Development of a chemically defined medium for Planctopirus limnophila to increase biomass production

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.     

碳源、氮源及其比例对香菇液体深层培养的影响

通过摇瓶培养,研究香菇液体深层培养最适发酵培养时间、最适碳源、最适氮源及最佳碳源与氮源质量配比.结果表明最适发酵培养时间为168 h,所得菌丝体干重达0.399 g/50 mL菌液,最适碳源为蔗糖,菌丝体干重达到0.396 g/50 mL菌液;最适氮源为牛肉膏,菌丝干重达到0.421 g/50 mL菌液,并通过正交实验筛选出最佳碳源与氮源质量配比为:W(蔗糖):W(牛肉膏):W(麦芽糖)=2.5:1:1.     

Kinetics study on biomass pyrolysis for fuel gas production

Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China     

Kinetics study on biomass pyrolysis for fuel gas production

INTRODUCTIONSincebiomassisanabundant,inexpensiveandrenewableresource ,itsconversiontosyn theticfuelsandchemicalproductsappearsat tractive.Amongallkindsofbiomassconversionroutes,pyrolysisisbeinggivenincreasingatten tionsincetheprocessissimpleandmaybeopti m…     

闽江口湿地互花米草地上生物量的月动态特征

利用2008年3月～10月闽江口湿地互花米草地上生物量等群落特征的调查资料,分析其地上生物量、地上生物量的绝对生长速率和相对生长速率、株高、密度的月动态特征,同时利用spss软件对生物量、株高、密度作相关分析.结果表明:①地上生物量在7月中旬达到最大值,为2658.9g/m2,其月变化经历了一个"增加-减小-缓慢增加"的过程;②绝对生长速率在5月～6月达到最大值,为32.48 g/(m~2·d),之后波动变化,在7月～8月出现负值;③相对生长速率在4月～5月达到最大值,为0.043 g/(g·d),也在7月～8月出现负值;④株高在7月份达到最高点,平均株高达219cm;密度在5月份达到最高点,为208株/m~2;⑤株高与地上生物量呈极显著正相关,而平均密度与地上生物量、平均株高则无显著相关.     

生物质潜力及其能源转换

本文预测估计了生物质未来的潜力，其能量潜力可达到现今世界总能耗的180-200倍；在生物质能的各种转换技术中，沼气技术、生物质发酵生产燃料乙醇和生物质直接燃烧发电技术已形成规模化生产和利用；生物质气化、生物质固化成形技术已开始进入规模化生产；其余技术仍处于研制试     

工业锅炉集中监视与监控系统

为了保证工业锅炉系统安全高效地运行,对工业锅炉进行了集中监视与控制。集中监视与控制系统由两级计算机组成。上位机是工业控制计算机,主要完成智能化的后台管理和实时显示运行信息等功能,下位机是可编程控制器,主要完成现场信号和数据的采集及实时控制。该系统为工业锅炉高效安全生产提供了可靠的保障。     

基于DDC的锅炉温度控制系统的设计

本次设计主要通过带有A/D、D/A功能的数据采集模块及外围的检测与执行元件,结合试验室所提供的过程控制对象,针对双层锅炉夹套水温为被控参数,设计研究锅炉温度控制系统,完成了系统的锅炉温度控制定值控制。     

污油池油位远程监控报警系统的研发

介绍了双良燃油锅炉经常发生污油池出口有污油溢出现象,并针对性对污油池的电控部分创新研发污油池油位远程监控报警系统装置,有效地解决了污油池出口有污油溢出现象,避免能源浪费和环境污染。     

三江源移民安置区农户能源利用及对生态环境影响——以贵南县为例

三江源地区是长江、黄河、澜沧江三大河流的发源地,是我国重要水源涵养区,由于其生态系统十分脆弱,生态地位特殊,受到广泛的关注。本研究从三江源移民安置区农户能源利用对三江源生态系统影响的角度,使用问卷调查法、半开放式访谈法和生态系统服务功能评价法,对三江源移民安置区农户能源利用现状、农户对现有能源满意度和农户能源环保认知对三江源生态系统服务功能价值影响进行研究,结果表明:①三江源移民安置区种植农户能源利用结构较多样,以畜粪和秸秆为主要能源,放牧农户能源利用结构单一,基本依靠畜粪;②农户普遍对能源现状满意度低,放牧农户满意度低于种植农户;③农户倾向于使用环保能源,但对能源环保认知度较低,阻碍了清洁能源的广泛使用;④农户使用生物质能源导致生态系统服务功能价值每年损失约23.6737亿元。