DO11.10小鼠卵清蛋白免疫耐受模型的建立

为建立D011.10小鼠的卵清蛋白(OVA)免疫耐受模型,试验组小鼠尾静脉注射5 μg/只OVA,对照组注射PBS,共3次,每次间隔5 d.最后一次注射后的第3天、第12天分别用OVA进行免疫,第18天颈椎脱臼处死小鼠.利用MTT法检测小鼠OVA、OVA323-339肽段特异性脾淋巴细胞增殖情况,利用流式细胞术检测CD...     

溶氧浓度对微生物谷氨酰胺转胺酶发酵的影响

研究了不同溶氧(DO)浓度对微生物谷氨酰胺转胺酶(M TG)发酵的影响。结果表明,当溶氧浓度为2.88 m g/L时,M TG活性和菌体干重最高,分别达到4.32 U/mL和23.5 g/L,底物利用率为81.6%;当溶氧浓度继续升高时,发酵后期M TG活性下降显著。为此采用了分阶段溶氧控制策略,即在0~34 h控制溶氧浓度为2.88m g/L,34 h后控制溶氧浓度为0.96 m g/L,最终M TG活性达到4.72 U/mL,菌体干重达到27.32 g/L,较恒定2.88 m g/L溶氧浓度时分别提高了9.26%和16.26%,其底物利用率达83.2%。     

Effect of plant-mediated oxygen supply and drainage on greenhouse gas emission from a tropical peatland in Central Kalimantan,Indonesia

Abstract

To evaluate the hypothesis that plant-mediated oxygen supplies decrease methane (CH₄) production and total global warming potential (GWP) in a tropical peatland, the authors compared the fluxes and dissolved concentrations of greenhouse gases [GHGs; CH₄, carbon dioxide (CO₂) and nitrous oxide (N₂O)] and dissolved oxygen (DO) at multiple peatland ecosystems in Central Kalimantan, Indonesia. Study ecosystems included tropical peat swamp forest and degraded peatland areas that were burned and/or drained during the rainy season. CH₄ fluxes were significantly influenced by land use and drainage, which were highest in the flooded burnt sites (5.75 ± 6.66 mg C m^?2 h^?1) followed by the flooded forest sites (1.37 ± 2.03 mg C m^?2 h^?1), the drained burnt site (0.220 ± 0.143 mg C m^?2 h^?1), and the drained forest site (0.0084 ± 0.0321 mg C m^?2 h^?1). Dissolved CH₄ concentrations were also significantly affected by land use and drainage, which were highest in the flooded burnt sites (124 ± 84 μmol L^?1) followed by the drained burnt site (45.2 ± 29.8 μmol L^?1), the flooded forest sites (1.15 ± 1.38 μmol L^?1) and the drained forest site (0.860 ± 0.819 μmol L^?1). DO concentrations were influenced by land use only, which were significantly higher in the forest sites (6.9 ± 5.6 μmol L^?1) compared to the burnt sites (4.0 ± 2.9 μmol L^?1). These results suggest that CH₄ produced in the peat might be oxidized by plant-mediated oxygen supply in the forest sites. CO₂ fluxes were significantly higher in the drained forest site (340 ± 250 mg C m^?2 h^?1 with a water table level of ?20 to ?60 cm) than in the drained burnt site (108 ± 115 mg C m^?2 h^?1 with a water table level of ?15 to +10 cm). Dissolved CO₂ concentrations were 0.6–3.5 mmol L^?1, also highest in the drained forest site. These results suggested enhanced CO₂ emission by aerobic peat decomposition and plant respiration in the drained forest site. N₂O fluxes ranged from ?2.4 to ?8.7 μg N m^?2 h^?1 in the flooded sites and from 3.4 to 8.1 μg N m^?2 h^?1 in the drained sites. The negative N₂O fluxes might be caused by N₂O consumption by denitrification under flooded conditions. Dissolved N₂O concentrations were 0.005–0.22 μmol L^?1 but occurred at < 0.01 μmol L^?1 in most cases. GWP was mainly determined by CO₂ flux, with the highest levels in the drained forest site. Despite having almost the same CO₂ flux, GWP in the flooded burnt sites was 20% higher than that in the flooded forest sites due to the large CH₄ emission (not significant). N₂O fluxes made little contribution to GWP.     

中生菌素发酵过程中溶解氧参数的分析

通过试验测定了所用发酵罐的体积氧传递系数，发现中生菌素分批发酵过程中溶解氧浓度呈现规律性变化，得出生长临界氧浓度为１２％，发酵的最适溶解氧浓度为４０％左右。溶解氧的变化可以作为判断发酵过程状态的指标。     

水产养殖系统中机械增氧与液态氧增氧的效果比较

【研究目的】为分析水产养殖系统中机械增氧与液态氧增氧的增氧效果;【方法】设置增氧潜力、溶解氧（DO）扩散速度、水质因子、对虾生长等多个处理组,对比两增氧系统在各方面的差异。【结果】液态氧的增氧潜力是机械增氧的3倍左右,且DO扩散速度快;液态氧增氧系统和机械增氧系统的DO含量、水温、盐度和pH变化趋势相似,且均相对稳定。与机械增氧系统相比,液态氧增氧系统的氨态氮（TAN）、亚硝态氮（N02-N）和可溶性磷（PO4-P）含量变化剧烈;液态氧增氧系统中开启增氧机会在一定程度上降低DO含量。液态氧增氧的运行成本与机械增氧相当;但液态氧增氧的效果稳定,且无噪音、无污染、不受外界气压等环境因素的影响。【结论】液态氧增氧在增氧潜力及增氧速度等多个方面均优于机械增氧。     

Application of sediment microbial fuel cell for in situ reclamation of aquaculture pond water quality

Performance of sediment microbial fuel cell (SMFC) with external resistance (SMFC-1) as well as short-circuited mode (SMFC-2) was evaluated at different operating temperatures (28–30 °C and 21–25 °C) and in presence and absence of aeration at the cathode. The performance was evaluated in terms of chemical oxygen demand (COD) removal and total kjeldahl nitrogen (TKN) removal for offering in situ treatment of aquaculture pond water. SMFC-2 demonstrated maximum COD and TKN removal efficiencies both in the absence and presence of aeration near cathode as compared to SMFC-1. With aeration at cathode, the COD and TKN removal efficiencies were 79.4% and 92.6% in SMFC-1 and 84.4% and 95.3% in SMFC-2, respectively. Without aeration and at lower operating temperature, the COD and TKN removals were slightly lower, yet satisfying aquaculture quality norms. SMFCs demonstrated effective in situ remediation of aquaculture water and can drastically save the operating cost of aquaculture.     

河口区斑节对虾三种淡化养殖模式的比较

提出了河口区斑节对虾(Penaeus mortodon)三种淡化养殖模式，在全封闭、半封闭与逐添换淡水的三种水质管理方式下，养殖管理的关键技术为：虾苗放养前需经6d以上淡化驯养至养殖池水盐度，待幼虾体长至4cm时，按日-均降盐度1．2％～1．6％的速率，逐步添加淡水，缓慢递降池水盐度，幼虾体长至8～l0cm时，幼虾可在近淡水(S≥0．55)水中养殖，但虾塘水质类型始终保持为海水类型(ClⅢ^Na)；养殖周期内，池水处于高溶解氧状态。试验结果显示，在71～90d养殖周期内，斑节对虾生长良好，起捕虾体长为11．0～13．0cm，产量达到2310．0～2557．5kg／hm^2。     

Promotive effect of soil solution on germination of Monochoria vaginalis under paddy conditions

ABSTRACT

Growth of the weed Monochoria vaginalis (Burm. f.) Kunth under the conditions of organic rice production is a serious problem. The reason for the growth of M. vaginalis being dominant, especially in organic rice production, is not fully understood. In this study, laboratory experiments were conducted to analyze soil and seed factors in relation to the promotion of germination. (1) After incubation of flooded soil with or without the addition of rice bran (0.3%, 0.6%, and 0.9% in an air-dried soil basis), soil solutions were recovered and seeds of M. vaginalis were incubated in the soil solutions. Germination in the soils solutions without and with 0.3% rice bran was greater than that in distilled water. However, germination was suppressed in the presence of 0.6% and 0.9% of rice bran. These findings indicate that the solution from the soils with rice bran has different effects that may either increase or decrease germination. (2) A mixture of air-dried soil and distilled water was filtered to obtain a soil solution. Seeds were incubated in the soil solution (same as above). Environmental and physiological factors affected germination: exposure of seeds to light was an environmental factor and high germination activity and shallow dormancy of seed were physiological. The recovered soil solution promoted germination when these factors were not optimized. (3) There was a negative and significant correlation between dissolved oxygen (DO) in the soil solution and germination, indicating that a low content of DO was a promotive factor for germination. (4) Based on an experiment using pH buffers, germination increased with decrease in pH of soil solution, as long as the pH ranged from 4.0 to 7.0. This finding indicates that pH is also a factor that promotes germination.