; the volume and duration of H2 production of C. pyrenoidosa can be increased by the repeated H2 production method. Under sulfur deprived condition, C. pyrenoidosa can re-produce H2 after one day cultivation without sodium acetate addition, and the H2 yield increased with the increasing of repetition times, which indicating that there are two different metabolic pathways for C. pyrenoidosa under sulfur-deprived and sulfur replete conditions.
The cultivation and direct H2 production of C. pyrenoidosa in wastewater (municipal wastewater and biogas slurry) was investigated. It was found that C. pyrenoidosa had good adaptability in wastewater。The removal efficiency of COD, ammonia nitrogen and total phosphorus were 67%, 97% and 98% respectively for biogas slurry. It was found that C. pyrenoidosa could release H2 without replace medium in biogas slurry. The H2 production could be increased from 16 mL·L-1to 70 mL·L-1 after acetate added into medium，In addition, after 24 hours of cultivation with sodium acetate , the H2 production of C. pyrenoidosa sharply raised to 150 mL·L-1.
The H2 production of C. pyrenoidosa in municipal wastewater and biogas slurry was comparatively investigated; it was found that the maximum H2 production of C. pyrenoidosa, which was cultivated in 25% biogas slurry with supply of 2% CO2, was much higher than C. pyrenoidosa, which was cultivated in municipal wastewater with supply of 2% CO2. The maximum H2 production of C. pyrenoidosa was 130.9 mL·g-1 dry weight in biogas slurry, indicating that the method of cultivation and H2 production for C. pyrenoidosa in biogas slurry was feasible.
|王环宇. 绿藻氢化酶氧耐受性表征与光合产氢过程研究[D]. 北京. 中国科学院研究生院,2012.|