林可霉素菌(Streptomyces lincolnensis)利用吡唑酮废水的研究

采用被吡唑酮废液驯化、分离、筛选后的林可霉素菌,并对其在摇瓶上利用吡唑酮废液中的硫酸铵发酵(7 d)生产林可霉素进行了研究。实验结果表明,废液加入培养基体积比都为1∶10,实验1中菌丝代谢和对照比正常,其中还原糖利用最快,在发酵后期为0.24 mg/L,林可霉素起步效价最低为2 100 IU/mL,与对照相比最后发酵效价降低了70 IU/mL;实验2发酵过程pH值偏低,全程为5.86～6.50,氨基氮代谢缓慢为40 mg/100 mL,最后林可霉素效价最低为4 480 IU/mL;实验3中废液在发酵进入48 h中后期的时候补入能促进菌丝体分泌,最后林可霉素为5 180 IU/mL,比对照发酵水平高出8.82%。可见实验3的实验设计有利于林可霉素菌利用吡唑酮废液生产林可霉素,为废物循环利用、变废为宝的可行性作了有意义尝试。     

Use of whole-body and subcellular Cu residues of Lumbriculus variegatus to predict waterborne Cu toxicity to both L. variegatus and Chironomus riparius in fresh water

We tested the use of whole-body and subcellular Cu residues (biologically-active (BAM) and inactive compartments (BIM)), of the oligochaete Lumbriculus variegatus to predict Cu toxicity in fresh water. The critical whole-body residue associated with 50% mortality (CBR₅₀) was constant (38.2-55.6 μg g⁻¹ fresh wt.) across water hardness (38-117 mg L⁻¹ as CaCO₃) and exposure times during the chronic exposure. The critical subcellular residue (CSR₅₀) in metal-rich granules (part of BIM) associated with 50% mortality was approximately 5 μg g⁻¹ fresh wt., indicating that Cu bioavailability is correlated with toxicity:subcellular residue is a better predictor of Cu toxicity than whole-body residue. There was a strong correlation between the whole-body residue of L. variegatus (biomonitor) and survival of Chironomus riparius (relatively sensitive species) in a hard water Cu co-exposure. The CBR₅₀ in L. variegatus for predicting mortality of C. riparius was 29.1-45.7 μg g⁻¹ fresh wt., which was consistent within the experimental period; therefore use of Cu residue in an accumulator species to predict bioavailability of Cu to a sensitive species is a promising approach.     

餐厨垃圾混菌发酵制备燃料乙醇

以校园餐厨垃圾为原料,利用根霉和枯草芽胞杆菌进行糖化预处理,再接种啤酒酵母发酵产乙醇。通过单因素实验,以乙醇产量为响应值,对发酵条件进行优化。实验结果表明:乙醇产量最佳的发酵条件为:当底料含水率为22.79%,啤酒酵母接种量为15%,30℃培养条件下,经过5 d发酵,乙醇产量最高可达到6.67%。选用餐厨垃圾丰富了燃料乙醇的取材途径,实现了原材料的多元化,采用微生物预降解原材料为实现高产乙醇奠定了基础。     

The formation of bound residues of diazinon in four UK soils: implications for risk assessment

The behaviour of diazinon in the soil determines the likelihood of further pollution incidents, particularly leaching to water. The most significant processes in the control of the fate of diazinon in the soil are microbial degradation and the formation of bound residues. Soils from four sites in the UK were amended with diazinon and its ¹⁴C labelled analogue and incubated for 100 days. After 0, 10, 21, 50 and 100 days, the formation of bound residues was assessed by solvent extraction, and the microbial degradation of diazinon by mineralisation assay. In microbially active soils, diazinon is degraded rapidly, reducing the risk of future pollution incidents. However, where there was limited mineralisation there was also significantly lower formation of bound residues, which may lead to water pollution via leaching. The formation of bound residues was dependent on extraction type. Acetonitrile extraction identified bound residues in all soils, with the bound residue fraction increasing with increasing incubation time.     

响应面法和神经网络优化Acinetobacter sp. DNS32发酵基质

为了提高阿特拉津降解菌Acinetobacter sp.DNS32的产量,分别采用响应曲面法和基于人工神经网络的遗传算法对阿特拉津降解菌DNS32发酵培养基中3个重要基质成分(玉米粉、豆饼粉、K2HPO4)进行优化研究。响应曲面法确定3种成分的含量为玉米粉39.494 g/L,豆饼粉25.638 g/L和K2HPO43.265 g/L时,预测发酵活菌最大生物量为7.079×108CFU/mL,实测量为7.194×108CFU/mL;人工神经网络结合遗传算法优化确定3种主要成分含量为玉米粉为39.650 g/L,豆饼粉为25.500 g/L,K2HPO4为2.624 g/L时,预测最大值为7.199×108CFU/mL,实测量为7.244×108CFU/mL;最终确定培养基配方:玉米粉为39.650 g/L,豆饼粉为25.500 g/L,K2HPO4为2.624 g/L,CaCO3为3.000 g/L,MgSO4.7H2O和NaCl均为0.200 g/L;优化后阿特拉津降解菌DNS32发酵生物量比优化前提高了36.6%。结果表明,在阿特拉津降解菌DNS32发酵培养基组分优化方面,响应面法和基于人工神经网络的遗传算法都是可行的,基于人工神经网络的遗传算法具有更好的拟合度和预测准确度。     

牛粪厌氧发酵的载体筛选试验研究

为了提高厌氧发酵装置的效率，人们研究了各种各样的方法和措施，其中应用填料或载体使生物菌能够延长驻留期是其中的方法之一，开展载体筛选及其结构设计在厌氧发酵装置中的试验，有助于对此问题的深入研究以及将其成果应用于生产实践。通过静态载体筛选试验选择了玻璃纤维作为载体、PVC塑料管作为载体骨架制成的装置在动态序批式厌氧发酵装置中进行了试验。结果表明：此载体骨架结构对于牛粪动态厌氧发酵具有明显的提高产气效率、改变产气质量和促进有机物转化为挥发性脂肪酸的作用。     

用碳化法从制碱废渣一次盐泥中制取轻质氧化镁的研究

本研究是用制碱废渣一次盐泥作原料，采用二氧化碳碳化法制取轻质氧化镁。同时分析了提取轻质氧化镁后的残渣用于制造水泥或其它胶凝材料的原料的可行性。     

微生物法降解药渣中残留四环素的试验研究

发酵法生产四环素过程中会产出大量废弃药渣,其中含有丰富的营养物质,但同时也残留一定量未提取完的四环素,从而限制其资源化利用。研究筛选到一株对药渣中残留四环具有高效降解作用的优势菌株,经16S rDNA鉴定为无丙二酸柠檬酸杆菌(Citrobacteramalonaticus)。该菌株在35℃、初始pH 5.5、装液量为50 mL、接种量为5%、转速为150 r/min条件下,处理四环素药渣72 h,药渣中残留四环素的降解率为86.1%。     

不同堆沤处理对玉米秸秆厌氧发酵的影响

研究利用纤维素分解菌F2对玉米秸秆进行堆沤预处理,将经不同堆沤预处理时间后的秸秆与猪粪混合进行厌氧发酵产沼气试验。结果发现,堆沤15 d后秸秆的总有机碳含量降低了10.06%,VS去除率和纤维素降解率比未加菌堆沤预处理分别提高了10.74%、10.60%;加菌堆沤预处理后的秸秆厌氧发酵甲烷产气率、干物质产气率、发酵前后VS去除率均高于未加菌堆沤预处理后的秸秆,且产气效率也有明显的提高;加菌堆沤预处理10 d的秸秆比未加菌堆沤预处理15 d的秸秆提前了2 d达到产气高峰,累计产气量达到21 957 mL,比未加菌堆沤预处理15 d的秸秆增加了1 629 mL。实验结果表明:该纤维素分解菌对玉米秸秆纤维素有较强的降解能力,并在一定程度上促进了有机碳的矿化;有效地提高了秸秆的生物降解性能,缩短了预处理所需时间;同时提高了玉米秸秆的利用率和产气潜力。