低速大转矩永磁游标电机在发酵罐中的应用

采用秸秆生产丁醇时,为了达到高效率发酵,需要使发酵液中菌体分布均匀,所加物料需要及时搅拌。工业化生产丁醇的发酵罐尺寸较大,搅拌过程对驱动电机的输出转矩要求较高,因此高效率、小体积、低速大转矩的秸秆发酵搅拌电机对工业化发酵生产丁醇意义重大。设计了一种定转子永磁游标电机用于发酵液搅拌,并对电机的槽极数、电磁性能进行了具体的研究。制造样机并采用滞环控制实现了对液态发酵对象的快速响应,且实现了低能耗、高效率的发酵过程。     

A straw-soil co-composting and evaluation for plant substrate in BLSS

Material closure is important for the establishment of Bioregenerative Life Support System, and many studies have focused on transforming candidate plant residues into plant culture medium. For the limitations of using wheat straw compost as substrate for plant cultivation, a straw-soil co-composting technique was studied. The changes of pH, C/N value, germination index, cellulose, lignin and so on were monitored during the co-composting process. The maturity was evaluated by the C/N value and the germination index. The result showed that after 45 days’ fermentation, the straw-soil final co-compost with inoculation (T1) became mature, while the co-compost without inoculation (T0) was not mature. In the plant culture test, the T1 substrate could satisfy the needs for lettuce’s growth, and the edible biomass yield of lettuce averaged 74.42 g pot⁻¹ at harvest. But the lettuces in T0 substrate showed stress symptoms and have not completed the growth cycle. Moreover, the results of nitrogen (N) transformation experiment showed that about 10.0% and 3.1% N were lost during the T1 co-composting and plant cultivation, respectively, 23.5% N was absorbed by lettuce, and 63.4% N remained in the T1 substrate after cultivation.     

Tween-20协同麦草酶水解的研究

采用正交试验设计的方法,对在混合酶(纤维素酶 Celluclast 1.5 l,β-葡萄糖苷酶 Novozym 188)与Tween-20协同作用下,经乙醇预处理的麦草酶水解工艺条件进行研究,详细讨论了反应温度、底物浓度、Tween-20用量、纤维素酶用量对还原糖浓度和得率的影响,并对酶水解工艺进行优化.结果表明,最佳工艺条件为反应温度50 ℃,底物质量浓度100 g·L~(-1),Tween-20用量0.03 g·g~(-1),纤维素酶用量15 FPU·g~(-1).在此条件下,水解72 h时,还原糖质量浓度和得率分别达到46.1 g·L~(-1)和41.5%.     

植酸酶发酵过程控制系统设计

设计基于研华工控机和ADAM模块发酵过程控制系统,介绍该系统的软、硬件结构与功能,以及发酵过程参数的优化控制方法。     

O2 evolution and cyclic electron flow around photosystem I in long-term ground batch culture of Euglena gracilis

Based on the purpose of better exploring the function of green producers in the closed aquatic biological life support system, the condition of dynamic O₂ evolution and performance of cyclic electron flow around photosystem I (CEF-PSI) in long-term ground batch culture of Euglena gracilis were studied, the relationship between linear electron flow (LEF) and CEF-PSI was revealed, the function of CEF-PSI was investigated. Excellent consistency in O₂ evolution pattern was observed in cultures grown in both closed and open containers, O₂ evolution was strictly suppressed in phase 1, but the rate of it increased significantly in phase 2. CEF-PSI was proposed to be active during the whole course of cultivation, even in the declining phase 3, it still operated at the extent of 47–55%. It is suggested that the relationship between LEF and CEF-PSI is not only competition but also reciprocity. CEF-PSI was proposed to contribute to the considerable growth in phase 1; it was also suggested to play an important protective role against photosystem II (PSII) photoinhibition at the greatly enhanced level (approximately 80–95%) on the 2nd day. Our results in this research suggest that E. gracilis had very particular photosynthetic characteristics, the strict O₂ evolution suppression in the initial culture phase might be a special light acclimation behavior, and CEF-PSI could be an important mechanism involved in this kind of adaptation to the changeable light environment.     

Characteristics of the soil-like substrates produced with a novel technique combining aerobic fermentation and earthworm treatment

The soil-like substrate (SLS) technique is key for improving the closure of bioregenerative life support system (BLSS) by recycling the inedible biomass of higher plants. In this study, a novel SLS technique (NSLST) was proposed: aerobic fermentations at 35 °C for 1 day, then 60 °C for 6 days, finally 30 °C for 3 days, followed by earthworm treatment for 70 days. Comparing with the original SLS technique (OSLST), its process cycle was 13 days shorter, and the dry weight loss rate (81.1%) was improved by 24.77%. The cellulose and lignin degradation rates were 96.6% and 94.6%. The concentrations of available N, P and K in mature SLS were respectively 776.1 mg/L, 348.0 mg/L and 7943.0 mg/L. Low CH₄ and NH₃ production was observed, but no accumulation. According to the seed germination test, the SLSs were feasible for plant growth. This investigation will provide a preliminary foundation for BLSS design.     

仿人智能开关算法在发酵温控中的应用

发酵温度对象具有严重非线性、时变不确定、大滞后等特点,且受环境温度影响非常大,目前微型发酵罐的全过程温度自动控制是个较难解决的问题。常规PID控制中的比例、积分、微分能够模拟人脑的功能,但缺乏智能性,控制效果不佳。针对此问题设计了仿人智能开关控制器,并在东北大学发酵实验室微型发酵罐温度控制中进行了应用。实验结果表明,仿人智能开关控制器比传统的PID控制器的控制精度更高、稳态性能更好,具有较高的应用价值。     

一株高活力纤维素酶产生菌-黑曲霉No.5.1产酶条件研究

以黑曲霉突变株No.5.1为实验材料,采用液体深层发酵方法,对其所产纤维素酶进行了研究。结果表明在产酶培养基为(W/V):纤维素粉3%、硝酸钾3%、聚乙二醇0.1%、初始pH为6.0的条件下,液体发酵最佳培养条件为:250 mL三角瓶装25 mL培养基、接种种龄为1 d的种子培养液2.5 mL、在32℃培养5 d,这将为纤维素酶液体发酵的工业化生产和应用提供参考依据。