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Mosaic loss of chromosome Y (mLOY) in leukocytes has attracted much attention as an emerging biomarker of aging and aging-related diseases. We evaluated the usefulness of saliva for mLOY analysis and showed that saliva-derived mLOY is significantly associated with aging and increased physical activity, but not with smoking. While these data support the robust association between saliva-derived mLOY and aging, caution is required when comparing data from saliva-derived and blood-derived mLOY. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fly-ash leachate doubled CO production via catalyzed CO 2 gasification at 800 °C. • CO 2 increased specific surface area and porosity of the pyrolysis biochar. • Fly-ash leachate enhanced wettability and electroactive surface area of biochar. • CO 2 and ash-amended biochar significantly shortened the digestion time of waste oil. Biomass-derived biochar is attracting growing interest as an effective additive for anaerobic digestion (AD). To improve energy yield and digestion performance through an integrated process of biochar production and AD, biochar upgrading using biomass fly ash leachate as a sustainable metal catalyst was investigated. The results indicate that the bark soaked in the leachate improved the pyrolysis reactivity of biomass with CO 2 and reduced the temperature at which the reaction rate reached its maximum from 943 °C to 801 °C. This resulted in a doubling of CO production during CO 2 -assisted pyrolysis at 800 °C. In addition, the combined use of fly ash leachate and CO 2 in bark pyrolysis improved not only the porosity of the resulting biochar but also its wettability and liming potential. Moreover, biochar amended with fly ash leachate and CO 2 significantly reduced the lag time in the anaerobic digestion of grease trap waste. [ABSTRACT FROM AUTHOR]

This study investigated early stages of biofilm formation from sieved fine particles of anaerobic granules in the presence of various cationic substances using a quartz crystal sensor to improve biofilm formation in the anaerobic treatment of saline wastewater. The biomass attached on the sensor was greatly increased with Ca within the low range (8–16 mM), which was not affected by 50 mM of Na. However, the positive effect of 16 mM of Ca was strongly reduced in the co-presence of Ca and Na when Na concentrations were in the range from 25 to 150 mM because Ca may compete with Na for the limited binding sites in biofilm. The addition of cationic polymer at 150 mM of Na increased biomass adhesion by several folds at only 10–80 mg/L compared to the addition of 16 mM of Ca. Moreover, no methanogenic inhibition was presented below the polymer content of 20 mg/L. [ABSTRACT FROM AUTHOR]

In order to boost the economics of biogas utilization in those small facilities for food waste (FW) digestion, proximate grease trap waste (GTW) was employed to co-digest with FW. A bench-scale continuous stirred tank reactor was set up and operated at mesophilic temperature to investigate the co-digestion limit and lipid/long chain fatty acid (LCFA) conversion by increasing lipid loading stepwise. Mixing FW and GTW at lipid/total solids (TS) 55%, where the lipid loading was 1.61 g/(L·d), was proved to be appropriate, and the maximum methane yield reached 68% higher than the mono-digestion of FW, with a similar lipid reduction at approximately 90%. In addition, since acetic acid accumulation above 100 mg HAc/L had been observed under the optimal loading, the threshold value for anaerobic co-digestion of FW and GTW was confined to the lipid loading around 1.61 g/(L·d). The rapid recovery strategy of mixing the inhibited sludge with fresh inoculum at 1:4 (V/V) took effect after process failure resulted from further increasing lipid/TS to 70%. Lipid/LCFA concentrations in the effluent rose with the increased lipid loading, while palmitic acid accounted for the most percentage among the residual LCFAs, as high as 73.7% at lipid/TS 55%. Acetoclastic methanogens played an important role in accelerating process conversion, due to the fact that raising GTW addition led to the increased methanogenic activity, with a value of 26.9 mL-CH 4 /(g-VS·d) at the optimal loading. [ABSTRACT FROM AUTHOR]

The effects of organic loading rate (OLR) and operating temperature on the performance of siphon-driven self-agitated anaerobic reactor (SDSAR) in an on-site food waste (FW) treatment system were investigated. Two reactors were operated in parallel for comparison between mesophilic condition (35 ± 1 °C) and thermophilic condition (55 ± 1 °C). With HRT above 15 d and OLR below 4.8 kg-COD/m 3 /d, relatively high COD removal in the range of 84.5–92.3% was obtained in both reactors. The limits of the loading capacity of the mesophilic SDSAR were observed when OLR was further increased to 7.3 kg-COD/m 3 /d by shortening HRT. Blocking and gas production reduction occurred and COD removal decreased sharply to 75.9% in the mesophilic reactor. In contrast, the thermophilic reactor can be operated at this OLR with satisfactory COD removal and biogas production. Furthermore, at OLR of 14.4 kg-COD/m 3 /d, the COD removal was maintained as high as 87.5% in the thermophilic reactor. The conversion of influent COD to methane was maintained above 80% at all the OLR applied in both reactors. The results of this study indicated that thermophilic SDSAR is preferred for the on-site FW treatment. [ABSTRACT FROM AUTHOR]

This study investigated the effect of combination of pretreatment methods such as ultra-sonication and electrolysis for the minimum energy input to recover the maximal carbohydrate and solubilization (in terms of sCOD) from mixed microalgae biomass. The composition of the soluble chemical oxygen demand (COD), protein, carbohydrate revealed that the hydrolysis method had showed positive impact on the increasing quantity and thus enhanced methane yields. As a result, the combination of these 2 pretreatments showed the greatest yield of soluble protein and carbohydrate as 279 and 309 mg/L, which is the recovery of nearly 85 and 90% in terms of total content of them. BMP tests showed peak methane production yield of 257 mL/g VS added , for the hydrolysate of combined pretreatment as compared to the control experiment of 138 mL/g VS added. [ABSTRACT FROM AUTHOR]

Biohydrogen production from lignocellulosic biomass (LCB) is an active research area. Several workers have tested a number of substrates under different operational conditions and brought forward the many positive process performance features and identified the main sources of inhibition. This review analyzes selected fermentative biohydrogen production processes by revisiting the core biohydrogen production performances in terms of gas production rates and yields and equally addresses the options for process enhancement by the application of through pretreatment methods and detoxification of process inhibitors. In addition, the issues related to continuous biohydrogen operation in different reactor configurations are highlighted. Lastly, future avenues of research which may be engendered and engineered to enhance the biohydrogen generation and process biokinetics are discussed. This review intends to provide the fundamental understanding of biohydrogen production and provides a perspective on future developments in this area of applied research. [ABSTRACT FROM AUTHOR]

Long chain fatty acids (LCFAs) are the intermediates from anaerobic digestion of lipid-rich waste, and limit the digestion even at millimolar concentrations. The digestion characteristics of unsaturated and saturated LCFAs, represented by oleic and palmitic acids, are investigated. Consequently, palmitic acid was far less inhibitory than oleic acid. Palmitic acid was almost not degraded before 20 d, and the subsequent methane was also produced at a lower rate, below a half for oleic acid. The heterogeneity between methanogenic sludge and palmitic acid was the likely reason. The abatement methods of soluble calcium addition and bentonite addition were synchronously compared to evaluate the effectiveness in upgrading the anaerobic performance of LCFAs. Limited improvement for palmitic digestion was observed. In contrast, calcium addition was more effective than bentonite addition in shortening lag-phase time, reducing reagent dosage, and decreasing solid concentration of digestate. Delaying the addition time of calcium salt had a negative effect on the abating the inhibition caused by oleic acid. The methanogenic activity decreased exponentially with the addition time of calcium salt, following the equation: Methanogenic activity (%) = 91.0e −t/942.5 +24.8e −t/6.2 −15.9. [ABSTRACT FROM AUTHOR]

Restaurant grease trap waste (GTW) is a potentially feasible energy source that can be used as an alternative to liquid fossil fuels and natural gas. However, GTW must be collected from many different resources for energy production because restaurants in Japan only produce an average of 486 kg GTW per year. This study investigated the variation in oil properties and methane generation potential of 44 GTW samples from 13 types of restaurants during different seasons. The GTW samples had high variation in oil content and oil properties. Biofuel oil was extracted from most GTW samples at a high efficiency (more than 80 wt%). In contrast, the methane yield varied little among de-oiled GTW samples. All types of GTWs are potential sources of biomethane generation. GTW samples are classified into five major oil property clusters according to solid chemical stability. Oil properties depend little on the season and heavily on the restaurant type. [ABSTRACT FROM AUTHOR]

The use of liquid fraction of pressed municipal solid waste (LPW) for hydrogen production was evaluated via electrohydrogenesis in a single-chamber microbial electrolysis cell (MEC). The highest hydrogen production (0.38 ± 0.09 m 3 m −3 d −1 and 30.94 ± 7.03 mmol g −1 COD added ) was achieved at an applied voltage of 3.0 V and pH 5.5, increasing by 2.17-fold than those done at the same voltage without pH adjustment (pH 7.0). Electrohydrogenesis was accomplished by anodic oxidation of fermentative end-products (i.e. acetate, as well as propionate and butyrate after their acetification), with overall hydrogen recovery of 49.5 ± 11.3% of COD added . These results affirm for the first time that electrohydrogenesis can be a noteworthy alternative for hydrogen recovery from LPW and simultaneous organics removal. Electrohydrogenesis efficiency of this system has potential to improve provided that electron recycling, electromethanogenesis and deposition of non-conductive aggregates on cathode surface, etc. are effectively controlled. [ABSTRACT FROM AUTHOR]

Dosage of nutrients for anaerobic digestion is essential to maintain their treatment performance. Kitchen waste generally contains low concentrations of nutrients, especially metals. However, for de-oiled grease trap waste (GTW), such a kitchen waste, little data are available in terms of nutrient supplementation to enhance anaerobic digestion. In order to determine the effects of different concentrations of metals on anaerobic digestion of de-oiled GTW and the optimal metal dosages, a step-wise batch experiment for four metals, potassium (K), magnesium (Mg), zinc (Zn), and manganese (Mn), with a blank test as control, was conducted to gradually lower the concentrations of metals. The supplementation of individual K, Mg, Zn, and Mn did have effects on enhancing the process to different extents. The appropriate concentrations of investigated metals for accelerating anaerobic digestion of de-oiled GTW were as follows: K 720.2mg/g COD, Mg 47.3mg/g COD, Zn 1.1mg/g COD, and Mn 11.6mg/g COD, respectively. The requirements of four metals obtained in the experiment agreed with the results of theoretical calculations. [ABSTRACT FROM AUTHOR]

Renewable energy recovery from submerged aquatic plants such as Egeria densa ( E. densa ) via continuous anaerobic digestion (AD) represents a bottleneck because of process instability. Here, a single-chamber membrane-free microbial electrolysis cell (MEC) equipped with a pair of Ti/RuO 2 mesh electrodes (i.e. the combined MEC-AD system) was implemented at different applied voltages (0–1.0 V) to evaluate the potential effects of bioelectrochemical stimulation on methane production and process stability of E. densa fermentation. The application of MEC effectively stabilized E. densa fermentation and upgraded overall process performance, especially solid matters removal. E. densa AD process was operated steadily throughout bioelectrochemical process without any signs of imbalance. The solubilization-removal of solid matters and methane conversion efficiency gradually increased with increasing applied voltage, with an average methane yield of approximately 248.2 ± 21.0 mL L −1 d −1 at 1.0 V. Whereas, the stability of the process became worse immediately once the external power was removed, with weaken solid matters removal along with methane output, evidencing the favorable and indispensable role in maintaining process stability. The stabilizing effect was further quantitatively demonstrated by statistical analysis using standard deviation (SD), coefficient of variance (CV) and box-plots. The syntrophic and win–win interactions between fermenting bacteria and electroactive bacteria might have contributed to the improved process stability and bioenergy recovery. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the feasibility of co-digesting food waste (FW) and de-oiled grease trap waste (GTW) to improve the biogas production. A lab-scale mesophilic digester (MD), a temperature-phased anaerobic digester (TPAD) and a TPAD with recycling (TPAD-R) were synchronously operated under mono-digestion (FW) and co-digestion (FW + de-oiled GTW). Co-digestion increased the biogas yield by 19% in the MD and TPAD-R, with a biogas yield of 0.60 L/g VS added. Specific methanogenic activity in the TPAD-R was much higher than that in the MD. In addition to methane, hydrogen at a yield of approximately 1 mol/mol hexose was produced in the TPAD-R. Alkalinity was consumed more in the co-digestion than in mono-digestion. Co-digestion resulted in more lipid accumulation in each digester. The MD favored the degradation of lipid and conversion of long-chain fatty acids more than the TPAD and TPAD-R. [ABSTRACT FROM AUTHOR]

Anaerobic digestion is an effective technology to recover energy from oily food waste. A single-stage system and temperature-phased two-stage systems with and without recycle for anaerobic digestion of oily food waste were constructed to compare the operation performances. The synchronous operation indicated the similar ability to produce methane in the three systems, with a methane yield of 0.44 L/g VS added . The pH drop to less than 4.0 in the first stage of two-stage system without recycle resulted in poor hydrolysis, and methane or hydrogen was not produced in this stage. Alkalinity supplement from the second stage of two-stage system with recycle improved pH in the first stage to 5.4. Consequently, 35.3% of the particulate COD in the influent was reduced in the first stage of two-stage system with recycle according to a COD mass balance, and hydrogen was produced with a percentage of 31.7%, accordingly. Similar solids and organic matter were removed in the single-stage system and two-stage system without recycle. More lipid degradation and the conversion of long-chain fatty acids were achieved in the single-stage system. Recycling was proved to be effective in promoting the conversion of unsaturated long-chain fatty acids into saturated fatty acids in the two-stage system. [ABSTRACT FROM AUTHOR]

De-oiled grease trap waste (GTW) could be a feasible substrate for anaerobic digestion. However, due to high concentration of lipid, the long-chain fatty acid (LCFA), as an intermediate in the anaerobic lipid degradation, easily inhibits the anaerobic digestion, resulting in long recovery period. Four recovery strategies: bentonite addition, water dilution, mixing with low LCFA substrate and mixing with inocula, with control test as comparison, were employed in order to accelerate the recovery process of mesophilic anaerobic sludge. Adding bentonite, water dilution with 80% mixing ratio and mixing with active inocula achieved shortening of the recovery process. The whole recovery time took approximately 3.5 months for the control test, as calculated from the beginning to the end of the lag time after de-oiled GTW was re-added as F/I ratio of 0.4. At least 10 g l −1 of bentonite addition was necessary for the fast recovery of the inhibited sludge, with the whole recovery time one month shorter than the control test. 1.5 months could be saved for the whole recovery process when the strategy of water dilution with 80% mixing ratio was considered. The more inocula were mixed with the inhibited sludge, the more the recovery period was lessened. For the strategy of mixing with inocula with the mixing ratio 80%, only 20 days were needed for the whole recovery process. [ABSTRACT FROM AUTHOR]

Samples taken from the full-scale and lab-scale anaerobic digesters feeding with different organic solid waste were investigated with assessment of the substrate effects. To understand the substrate effects on the microbial community diversity, heterogeneity, and functional structure, twelve samples were analyzed by constructing 16S rRNA gene clone libraries and statistical analysis. Microbial diversity varied according to substrate types and operating parameters. With acetoclastic methanogen of genus Methanosaeta predominated in full scale and Methanosarcina predominated in the lab-scale digesters, a significant difference archaeal communities were found. Principal component analysis clearly indicates that both bacterial and archaeal communities create independent clusters according to substrate types. However, the relationship between acetogenic bacteria and the acetoclastic methanogens had a similar variation tends in most of full-scale and lab-scale reactors. Canonical correlation analysis and variance partitioning analysis implied that bacterial and archaeal community variations were significantly affected by substrate and the operation conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar produced at different temperatures and with/without K 2 CO 3. • K 2 CO 3 improved surface area, hydrophilicity, and conductivity of biochar. • Anaerobic degradation rate of palmitic acid not improved by normal biochar. • K 2 CO 3 -activated biochar produced at 800 °C accelerated palmitic acid degradation. Engineered biochar production and utilization in anaerobic digestion (AD) potentially overcome its limited application to the treatment of slowly degradable or inhibitory substrates. Here an attempt was made to develop an optimized biochar production procedure for use in AD to stimulate palmitic acid biodegradation via direct interspecies electron transfer (DIET). The electrical conductivity of biochar was greatly increased with an elevated pyrolysis temperature and K 2 CO 3 activation, and the conductivity reached a comparable level (0.6–1.4 S/cm) to that of carbon black at 800 °C. In addition, the K 2 CO 3 activation greatly improved biochar wettability. When using K 2 CO 3 -activated biochar produced at 800 °C, the maximum methane production rate from palmitic acid was 1.3 times that of a control without biochar addition. [ABSTRACT FROM AUTHOR]

To better understand the underlying mechanisms for methane bioelectrosynthesis, a two-chamber MECs containing a carbon biocathode was developed and studied. Methane production substantially increased with increasing cathode potential. Considerable methane yield was achieved at a poised potential of −0.9 V (vs. Ag/AgCl), reaching 2.30 ± 0.34 mL after 5 h of operation with a faradaic efficiency of 24.2 ± 4.7%. Confirmatory tests done at 0.9 V by switching the type of flushed substrates (CO 2 /N 2 ) or the electrical exposure modes (ON/OFF) demonstrated that cathode serving as an electron donor was the vital driving force for methanogenesis occurring at microbe–electrode surface. Fluorescence in situ hybridization reveled Methanobacteriaceae (particularly Methanobacterium ) was the predominant methanogens, supporting the mechanisms of direct electron transfer between cell-electrode. Additionally, the analysis of scanning electron microscope confirmed that the multiple pathways of electron transfer, including direct cathode-to-cell, interspecies exchange and semi-conductive conduits all together ensured the successful electromethanogenesis process. [ABSTRACT FROM AUTHOR]

An effective way for restaurant grease trap waste (GTW) treatment to generate fuel oil and methane by the combination of physiological and biological processes was investigated. The heat-driven extraction could provide a high purity oil equivalent to an A-grade fuel oil of Japanese industrial standard with 81–93 wt% of extraction efficiency. A post-extracted residue was treated as an anaerobic digestion feedstock, and however, an inhibitory effect of long chain fatty acid (LCFA) was still a barrier for high-rate digestion. From the semi-continuous experiment fed with the residual sludge as a single substrate, it can be concluded that the continuous addition of calcium into the reactor contributed to reducing LCFA inhibition, resulting in the long-term stable operation over one year. Furthermore, the anaerobic reactor performed well with 70–80% of COD reduction and methane productivity under an organic loading rate up to 5.3 g-COD/L/d. [ABSTRACT FROM AUTHOR]

The effect of mixing by siphon flow on anaerobic digestion, sludge distribution and microbial community were examined in parallel experiments using a siphon-mixed reactor (SMR), an unmixed reactor (UMR) and a continuously mixed reactor (CMR). The SMR performed well without the accumulation of fatty acids under COD loading rates varying from 3 to 18 kg/m3/day, while the UMR was totally acidified when the loading rate increased to 10 kg/m3/day. The methane yield of the SMR was at least 10% higher than that of the UMR, and comparable to that of the CMR. Furthermore, the SMR was found to markedly improve the dispersion of solids and reduce deposit formation compared to the UMR. Besides, during stable operation, the fatty acids level in the effluent of the SMR and UMR was lower than that in the CMR, and the archaeal community structure of the SMR was similar to that of the UMR. [ABSTRACT FROM AUTHOR]

Biological desulfurization using a bubble column reactor was investigated in a continuous biogas treatment. Rapid biogas circulation between the digester and the bubble column for biological desulfurization was used to stimulate the gas-liquid mass transfer of H2S. A positive correlation between the biogas circulation rate and H2S removal rate was observed. Moreover, the increase in the circulation rate stimulated the O2 mass transfer, eventually translating into an increase in sulfate production from the oxidation of H2S. Throughout the continuous experiment, the reactor retained sufficient levels of sulfide-oxidizing bacteria. A comparison of the results of the continuous biogas treatment and batch tests suggests that the gas-liquid mass transfer rate of H2S was the rate-limiting step in the biological desulfurization in the reactor, indicating that the mass transfer efficiency of H2S needs to be improved to enhance the desulfurization performance. [ABSTRACT FROM AUTHOR]

Abstract: Municipal solid wastes (MSW) collected in Kyoto city were carefully separated, and the waste-type proportion in MSW was surveyed. A hydrogen/methane fermentation batch experiment was conducted under thermophilic condition using twenty different types of MSW components. Biodegradable wastes in the MSW almost consist of vegetable kitchen waste, and the characteristics of hydrogen and methane fermentation of MSW were similar to that of vegetable kitchen waste. Hydrogen production per g VS added was considerably positively correlated with easily degradable carbohydrates concentration and negatively correlated with cellulosic materials concentration. The various feedstocks could be classified into four groups according to nutrient composition (protein, fat, cellulosic materials and easily degradable carbohydrates), and the feedstocks belonging to carbohydrates rich group showed higher hydrogen yields than the other feedstocks. Rough hydrogen yield could be easily predicted by concentration of easily degradable carbohydrates. [Copyright &y& Elsevier]

Abstract: The two-stage hydrogen–methane fermentation process with different patterns of recirculation was investigated. Operations with the circulation of heat-treated sludge performed considerably better than those with the recirculation of raw sludge with respect to both the hydrogen production rate and yield. In addition, the results of the batch tests demonstrated that circulated sludge was capable of consuming hydrogen under acidogenic pH while the heat-treated sludge was not. These results suggest that the recirculation of active methanogenic sludge had an inhibitive effect on the hydrogen production, which can likely be attributed to the high hydrogen-consuming activity of microorganisms present in the circulated sludge. On the other hand, operations without any sludge recirculation did not perform well in terms of hydrogen production or carbohydrates degradation compared to those with recirculation, perhaps due to a shortage of available nitrogen. This suggests that sludge recirculation in effect supplemented the NH4 + in the hydrogen reactor. [Copyright &y& Elsevier]

The microbial mats responsible for biological desulfurization from biogas in a full-scale anaerobic digester were characterized in terms of their structure, as well as their chemical and microbial properties. Filament-shaped elemental sulfur 100-500 μm in length was shown to cover the mats, which cover the entire headspace of the digester. This is the first report on filamentous sulfur production in a non-marine environment. The results of the analysis of the mats suggest that the key players in the sulfide oxidation and sulfur production in the bio-desulfurization in the headspace of the digester were likely to be two sulfide-oxidizing bacteria (SOB) species related to Halothiobacillus neapolitanus and Sulfurimonas denitrificans, and that the microbial community, cell density, activity for sulfide oxidation varied according to the environmental conditions at the various locations of the mats. Since the water and nutrients necessary for the SOB were provided by the digested sludge droplets deposited on the mats, and our results show that a higher rate of sulfide oxidation occurred with more frequent digested sludge deposition, the habitat of the SOB needs to be made in the lower part of the headspace near the liquid level of the digested sludge to maintain optimal conditions. [ABSTRACT FROM AUTHOR]

Abstract: The effect of starch addition on the microbial composition and the biological conversion was investigated using two upflow anaerobic sludge bracket (UASB) reactors treating methanolic wastewater: one reactor was operated with starch addition, and another reactor was operated without starch addition. Approximately 300days of operation were performed at 30kg COD/m3/d, and then, the organic load of the reactors was gradually increased to 120kg COD/m3/d. Successful operation was achieved at 30kg COD/m3/d in both reactors; however, the methanol-fed reactor did not perform well at 120kg COD/m3/d while the methanol–starch-fed reactor did. The granule analysis revealed the granule developed further only in the methanol–starch-fed reactor. The results of the microbial community analysis revealed more Methanosaeta cells were present in the methanol–starch-fed reactor, suggesting the degradation of starch produced acetate as an intermediate, which stimulated the growth of Methanosaeta cells responsible for the extension of granules. [Copyright &y& Elsevier]

Abstract: The continuous operation of a newly developed methane fermentation reactor, which requires no electricity for the agitation of the fermentation liquid was investigated, and the extent of the biological desulfurization was monitored. Inside the reactor, the continual change in the liquid level and the self-agitation, occurring between 5 and 16times every day, distributed the organic load near the inlet port of the reactor, as well as providing a nutrient supply to the hydrogen sulfide oxidizing bacteria. At different CODCr loading rates (5, 7, 10kgm3 d−1), the reactor achieved a biogas production yield of 0.72–0.82m3 g−1-TS, a CODCr reduction of 79.4–85.5% and an average of 99% hydrogen sulfide removal. This investigation demonstrated that the self-agitated reactor is comparable in digestion performance to the completely stirred tank reactor (CSTR) investigated in a previous study, and that the desulfurization performance was significantly enhanced compared to the CSTR. [Copyright &y& Elsevier]

Abstract: Successful start-up strategy for anaerobic digestion of waste-activated sludge using internal inoculum and relationship between the shift of methanogenic community and the digester performance during start-up was investigated. Combination of TS control of inoculum and batch operation during early days enabled the successful start-up operation without serious volatile fatty acid accumulation, followed by the stable continuous operation. However, the propionate degradation was rate-limiting step during the batch operation. The results of real-time quantitative polymerase chain reaction analysis suggested that there was a correlation between the population of the genus Methanosarcina and the methane production rate coupled with acetate consumption during batch operation, and the results of terminal-restriction fragment length polymorphism (T-RFLP) revealed that the increasing intensity of T-RF peaks of hydrogenotrophic methanogens was associated with a decrease in the level of C3-acids. [Copyright &y& Elsevier]

Free sphingoid bases, which have been considered not to occur naturally, were detected in murine tissues by derivatization with o-phthalaldehyde and the use of high-performance liquid chxomatography. The concentrations were 10-30 pmol/mg tissue. The lung contained the largest amounts of sphingoid bases. In the molecular species of sphingoid bases, the most abundant was C18-sphingenine followed by C18-sphinganine, 4-hydroxysphinganine and C20-sphingenine, in that order. The central nervous tissues contained relatively high amounts of C20sphingenine and there was a high concentration of 4-hydroxysphinganine in the kidney. In addition, galactosylsphingenine was detected simultaneously in the spinal cord and sciatic nerve. Sphingoid bases were purified from normal murine lungs using lipid-extraction, cation-exchange and silicic acid column chromatographies, alkaline saponification and preparative thin-layer chromatography. In the purified sphingoid bases, erythro-C18sphingenine and erythro-C18-sphinganine were identified using thin-layer chromatography, high-performance liquid chromatography and fast-atom-bombardment mass spectrometry. Free sphingoid bases occurring in normal tissues may be metabolic intermediates required for the synthesis or be products of degradation of the sphingotipids and function to regulate cellular metabolism. [ABSTRACT FROM AUTHOR]

June-bearing strawberry cultivars have been widely grown in Japan. Since they are harvested in winter and spring, little produce is available in summer and autumn. To achieve stable year-round supply, we need to expand the production area of ever-bearing cultivars. Here, we examined whether it is possible to increase dry matter (DM) production and fruit yield by increasing the CO2 concentration within the plant canopy through local application to promote photosynthesis in summer and autumn protected culture. We investigated the CO2 concentration in the plant canopy, DM production characteristics, yield characteristics, fruit quality, projected leaf area, cumulative light interception, and light use efficiency. We confirmed that the CO2 concentration within the plant canopy could be increased in summer and autumn (Control; 398 ppm, CO2; 1280 ppm), significantly increasing DM production and total yield (Control; 349 g, CO2; 447.5 g). We consider that local application of CO2 increased the projected leaf area and thus cumulative light interception. This method may help to increase fruit yield in summer and autumn protected culture. [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate cancer is the most common cancer in men. The pursuit of novel biomarkers for early detection of prostate cancer poses a contemporary challenge given the age-associated escalation in prostate cancer risk and severity. Our focus was directed towards evaluating leukocyte telomere length (LTL) and myeloid-derived suppressor cells (MDSC) in prostate cancer patients, considering their potential as adjunctive diagnostic markers. In a study of 102 patients who underwent prostate biopsy, those diagnosed with prostate cancer demonstrated significantly shorter LTL and an increased proportion of M-MDSC prior to diagnosis, along with elevated PSA levels and age, in comparison to controls. Furthermore, a significant negative correlation was observed between LTL and MDSC levels. This initial report of those findings could potentially contribute to a deeper understanding of the molecular, biological, and immunological factors involved in cancer development. Background: Leukocyte telomere length (LTL) and myeloid-derived suppressor cells (MDSC) are associated with aging and the development and progression of cancer. However, the exact nature of this relationship remains unclear. Our study aimed to investigate the potential of LTL and MDSC as diagnostic biomarkers for prostate cancer while also seeking to deepen our understanding of the relationship of these potential biomarkers to each other. Methods: Our study involved patients undergoing a prostate biopsy. We analyzed the relative LTL in genomic DNA obtained from peripheral blood leukocytes as well as the percentage of MDSC and their subtypes in peripheral blood mononuclear cells (PBMC). Our evaluation focused on examining the relationship between LTL and MDSC and pathological diagnoses as well as investigating the correlation between LTL and MDSC levels. Results: In our study of 102 participants, 56 were pathologically diagnosed with localized prostate cancer (cancer group), while 46 tested negative (control group). The cancer group exhibited significantly shorter LTL in comparison to the control group (p = 0.024). Additionally, the cancer group showed a tendency towards a higher percentage of monocytic MDSC (M-MDSC), although this difference did not reach statistical significance (p = 0.056). Our multivariate logistic regression analysis revealed that patients with shorter LTL and higher percentages of M-MDSC had a 2.98-fold (95% CI = 1.001–8.869, p = 0.049) and 3.03-fold (95% CI = 1.152–7.977, p = 0.025) increased risk of prostate cancer diagnosis, respectively. There was also a significant negative correlation between LTL and M-MDSC. (r = −0.347, p < 0.001). Conclusions: Our research has established a correlation between LTL and MDSC in patients undergoing biopsy for prostate cancer. Notably, we observed that individuals with localized prostate cancer tend to have shorter LTL and a higher percentage of M-MDSC prior to their diagnosis. These findings suggest that LTL and M-MDSC could potentially serve as adjunctive biomarkers for the early diagnosis of prostate cancer. [ABSTRACT FROM AUTHOR]

• DBDE degradation rate under thermophilic condition is higher than that under mesophilic condition. • DBDEs are degraded into PBDEs with fewer bromide atoms under anaerobic digestion. • With the increase of initial DBDE dosing mass, the degradation rate increases gradually. • The optimal pH for DBDE digestion is 7. In this study, a 200-day deca-brominated diphenyl ether (deca-BDE) degradation activity experiment was carried out, using consumer-use curtain material as the substrate. During the degradation process, polybrominated diphenyl ether (PBDE) products with fewer bromine atoms were gradually generated by the debromination of deca-BDE. The influences of temperature, initial substrate dosing mass, and pH were also investigated. Interestingly, thermophilic conditions proved more beneficial for deca-BDE degradation than mesophilic conditions. The results also demonstrate that the debromination rate increased with the initial deca-BDE dosing mass, and that pH 7 was the most suitable for the reaction. [ABSTRACT FROM AUTHOR]

Abstract It is becoming increasingly urgent to investigate the partition coefficients (expressed as log K DOC values) of polybrominated diphenyl ethers (PBDEs) in dissolved organic carbon (DOC) present in wastewater. In the current study, after 72 h of equilibration, the concentrations of four common PBDEs were measured in the presence of four DOC solutions from two laboratories and two full-scale anaerobic digestion plants. Sixteen log K DOC s were determined by calculation and unit conversion. The results for the laboratory samples, such as log K DOC s for 2,2′,4,4′,5,5′-hexabromodiphenyl ether being 6.38 and 5.46 at different reaction temperatures during the cultivate procedure, suggest that a thermophilic environment promotes the solubility of PBDEs to a greater extent than mesophilic conditions. DOC composition directly influences the solubility of PBDEs, even at the same cultivating temperature: the highest log K DOC s for 2,2′,4,4′,5,6′-hexabromodiphenyl ether were 6.71 and 6.33 in different full-scale plant digestates. A linear regression with an R2 of 0.9863 was used to construct a model describing the potential relationship between log K DOC and the composition of DOC, which includes proteins, polysaccharides and lipids, and which takes into account the positions of bromine atoms, for use in predicting the log K DOC values of PBDEs in different water systems. Graphical abstract Image 1 Highlights • Dissolved organic carbon can increase PBDEs' solubility in anaerobic digestate. • Thermophilic digester enhances PBDEs solubilization compared to mesophilic one. • The log K DOC increases with the molecular weights of PBDEs and the highest value is 6.71 (BDE-153). • A liner regression on protein, polysaccharide and lipids is established to simulate the log K DOC. [ABSTRACT FROM AUTHOR]

This study assessed the co-digestion of macro and microalgal biomass towards the improvement of hydrogen production. The red macroalgal biomass ( Gelidium amansii ) and green mixed microalgal biomass was mixed in a ratio of 8:2, with an initial substrate concentration of 10 g/L, and various amount of inoculum addition range from 3 to 15% (v/v) was evaluated to assess the feasible substrate to inoculum ratio for the effective co-digestion of the algal biomass. The results showed that the co-digestion with 6% inoculum addition provided the peak hydrogen yield of 45 mL/g dry biomass added with a high hydrogen content of 24% in the gas phase. The other tested conditions showed moderate hydrogen content in the range of 17–22%, respectively. These results suggest that anaerobic co-digestion of macro and microalgal biomass, with appropriate initial biomass loading (6%) is essential for enhanced hydrogen production. [ABSTRACT FROM AUTHOR]

This research investigated the effects of various dilute acid (HCl, H 2 SO 4 , HNO 3 , H 3 PO 4 ) pretreatment on the solubilization of marine macroalgal biomass Gelidium amansii and subsequent hydrogen fermentation in a batch vials. The dry grounded biomass was hydrolyzed at temperature of 121 °C, solid/liquid (S/L) ratio of 5% (w/v), dilute acid concentration (1%) of various reagents, and reaction time of 30 min. The hydrolyzates obtained at these conditions were then fed to batch hydrogen fermentation. Results revealed that only H 2 SO 4 pretreatment method had a significant effect on improvement of biohydrogen production from Gelidium amansii , whereas the other pretreatment conditions were even worse than the control experiment. Dilute sulfuric acid (1%) provided a maximum hydrogen production of 52 mL-H 2 /g-dry biomass, whereas control experiment provided a hydrogen efficiency of 27 mL-H 2 /g-dry biomass. The results showed that selection of appropriate pretreatment method is essential for enhanced hydrogen production from macroalgal biomass. [ABSTRACT FROM AUTHOR]

The dispersion of granules in upflow anaerobic sludge blanket (UASB) reactor represents a critical technical issue in methanolic wastewater treatment. In this study, the potentials of coupling a microbial electrolysis cell (MEC) into an UASB reactor for improving methanolic wastewater biodegradation, long-term process stability and biomethane recovery were evaluated. The results indicated that coupling a MEC system was capable of improving the overall performance of UASB reactor for methanolic wastewater treatment. The combined system maintained the comparatively higher methane yield and COD removal efficiency over the single UASB process through the entire process, with the methane production at the steady-state conditions approaching 1504.7 ± 92.2 mL-CH 4 L − 1 -reactor d − 1 , around 10.1% higher than the control UASB (i.e. 1366.4 ± 71.0 mL-CH 4 L − 1 -reactor d − 1 ). The further characterizations verified that the input of external power source could stimulate the metabolic activity of microbes and reinforced the EPS secretion. The produced EPS interacted with Fe 2+/3+ liberated during anodic corrosion of iron electrode to create a gel-like three-dimensional [-Fe-EPS-] n matrix, which promoted cell-cell cohesion and maintained the structural integrity of granules. Further observations via SEM and FISH analysis demonstrated that the use of bioelectrochemical stimulation promoted the growth and proliferation of microorganisms, which diversified the degradation routes of methanol, convert the wasted CO 2 into methane and accordingly increased the process stability and methane productivity. [ABSTRACT FROM AUTHOR]

In this study, a newly established bench-scale thermophilic continuously stirred fluidized bed reactor (CSFBR) was applied for anaerobic co-digestion of food waste (FW) with grease trap waste (GTW). The performance of CSFBR regarding stability and treatment efficiency was inspected through a laboratory contrast experiment with two traditional continuous stirred tank reactors (CSTRs). In the OLR range of 3.19–7.41 g COD/L/d, the methane production rate of the thermophilic CSFBR was about as high as that of the thermophilic CSTR. Nevertheless, the thermophilic CSFBR had much lower VFAs (<1000 mg/L) and LCFA concentrations (<100 mg/L) as compared with the thermophilic CSTR. Unlike the mesophilic CSTR, there was no foaming that occurred in the CSFBR during the whole experimental period. The results all suggested that CSFBR simultaneously provided high treatment capacity and process stability in anaerobic digestion with high-lipid loading. [ABSTRACT FROM AUTHOR]

Continuous primary energy consumption has motivated the scientists of the world to search for renewable energy sources that could substitute fossil fuels. Microalgae can be an alternative substrate for renewable energy recovery. In this study, biochemical methane potential (BMP) assays were used as a tool to examine the technical potential of methane production from microalgae (MA) through co-digesting with food waste (FW) at different MA: FW ratios on volatile solids (VS). Three mathematical models (i.e. first-order kinetic, modified Gompertz, and Cone models) were also utilized to fit the experimental data, with the purpose of elucidating the biological degradation and principle kinetics of the co-digestion. The results showed that supplementing food waste significantly improved microalgae digestion performance, with the highest methane yield of 639.8 ± 1.3 mL/g VS added obtained at a MA:FW ratio of 0.2:0.8, which was 4.99-fold increase with respect to that (106.9 ± 3.2 mL/g VS added ) of the microalgae alone. Cone model had the best fitness and reliability to the experimental results and could describe the co-digestion kinetics more reasonably. Parameter analysis and synergistic impact evaluation together revealed that the improvement in methanogenesis potential ( f d ) caused by the synergy of co-digestion might be the fundamental cause for the upgraded methane production. These results validated the superiority of co-digestion as a step towards maximizing methane production from microalgae, aiding the development of multi-biomass co-disposal and ultimately bioenergy recovery techniques. [ABSTRACT FROM AUTHOR]

This review portrays the status and perspectives of bioaugmented hydrogen fermentation, an emerging strategy of process intensification. Firstly, the paper introduces the potentials and limitations of dark fermentative hydrogen production and describes the technologies available for its enhancement including bioaugmentation. The theoretical background and practical features of augmentation methods for biohydrogen generation are subsequently assessed and surveyed in details. Furthermore, a throughout evaluation of the recent and novel achievements reported in the concept of “augmented hydrogen fermentation” is given in association with (i) bioreactor start-up, (ii) utilization of solid wastes, wastewaters, (iii) the feasibility in continuous systems as well as in complementary – integrated – applications. The article is intended to provide an insight to the advancements made for realizing more viable biohydrogen formation via bioaugmentation and hence it might be encouraging for further studies in the field. [ABSTRACT FROM AUTHOR]

This study investigated the effect of controlling pH (5.5) and heat pre-treatment of seed inoculum in dark fermentative hydrogen production. The results showed that only inoculum source plays an important role rather than pH and heat treatment. Seed source is vital factor despite, heat treatment and pH controlled at 5.5. Mesophilic fermentation resulted in CH 4 generation, however, thermophilic fermentation while using thermophilic inoculum is opted for H 2 generation. In contrast promoted mesophilic inoculum (mesophilic to thermophilic) still documented for CH 4 generation. Peak hydrogen production rate (HPR) and methane production rate (MPR) were noted as 90 and 117 mL/L-d, during the conditions of thermo inoculum (thermophilic, pH 5.5) and pH no control (mesophilic) experiments, respectively. Peak, total solids (TS) and chemical oxygen demand (COD) removal were achieved as 56 and 42% at mesophilic condition. Volatile fatty acid (VFA) profiling revealed the background of the process performances. Microbial community analysis via fluorescent in-situ hybridization (FISH) narrated that bacteria and archaea communities were enriched during thermophilic and mesophilic experiments, respectively. Besides, the presence of methanogens revealed that heat treatment and controlling moderately acidic pH (5.5) could not completely eliminate them and resulted in CH 4 generation, rather than H 2 production. [ABSTRACT FROM AUTHOR]

Microbial electromethanogenesis, relying on electrochemically active biofilm on biocathode to convert carbon dioxide to methane, provides a novel approach for renewable energy storage. One key factor that governs electron exchange and methane formation efficiencies is the electrode material. To promote methane production, a biocathode via modifying plain carbon stick with a layer of graphite felt (GF) (hereafter referred as “hybrid GF-biocathode”) was developed and evaluated in a two-chamber microbial electrolysis cells (MECs). Methane production with hybrid GF-biocathode reached 80.9 mL/L at the potential of −1.4 V after 24 h of incubation with coulombic efficiency of 194.4%. The tests by flushing three substrates (CO 2 , N 2 and H 2 –CO 2 [80:20]) revealed that direct electron transfer rather than intermediate H 2 contributed more to the electromethanogenesis. Cyclic voltammetry showed that GF enhanced the microbial electrocatalysis activity and reduced the cathode overpotential needed for methane production. Scanning electron microscope and fluorescence in situ hybridization analysis confirmed that the three-dimensional GF afforded the abundant space for the growth of electroactive microorganisms and promoted the electron exchange (e.g. cathode-to-cell etc.) via severing as “artificial pili”. This study reveals that GF with the open structure and high conductivity has the substantial potential to upgrade electromethanogenesis efficiency. [ABSTRACT FROM AUTHOR]

The feasibility of anaerobic co-digestion of waste activated sludge (WAS) and grass Egeria densa ( E.d. ) with four different WAS: E.d. ratios was evaluated for the first time under mesophilic conditions. First-order kinetic, modified Gompertz, and Cone models were employed to reveal the principle kinetics of methane-rich bioenergy production from co-digestion. The results showed that the addition of E.d. could greatly upgrade the sludge methane production, and the highest methane yield averaged 198.32 ± 2.61 mL/g VS added for WAS: E.d. ratio of 0.7: 0.3, 18.72 ± 0.14% higher respective to that of WAS alone (about 176.36 mL/g VS added ). E.d. improved the solubilization of co-substrates and avoided the build-up of volatile fatty acids (VFAs) and free ammonia ([NH 3 ]) and subsequent inhibition, inducing a stable digestion environment. Model simulation indicated Cone model best fitted the actual evolution of methane production, as evidenced by low Root Mean Square Prediction Error (rMSPE) and Akaike’s Information Criterion (AIC), as well as high Pearson’s correlation between the predicated and actual values. Additionally, the parameters analysis highlighted that the co-digestion with E.d . substantially promoted the hydrolysis rate ( k hyd ) and methanogenesis potential ( f d ) of sludge, further explaining the increased solids removal and output of methane. This study demonstrated the sustainability and attractiveness of anaerobic co-digestion of sludge and grass E.d. , providing a sound basis for cost-efficient biomass stabilization and bioenergy recovery. [ABSTRACT FROM AUTHOR]

The characteristics of hydrogen fermentation in a membrane bioreactor (HF-MBR) fed with food waste were investigated at thermophilic condition. The HF-MBR was operated at three different organic loading rates (OLRs) of 70.2, 89.4 and 125.4 kg-COD/m 3 /day. Biogas production rate increased from 22.4 to 32.8 and 62.5 l/day with OLR. The maximum Hydrogen yield and production rate were 111.1 mL-H 2 /g-VS added and 10.7 l-H 2 /L/day at an OLR of 125.4 kg-COD/m 3 /day. The total carbohydrate degradation was better than 96% throughout the experimental runs. Continuous H 2 production from food waste with CH 4 -free biogas was successfully sustained in the HF-MBR for 90 days. The microbial community was dominated by Clostridium sp. strain Z6. The H 2 production was significantly improved by shortening the retention time and increasing the OLRs. The HF-MBR showed an H 2 production capacity at the high OLRs due to its higher cell retention. [ABSTRACT FROM AUTHOR]

Anaerobic digestion of decabromodiphenyl ether was carried out and compared in two continuously stirred anaerobic bioreactors for 210 days under thermophilic and mesophilic conditions. Results show that the degradation of decabromodiphenyl ether followed the first-order reaction kinetics, which exhibited a higher removal rate in the thermophilic reactor when compared to the mesophilic one, reaching its maximum of 1.1 μg·day−1. The anaerobic digestion of decabromodiphenyl ether was found to involve the replacement of bromines from polybrominated diphenyl ether by hydrogen atoms, gradually forming nona-, octa- and hepta-brominated diphenyl ether, respectively. Under the thermophilic condition, the reactors were dominated by Bacillus sp. and Methanosarcina sp. with high bioactivity and high concentrations of debromination microorganisms. [Display omitted] • Temperature accelerates deca-BDE anaerobic digestion, fitting the first-order. • The maximum deca-BDE degradation rate reached 1.1 μg·day−1. • Bacillus sp. and Methanosarcina sp. accelerate the deca-BDE degradation rate. [ABSTRACT FROM AUTHOR]

• Anaerobic wet fermentations were conducted for treating genuine radioactive grass. • Alkaline-heat and ultrasonic methodologies were used to pre-treat the grass. • Alkaline-heat-treated grass showed an optimal anaerobic conversion efficiency. • Pre-treatments and wet fermentations barely leached Rad-Cs from grass. • Soil with high cesium affinity mixed with grass limited the Rad-Cs leaching. Persistent concerns regarding environmental hazards arise from the difficulty in disposing of radioactive plant-based wastes originating from the nuclear accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) in Japan in 2011. In this study, three anaerobic digestion (AD) strategies were proposed: Sole anaerobic wet fermentation, and wet fermentations with either alkaline-heat or ultrasonic pre-treatment, which were employed for long-term anaerobic treatment of a genuine radioactive grass stemming from the FNPP accident. The objectives of this work are to investigate the effects of pre-treatments on biomass conversion efficiency and to gain insight into the leaching behavior of radiocaesium (Rad-Cs) within AD processes. Experimental results indicate that by introducing alkaline-heat and ultrasonic pre-treatments to AD systems, the removal efficiencies of total solids (TS) from the raw grass increased by 60.8 % and 42.5 %, respectively, compared to sole wet fermentation. Pre-treatments have been shown to enhance the stability of AD systems, both in terms of enhancing methane production and mitigating pH fluctuations triggered by the accumulation of organic acids. Remarkably, even though the Rad-Cs leaching rate was highest when the AD system was fed with the alkaline-heat pre-treated grass, it remained unsatisfactory at only 5.77 %. We inadvertently isolated a soil-like component from the raw grass, and analyzed both its proportion in the raw grass and the radioactivity intensity. The results indicate that although the soil constituted only 9.51 % TS of the raw grass, it accounted for a significant 81.35 % of the total radioactivity. The soil, which has a pronounced affinity for ionic Cs, being mixed into the raw grass, was identified as the primary factor limiting the leaching efficiency of Rad-Cs throughout both the pre-treatment and wet fermentation phases. [Display omitted] [ABSTRACT FROM AUTHOR]

• Mono-digestion of sorghum was conducted for more than 420 days. • Nutrients deficiencies of sulfur and cobalt were confirmed. • Bioavailability of micronutrients was analyzed in sorghum digestion. • Sulfur was confirmed as a key factor affecting bioavailability of micronutrients. • Methane yield of 223 mL-CH 4 /g-VS was achieved through nutrients augmentation. This study investigated the effects of the addition of micro- (Fe, Co, Ni, and Mo) and macro-(Sulfur) nutrients on mono-digestion of sorghum under mesophilic conditions. A continuous stirred-tank reactor was operated for more than 420 days under seven different experimental conditions. The experimental results showed poor performance for methane production and process stability without nutrient supplementation. Serious deficiencies in Co and S were confirmed by nutrient analysis of dry sorghum and digestate. Nutrient augmentation efficiently enhanced methane production and volatile fatty acid (VFA) removal. Methane production reached 223 mL-CH 4 /g-VS, almost matching the yield predicted by biochemical methane potential (BMP) test. S was demonstrated to have a critical effect on metal availability in the digester. Consequently, to maintain stable methane fermentation, suitable supplementations of S and Co are recommended for anaerobic sorghum mono-digestion. [ABSTRACT FROM AUTHOR]

• Aggregation of immobilized enzyme resins was observed. • The material of the reaction vial affected the aggregate form of the enzyme resins. • Thin-layer aggregate showed a high reaction yield (0.932). • Bulky aggregate showed a low reaction yield (0.454). • Removal of the glycerin phase prevented the generation of bulk aggregate. During the transesterification of triglycerides with methanol catalyzed by immobilized lipase resin (Novozym 435 (N435)) in a glass vial, two types of aggregate of N435 particles were observed: a thin-layer aggregate on the glass surface inside the vial, and bulky aggregates. This prompted us to investigate the conditions under which only one type of aggregate could be formed, by changing the material from which the reaction vial was made and the feed ratio of N435 to the cross section of the reaction glass vial. When a polypropylene vial was used, only the bulky aggregates were formed, and reducing the feed ratio led to only the thin-layer aggregate being formed. We also examined the influence of morphological variation of the aggregates on the reaction yield. The thin-layer aggregate showed high activity, with a reaction yield of 0.932. In contrast, the bulky aggregate grew as the reaction time elapsed, resulting in a reduction in the surface area of the enzyme resin, consequently giving not only a reaction yield of about 0.454 but also low repeatability. These results show that the reactor material and feed ratio strongly affect the reaction yield as well as the aggregation form of enzyme resin. Finally, the durability of the thin-layer aggregate and the effect of accumulation of glycerin were investigated. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the effect of light intensity on three various microalga consortia collected from natural ecological water bodies (named A, B and C) towards their fatty acid profiling and fractions, carbohydrate and protein production at different light intensities of 100, 200 and 300 μmol m−2 s−1. The results indicating that increasing light intensity positively correlated with the lipid production than carbohydrate and protein. Irrespective to the solids (Total and Volatile Solid) content, lipids and carbohydrate has varied significantly. Consortia C showed higher productivity toward lipids, whereas consortia A and B accumulated more carbohydrate and protein, respectively. The microscopic images revealed the breakdown of cells during the increase in light intensity, in spite, the similar algal species were observed in all consortia experimented. Principal component analysis (PCA) revealed that low light intensity aid relatively in high protein, Total Nitrogen and Total Phosphorus, meanwhile high intensity attributed carbohydrates and unsaturated fatty acids (USFA) contents. Highlights • 3 various microalgae consortia have been evaluated at 3 different light intensities. • High light intensity attributed to higher SFA concentrations. • Principal Component Analysis revealed the relativeness of low and high light intensities. • Light intensity of 300 μmol m−2s−1 positively enhanced the C and N content. [ABSTRACT FROM AUTHOR]

Each carbon-based material, due to the discrepancy in critical properties, has distinct capability to enrich electroactive microbes able to electrosynthesize methane from CO 2 . To optimize electromethanogenesis process, this study physically prepared and examined several carbon-based cathode materials: carbon stick (CS), CS twined by Ti wire (CS-Ti) or covered with carbon fiber (CS-CF), graphite felt (CS-GF) and carbon cloth (CS-CC). CS-GF electrode had constantly stable methane production (75.8 mL/L/d at −0.9 V vs. Ag/AgCl) while CS-CC showed a suppressed performance over time caused by the desposition of inorganic shell. Electrode material properties affected biofilms growth, cell-electrode contact behaviors and electron exchange. Methane formation with CS-CC biocathode was H 2 -concnetration dependent; CS-GF cathode possessed high antifouling properties and extensive space, enriching the microorganisms capable of catalyzing electromethanogenesis through more efficient non-H 2 route. This study re-interpreted the application potentials of carbon-based materials in CO 2 electroreduction and electrofuel recovery, providing valuable guidance for materials’ selection. [ABSTRACT FROM AUTHOR]

This study assessed the impact of swine manure (SM) dilution ratio on the microalgal biomass cultivation and further tested for biohydrogen production efficiency from the mixed microalgal biomass. At first, various solid/liquid (S/L) ratio of the SM ranged from 2.5 to 10 g/L was prepared as a nutrient medium for the algal biomass cultivation without addition of the external nutrient sources over a period of 18 d. The peak biomass concentration of 2.57 ± 0.03 g/L was obtained under the initial S/L loading rates of 5 g/L. Further, the cultivated biomass was subjected to two-step (ultrasonication + enzymatic) pretreatment and evaluated for biohydrogen production potential. Results showed that the variable amount of hydrogen production was observed with different S/L ratio of the SM. The peak hydrogen yield of 116 ± 6 mL/g TS added was observed at the 5 g/L grown SM mixed algal biomass. [ABSTRACT FROM AUTHOR]