共查询到20条相似文献,搜索用时 31 毫秒
1.
A. E. Ivanova I. A. Borzenkov A. L. Tarasov E. I. Milekhina S. S. Belyaev 《Microbiology》2007,76(4):461-468
The numbers of microorganisms belonging to ecologically significant groups and the rates of terminal microbial processes of sulfate reduction and methanogenesis were determined in the liquid phase of an underground gas storage (UGS) in the period of gas extraction. The total number of microorganisms in water samples from the operation and injection wells reached 2.1 × 106 cells/ml. Aerobic organotrophs (including hydrocarbon-and oil-oxidizing ones) and various anaerobic microorganisms (fermenting bacteria, methanogens, acetogens, sulfate-, nitrate-, and iron-reducing bacteria) were constituent parts of the community. The radioisotopic method showed that, in all the UGS units, the terminal stages of organic matter decomposition included sulfate reduction and methanogenesis, with the maximal rate of these processes recorded in the aqueous phase of above-ground technological equipment which the gas enters from the operation wells. A comparative analysis by these parameters of different anaerobic ecotopes, including natural hydrocarbon fields, allows us to assess the rate of these processes in the UGS as high throughout the annual cycle of its operation. The data obtained indicate the existence in the UGS of a bacterial community that is unique in its diversity and metabolic capacities and able to make a certain contribution to the geochemistry of organic and inorganic compounds in the natural and technogenic ecosystem of the UGS and thus influence the industrial gas composition. 相似文献
2.
The liquid phase of different units of an underground gas storage (UGS) in the period of gas injection was studied with respect to its hydrochemical composition and characterized microbiologically. The presence of viable aerobic and anaerobic bacteria was revealed in the UGS stratal and associated waters. An important source of microorganisms and biogenic elements in the ecosystem studied is water and various technogenic admixtures contained in trace amounts in the gas entering from the gas main in the period of gas injection into the storage. Owing to this fact, the bacterial functional diversity, number, and activity are maximal in the system of gas treatment and purification and considerably lower in the observation well zone. At the terminal stages, the anaerobic transformation of organic matter in the UGS aqueous media occurs via sulfate reduction and methanogenesis; exceptionally high rates of these processes (up to 4.9 x 10(5) ng S(2-)l(-1) day(-1) and 2.8 x 10(6) nl CH4 l(-1) day(-1), respectively) were recorded for above-ground technological equipment. 相似文献
3.
T. N. Nazina A. A. Grigor’yan N. M. Shestakova T. L. Babich V. S. Ivoilov Qingxian Feng Fangtian Ni Jianqiang Wang Yuehui She Tingsheng Xiang Zhibin Luo S. S. Belyaev M. V. Ivanov 《Microbiology》2007,76(3):287-296
The physicochemical conditions and microbiological characteristics of the formation waters of the Kongdian oilfield of the Dagang oilfield (China) were studied. It was demonstrated that this oilfield is a high-temperature ecosystem with formation waters characterized by low mineralization. The concentrations of nitrogen and phosphorus compounds, as well as of electron acceptors, are low. Oil and oil gas are the main organic matter sources. The oilfield is exploited with water-flooding. The oil stratum was inhabited mostly by anaerobic thermophilic microorganisms, including fermentative (102–105 cells/ml), sulfate-reducing (0–102 cells/ml), and methanogenic (0–103 cells/ml) microorganisms. Aerobic bacteria were detected mainly in the near-bottom zone of injection wells. The rate of sulfate reduction varied from 0.002 to 18.940 μg S2? l?1 day?1 and the rate of methanogenesis from 0.012 to 16.235 μg CH4 l?1 day?1. Microorganisms with great biotechnological potential inhabited the oilfield. Aerobic thermophilic bacteria were capable of oxidizing oil with formation of biomass, the products of partial oxidation of oil (volatile acids), and surfactants. During growth on the culture liquid of oil-oxidizing bacteria, methanogenic communities produced methane and carbon dioxide, which also had oil-releasing capabilities. Using various labeled tracers, the primary filtration flows of injected solutions at the test site were studied. Our comprehensive investigations allowed us to conclude that the method for microbial enhancement of oil recovery based on the activation of the stratal microflora can be applied in the Kongdian oilfield. 相似文献
4.
A. S. Savvichev I. I. Rusanov N. V. Pimenov E. E. Zakharova E. F. Veslopolova A. Yu. Lein K. Crane M. V. Ivanov 《Microbiology》2007,76(5):603-613
The research performed in August 2004 within the framework of the Russian-American Long-term Census of the Arctic (RUSALCA) resulted in the first data concerning the rates of the key microbial processes in the water column and bottom sediments of the Bering strait and the Chukchi Sea. The total bacterial counts in the water column varied from 30 × 103 cells ml?1 in the northern and eastern parts to 245 × 103 cells ml?1 in the southern part. The methane content in the water column of the Chukchi sea varied from 8 nmol CH4l?1 in the eastern part of the sea to 31 nmol CH4l?1 in the northern part of the Herald Canyon. Microbial activity occurred in the upper 0–3 cm of the bottom sediments; the methane formation rate varied from 0.25 to 16 nmol CH4dm?3 day?1. The rates of methane oxidation varied from 1.61 to 14.7 nmol CH4dm?3 day?1. The rates of sulfate reduction varied from 1.35 to 16.2 μmol SO 4 2? dm?1 day?1. The rate of methane formation in the sediments increased with depth, while sulfate reduction rates decreased (less than 1 μmol SO 4 2? dm?3 day?1). These high concentrations of biogenic elements and high rates of microbial processes in the upper sediment layers suggest a specific type of trophic chain in the Chukchi Sea. The approximate calculated balance of methane emission from the water column into the atmosphere is from 5.4 to 57.3 μmol CH4m?2 day?1. 相似文献
5.
The performance and microbial community structure of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor inoculated with flocculent sludge were investigated over 52 days. The characteristics of corn-ethanol wastewater were as follows: CODCr, 1,050–4,970 mg l?1; ammonia, 14–298 mg l?1; and alkalinity, 332–2,867 mg l?1. The UASB could start up smoothly with a hydraulic loading rate lower than 180 l h?1 and a ratio of volatile fatty acid versus alkalinity between 0.04 and 0.48. The maximum gas production rate was 432 l h?1 and the highest volumetric loading rate of 7.2 kg m?3 day?1 was obtained after 48 days. The 1 mm granules could form a complex network and were composed of many Methanosaeta. Aceticlastic methanogens served as a dominant methanogenic group, which accounted for the relatively high resistance to shock loading. 相似文献
6.
Till Harter Peter Bossier Johan Verreth Samuel Bodé David Van der Ha Ann-Eline Debeer Nico Boon Pascal Boeckx Wim Vyverman Nancy Nevejan 《Journal of applied phycology》2013,25(2):359-368
The biotreatment of flue gases with algae cultures is a promising option to sequestrate CO2, yet the emission of other greenhouse gases (GHG) from the cultures can hamper their environmental benefit. Quantitative data on the sequestration potential for CO2 and NO x in relation to the direct production of CH4 and N2O are urgently required. The present study assessed the flows of carbon (C) and nitrogen (N) through cultures of the green alga Dunaliella salina, supplied with biodiesel flue gas, by means of mass balancing. D. salina was grown in artificially lighted, field- (42-L bubble column reactor) and laboratory-scale cultures (23 °C, pH 7.5). In the bubble column reactor, algae grew with an average specific growth rate of 0.237 day?1 under flue gas supplementation (6.3 % (v/v) CO2, 1.2 ppmv NO x ), and CO2 was retained to 39 % in the system. The specific sequestration rate for CO2 was low, with 0.13 g CO2 L?1 day?1. Cultures emitted up to 13.03 μg CH4 L?1 day?1 and 4261 μg N2O L?1 day?1. The moderate retention of NO x -N was outweighed by emissions of N2O-N, and total N in the system decreased by 15.48 % during the 9-day trial. Results suggest that GHG production was mainly the outcome of anaerobic microbial processes and their emission was lower in pre-sterilized cultures. Under the tested conditions, up to six times more CO2 equivalents were emitted during flue gas treatment. Therefore, the direct GHG emissions of algae culture systems, intended for flue gas treatment (i.e. open ponds) need to be reviewed critically. 相似文献
7.
J. Camacho-Rodríguez A. M. González-Céspedes M. C. Cerón-García J. M. Fernández-Sevilla F. G. Acién-Fernández E. Molina-Grima 《Applied microbiology and biotechnology》2014,98(6):2429-2440
Different pilot-scale outdoor photobioreactors using medium recycling were operated in a greenhouse under different environmental conditions and the growth rates (0.1 to 0.5 day?1) obtained evaluated in order to compare them with traditional systems used in aquaculture. The annualized volumetric growth rate for Nannochloropsis gaditana was 0.26 g l?1 day?1 (peak 0.4 g l?1 day?1) at 0.4 day?1 in a 5-cm wide flat-panel bioreactor (FP-PBR). The biomass productivity achieved in this reactor was 10-fold higher than in traditional reactors, reaching values of 28 % and 45 % dry weight (d.w.) of lipids and proteins, respectively, with a 4.3 % (d.w.) content of eicosapentaenoic acid (EPA). A model for predicting EPA productivity from N. gaditana cultures that takes into account the existence of photolimitation and photoinhibition of growth under outdoor conditions is presented. The effect of temperature and average irradiance on EPA content is also studied. The maximum EPA productivity attained is 30 mg l?1 day?1. 相似文献
8.
Bacterial dynamics in two high-arctic lakes 总被引:1,自引:0,他引:1
The heterotrophic planktonic bacteria in two high-arctic lakes were studied by direct microscope count and the enzymatic uptake of 14C labelled glucose which generally conformed to Michaelis-Menten kinetics. Bacterial numbers and activity in oligo-trophic Char Lake ranged from 0.1 to 2.0×10?3 bacteria/l and a maximum uptake velocity (Vmax) of 1.8 × 10?3μg glucose l? h?1. Nearby Meretta Lake received waste water from the Department of Transport Base at Resolute and this eutrophication was reflected in higher bacterial numbers of 2-80 × 108/1 and Kmax of 0.1 × 10?1-7.5 × 10?1 fig glucose l?1 h?1 The Kmax per cell in Char Lake was 3 × 10?11μg glucose l?1 h?1 and changed little between the period of solid ice cover in May and ice-free conditions in August. Bacterial cycles could not be related to phytoplankton cycles in either lake. Comparison of kinetic data from several lakes suggests a relationship between the bacterial uptake rate of glucose and phytoplankton production. Both bacterial numbers and activity in Char Lake may be very close to the minima to be expected in undisturbed freshwater environments. 相似文献
9.
Özlem Aydoğan Emine Bayraktar Mahmut Parlaktuna Tanju Mehmetoğlu 《Biocatalysis and Biotransformation》2013,31(5):365-372
l-Aspartic acid (l-Asp) was produced using Escherichia coli (ATCC 11303), and its recovery from the reaction mixture was studied using reverse micelle and gas hydrate methods. The effect of initial substrate concentration on l-Asp production was also investigated, and inhibition was shown to occur above 0.75 mol L?1. The values of the kinetic constants were determined as rmax=2.33×10?4 mol L?1 min?1, KM=0.19 mol L?1, and Kss=3.98 mol L?1. The reverse micelle phase used for extraction contained Aliquat-336, 1-decanol and isooctane, and a micro-injection technique was used for extraction of l-Asp. The reverse micelle system is a useful technique for obtaining small particle sizes, which can be used for the synthesis of nanoparticle biomolecules. Recovery of l-Asp from reverse micelles using CO2 hydrates was carried out, giving a recovery of 55%. The formation of CO2 hydrate from the reverse micelle solution breaks the micelle by reducing the amount of water in the micelle structure, thus precipitating the l-Asp. 相似文献
10.
Livestock manure management accounts for almost 10% of greenhouse gas emissions from agriculture globally, and contributes an equal proportion to the US methane emission inventory. Current emissions inventories use emissions factors determined from small‐scale laboratory experiments that have not been compared to field‐scale measurements. We compiled published data on field‐scale measurements of greenhouse gas emissions from working and research dairies and compared these to rates predicted by the IPCC Tier 2 modeling approach. Anaerobic lagoons were the largest source of methane (368 ± 193 kg CH4 hd?1 yr?1), more than three times that from enteric fermentation (~120 kg CH4 hd?1 yr?1). Corrals and solid manure piles were large sources of nitrous oxide (1.5 ± 0.8 and 1.1 ± 0.7 kg N2O hd?1 yr?1, respectively). Nitrous oxide emissions from anaerobic lagoons (0.9 ± 0.5 kg N2O hd?1 yr?1) and barns (10 ± 6 kg N2O hd?1 yr?1) were unexpectedly large. Modeled methane emissions underestimated field measurement means for most manure management practices. Modeled nitrous oxide emissions underestimated field measurement means for anaerobic lagoons and manure piles, but overestimated emissions from slurry storage. Revised emissions factors nearly doubled slurry CH4 emissions for Europe and increased N2O emissions from solid piles and lagoons in the United States by an order of magnitude. Our results suggest that current greenhouse gas emission factors generally underestimate emissions from dairy manure and highlight liquid manure systems as promising target areas for greenhouse gas mitigation. 相似文献
11.
Avila-Leon I Chuei Matsudo M Sato S de Carvalho JC 《Journal of applied microbiology》2012,112(6):1086-1094
Aims: Arthrospira platensis has been studied for single‐cell protein production because of its biomass composition and its ability of growing in alternative media. This work evaluated the effects of different dilution rates (D) and urea concentrations (N0) on A. platensis continuous culture, in terms of growth, kinetic parameters, biomass composition and nitrogen removal. Methods and results: Arthrospira platensis was continuously cultivated in a glass‐made vertical column photobioreactor agitated with Rushton turbines. There were used different dilution rates (0·04–0·44 day?1) and urea concentrations (0·5 and 5 mmol l?1). With N0 = 5 mmol l?1, the maximum steady‐state biomass concentration was1415 mg l?1, achieved with D = 0·04 day?1, but the highest protein content (71·9%) was obtained by applying D = 0·12 day?1, attaining a protein productivity of 106·41 mg l?1 day?1. Nitrogen removal reached 99% on steady‐state conditions. Conclusions: The best results were achieved by applying N0 = 5 mmol l?1; however, urea led to inhibitory conditions at D ≥ 0·16 day?1, inducing the system wash‐out. The agitation afforded satisfactory mixture and did not harm the trichomes structure. Significance and Impact of the Study: These results can enhance the basis for the continuous removal of nitrogenous wastewater pollutants using cyanobacteria, with an easily assembled photobioreactor. 相似文献
12.
Aims: A microbiological bioassay using Geoacillus stearothermophilus was optimized to detect betalactams at concentrations near to the Maximum Residue Limits (MRLs), with low cross‐specificity for tetracycline. Methods and Results: A factorial design (3 × 4) was used to evaluate the effects of concentration of spores (2·0 × 106, 4·0 × 106 and 8·0 × 106 spores ml?1) and incubation time (3·0, 3·5, 4·0 and 4·5 h) on the response of the bioassay. Then, desirability function to raise the detection capabilities (CCβ) of tetracyclines and increase sensitivity to betalactams was implemented. Significant effects of Log[S] and incubation time [It] on the CCβ of betalactams and tetracyclines were observed. Finally, high value of global desirability (D = 0·853), adequate betalactams CCβ (3·8 μg l?1 of penicillin ‘G’, 27 μg l?1 of oxacillin, 8·1 μg l?1 of ampicillin, 48 μg l?1 of cloxacillin) and high tetracyclines CCβ (5260 μg l?1 chlortetracycline, 1550 μg l?1 of oxytetracycline, 1070 μg l?1 of tetracycline) were calculated. Conclusions: The application of chemometric tools allows the optimization of a bioassay that detects betalactam residues in milk. The more robust conditions have been achieved in Log[S] = 6·30 and [It] = 4·20 h. Significance and Impact of the Study: The logistic regression model and the desirability function are adequate chemometric techniques to improve the properties of the methods, because it is possible to increase sensitivity and decrease cross‐specificity simultaneously. 相似文献
13.
K. P. Krishnan Christabelle E. G. Fernandes Sheryl Oliveira Fernandes P. A. Loka Bharathi 《Geomicrobiology journal》2013,30(1):31-36
Bacteria isolated from cobalt–enriched ferromanganese crusts on the Afanasiy Nikitin Seamounts in the Equatorial Indian Ocean were examined for their ability to tolerate, and immobilize cobalt in unamended seawater and seawater amended with 0.01% glucose. Retrievable bacterial counts in the form of CFU (colony forming units) on media supplemented with 1 mmol Co l?1 (58 mg Co l?1) and 1 mmol Mn l?1 (54 mg Mn l?1) were in the range of 1.71 × 104 to 1.05 × 105 gm?1 (wet wt) of crust, respectively. Most of the isolates (14/24) were pigmented and showed taxonomic affinities to Flavobacterium sp. Two representative isolates were tested for their tolerance of cobalt. We observed that in amended medium, the isolates tolerated up to 1 mmol Co l?1, whereas in unamended medium they tolerated upto 10 mmol Co l?1. Microscopic observations of cultures incubated with 10 mmol Co l?1 showed the occurrence of an extracellular slime layer, which may be responsible for immobilizing the cobalt from the liquid phase. In the unamended medium, the tolerance and stimulation in total cell counts was similar to that in amended medium or sometimes greater. Total cell counts peaked at 100 μmol Co l?1 for incubations in unamended medium (1.1–2.5 × 1011 cells l?1) and at 0.1–1 μmol Co l?1 for incubations in amended medium (1.5–2.6 × 1011 cells l?1). Counts of formazan-stained respiring cells of both the isolates in the unamended medium reached up to a maximum of 2.9–7.8 × 1010 l?1 after incubation for 10 days at 23(±1)°. In the amended medium cell counts of respiring cells attained a maximum in the range of 4.6–15.8 × 1010 l?1 at 100 μmol Co l?1. The Co immobilization rate was on average 82 (± 87.9, n = 24) μmol of Co d?1. Since the isolates were naturally occurring bacteria from crusts, they could be more environmentally acceptable and safe if used for metal recovery and bio-leaching. 相似文献
14.
Lisa M. Gieg Irene A. Davidova Kathleen E. Duncan Joseph M. Suflita 《Environmental microbiology》2010,12(11):3074-3086
Petrochemical and geological evidence suggest that petroleum in most reservoirs is anaerobically biodegraded to some extent. However, the conditions for this metabolism and the cultivation of the requisite microorganisms are rarely established. Here, we report on microbial hydrocarbon metabolism in two distinct oilfields on the North Slope of Alaska (designated Fields A and B). Signature anaerobic hydrocarbon metabolites were detected in produced water from the two oilfields offering evidence of in situ biodegradation activity. Rate measurements revealed that sulfate reduction was an important electron accepting process in Field A (6–807 µmol S l?1 day?1), but of lesser consequence in Field B (0.1–10 µmol S l?1 day?1). Correspondingly, enrichments established at 55°C with a variety of hydrocarbon mixtures showed relatively high sulfate consumption but low methane production in Field A incubations, whereas the opposite was true of the Field B enrichments. Repeated transfer of a Field B enrichment showed ongoing methane production in the presence of crude oil that correlated with ≥ 50% depletion of several component hydrocarbons. Molecular‐based microbial community analysis of the methanogenic oil‐utilizing consortium revealed five bacterial taxa affiliating with the orders Thermotogales, Synergistales, Deferribacterales (two taxa) and Thermoanaerobacterales that have known fermentative or syntrophic capability and one methanogen that is most closely affiliated with uncultured clones in the H2‐using family Methanobacteriaceae. The findings demonstrate that oilfield‐associated microbial assemblages can metabolize crude oil under the thermophilic and anaerobic conditions prevalent in many petroleum reservoirs. 相似文献
15.
Gilles Adam Sébastien Lemaigre Anne-Claude Romain Jacques Nicolas Philippe Delfosse 《Bioprocess and biosystems engineering》2013,36(1):23-33
This study aimed at analysing the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An array of non specific metal oxide semiconductor gas sensors were used to detect process faults due to organic overload events in twelve 1.8-L anaerobic semi-continuous reactors. Three different load strategies were followed: (1) a cautious organic load (1.3 gVS L?1 day?1); (2) an increasing load strategy (1.3–5.3 gVS L?1 day?1) and (3) a cautious organic load with load pulses of up to 12 gVS L?1 day?1. A first monitoring campaign was conducted with three different substrates: sucrose, maize oil and a mix of sucrose/oil during 60 days. The second campaign was run with dry sugar beet pulp for 45 days. Hotelling’s T 2 value and upper control limit to a reference set of digesters fed with a cautious OLR (1.3 gVS L?1 day?1) was used as indirect state variable of the reactors. Overload situations were identified by the e-nose apparatus with Hotelling’s T 2 values at least four times higher in magnitude than the upper control limit of 23.7. These results confirmed that the e-nose technology appeared promising for online detection of process imbalances in the domain of anaerobic digestion. 相似文献
16.
P. J. T. Denusta E. G. T. de Jesus‐Ayson M. A. Laron L. M. B. Garcia 《Zeitschrift fur angewandte Ichthyologie》2014,30(3):448-453
This study determined the effect of human chorionic gonadotropin (hCG) and handling stress on the spermiation and milt response of silver perch Leiopotherapon plumbeus based on the measurement of spermatocrit, sperm density, and milt production. Compared to saline‐injected fish, the mean spermatocrit (or packed sperm) of hCG‐treated fish was significantly lower at 18 h (47.9%) and 30 h (40.2%) post‐injection while mean sperm density was significantly lower at 30 h post‐injection (3.6 × 106 cells μl?1) but not at 18 h. At 18 h (1.8 μl g‐BW?1) and 30 h (2.5 μl g‐BW?1) post‐injection, mean milt production of hCG‐treated fish was significantly higher than in the saline group. Milt consistency was also thinner in the hCG‐treated group. Mean sperm density of handled fish (18.0 × 106 cells μl?1) was significantly lower than control fish (23.4 × 106 cells μl?1). However, mean sperm density of handled plus saline‐injected (16.2 × 106 cells μl?1) and handled plus hCG‐treated fish (8.4 × 106 cells μl?1) was significantly lower than in the control goup. Having thicker milt consistency, mean spermatocrit and milt production of handled (77.5%; 1.1 μl g‐BW?1, respectively) and handled plus saline‐injected fish (75.4%; 1.1 μl g‐BW?1, respectively) were not significantly different from the control fish (76.2%; 1.3 μl g‐BW?1, respectively). Handled plus hCG‐treated fish had the lowest mean sperm density (8.4 × 106 cells μl?1) and spermatocrit (54.7%), but had the highest mean milt production (5.5 μl g‐BW?1) among the treatment groups. These results demonstrate that the hCG injection effectively induces spermiation and milt expression and that handling‐related stress negatively affects such responses. The spermatocrit method may be used to assess the spermiation and milt response of silver perch. 相似文献
17.
Navid Reza Moheimani 《Journal of applied phycology》2013,25(2):387-398
There has been considerable interest in cultivation of green microalgae (Chlorophyta) as a source of lipid that can alternatively be converted to biodiesel. However, almost all mass cultures of algae are carbon-limited. Therefore, to reach a high biomass and oil productivities, the ideal selected microalgae will most likely need a source of inorganic carbon. Here, growth and lipid productivities of Tetraselmis suecica CS-187 and Chlorella sp were tested under various ranges of pH and different sources of inorganic carbon (untreated flue gas from coal-fired power plant, pure industrial CO2, pH-adjusted using HCl and sodium bicarbonate). Biomass and lipid productivities were highest at pH 7.5 (320?±?29.9 mg biomass L?1 day?1and 92?±?13.1 mg lipid L?1 day?1) and pH 7 (407?±?5.5 mg biomass L?1 day?1 and 99?±?17.2 mg lipid L?1 day?1) for T. suecica CS-187 and Chlorella sp, respectively. In general, biomass and lipid productivities were pH 7.5?>?pH 7?>?pH 8?>?pH 6.5 and pH 7?>?pH 7.5?=?pH 8?>?pH 6.5?>?pH 6?>?pH 5.5 for T. suecica CS-187 and Chlorella sp, respectively. The effect of various inorganic carbon on growth and productivities of T. suecica (regulated at pH?=?7.5) and Chlorella sp (regulated at pH?=?7) grown in bag photobioreactors was also examined outdoor at the International Power Hazelwood, Gippsland, Victoria, Australia. The highest biomass and lipid productivities of T. suecica (51.45?±?2.67 mg biomass L?1 day?1 and 14.8?±?2.46 mg lipid L?1 day?1) and Chlorella sp (60.00?±?2.4 mg biomass L?1 day?1 and 13.70?±?1.35 mg lipid L?1 day?1) were achieved when grown using CO2 as inorganic carbon source. No significant differences were found between CO2 and flue gas biomass and lipid productivities. While grown using CO2 and flue gas, biomass productivities were 10, 13 and 18 %, and 7, 14 and 19 % higher than NaHCO3, HCl and unregulated pH for T. suecica and Chlorella sp, respectively. Addition of inorganic carbon increased specific growth rate and lipid content but reduced biomass yield and cell weight of T. suecica. Addition of inorganic carbon increased yield but did not change specific growth rate, cell weight or content of the cell weight of Chlorella sp. Both strains showed significantly higher maximum quantum yield (Fv/Fm) when grown under optimum pH. 相似文献
18.
The influence of ammonia on the anaerobic degradation of peptone by mesophilic and thermophilic populations of biowaste was
investigated. For peptone concentrations from 5 g l−1 to 20 g l−1 the mesophilic population revealed a higher rate of deamination than the thermophilic population, e.g. 552 mg l−1 day−1 compared to 320 mg l−1 day−1 at 10 g l−1 peptone. The final degree of deamination of the thermophilic population was, however, higher: 102 compared to 87 mg NH3/g peptone in the mesophilic cultures. If 0.5–6.5 g l−1 ammonia was added to the mesophilic biowaste cultures, deamination of peptone, degradation of its chemical oxygen demand
(COD) and formation of biogas were increasingly inhibited, but no hydrogen was formed. The thermophilic biowaste cultures
were most active if around 1 g ammonia l−1 was present. Deamination, COD degradation and biogas production decreased at lower and higher ammonia concentrations and
hydrogen was formed in addition to methane. Studies of the inhibition by ammonia of peptone deamination, COD degradation and
methane formation revealed a K
i (50%) for NH3 of 92, 95 and 88 mg l−1 at 37 °C and 251, 274 and 297 mg l−1 at 55 °C respectively. This indicated that the thermophilic flora tolerated significantly more NH3 than the mesophilic flora. In the mesophilic reactor effluent 4.6 × 108 peptone-degrading colony-forming units (cfu)/ml were culturable, whereas in the thermophilic reactor effluent growth of only
5.6 × 107 cfu/ml was observed.
Received: 24 April 1998 / Received revision: 26 June 1998 / Accepted: 27 June 1998 相似文献
19.
Cement plants account for significant emissions of CO2 and other pollutants into the atmosphere. As a means for its mitigation, we tested the effect of a cement industry-based flue gas simulation (FGS — 18% CO2, 9% O2, 300 ppm NO2, 140 ppm SO2) on the green alga, Chlorella sorokiniana. Culture pH, cell density, cell viability and productivity, specific growth rates, photosynthetic performance, and biochemical composition were monitored. The treatments consisted of different FGS volumes (0.1, 0.3, 0.8, 1.5, 6, and 48 L day?1) that were applied in a series of laboratory-scale semi-continuous batch cultures under controlled conditions. Controls were exposed to 18% CO2 enriched air. Cell density showed that C. sorokiniana was able to grow in all treatments, but compared to the controls, low pH (~ 5.0) caused by 48 L FGS day?1 led to 27% decrease in specific growth rate. Increasing FGS exposure decreased maximum and operational quantum yields obtained by pulse amplitude modulated fluorometry, while photochemical quenching remained constant (~ 0.93). The α and rETR max parameters calculated from rapid light curves decreased with increasing FGS exposure. Total proteins and carbohydrates (per cell basis) increased after 6 and 48 L FGS day?1, which can be advantageous for biotechnological applications, but cell productivity (cells L?1 day?1) decreased. Despite the effects in physiology, C. sorokiniana could withstand a pH range of 6.0–5.0 imposed by 48 L FGS day?1. Overall, C. sorokiniana can be considered a robust species in flue gas bioremediation. 相似文献
20.
N. R. Moheimani 《Journal of applied phycology》2016,28(4):2139-2146
The accumulation of atmospheric CO2, primarily due to combustion of fossil fuels, has been implicated in potential global climate change. The high rate of CO2 bioremediation by microalgae has emerged as a favourable method for reducing coal-fired power plant emissions. However, coal-fired power station flue gas contains other chemicals such as SOx which can inhibit microalgal growth. In the current study, the effect of untreated flue gas as a source of inorganic carbon on the growth of Tetraselmis in a 1000 L industrial-scale split-cylinder internal-loop airlift photobioreactor was examined. The culture medium was recycled after each harvest. Tetraselmis suecica grew very well in this airlift photobioreactor during the 7-month experiment using recycled medium from an electroflocculation harvesting unit. Increased medium SO4 2? concentration as high as 870 mg SO4 2??L?1 due to flue gas addition and media recycling had no negative effect on the overall growth and productivity of this alga. The potential organic biomass productivity and carbon sequestration using an industrial-scale airlift PBR at International Power Hazelwood, Gippsland, Victoria, Australia, are 178.9?±?30 mg L?1 day?1 and 89.15?±?20 mg?‘C’?L?1 day?1, respectively. This study clearly indicates the potential of growing Tetraselmis on untreated flue gas and using recycled medium for the purpose of biofuel and CO2 bioremediation. 相似文献