Biological Coal Conversions

Abstract

The discovery in 1982 that microorganisms can interact with, and presumably modify, the chemical structure of coal has focused attention on the potential for the use of microbial cultures or isolated microbial enzymes in coal conversion. Biological processes based on this activity will promote the effective utilization of lowrank coal, which is poorly suited to direct combustion. Research in this area may also support the development of improved biological technologies for the cleaning of highrank coal and/or the treatment of coalderived waste.     

A step-wise discriminant analysis of the effects of long term coal mine drainage and coal dredging on phytoplankton of the Guyandotte River

Phytoplankton was sampled from the lower 60 miles portion of the Guyandotte River where three active coal dredging operations presently exist and five more permits are pending. Comparisons were made with phytoplankton from a similar stretch of the Mud River, a stream of minimal mine drainage and no coal dredges along its entire course.Diatoms were the predominant planktonic algae on both streams. The number of all phytoplankton species was 24% higher for the Mud River than for the Guyandotte River. Equitability and species diversity indices plus the distribution of mine water indicator algae show that the Guyandotte River is heavily polluted with domestic wastes and mine drainage. No correlation could be established for turbidity, specific conductance, or pH and locations of dredging operations, when the data were analyzed for differences among sampling stations.Step-wise discriminant analysis was used to compare the two streams and the biological, physical, and chemical variables. Based on coefficients for canonical variables, conductivity and pH are the two most influential variables in separating the two streams. Analysis of variance indicates that the canonical means of the stations on the Guyandotte River are significantly different from the Mud River stations.     

Isolation of Coal Degrading Fungus from Drilled Core Coal Sample and Effect of Prior Fungal Pretreatment on Chemical Attributes of Extracted Humic Acid

Fungal degradation of low rank coal has appeared as an alternative technique for exploitation of non-fuel options. A fungal isolate, MW1, was isolated and coal sample was subjected to fungal pretreatment. The residual coal was processed for extraction of humic acid for determining the effect of such pretreatment. Extracted humic acid was analyzed on the basis of elemental composition and spectroscopy. Fungal pretreatment caused improvement in oxygen content, E₄/E₆ ratio, and absorption bands related to humic materials. Conclusively, pretreatment resulted in improving chemical attributes of humic acid molecule, thus, warranting supplementary high-tech investigations for the optimization of process upscale.     

Geochemistry Shapes Bacterial Communities and their Metabolic Potentials in Tertiary Coalbed

Culture-dependent and independent approaches were used to understand the microbiota thriving in tertiary coalbed, located in Jammu and Kashmir, India. We observed changes in physicochemical properties of the surface sediment (CM1) and coalbed (CM2) which detailed the influence of environmental factors on the structure and capabilities of bacterial communities. A total of 316 bacterial isolates representing 35 genera were isolated. We noted comparable difference in uncultivable bacterial communities which revealed the predominance of Proteobacteria in both the study sites. Moreover, we observed differential abundance of phyla Actinobacteria (49.6%), Firmicutes (4.2%), and Bacteroidetes (0.8%) in CM1, whereas Actinobacteria (11%), Firmicutes (37.8%), and Bacteroidetes (2.3%) in CM2. Additionally, functional imputations using PICRUSt depicted ～30% higher assemblage of major gene families in CM1 in comparison to CM2. Bacterial communities residing at CM1 were predominantly involved in methane oxidation, whereas CM2 communities found to play a vital process of conversion of coal to biogenic-methane enabling microbes to survive under constraints of high sulfur content, salt precipitation, and low nutrients and also provide clues to understand the potential of methanogenesis.     

煤的预处理对高阶煤微生物溶解的影响

研究了煤的溶胀预处理和氧化预处理对微生物溶煤的影响,以及两种预处理方法处理过的煤样在固态培养基和液态培养基中的溶煤效果。考察了预处理方法、培养基选择、接种量等因素对溶煤作用的影响,得出了溶煤效果较好的适宜条件,并且对微生物溶煤的作用机理做了初步的探讨。     

On Comparison Between Fungal and Bacterial Pretreatment of Coal for Enhanced Biogenic Methane Generation

Owing to better understanding of subsurface geochemical carbon recycling and real-time active methanogenesis in major coal basins around the globe, substantial share of subsurface methane generation is attributed to biogenic origin. Since coal, being complex geopolymer, does not appear to be a favorable microbial substrate, enhancement in biogenic methane yield depends on its degradation into simpler organic substrates. This review puts forward a comparative analysis of fungal and bacterial pretreatment for determining the extent of facilitation in initial degradation of coal, which is still rate limiting step in overall conversion of coal into methane. Primarily, the initial fungal degradation of coal differs from bacterial pretreatment of coal in terms of the nature of released organics. On the basis of previous reports, fungal pretreatment of coal yields, majorly, polyaromatic hydrocarbons, however, bacterial pretreatment results in the generation of mixed organics pool of aromatics and aliphatics. The presence of aliphatics may be prospected for achieving greater conversion rates of coal conversion into methane. Considering the criticality of preliminary degradation of coal and associated issues, the fate of commercial biogenic methane generation would be dictated by the factors pertaining to geological considerations and reservoir geology, chemistry of coal and associated water tables, geomicrobial considerations and economic viability.     

露天煤矿煤粉沉降对矿区周边主要植物的生理影响

随着新疆准东煤田开采的日益加剧,露天开采及运输造成的煤粉尘不仅影响区域大气环境,同时在一定程度上影响周边植物的生理生长。为探讨煤粉尘对周边植物的生理影响,以准东露天煤矿周边人工绿化树种白榆、乡土植物梭梭和柽柳为研究对象,通过野外控制实验,探究覆尘、无尘条件下3种植物的光合生理特性的变化。结果表明:煤粉沉降对3种植物的光合生理均产生了明显影响,覆尘叶片在不同光照强度下净光合速率、气孔导度、蒸腾速率均降低,净光合速率柽柳(18.6%)梭梭(28.3%)白榆(30.7%),气孔导度梭梭(24.1%)柽柳(30.9%)白榆(33.2%),蒸腾速率梭梭(16.7%)白榆(18%)柽柳(39.1%);煤尘对白榆、梭梭的影响主要为非气孔因素,对柽柳的影响有待继续研究。因此露天煤矿开采造成的粉尘会在一定程度上影响周边植物的光合生理过程,抑制其生长,长期排放可能会导致植被覆盖度降低。     

鹤岗矿区生态系统服务价值

生态系统服务与人类福祉有着密切的关系。采用修正后的单位面积生态系统价值当量因子的方法,对鹤岗矿区不同沉陷时期（1993、2000、2013年）9种类型生态系统服务价值进行核算。结果表明：①1993、2000和2013年鹤岗矿区生态系统的总服务价值量分别为2219.21、1025.15和3531.95万元。就生态系统而言,耕地的平均服务价值最高,占平均总价值的189.35%;其次是林地和水域,分别占平均总价值的46.50%和26.83%。②就生态系统服务类别而言,支持功能服务价值最高,平均价值量占平均总价值量的186.67%,其次是调节服务,占45.34%,文化服务占5.73%,供给服务占-137.74%。③1993-2013年,鹤岗矿区生态系统服务价值自西向东递增,这与采煤方向和开采程度差异有关。这种分布趋势主要受由采矿活动引起的土地利用类型、面积及质量变化的影响。④与无考虑空间异质性因素情况相比,1993、2000年鹤岗矿区生态系统服务总价值分别减少了152.96和580.12万元,2013年增加了781.63万元。随煤炭开采,1993-2013年鹤岗矿区采煤沉陷地自然生态环境状况呈现一个由下降到好转的过程。     

湘鄂边境地区茅口组上段褐藻类化石的发现及其意义

本文扼要地叙述湘鄂边境地区下二叠统茅口组上段含碳硅质泥岩(石煤)中褐藻类化石的发现,定名为拟墨角藻(来定种)Quasifucus sp.,并由此推测藻类是形成石煤的一种主要物质成分。     

大柳塔长焰煤中灰分和无机矿物对生物产气的影响

【目的】以不同密度等级大柳塔长焰煤作为产气底物,前期驯化培养厌氧菌群进行生物模拟产气实验,研究不同密度等级煤中的灰分和无机矿物对生物产气的影响。【方法】利用小浮沉将大柳塔长焰煤分成不同密度等级的煤样,采用工业分析、XRD、XRF分析小浮沉处理得到煤样的理化性质,利用这些煤样进行生物产气模拟实验,以甲烷产量作为评价指标,分析不同密度等级煤样中灰分对产气的影响。最后,通过添加几种标准矿物方式比较了煤中无机矿物对生物产气的可能影响。【结果】不同密度等级煤样中灰分对产气量存在一般显著影响(P=0.035),且灰分与甲烷含量呈负相关关系,其灰分中的无机矿物如高岭土、菱铁矿、氧化亚铁镁等的积累对产气有抑制作用。不同矿物配比产气实验证实低含量的粘土矿物促进甲烷的生成,高含量的粘土矿物抑制产气。【结论】不同密度等级煤中的灰分对生物产气存在一般显著的影响,高灰分煤的产气量低,而低灰分煤的产气量高。     

Analysis of low-molecular mass products from biosolubilized coal

Abstract A relatively simple, rapid sample preparation method has been developed for analysis of low-molecular mass compounds present in soluble coal products generated by microbial coal solubilizing agents. Acidification of the sample followed by direct extraction into hexanes is coupled with gas chromatography/mass spectrometry analysis for characterization of the soluble coal products. Characterization of the products can contribute to a more complete understanding of the solubilization processes involved, provide further information as to the structure of coal and identify products of potential commercial value.     

Potential for Aerobic Methane Oxidation in Carboniferous Coal Measures

Carbon (C), geologically sequestered in coal, is gradually released to the atmosphere as CH₄ and CO₂. Recent anthropogenic activity (coal mining) has rapidly increased the rate of C reallocation from coal deposits into the atmosphere, which has deleterious effect on the climate as both gases are effective infrared absorbers. In the current study we demonstrate that the coal bearing sedimentary rocks possess potential of biological methane oxidation. Viable methanotrophic bacteria, capable of methane oxidation at ambient air and a range of methane concentrations were found in coalbearing formations of the Upper Silesian (USCB) and Lublin Coal Basins (LCB). Factors controlling activity of the aerobic methanotrophic bacteria in the deep subsurface such as, depth, methane concentration, available electron acceptors, moisture and nutrients availability were investigated along with paleoenvironmental factors (temperature changes during and after burial and paleohydrological infiltration). The distribution and activity of the methanotrophic bacteria in the deep subsurface were found to be influenced by geological conditions among which evolution of paleotemperatures and paleohydrological conditions play a predominant role. The data presented along with analysis of molecular composition of the coalbed gases in various coal basins worldwide has led to the conclusion that aerobic methanotrophy may be a widespread process, which, to our knowledge, so far has not been included in investigations concerning C cycling in the subsurface.     

煤炭开采对野生植物物种丰富度和物种组成的影响

煤炭开采引发的生态环境破坏早已引起关注,对其破坏机理和修复方法进行研究显得非常重要。本文探讨了煤炭开采对野生植物物种丰富度和物种组成成分的影响。从分布在晋西北地区的338个煤矿中,随机选择16个煤矿作为研究对象,调查了煤炭采空区和非采空区地面的野生植物物种,用Gleason丰富度指数分析了煤矿采空区和非采空区的野生植物物种丰富度差异,同时用Srensen指数分析了煤炭采空区野生植物物种组成成分和非采空区植物物种组成成分的相似性。结果表明:煤炭开采造成了野生植物物种数的减少,采空区的野生物种丰富度明显少于非采空区;煤炭开采也造成了野生植物物种组成成分的变化,采空区和非采空区的野生植物物种组成成分出现明显差异。     

Chemical reactivity of the carbon-centered free radicals and ferrous iron in coals: Role of bioavailable Fe2+ in coal workers' pneumoconiosis

Striking differences in the prevalence of coal workers' pneumoconiosis (CWP) exist between different coal mine regions. The major factors responsible for the observed regional differences in CWP have not yet been identified. In the present study, chemical reactivity of the carbon-centered free radicals in coals and lung tissues, as well as ferrous iron in the coals, were studied by ESR techniques. The ESR spectra clearly demonstrated the presence of at least two types of carbon-centered free radical species, which might respectively attribute to the macromolecular phase and the molecular phase of coal. Grinding produced free radicals in coals. Exposure of freshly ground coal to air for 28 h induced a slight increase of free radicals for most of the coals, and a slight decrease after 4 months' exposure. The lung tissue samples of coal workers deceased of CWP showed similar ESR spectra as coal samples, and these radicals were highly stable in the lung. After incubation of coals with glutathione, hydrogen peroxide, sodium formate or oxygen, the coal sample from the Gardanne mine which has never induced CWP, and thus is the least hazardous coal, showed the most significant change in the carbon-centered free radical concentration. No significant changes were observed among other coals reported to induce CWP. On the other hand, we found that the coals released different amounts of Fe²⁺ in an acidic medium. Interestingly, the prevalence of CWP correlates positively with the released Fe²⁺ content in these coals and with the amount of oxygen radicals produced by the interaction of Fe²⁺ with O₂ in the acidified coal filtrates. Our studies indicate that the carbon-centered free radicals may not be biologically relevant to coal dust-induced pneumoconiosis, whereas the acid soluble Fe²⁺, which may be dissolved in the phagolysosomes of macrophages, can then lead to Fe²⁺-induced oxidative stress and eventual CWP development.     

Energy analysis of the coal fuel cycle in an appalachian coal county

Preliminary results from an energy analysis of the coal fuel cycle in an Appalachian coal county have provided a systematic assessment of hidden energy subsidies in extraction, transport, processing, and combustion. Current results indicate that the system operates at an annual energy deficit of approximately 350 × 10¹⁰ kcal. A major loss is depletion of the coal resource base by use of inefficient mining techniques. Although of smaller magnitude, reductions in work force and community productivity from occupational accidents, disease, and road maintenance requirements for transport also appear to be significant. Further assessment is needed to verify assumptions and characterize additional data bases.     

芦岭煤田微生物群落结构和生物成因气的产甲烷类型研究

【目的】揭示芦岭煤田微生物群落组成,并分析其潜在的产甲烷类型及产甲烷途径。【方法】采集芦岭煤田的煤层气样品和产出水样品,分别分析样品的地球化学性质特征;利用Illumina HiSeq高通量测序技术分析产出水中的微生物群落结构;采用添加不同底物的厌氧培养实验进一步证实芦岭煤田生物成因气的产甲烷类型。【结果】该地区煤层气为生物成因和热成因的混合成因气;古菌16S rRNA基因分析表明在产出水中含有乙酸营养型、氢营养型和甲基营养型的产甲烷菌。丰度较高的细菌具有降解煤中芳香族和纤维素衍生化合物的潜力。厌氧富集培养结果表明,添加乙酸盐、甲酸盐、H2+CO2为底物的矿井水样均有明显的甲烷产生。【结论】芦岭煤田具有丰富的生物多样性,该地区同时存在三种产甲烷类型。本研究为利用微生物技术提高煤层气的采收率,实现煤层气的可持续开采提供科学依据。     

美国煤矿废弃地的生态修复

在对美国煤矿废弃地生态修复项目实地考察的基础上,结合相关文献资料,介绍了其煤矿废弃地生态修复的管理体系、资金来源及使用\\技术路线及保障措施。结合实例介绍了美国煤矿废弃地生态修复的工程措施,并重点介绍了"师法自然生态修复法"的新理念及其指导下的生态修复设计和生态修复工程建设。"师法自然生态修复法"是基于地形、地貌、水文、气象、气候等条件,模拟自然的生态修复过程。"师法自然生态修复法"将会对我国的生态修复产生积极而深远的影响。     

Solubilization of coal by biosurfactant derived from candida bombicola

Partial solubilization of North Dakota Beulah Zap lignite coal was demonstrated using crude biosurfactant preparations from glucose‐based stationary‐phase cultures of Candida bombicola. Results suggest that biosurfactant activity by this organism is a minor mechanism by which portions of coal can be biologically solubilized.     

Enzymatic Properties of Alkaline Proteinase from Aspergillus candidus

Some enzymatic properties were examined with the purified alkaline proteinase from Aspergillus candidus. The isoelectric point was determined to be 4.9 by polyacrylamide gel disc electrofocusing. The optimum pH for milk casein was around 11.0 to 11.5 at 30°C. The maximum activity was found at 47°C at pH 7.0 for 10 min. The enzyme was stable between pH 5.0 and 9.0 at 30°C and most stable at pH 6.0 at 50°C. The enzyme activity over 95% remained at 40°C, but was almost completely lost at 60°C for 10 min. Calcium ions protected the enzyme from heat denaturation to some extent. No metal ions examined showed stimulatory effect and Hg²⁺ ions inhibited the enzyme. The enzyme was also inhibited by potato inhibitor and diisopropylphosphorofluoridate, but not by metal chelating agent or sulfhydryl reagents. A. candidus alkaline proteinase exhibited immunological cross-reacting properties similar to those of alkaline proteinases of A. sojae and A. oryzae.     

Two new late Carboniferous Neuropteris species (Medullosales) from Saarland, Germany and their palaeobiogeographical significance

Two new species ( Neuropteris terminiscus and N. kneuperi ) are described from the Bolsovian ('Westphalian C') of Saarland. N. terminiscus had previously been misidentified as Paripteris pseudograndinioides , but the pinnae are clearly imparipinnate and thus cannot belong to that morphogenus. N. kneuperi had previously been misidentified as Neuropteris obliqua and N. heterophylla , both which appear to be absent from Saar-Lorraine. This is considered further evidence of the distinctive nature of the Westphalian vegetation of the Saar-Lorraine Basin, especially among the seed-plants.  © 2002 The Linnean Society of London , Botanical Journal of the Linnean Society , 2002, 139 , 193–205.