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.

Artificial bioconversion of carbon dioxide

CO2 is not only the most important greenhouse gas but also an important resource of elemental carbon and oxygen.From the perspective of resource and energy strategy,the conversion of CO2 to chemicals driven by renewable energy is of significance,since it can not only reduce carbon emission by the utilization of CO2 as feedstock but also store low-grade renewable energy as high energy density chemical energy.Although studies on photoelectrocatalytic reduction of CO2 using renewable energy are increasing,artificial bioconversion of CO2 as an important novel pathway to synthesize chemicals has attracted more and more attention.By simulating the natural photosynthesis process of plants and microorganisms,the artificial bioconversion of CO2 can efficiently synthesize chemicals via a designed and constructed artificial photosynthesis system.This review focuses on the recent advancements in artificial bioreduction of CO2,including the key techniques,and artificial biosynthesis of compounds with different carbon numbers.On the basis of the aforementioned discussions,we present the prospects for further development of artificial bioconversion of CO2 to chemicals.

Optimization of Two-species Whole-cell Immobilization System Constructed with Marine-derived Fungi and Its Biological Degradation Ability

Mycelia pellet formed spontaneously in the process of cultivation was exploited as a biological carrier for whole-cell immobilization due to its unique structural characteristic. An innovative two-species whole-cell im- mobilization system was achieved by inoculating the marine-derived fungus Pestalotiopsis sp. J63 spores into cul- ture medium containing another fungus Penicillium janthinellum P1 pre-grown mycelia pellets for 2 days without any pretreatment. In order to evaluate the biological degradation capacity of this novel constructed immobilization system, the immobilized pellets were applied to treat paper mill effluent and decolorize dye Azure B. The use of the constructed immobilization system in the effluent resulted in successful and rapid biodegradation of numerous in- soluble fine fibers. The optimum conditions of immobilized procedure for maximum biodegradation capacity were determined using orthogonal design with biomass of P1 pellets 10 g （wet mass）, concentration of J63 spore 2x109 mlq, and immobilization time 2 d. The results demonstrate that immobilized pellets have more than 99% biodegradation capacity in a ten-hour treatment process. The kinetics of biodegradation fits the Michaelis-Menten equation well. Besides, the decolorization capability of immobilized pellets is more superior than that of P1 mycelia pellets. Overall, the present study offers a simple and reproducible way to construct a two-species whole-cell immobiliza- tion system for sewage treatment.

Whole-cell recordings of calcium and potassium currents in acutely isolated smooth muscle cells

AIM： To record calcium and potassium currents in acutely isolated smooth muscle cells of mesenteric arterial branches in rats. METHODS： Smooth muscle cells were freshly isolated by collagenase digest and mechanical trituration with polished pipettes. Patch clamp technique in whole-cell mode was employed to record calcium and potassium currents. RESULTS： The procedure dissociated smooth muscle cells without impairing the electrophysiological characteristics of the cells. The voltage-gated Ca^2＋ and potassium currents were successfully recorded using whole-cell patch clamp configuration. CONCLUSION： The method dissociates smooth muscle cells from rat mesenteric arterial branches. Voltage-gated channel currents can be recorded in this preparation.

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 the stability 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%.

Whole-cell recording of the robust nucleus of the arcopallium neurons in the adult zebra finch

BACKGROUND： Electrophysiological properties of the song nucleus have been revealed using conventional techniques, such as intracellular and extracellular recording. Research concerning the neuronal activation properties and regulations of the song system at the cellular and ion channel level may help reveal the neural mechanism of song learning. OBJECTIVE： To perform whole-cell recording of robust nucleus of the arcopallium （RA） neurons in brain slices from adult zebra finches （Taeniopygia guttata） and observe the action potential, sodium/potassium current and the spontaneous postsynaptic current of RA neurons. DESIGN, TIME AND SETTING： Self-controlled, neuroelectrophysiological experiment. The study was performed at the Neurophysiology Laboratory of South China Normal University from April to September 2008. MATERIALS： Flaming/Brown puller P-97 was purchased from Sutter Ins, USA; Axopatch 700B amplifier and Digidata 1332A converter were purchased from Axon Instrument, USA; pClamp software was provided by Axon Instrument, USA. METHODS： RA neurons were acutely isolated from 24 healthy male zebra finches. The action potential, voltage-gate sodium/potassium current and spontaneous postsynaptic current were recorded by whole-cell recording technology. Data were analyzed by pClamp software. MAIN OUTCOME MEASURES： The amplitude and frequency of the action potential, and the amplitude of the voltage-dependent and spontaneous postsynaptic currents, were measured. RESULTS： （1） Testing of action potential： Cells exhibited a stable current-voltage relationship following a series of hyperpolarization stepped currents, and an action potential was triggered by the spike threshold. All the recorded cells displayed repetitive firing following depolarizing current injection, with a frequency beyond 100 Hz. （2） Testing of voltage-gate currents： The inward and outward whole-cell currents were observed after a series of depolarizing voltage steps. The inward current disappeared following the application of tetrodotoxin and the outward current was significantly inhibited by application of 4-aminopyfidione and tetraethylammonium chloride. （3） Testing of spontaneous postsynaptic current： The majority of recorded cells exhibited an inward synaptic current when the membrane potential was maintained at -60 mV, with some cells exhibiting a robustly outward current when the membrane potential was maintained at -30 mV. Tetrodotoxin was unable to affect the spontaneous postsynaptic current. Following application of bicuculline [y-aminobutyric acid （A） receptor antagonist] and high concentration kynurenic acid （ionotropic glutamate receptor antagonist）, the inward and outward currents were completely inhibited. CONCLUSION： Under these experimental conditions, the action potential, sodium/potassium current and spontaneous postsynaptic current were recorded successfully in RA neurons. This indicates that the cells preserved relatively intact synaptic connections and normal physiological activity, which is required for investigating ion channels. The inward and outward whole-cell currents were sodium and potassium currents, respectively. The postsynaptic y-aminobutyric acid （A） receptors and ionotropic glutamate receptors contributed to the spontaneous postsynaptic current.

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.

Evaluation of Nutrient Digestion of Tamarind Seeds Spontaneous Bioconversion in Local Timor Pigs

Tamarind seeds are one of the waste crops that were usually given to pigs and the use of spontaneous bioconversion can increase digestibility. The research objective was to evaluate nutrient digestibility spontaneous bioconversion of tamarind seeds at Timor Local Pig. The study was conducted from May to July 2017 in the Laboratory of Animal Production and Reproduction of Kupang State Agricultural Polytechnic. The study used local male pigs grower phase of 3-4 months old aged and used a randomized block design with four treatments and five replications, namely R0 = ration without bioconversion spontaneous tamarind seeds, R1 = rations containing 10% bioconversion spontaneous tamarind seeds, R2 = ration containing 20% bioconversion spontaneous tamarind seeds, R3 = ration containing 30% bioconversion spontaneous tamarind seeds. The variables measured were dry matter digestibility, crude protein, crude fiber, and tannins. The results showed that spontaneous bioconversion of tamarind seeds affected significantly （p 〈 0.01） on dry matter digestibility, crude protein, ether extract, ash, and tannin digestibility but no effect （p 〉 0.05） on crude fiber digestibility. It was concluded that the use of tamarind seeds spontaneous bioconversion in livestock rations of local pigs Timor should be as much as 20%.

Whole-cell recordings of voltage-gated Calcium,Potassium and Sodium currents in acutely isolated hippocampal pyramidal neurons

Objective：To record Calcium, Potassium and Sodium currents in acutely isolated hippocampal pyramidal neurons. Methods：Hippocampal CA3 neurons were freshly isolated by 1 mg protease/3 ml SES and mechanical trituration with polished pipettes of progressively smaller tip diameters. Patch clamp technique in whole-cell mode was employed to record voltage-gated channel currents. Results：The procedure dissociated hippocampal neurons, preserving apical dendrites and several basal dendrites, without impairing the electrical characteristics of the neurons. Whole-cell patch clamp configuration was successfully used to record voltage-gated Ca^2＋ currents, delayed rectifier K^＋ current and voltage-gated Na^＋ currents. Conclusion：Protease combined with mechanical trituration may be used for the dissociation of neurons from rat hippocampus. Voltage-gated channels currents could be recorded using a patch clamp technique.

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.

出芽短梗霉LHS-m022黑色素葡聚糖的发酵影响因素和生物活性

为探索出芽短梗霉LHS-m022黑色素多糖的发酵影响因素和生物活性,采用菌种发酵、分离提取及生物检测方法,对发酵液性质、产物收率、生物转化率及生物活性进行测定分析。结果表明,LHS-m022黑色素多糖发酵的最佳碳、氮源分别是蔗糖和胰酪蛋白胨,蔗糖最佳浓度为60 g/L;发酵培养基中诱导剂L-多巴的最适添加量为2.0 g/L,发酵液黑变活性和生物转化率分别是2.481和71.93%;细胞通透剂鼠李糖脂的最适添加量是0.021μL/L,发酵液黑变活性和生物转化率分别高达2.794和73.9%。全波长扫描、FTIR与HPLC分析表明,WAI为黑色素,PsB为黑色素葡聚糖结构。研究结果揭示,粗黑色素葡聚糖样品经121℃以上高温处理,仍然得到95.37%的絮凝率。采用1.50和2.00 g/L的样品浓度进行检测,分别得到99.55%的羟自由基清除活性和99.00%的抗氧化活性。

黑曲霉全细胞催化甘蔗糖蜜生产低聚果糖研究

为了探明黑曲霉全细胞催化产低聚果糖(FOS)的变化规律,本研究采用单因素实验,HPLC检测FOS含量。结果表明:全细胞催化产FOS单因素优化条件为柠檬酸缓冲液、pH值6.0、湿菌丝体种龄48 h、全细胞催化剂浓度120 g/L、底物蔗糖浓度400 g/L、转化温度50℃。在此生产工艺条件下,低聚果糖的产量达到了201.23 g/L,超过目前报道糖蜜生产低聚果糖160 g/L,达到了较高的生产水平。

不同促长灭菌助剂对代料香菇生产的影响

为明确不同促长灭菌助剂对代料香菇生产的影响,筛选出适合代料香菇量产的助剂种类,采用对比分析法研究了不同促长灭菌助剂对代料香菇接种成活率、鲜菇产量(生物转化率)、营养成分、农药残留、重金属含量以及相对利润的差异。研究结果显示,使用0.2%增菇酶和0.2%菇力源肽对接种成活率影响较高,分别达到86.07%、84.92%,显著高于对照和其他处理;0.2%菇力源肽处理的鲜菇产量及生物转化率最高,单筒平均产量为0.98 kg,生物转化率为53.91%;各处理间鲜菇营养成分、农药残留、重金属含量差异不显著,检测结果全部符合国家标准;0.2%增菇酶和0.2%菇力源肽处理相对利润总值分别为1071.6元、1112.4元,高于其他处理,结合TOPSIS综合评价结果,0.2%菇力源肽为最优助长灭菌助剂。

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。

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。

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.