Understanding poromechanical response of a biogenic coalbed methane reservoir

Biogenic coalbed methane(BCBM)reservoirs aim to produce methane from in situ coal deposits following microbial conversion of coal.Success of BCBM reservoirs requires economic methane production within an acceptable timeframe.The work reported here quantifies the findings of previously published qualitative work,where it was found that bioconversion induces strains in the pore,matrix and bulk scales.Using imaging and dynamic strain monitoring techniques,the bioconversion induced strain is quantified here.To understand the effect of these strains from a reservoir geomechanics perspective,a corresponding poromechanical model is developed.Furthermore,findings of imaging experiments are validated using core-flooding flow experiments.Finally,expected field-scale behavior of the permeability response of a BCBM operation is modeled and analyzed.The results of the study indicated that,for Illinois coals,bioconversion induced strains result in a decrease in fracture porosity,resulting in a detrimental permeability drop in excess of 60%during bioconversion,which festers itself exponentially throughout its producing life.Results indicate that reservoirs with high initial permeability that will support higher Darcian flowrates,would be better suited for coal bioconversion,thereby providing a site-selection criteria for BCBM operations.

植物细胞壁抗降解屏障研究进展与展望

纤维素是地球上最丰富的可再生资源,经酶促水解反应生成葡萄糖是纤维素转化的理想方式,但转化效率低,探究相关的抑制因素及其特点成为纤维素高值化应用的首要基础科学问题。本研究首先从宏观形态、显微结构、超微结构、分子、基团、元素、化学键和基因水平,多角度、多层次总结制约纤维素酶促水解反应效率的关键抑制因素,阐述抗降解屏障的内涵;其次明确抗降解屏障表现出的在不同生物质的特有异质性、在植物发育不同阶段的高度动态性以及在预处理过程的复杂联动性;最后展望生物质抗降解屏障破解研究的新趋势和新策略:细胞壁界面抗降解屏障的新认识,细胞壁修饰与改造方法,细胞壁精准解构与组分分级利用的新技术和多酶协同酶解体系的建立等。

不同碳氮比典型食品废弃物对黑水虻生长发育的影响

黑水虻处理餐厨垃圾是当前食品废弃物处理领域的热点,但存在对不同食品废弃物的处理效率差异大的问题。本研究以豆渣、餐厨垃圾和菌渣3种常见的食品废弃物作为食物源,考察不同碳氮比(C/N)值(5.00、10.00和15.00)对黑水虻幼虫体长、体质量及生物转化率等生长指标的影响。结果表明:黑水虻在不同C/N的饲料中的生长速率不同,由高至低依次为餐厨垃圾、豆渣和菌渣,幼虫喂养10 d后的平均体长分别为2.06、1.93和1.82 cm,平均体质量分别为75.0、54.2和42.1 mg,生物转化率分别为14.89%、13.11%和4.15%。当饲料的C/N值为10.00时,有利于黑水虻的高效生长和生物转化。当将菌渣和豆渣以质量比2∶8混合喂养(C/N值为10.04)时,黑水虻的生物转化率提高至15.81%。可见,调节饲料C/N值以提高黑水虻对食品废弃物的生物转化率是一条可行的研究路径。

有机固废生物转化中的生物激励素及其农业利用价值

生物转化技术是有机固废转化为高价值产品的重要途径。介绍了有机固废生物转化过程中的生物激励素及其在农业上的价值。腐殖酸类物质、微生物菌剂及提取物、蛋白质水解物、大量和微量元素是有机固废生物转化过程中的主要生物激励素,可以作为肥料和农药的补充或部分替代,提高作物产量和品质,增强植物对环境胁迫的抗逆性。此外,还讨论了有机固废生物转化过程中生物激励素合成转化及其作用机理的复杂性,以及存在的知识空白、挑战和机遇,需要建立更完善的理论研究基础,以促进有机固废生物转化技术在未来农业领域的应用。

不同废弃物对黑水虻幼虫生长、营养组成及生产性能影响研究

本文以黑水虻Hermetia illucens为研究对象,探索不同废弃物对其幼虫生长、营养组成及生产性能的影响。结果表明,黑水虻幼虫可将餐厨垃圾(FW)、厨余垃圾(KW)、蔬菜废弃物(VW)、猪粪(PM)、牛粪(DM)、鸡粪(CM)等转化成优质蛋白质和脂肪。以FW和KW作为基质养殖10 d后,幼虫体长(19.0 mm、17.1 mm)与单头重(171.54 mg、136.82 mg)显著高于其它处理。虫粉粗蛋白含量受废弃物种类影响相对较小。不同废弃物处理虫粉均显示出良好氨基酸谱。尽管各处理虫粉总必需氨基酸含量低于鱼粉和豆粕,但FW、KW和CM处理虫粉缬氨酸含量高于鱼粉和豆粕,VW处理虫粉异亮氨酸和缬氨酸含量高于鱼粉和豆粕,PM处理虫粉组氨酸和缬氨酸含量高于鱼粉和豆粕。以FW和KW作为基质养殖10 d后,尽管虫粉不饱和脂肪酸和必需脂肪酸比例低于采食PM和DM的处理,但远高于其它处理的虫粉粗脂肪含量(42.13%、37.49%),虫粉不饱和脂肪酸和必需脂肪酸含量也最高;料虫比(6.06、7.90)显著低于其它处理,幼虫转化率(59.40%、52.07%)显著高于其它处理;废弃物减量化率(89.53%、84.46%)仅低于VW处理(94.86%)。利用黑水虻幼虫处理FW和KW,幼虫生长性能和营养组成优于其它废弃物处理,且生产性能最好。

固体废弃物资源化处理技术综述

随着全球人口的增长和经济的发展,固体废弃物产生量不断增加,给环境带来严重的挑战。为了实现可持续发展,有必要对固体废弃物进行资源化处理。目前,固体废弃物资源化处理技术主要有生物转化、热解裂解、气化等。本文结合固体废弃物资源化处理技术现状,分析不同技术的优势,指出面临的挑战,以期为固体废弃物处理提供理论参考。

Evaluation of fungal potentiality for bioconversion of domestic wastewater sludge

This study was undertaken to screen the filamentous fungi isolated from its relevant habitats(wastewater, sewage sludge and sludge cake) for the bioconversion of domestic wastewater sludge. A total of 35 fungal strains were tested against wastewater sludge (total suspended solids, TSS 1%—5% w/w) to evaluate its potentiality for enhancing the biodegradability and dewaterability using liquid state bioconversion(LSB) process. The strains were divided into five groups i.e. Penicillium, Aspergillus, Trichoderma, Basidiomycete and Miscellaneous, respectively. The strains WWZP1003, SCahmA103, SCahmT105 and PC-9 among their respective groups of Penicillium, Aspergillus, Trichoderma and Basidiomycete played potential roles in terms of separation(formation of pellets/flocs/filaments), biodegradation(removal of COD) and filtration(filterability) of treated domestic wastewater sludge. The Miscellaneous group was not considered due to its unsatisfactory results as compared to the other groups. The pH value was also influenced by the microbial treatment during fermentation process. The filterability of treated sludge was improved by fungal treatment, and lowest filtration time was recorded for the strain WWZP1003 and SCahmA103 of Penicillium and Aspergillus groups respectively compared with other strains.

Preparation of 6-APA by Enzymatic Bioconversion in an Emulsion Liquid Membrane Reactor

Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected tilestability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the di-carriers was used separately.The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.

Production of bio-energy from low-value biomass by bioconversion

Since 1993, China has become a net importer of energy from a net exporter. The total energy con- sumption has been greater than the total supply, and the external dependence of the energy demand increases rapidly. China＇ s crude oil import volume and imports amount reached 253.78 million tons and 196.664 billion US dollars in 2011, with a growth rate of 6 % and 45.3 %, respectively, year-on-year. The significant increase in demand for oil and the caused structural contradictions are increasingly becoming the greatest challenge for China＇ s energy security. The energy crisis has not only touched everyone＇ s nerves, but also sparked a strong desire to find alternative energy.

Phenolic Acids from <i>Parthenium hysterophorus</i>: Evaluation of Bioconversion Potential as Free Radical Scavengers and Anticancer Agents

Parthenium hysterophorus is a globally recognized invasive alien weed that prominently colonizes grazing areas and cultivated lands causing adverse effect on crop production. Major allelochemicals released from parthenium include sesqueterpene lactones and phenolic acids. Among these the presence of caffeic, vanillic and ferulic acids is of industrial significance as they possess potent free radical scavenging and anticancer activities. This study reports for the first time, high total phenolic acid content (20.82 ± 0.82 mg GAE/g dry sample) in parthenium. The GC-MS analysis indicated the presence of ferulic, p-coumaric, vanillic and gallic acid as major phenolic components. Free radical scavenging activity of the phenolic acids extract gave an EC50 value 130.4 μg/ml when measured using DPPH assay. Anticancer activity of parthenium phenolic extract against A-498 (IC50 0.5237 μg/ml) and MDA-MB231 (IC50 and 0.2685 μg/ml) cancerous cell lines indicated its potential to be used as anticancer agent.

Effects of Different Genotypes of Switchgrass as a Bioenergy Crop on Yield Components and Bioconversion Potential

Switchgrass (Panicum virgatum L.) is a native warm-season grass and it is one of potential bioenergy crops. The objectives of this study were to: 1) assess the best performing switchgrass genotype suitable for Kansas soil and climatic condition in the USA, 2) determine the correlation between plant height or tiller numbers per plant and dry biomass of various switchgrass genotypes, and 3) assess a bioconversion efficiency of certain varieties of switchgrass. Twenty-two different genotypes of seedlings were allowed to grow in cones for 30 days under controlled environments. The genotype Cave-in-Rock was the shortest among the genotypes. Significant difference in number of tillers per plant was observed among the genotypes. The genotypes Alamo recorded the highest numbers of tiller plant-1 and the genotype Cave-in-Rock had the lowest numbers of tiller plant-1 compared with other genotypes. The genotypes Alamo, NL 94 C2-2, NL 94 C2-3, NSL 2009-1 and NSL 2009-2 had increased above ground biomass compared with other genotypes. The correlation study indicates that there was a significant positive correlation between number of tillers per plant and per plant dry weight (R2 = 0.93), number of tillers per plant and plant height (R2 = 0.94), and plant height and per plant dry weight (R2 = 0.82). Based on the biomass composition, the SWG 2007-2 genotype was the promising switchgrass line for the bioconversion through the sugar platform route due to high carbohydrate and low lignin content. On the other hand, the high biomass yield per unit area of field in NL 94 C2-1 led this genotype with the highest total carbohydrate yield per unit area of field despite the lowest total carbohydrate content in the genotype. These results are pertinent for crop breeders to develop the most promising switchgrass line with high biomass yield and high bioconversion efficiency to produce biofuel through the sugar platform route.

The Bioconversion of Municipal Solid Waste in the Biodrying Reactor

The bioconversion process of municipal solid waste was assessed on the basis of the results obtained from the biodrying reactor working at a full industrial scale.The bio-reactor is a part of mechanical-biological installation following mechanical stage.The bio-reactor was equipped with measuring devices allowing the analysis of the parameters like:temperature both inside the waste and also air above the waste and also the humidity of waste during the 14 days of the biodrying process.The kinetics of bioconversion was assessed basing on measured the loss of ignition(LOI)parameter detected during the biodrying process.The LOI value of the samples varied from 17.03%Am.to 30.34%d.m.depending on the location inside the reactor.The estimated kinetic rate constant kT of the bioconversion of biomass in the industrial reactor was kT=0.3141.In analyzed case study the calorific value of product leaving the full-scale bio-reactor is too low to use this product as an alternative fuel.As w'as stated the reason of this is too low a share of the carbon-rich fraction in the feedstock.

Solid State Bioconversion for Producing Common Bean(Phaseolus vulgaris L.)Functional Flour with High Antioxidant Activity and Antihypertensive Potential

The main objective of this investigation was to study the time effect during solid state bioconversion (SSB) on total phenolics content (TPC) and antioxidant activity (AoxA) of common beans to improve antihypertensive functionality. Cooked cotyledons of dehulled common beans were inoculated with a suspension of R. oligosporus NRRL 2710 (1 × 106 spores/mL), and incubated at 35℃ for times of 24, 36, 48, 60, 72, 84, 96 and 108 h (after 108 h the cotyledons showed off odor). Flours from bioprocessed dehulled common bean from each incubation time were blended with their corresponding milled seed coats. The best time for producing bioprocessed common bean (added with seed coats) functional flour with the highest AoxA (ORAC value = 17,468 μmol Trolox equivalents (TE)/100 gsample, dw;ABTS value = 13,505 μmol TE/100 gsample, dw) was 108 h. The SSB process substantially increased TPC and total hydrophilic AoxA and antihypertensive potential of common beans in 2.24, 2.45 - 2.73 and 6769 times, respectively. Proteins hydrolyzates from unprocessed whole and bioprocessed (108 h) common beans had IC50 [concentration needed to inhibit 50% the activity of angiotensin converting enzyme (ACE)] of 79.2 and 0.0117 μg/mL, respectively. The SSB is an efective strategy to improve the TPC of common beans for enhanced functionality with improved antioxidant activity and antihypertensive potential.

基于功能高分子材料的生物被膜构建及其生物转化应用进展

生物被膜是微生物附着在载体材料表面的高度有组织的微生物群体,主要由菌体和微生物的胞外分泌物构成。与浮游细菌相比,生物被膜内的微生物对抗菌剂、恶劣环境及宿主免疫防御机制的抗性显著增加,还具有自增殖、可重复利用等优点。近年来,生物被膜在污水处理、工业发酵、食品工程和生物制药等领域受到越来越多的关注。载体材料的理化性质对生物被膜的构建具有重要影响。有机高分子材料因价廉、具有较轻的比重和密度、易于表面改性等特点,成为介导生物被膜构建的优选载体材料。本文对水凝胶、高分子分离膜、聚合物纤维膜及移动床生物膜反应器(MBBR)载体等几大类功能高分子材料促进生物被膜构建及其生物转化应用研究进行综述,以期为相关科研工作者提供参考。

D-阿洛酮糖的生物转化及冷却结晶工艺优化

D-阿洛酮糖作为一种具有多重生理功能的食品添加剂,是近年来的研究热点。为完善D-阿洛酮糖上下游生产工艺,选取3种不同微生物来源的D-阿洛酮糖3-差相异构酶(D-allulose 3-epimerase,DAEase)在大肠杆菌表达宿主BL21(DE3)中进行异源表达,通过对全细胞生物转化工艺的探索和不同重组菌催化能力的分析对比,发现重组表达了来源于多尔氏菌属(Dorea sp.CAG317)的DAEase的全细胞生物转化率达到32.60%。在此基础上对反应液进行色谱分离和纯化,得到高纯度的D-阿洛酮糖料液。对D-阿洛酮糖料液采取冷却结晶法析出晶体,结果显示采用优化后的冷却结晶工艺,D-阿洛酮糖结晶率达到了77.43%,纯度达到了98.70%。该研究为工业化生产D-阿洛酮糖提供重要参考。

黑水虻生物处理餐厨垃圾与剩余污泥的效果

黑水虻生物转化技术可用于餐厨垃圾或剩余污泥的处理,解决其处置和资源化难题。分别考察了餐厨垃圾与剩余污泥在不同混合比例(污泥比例分别为0%、25%、50%、75%、100%)下作为培养底物时的处置转化情况以及黑水虻的生长和重金属富集情况。结果显示:经15 d处理后,不同组别餐厨垃圾和剩余污泥混合物的平均减量率为22.66%~56.16%,平均生物转化率为15.18%~27.84%,且处理后有机废物的恶臭气味消失,处置效果良好。此外,剩余污泥比例低于75%的组别都能保证黑水虻的正常生长,剩余污泥比例为25%和50%组别中,黑水虻的粗蛋白(21.22%、20.50%)和粗脂肪(18.91%、18.50%)含量相较于未添加剩余污泥组(40.75%、37.56%)略低,但其微量元素含量(14.24%、14.59%)相较于未添加剩余污泥组(10.02%)略高,剩余污泥比例为0%和25%的组别中,黑水虻的重金属生物富集系数均在阈值范围内(<1)。未添加剩余污泥培养的黑水虻可用作水生生物饲料,添加剩余污泥培养的黑水虻可作为禽畜饲料添加剂使用,实现固废养殖的黑水虻的资源化利用。

复合菌剂转化褐煤产腐植酸机理研究

以新疆褐煤为转化底物,构建复合菌剂(100 mL菌剂中枯草芽孢杆菌、苏云金芽孢杆菌、米曲霉和微紫青霉菌的体积分数分别为1.5%,1.5%,1.0%,2.5%)作为研究对象,通过工业分析、元素分析、X射线衍射分析、傅立叶红外光谱分析、X射线光电子光谱分析和紫外-可见光光谱分析等方法,研究了复合菌剂转化褐煤前后煤的腐植酸质量分数、元素组成、矿物组成、有机官能团、碳元素赋存形态的变化,以及转化褐煤过程中,复合菌剂和单一微紫青霉产生的锰过氧化物酶、木质素过氧化物酶、漆酶的活性变化。结果表明:经复合菌剂转化后,煤中总腐植酸和可溶性腐植酸质量分数分别由29.75%和6.24%增加到66.41%和33.44%;复合菌剂转化后,煤中灰分质量分数和固定碳质量分数分别由8.91%和55.72%降至8.07%和52.99%,而挥发分质量分数则由38.83%增加至42.36%。元素分析结果表明:经复合菌剂转化后,煤中C元素相对含量由71.56%降至69.93%;H,O,N等元素相对含量均升高,其中N元素相对含量上升最明显,由0.65%升至1.26%。经复合菌剂处理后,煤中无机矿物组成变化不明显,但C—C/C—H官能团和O C—O官能团增加,且部分不饱和C被饱和。微紫青霉产生的锰过氧化物酶、木质素过氧化物酶、漆酶的活性较单一,复合菌剂产生的锰过氧化物酶、木质素过氧化物酶、漆酶的活性均明显提高,其中漆酶活性达到16.09 U/mL。以上结果说明复合菌剂可将褐煤中大分子结构转化生成小分子腐植酸。与单一菌种相比,复合菌剂产生更多的胞外酶有助于腐植酸的产生。

蝇蛆生物转化餐厨残渣对产物特性的影响

昆虫生物转化有机废弃物是缓解饲料蛋白源短缺和生态环境压力的有效手段。受限于养殖工艺复杂,获取的昆虫蛋白和虫粪常存在物料特性均一性低、稳定性差等问题,加之对产物特性影响作用不明,导致市场接受度低而限制其产业化应用。该研究以获取优质蛋白原料和肥料为目的,以预处理餐厨残渣-腐生链生物转化中的过程产物为研究对象,分析蝇蛆生物转化餐厨残渣对蛆虫、虫粪理化特性的影响,并探究重金属、霉菌等有害物质消减规律。研究结果表明:蛆虫幼虫饲喂4 d收获最佳,此时蛆虫蛋白质质量分数超过14.79%,粗脂肪质量分数超过6.80%,蛆虫干粉氨基酸组成基本符合FAO/WHO推荐值,有害微生物和霉菌含量低于微生物饲料添加剂规定的最高允许量,可替代中国饲料原料三级红鱼粉使用。蛆虫对砷、铅、汞、镉、铬等重金属元素的生物富集系数分别为0.08、<0.01、0.17、3.71、0.04,对镉元素的富集能力最强,对铅元素的富集能力最小。经蛆虫生物转化处理后,虫粪中重金属元素质量分数明显降低,分别为0.25、1.50、0.03、<0.01、10.90 mg/kg,在与其他样品有机质含量差异不大的情况下,可作为优质肥料使用。该研究可为蝇蛆生物转化餐厨残渣提供重要的基础数据,为后续蛆虫品质评价、资源筛选及饲料化应用提供理论依据。

餐厨垃圾生物转化效率及其残渣肥料化利用潜力

为明确餐厨垃圾的生物转化效率及其残渣的肥料化利用潜力,分析探讨了通过养殖蝇蛆和黑水虻幼虫降解餐厨垃圾的料虫转化率、养分转化率、残渣理化性质、盐分残留量及养分资源供给能力等。结果表明:蝇蛆和黑水虻幼虫的料虫转化率约10%;蝇蛆对餐厨垃圾的养分转化率在12.53%—29.45%之间,养分转化率高低表现为钾>氮>有机质>磷,而黑水虻幼虫对餐厨垃圾的养分转化率在14.64%—41.94%之间,养分转化率高低表现为钾>磷>氮>有机质;蝇蛆和黑水虻幼虫虫体中氮、磷、钾总含量在12%左右,蛋白质含量分别为58.88%和47.56%。生物转化后残渣pH值接近中性,氮、磷、钾总养分含量>8%、有机质含量>50%,均满足有机肥料标准要求且活性有机质含量较高;残渣中含有少量钠盐和氯离子,应尽量避免长期直接施用带来的潜在风险。