Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, China

The Luliang and Baoshan basins are two small ba- sins in Yunnan Province. In the recent ten years or so, there have been found a number of natural gas pools of commercial importance in the two basins. Although the gas pools are small in size, the natural …     

未熟有机质发酵后

采用对未熟有机质富集培养本源菌再进行类发酵(Eh>-300mV)的模拟实验方法,重点研究了发酵样品中某些生物标志化合物的变化,探讨了在低演化阶段,由于细菌对有机质的参与和改造,液态烃类形成的地球化学特征。样品发酵后,烃类,尤其是低相对分子质量烃类含量增加,CPI和OEP值接近或略高于1。族组成中,沥青质含量减少,烃类和非烃增加。饱和烃中,C-13位上带有正烷基侧链的三环萜烷出现;高含量的伽马蜡烷被检出;生物构型藿类化合物向地质构型藿烷转化,C-22位上立体异构化平衡参数明显增大,接近或达到异构化终点值;单芳甾类烃与三芳甾类烃共存;甾体化合物含量的总体趋势是相对贫乏,平衡参数较低。     

海洋细菌LP621 右旋糖苷酶分批发酵动力学研究

对海洋细菌Pseudoalteromonas tetraodonis LP621右旋糖苷酶进行了50L发酵罐分批发酵的代谢特性的研究.结果表明LP621右旋糖苷酶合成和菌体生长呈部分生长偶联型.据分批发酵试验结果采用Logistic方程、Luedeking-Piret方程建立了描述菌株生长、产酶以及葡萄糖底物消耗分批发酵动力学模型.动力学模型计算值结果与实验值拟合良好,较好反映了菌株右旋糖苷酶分批发酵过程的动力学特征.     

Biological hydrogen production from organic wastewater with a novel strain B49 isolated from anaerobic sewage sludge

Water pollution of river basin has increased with increasing discharge of sewage and the water quality has deteriorated due to the discharge of organic wastewater. Pretreatment of organic wastewater before discharging is of significance for the protection of water resources. The anaerobic digestion of organic substrates has been a well-developed biological treatment method for wastewater and wastes. Especially, the biohydrogen production using organic wastewater can produce an energy product and simultaneously reduce the pollution intensity of the wastes. Microorganisms with high hydrogen-producing capacity perform an important function in biohydrogen production. In this paper, we investigated the zymolytic characteristics of a novel strain of bacteria B49 isolated from anaerobic activated sludge using waste liquid from a sugarhouse as substrate. The effect of yeast extract on microbial conversion of waste liquid from the sugarhouse was investigated. Different carbohydrates （such as glucose, sucrose, trisaccharide, molasses, etc.） in the waste liquid serve as major energy sources for B49＇s cell growth. The hydrogen yield of 2410 mL-H2/L-culture was obtained using glucose as substrate. When the waste liquid from the sugarhouse （molasses） was used as substrate, maximum hydrogen yield of 2460 mL-H2/L-culture was obtained at 2% of molasses.     

海洋放线菌Y18的分子鉴定、生物活性及其抗菌物质发酵条件优化

从北冰洋楚科奇海海洋沉积物中分离到一株放线菌Y18,其良好生长需要海水。经16S rRNA基因序列分析确定该菌株属于拟诺卡氏菌属(Nocardiopsis),次级代谢产物合成酶基因及抗菌活性筛选发现,它含有聚酮类Ⅱ型(PKSⅡ)和非核糖体含硫多肽类(non ribosome-bound sulfur-containing peptides,NRPS)化合物合成酶基因,并且对枯草芽孢杆菌和白色念珠菌有抑制作用。以枯草芽孢杆菌为指示菌对Y18的发酵条件进行了初步优化,适合的发酵条件为:发酵培养基(蛋白胨2 g,酪素水解物2 g,酵母膏2 g,葡萄糖1 g,海水1 L),种子液接种量4%,发酵温度28℃,发酵培养基初始pH值8.0,培养时间6天,1 000 mL三角瓶装液量20%。并对Y18发酵液稳定性进行了测定,结果显示:发酵液对酸碱、热的稳定性都较强,4℃下贮藏发酵液的抗菌活性保留时间较长。     

Optimization of fermentation conditions for 1,3-propanediol production by marine Klebsiella pneumonia HSL4 using response surface methodology

The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.     

黑土型退化草地时空格局遥感监测

准确及时地了解黑土型退化草地的时空分布特点,对祁连山地区草地退化修复治理具有重要意义。本文选取祁连县野牛沟乡西北部区域作为研究区,基于Landsat 8 OLI影像,结合地理国情监测成果,尝试利用分场景的决策树分类方法提取黑土型退化草地范围,并对比分析2014-2019年黑土型退化草地的时空变化特征。结果表明,多场景的决策树分类方法对黑土型退化草地监测具有很好的适用性;2014-2019年,研究区北部部分区域缓坡地和中部滩地黑土型退化问题有所好转,西部和西北部缓坡地黑土型退化问题有进一步恶化的趋势;好转草地主要以人工干预为主,恶化草地可能是受水热空洞效应、鼠害等多种因素的影响。     

绿潮藻浒苔微生物高效降解及生物乙醇制备

从绿潮藻暴发海域的底泥和腐烂浒苔(Ulva prolifera)中,筛选出一株可高效降解浒苔纤维素的微生物菌株(F菌株),通过刚果红染色实验以及真菌的ITS分析,鉴定为曲霉属真菌。以浒苔为诱导培养基制备F菌株的粗酶液,测得其滤纸纤维素酶活为34.79 U/m L。在发酵实验中,当酶解条件为6%的粗酶液添加量、反应温度为38℃、反应时间为60 h、pH为6.8时,浒苔纤维素降解效果最好,酶解液发酵乙醇产量最高达到28.98 g/L。     

天然沸石在畜禽饲养及粪便污染治理中的应用研究

在畜禽饲料中添加适量的河北省赤城所产的沸石矿粉,不仅可使肉蛋疸有所增加,提高饲料率,降低生产成本,而且可降低畜禽舍内的有害气体含量,改善饲养人员的劳动环境,并有僧于畜禽健康。采用人工干清粪、沸石－好氧细菌发酵治理畜禽粪便工艺,具有较大的技术和成本优势,可以改善饲养场的周边环境,对于水资源的保护和利用具有重要意义,为畜禽粪便的污染治理与商品化生产提供了新的途径。     

海洋弧菌Z010 产生几丁质酶的发酵条件研究

以海洋弧菌Ｚ０１０ 菌株为对象,研究了其产生几丁质酶的发酵条件。研究表明,其产酶的最佳发酵条件为：２２１６Ｅ液体培养基中含０．５％ （ｗ ／ｖ）的胶体几丁质,０．５％ （ｗ ／ｖ）的蛋白胨,培养起始ｐＨ值为７．０, ２５℃摇床２００ ｒ／ｍ ｉｎ 培养３６ｈ,几丁质酶产出最大。