1
|
Hu Q, Sun J, Sun D, Tian L, Ji Y, Qiu B. Simultaneous Cr(VI) bio-reduction and methane production by anaerobic granular sludge. BIORESOURCE TECHNOLOGY 2018; 262:15-21. [PMID: 29689436 DOI: 10.1016/j.biortech.2018.04.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/12/2018] [Accepted: 04/14/2018] [Indexed: 06/08/2023]
Abstract
Wastewater containing toxic hexavalent chromium (Cr(VI)) were treated with well-organized anaerobic granular sludge in this study. Results showed that the anaerobic granular sludge rapidly removed Cr(VI), and 2000 µg·L-1 Cr(VI) was completely eliminated within 6 min, which was much faster than the reported duration of removal by reported artificial materials. Sucrose added as a carbon source acted as an initial electron donor to reduce Cr(VI) to Cr(III). This process was considered as the main mechanism of Cr(VI) removal. Methane production by anaerobic granular sludge was improved by the addition of Cr(VI) at a concentration lower than 500 µg·L-1. Anaerobic granular sludge had a well-organized structure, which presented good resistance against toxic Cr(VI). Trichoccus accelerated the degradation of organic substances to generate acetates with a low Cr(VI) concentration, thereby enhancing methane production by acetotrophic methanogens.
Collapse
Affiliation(s)
- Qian Hu
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Jiaji Sun
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Dezhi Sun
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Lan Tian
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yanan Ji
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Bin Qiu
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| |
Collapse
|
2
|
Kallistova AY, Goel G, Nozhevnikova AN. Microbial diversity of methanogenic communities in the systems for anaerobic treatment of organic waste. Microbiology (Reading) 2014. [DOI: 10.1134/s0026261714050142] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
3
|
Calderón K, González-Martínez A, Gómez-Silván C, Osorio F, Rodelas B, González-López J. Archaeal diversity in biofilm technologies applied to treat urban and industrial wastewater: recent advances and future prospects. Int J Mol Sci 2013; 14:18572-98. [PMID: 24022691 PMCID: PMC3794796 DOI: 10.3390/ijms140918572] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 08/22/2013] [Accepted: 08/30/2013] [Indexed: 02/07/2023] Open
Abstract
Biological wastewater treatment (WWT) frequently relies on biofilms for the removal of anthropogenic contaminants. The use of inert carrier materials to support biofilm development is often required, although under certain operating conditions microorganisms yield structures called granules, dense aggregates of self-immobilized cells with the characteristics of biofilms maintained in suspension. Molecular techniques have been successfully applied in recent years to identify the prokaryotic communities inhabiting biofilms in WWT plants. Although methanogenic Archaea are widely acknowledged as key players for the degradation of organic matter in anaerobic bioreactors, other biotechnological functions fulfilled by Archaea are less explored, and research on their significance and potential for WWT is largely needed. In addition, the occurrence of biofilms in WWT plants can sometimes be a source of operational problems. This is the case for membrane bioreactors (MBR), an advanced technology that combines conventional biological treatment with membrane filtration, which is strongly limited by biofouling, defined as the undesirable accumulation of microbial biofilms and other materials on membrane surfaces. The prevalence and spatial distribution of archaeal communities in biofilm-based WWT as well as their role in biofouling are reviewed here, in order to illustrate the significance of this prokaryotic cellular lineage in engineered environments devoted to WWT.
Collapse
Affiliation(s)
- Kadiya Calderón
- Environmental Microbiology Group, Department of Microbiology, Faculty of Pharmacy, and Institute of Water Research, University of Granada, Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (C.G.-S.); (B.R.); (J.G.-L.)
| | - Alejandro González-Martínez
- Environmental Microbiology Group, Department of Civil Engineering, and Institute of Water Research, University of Granada; Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (A.G.-M.); (F.O.)
| | - Cinta Gómez-Silván
- Environmental Microbiology Group, Department of Microbiology, Faculty of Pharmacy, and Institute of Water Research, University of Granada, Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (C.G.-S.); (B.R.); (J.G.-L.)
| | - Francisco Osorio
- Environmental Microbiology Group, Department of Civil Engineering, and Institute of Water Research, University of Granada; Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (A.G.-M.); (F.O.)
| | - Belén Rodelas
- Environmental Microbiology Group, Department of Microbiology, Faculty of Pharmacy, and Institute of Water Research, University of Granada, Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (C.G.-S.); (B.R.); (J.G.-L.)
| | - Jesús González-López
- Environmental Microbiology Group, Department of Microbiology, Faculty of Pharmacy, and Institute of Water Research, University of Granada, Campus de Cartuja s/n, Granada 18071, Spain; E-Mails: (C.G.-S.); (B.R.); (J.G.-L.)
| |
Collapse
|
4
|
Khemkhao M, Nuntakumjorn B, Techkarnjanaruk S, Phalakornkule C. UASB performance and microbial adaptation during a transition from mesophilic to thermophilic treatment of palm oil mill effluent. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2012; 103:74-82. [PMID: 22466006 DOI: 10.1016/j.jenvman.2012.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 02/16/2012] [Accepted: 03/02/2012] [Indexed: 05/31/2023]
Abstract
The treatment of palm oil mill effluent (POME) by an upflow anaerobic sludge bed (UASB) at organic loading rates (OLR) between 2.2 and 9.5 g COD l(-1) day(-1) was achieved by acclimatizing the mesophilic (37 °C) microbial seed to the thermophilic temperature (57 °C) by a series of stepwise temperature shifts. The UASB produced up to 13.2 l biogas d(-1) with methane content on an average of 76%. The COD removal efficiency ranged between 76 and 86%. Microbial diversity of granules from the UASB reactor was also investigated. The PCR-based DGGE analysis showed that the bacterial population profiles significantly changed with the temperature transition from mesophilic to thermophilic conditions. In addition, the results suggested that even though the thermophilic temperature of 57 °C was suitable for a number of hydrolytic, acidogenic and acetogenic bacteria, it may not be suitable for some Methanosaeta species acclimatized from 37 °C. Specifically, the bands associated with Methanosaeta thermophila PT and Methanosaeta harundinacea can be detected during the four consecutive operation phases of 37 °C, 42 °C, 47 °C and 52 °C, but their corresponding bands were found to fade out at 57 °C. The DGGE analysis predicted that the temperature transition can result in significant methanogenic biomass washout at 57 °C.
Collapse
Affiliation(s)
- Maneerat Khemkhao
- Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | | | | | | |
Collapse
|
5
|
Lerm S, Kleyböcker A, Miethling-Graff R, Alawi M, Kasina M, Liebrich M, Würdemann H. Archaeal community composition affects the function of anaerobic co-digesters in response to organic overload. WASTE MANAGEMENT (NEW YORK, N.Y.) 2012; 32:389-399. [PMID: 22192420 DOI: 10.1016/j.wasman.2011.11.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 11/04/2011] [Accepted: 11/17/2011] [Indexed: 05/31/2023]
Abstract
Microbial community diversity in two thermophilic laboratory-scale and three full-scale anaerobic co-digesters was analysed by genetic profiling based on PCR-amplified partial 16S rRNA genes. In parallel operated laboratory reactors a stepwise increase of the organic loading rate (OLR) resulted in a decrease of methane production and an accumulation of volatile fatty acids (VFAs). However, almost threefold different OLRs were necessary to inhibit the gas production in the reactors. During stable reactor performance, no significant differences in the bacterial community structures were detected, except for in the archaeal communities. Sequencing of archaeal PCR products revealed a dominance of the acetoclastic methanogen Methanosarcina thermophila, while hydrogenotrophic methanogens were of minor importance and differed additionally in their abundance between reactors. As a consequence of the perturbation, changes in bacterial and archaeal populations were observed. After organic overload, hydrogenotrophic methanogens (Methanospirillum hungatei and Methanoculleus receptaculi) became more dominant, especially in the reactor attributed by a higher OLR capacity. In addition, aggregates composed of mineral and organic layers formed during organic overload and indicated tight spatial relationships between minerals and microbial processes that may support de-acidification processes in over-acidified sludge. Comparative analyses of mesophilic stationary phase full-scale reactors additionally indicated a correlation between the diversity of methanogens and the VFA concentration combined with the methane yield. This study demonstrates that the coexistence of two types of methanogens, i.e. hydrogenotrophic and acetoclastic methanogens is necessary to respond successfully to perturbation and leads to stable process performance.
Collapse
Affiliation(s)
- S Lerm
- International Centre for Geothermal Research (ICGR), GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany
| | | | | | | | | | | | | |
Collapse
|
6
|
Narihiro T, Sekiguchi Y. Oligonucleotide primers, probes and molecular methods for the environmental monitoring of methanogenic archaea. Microb Biotechnol 2011; 4:585-602. [PMID: 21375721 PMCID: PMC3819009 DOI: 10.1111/j.1751-7915.2010.00239.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 11/12/2010] [Indexed: 11/28/2022] Open
Abstract
For the identification and quantification of methanogenic archaea (methanogens) in environmental samples, various oligonucleotide probes/primers targeting phylogenetic markers of methanogens, such as 16S rRNA, 16S rRNA gene and the gene for the α-subunit of methyl coenzyme M reductase (mcrA), have been extensively developed and characterized experimentally. These oligonucleotides were designed to resolve different groups of methanogens at different taxonomic levels, and have been widely used as hybridization probes or polymerase chain reaction primers for membrane hybridization, fluorescence in situ hybridization, rRNA cleavage method, gene cloning, DNA microarray and quantitative polymerase chain reaction for studies in environmental and determinative microbiology. In this review, we present a comprehensive list of such oligonucleotide probes/primers, which enable us to determine methanogen populations in an environment quantitatively and hierarchically, with examples of the practical applications of the probes and primers.
Collapse
Affiliation(s)
- Takashi Narihiro
- International Patent Organism Depositary (IPOD), Tsukuba, Ibaraki 305‐8566, Japan
| | - Yuji Sekiguchi
- Bio‐medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305‐8566, Japan
| |
Collapse
|
7
|
Acharya BK, Pathak H, Mohana S, Shouche Y, Singh V, Madamwar D. Kinetic modelling and microbial community assessment of anaerobic biphasic fixed film bioreactor treating distillery spent wash. WATER RESEARCH 2011; 45:4248-4259. [PMID: 21704352 DOI: 10.1016/j.watres.2011.05.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/14/2011] [Accepted: 05/31/2011] [Indexed: 05/31/2023]
Abstract
Anaerobic digestion, microbial community structure and kinetics were studied in a biphasic continuously fed, upflow anaerobic fixed film reactor treating high strength distillery wastewater. Treatment efficiency of the bioreactor was investigated at different hydraulic retention times (HRT) and organic loading rates (OLR 5-20 kg COD m⁻³ d⁻¹). Applying the modified Stover-Kincannon model to the reactor, the maximum removal rate constant (U(max)) and saturation value constant (K(B)) were found to be 2 kg m⁻³ d⁻¹ and 1.69 kg m⁻³ d⁻¹ respectively. Bacterial community structures of acidogenic and methanogenic reactors were assessed using culture-independent analyses. Sequencing of 16S rRNA genes exhibited a total of 123 distinct operational taxonomic units (OTUs) comprising 49 from acidogenic reactor and 74 (28 of eubacteria and 46 of archaea) from methanogenic reactor. The findings reveal the role of Lactobacillus sp. (Firmicutes) as dominant acid producing organisms in acidogenic reactor and Methanoculleus sp. (Euryarchaeotes) as foremost methanogens in methanogenic reactor.
Collapse
Affiliation(s)
- Bhavik K Acharya
- BRD School of Bioscience, Sardar Patel Maidan, Vadtal Road, Satellite Campus, PO Box 39, Sardar Patel University, Vallabh Vidyanagar 388120, Gujarat, India
| | | | | | | | | | | |
Collapse
|
8
|
Khemkhao M, Nuntakumjorn B, Techkarnjanaruk S, Phalakornkule C. Effect of chitosan on UASB treating POME during a transition from mesophilic to thermophilic conditions. BIORESOURCE TECHNOLOGY 2011; 102:4674-4681. [PMID: 21316949 DOI: 10.1016/j.biortech.2011.01.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 05/30/2023]
Abstract
The effects of chitosan addition on treatment of palm oil mill effluent were investigated using two lab-scale upflow anaerobic sludge bed (UASB) reactors: (1) with chitosan addition at the dosage of 2 mg chitosan per g volatile suspended solids on the first day of the operation (R1), (2) without chitosan addition (the control, R2). The reactors were inoculated with mesophilic anaerobic sludge which was acclimatized to a thermophilic condition with a stepwise temperature increase of 5 °C from 37 to 57 °C. The OLR ranged from 2.23 to 9.47 kg COD m(-3) day(-1). The difference in biogas production rate increased from non-significant to 18% different. The effluent volatile suspended solids of R1 was 65 mg l(-1) lower than that of R2 on Day 123. 16S rRNA targeted denaturing gradient gel electrophoresis (DGGE) fingerprints of microbial community indicated that some methanogens in the genus Methanosaeta can be detected in R1 but not in R2.
Collapse
Affiliation(s)
- Maneerat Khemkhao
- The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | | | | | | |
Collapse
|
9
|
Lens PN, De Beer D, Cronenberg CC, Houwen FP, Ottengraf SP, Verstraete WH. Heterogeneous Distribution of Microbial Activity in Methanogenic Aggregates: pH and Glucose Microprofiles. Appl Environ Microbiol 2010; 59:3803-15. [PMID: 16349091 PMCID: PMC182535 DOI: 10.1128/aem.59.11.3803-3815.1993] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methanogenic aggregates, harvested from an upflow anaerobic sludge blanket reactor treating potato starch wastewater, were acclimatized to either glucose or a mixture of sugars and organic nitrogen compounds (i.e., diluted molasses). Both types of granules exhibited internal pH and substrate concentration gradients in mineral medium (pH 7.0, 30 degrees C) as was measured with microelectrodes. Glucose-acclimatized granules suspended in a mineral medium lacking glucose exhibited a distinct internal pH decrease of about 1 U within the granule, suggesting strong metabolism by the acidogenic bacteria. Molasses-acclimatized and aged granules suspended in mineral medium did not exhibit such a pH decrease, suggesting the importance of the metabolic state of these acidogens. The pH gradient did not occur in deactivated granules and was not observable in strongly buffered media (mineral medium containing 33 mM phosphate or reactor liquid). When glucose (0.5 to 5.0 mM) was added to the mineral medium, granules exhibited a convex pH profile. Glucose consumption was located exclusively in the outer 200 to 300 mum of the aggregates (mean diameter = 1.5 mm). The addition of 20 mM 2-bromoethanesulfonic acid to the mineral medium indicated that the higher pH levels in the centre of the granule appeared to be related to the activity of methanogens. It is suggested that acidogenic activity occurs predominantly in the outer 200 to 300 mum of the aggregate and methanogenic activity occurs predominantly in the center of the investigated granules.
Collapse
Affiliation(s)
- P N Lens
- Laboratory of Microbial Ecology and Centre for Environmental Sanitation, University of Gent, Coupure L. 653, 9000 Gent, Belgium, and Laboratory for Chemical Technology, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
10
|
Wu W, Jain MK, Zeikus JG. Formation of Fatty Acid-degrading, anaerobic granules by defined species. Appl Environ Microbiol 2010; 62:2037-44. [PMID: 16535336 PMCID: PMC1388874 DOI: 10.1128/aem.62.6.2037-2044.1996] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An endospore-forming, butyrate-degrading bacterium (strain BH) was grown on butyrate in monoxenic coculture with a methanogen. The culture formed dense aggregates when Methanobacterium formicicum was the methanogenic partner, but the culture was turbid when Methanospirillum hungatei was the partner. In contrast, a propionate-degrading, lemon-shaped bacterium (strain PT) did not form aggregates with Methanobacterium formicicum unless an acetate-degrading Methanosaeta sp. was also included in the culture. Fatty acid-degrading methanogenic granules were formed in a laboratory-scale upflow reactor at 35(deg)C fed with a medium containing a mixture of acetate, propionate, and butyrate by using defined cultures of Methanobacterium formicicum T1N, Methanosaeta sp. strain M7, Methanosarcina mazei T18, propionate-degrading strain PT, and butyrate-degrading strain BH. The maximum substrate conversion rates of these granules for acetate, propionate, and butyrate were 43, 9, and 17 mmol/g (dry weight)/day, respectively. The average size of the granules was about 1 mm. Electron microscopic observation of the granules revealed that the cells of Methanobacterium formicicum, Methanosaeta sp., butyrate-degrading, and propionate-degrading bacteria were dispersed in the granules. Methanosarcina mazei existed inside the granules as aggregates of its own cells, which were associated with the bulk of the granules. The interaction of different species in aggregate formation and granule formation is discussed in relation to polymer formation of the cell surface.
Collapse
|
11
|
Anaerobic digestion of renewable biomass: thermophilic temperature governs methanogen population dynamics. Appl Environ Microbiol 2010; 76:1842-50. [PMID: 20097828 DOI: 10.1128/aem.02397-09] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Beet silage and beet juice were digested continuously as representative energy crops in a thermophilic biogas fermentor for more than 7 years. Fluorescence microscopy of 15 samples covering a period of 650 days revealed that a decrease in temperature from 60 degrees C to 55 degrees C converted a morphologically uniform archaeal population (rods) into a population of methanogens exhibiting different cellular morphologies (rods and coccoid cells). A subsequent temperature increase back to 60 degrees C reestablished the uniform morphology of methanogens observed in the previous 60 degrees C period. In order to verify these observations, representative samples were investigated by amplified rRNA gene restriction analysis (ARDRA) and fluorescence in situ hybridization (FISH). Both methods confirmed the temperature-dependent population shift observed by fluorescence microscopy. Moreover, all samples investigated demonstrated that hydrogenotrophic Methanobacteriales dominated in the fermentor, as 29 of 34 identified operational taxonomic units (OTUs) were assigned to this order. This apparent discrimination of acetoclastic methanogens contradicts common models for anaerobic digestion processes, such as anaerobic digestion model 1 (ADM1), which describes the acetotrophic Euryarchaeota as predominant organisms.
Collapse
|
12
|
Malin C, Illmer P. Ability of DNA content and DGGE analysis to reflect the performance condition of an anaerobic biowaste fermenter. Microbiol Res 2007; 163:503-11. [PMID: 17765499 DOI: 10.1016/j.micres.2007.07.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 06/26/2007] [Accepted: 07/28/2007] [Indexed: 10/22/2022]
Abstract
Molecular-microbiological techniques have delivered insight into microbial populations present in anaerobic fermenters, although much information still remains to be elucidated. In this study, the ability of denaturing gradient gel electrophoresis (DGGE) to throw light on microbial community composition was investigated and latter data were compared with the gas production of a 750,000l anaerobic biogas fermenter. During 1 year, samples were taken from two different sites of the reactor and additionally from the substrate material. After DNA extraction and PCR with archaeal and bacterial primers, PCR products were run on denaturing gradient gels to compare band patterns. Using gel-imaging software (GelComparII), two major clusters could be identified. Dominant bands were excised from the gels, reamplified and sequenced. Most sequences were closely related to Lactobacilli and yet uncultured microorganisms. DNA content of all samples was significantly correlated with the gas production measured online. We concluded that PCR and subsequent DGGE are useful to monitor community shifts in anaerobic fermenter sludge. However, as these changes are not readily detectable via DGGE-pattern analysis, alternative factors influencing the fermenter functioning should be found and investigated. So far DNA-content measurement seems to be a good parameter to quickly determine anaerobic fermenter condition.
Collapse
Affiliation(s)
- Cornelia Malin
- Institute of Microbiology, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | | |
Collapse
|
13
|
Watanabe K, Baker PW. Environmentally relevant microorganisms. J Biosci Bioeng 2005; 89:1-11. [PMID: 16232691 DOI: 10.1016/s1389-1723(00)88043-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/1999] [Accepted: 12/03/1999] [Indexed: 11/19/2022]
Abstract
The development of molecular microbial ecology in the 1990s has allowed scientists to realize that microbial populations in the natural environment are much more diverse than microorganisms so far isolated in the laboratory. This finding has exerted a significant impact on environmental biotechnology, since knowledge in this field has been largely dependent on studies with pollutant-degrading bacteria isolated by conventional culture methods. Researchers have thus started to use molecular ecological methods to analyze microbial populations relevant to pollutant degradation in the environment (called environmentally relevant microorganisms, ERMs), although further effort is needed to gain practical benefits from these studies. This review highlights the utility and limitations of molecular ecological methods for understanding and advancing environmental biotechnology processes. The importance of the combined use of molecular ecological and physiological methods for identifying ERMs is stressed.
Collapse
Affiliation(s)
- K Watanabe
- Marine Biotechnology Institute, Kamaishi Laboratories, 3-75-1 Heita, Kamaishi, Iwate 026-0001, Japan
| | | |
Collapse
|
14
|
Leclerc M, Delgènes JP, Godon JJ. Diversity of the archaeal community in 44 anaerobic digesters as determined by single strand conformation polymorphism analysis and 16S rDNA sequencing. Environ Microbiol 2004; 6:809-19. [PMID: 15250883 DOI: 10.1111/j.1462-2920.2004.00616.x] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The diversity of Archaea in anaerobic digesters was characterized by strand conformation polymorphism (SSCP) analysis and the sequencing of 16S rDNA genes. The 44 digesters sampled, located in eight different countries, treated effluents from agriculture, the food processing and petro-chemical industries, pulp and paper plant, breweries, slaughterhouses and municipal waste. All the existing processes were represented among the samples (fixed-film, fluidized bed, stirred-tank, UASB, sequential batch reactor, lagoon). Single strand conformation polymorphism analysis targeting the V3 region of 16S rDNA revealed between four to six distinct archaeal peaks per digester. The diversity of dominant Archaea in the 44 digesters was estimated as 23 different 16S rDNA sequences. Cloning of archaeal 16S rRNA genes from 11 distinct total genomic DNA, screening of clones by SSCP and the sequencing of 170 of them made it possible to characterize these SSCP peaks. All the sequences retrieved were members of the Euryarchaeaota subdomain. Furthermore, most of the sequences retrieved were very close to already known and cultivated strains or to environmental clones. The most frequent archaeal sequences were close to Methanosaeta concilii and to a 16S rDNA clone vadinDC06 located in the Methanobacterium clade (84% and 73% of digesters respectively). The other sequences were members of the Methanobacteriales and the Methanomicrobiales families. Only one sequence was far from any sequence of the database and it could be grouped with several sequences of environmental clones. Each digester harboured between two to nine archaeal sequences with only one of them corresponding to a putative acetate-utilizing species. Furthermore, the process in the digesters appeared to play a part in the distribution of archaeal diversity.
Collapse
Affiliation(s)
- Marion Leclerc
- Laboratoire de Biotechnologie de l'Environnement, Institut National de la Recherche Agronomique, Avenue des Etangs, 11100 Narbonne, France
| | | | | |
Collapse
|
15
|
Conway de Macario E, Macario AJL. Molecular biology of stress genes in methanogens: potential for bioreactor technology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2003; 81:95-150. [PMID: 12747562 DOI: 10.1007/3-540-45839-5_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many agents of physical, chemical, or biological nature, have the potential for causing cell stress. These agents are called stressors and their effects on cells are due to protein denaturation. Cells, microbes, for instance, perform their physiological functions and survive stress only if they have their proteins in the necessary concentrations and shapes. To be functional a protein shape must conform to a specific three-dimensional arrangement, named the native configuration. When a stressor (e.g., temperature elevation or heat shock, decrease in pH, hypersalinity, heavy metals) hits a microbe, it causes proteins to lose their native configuration, which is to say that stressors cause protein denaturation. The cell mounts an anti-stress response: house-keeping genes are down-regulated and stress genes are activated. Among the latter are the genes that produce the Hsp70(DnaK), Hsp60, and small heat protein (sHsp) families of stress proteins. Hsp70(DnaK) is part of the molecular chaperone machine together with Hsp40(DnaJ) and GrpE, and Hsp60 is a component of the chaperonin complex. Both the chaperone machine and the chaperonins play a crucial role in assisting microbial proteins to reach their native, functional configuration and to regain it when it is partially lost due to stress. Proteins that are denatured beyond repair are degraded by proteases so they do not accumulate and become a burden to the cell. All Archaea studied to date possess chaperonins but only some methanogens have the chaperone machine. A recent genome survey indicates that Archaea do not harbor well conserved equivalents of the co-chaperones trigger factor, Hip, Hop, BAG-1, and NAC, although the data suggest that Archaea have proteins related to Hop and to the NAC alpha subunit whose functions remain to be elucidated. Other anti-stress means involve osmolytes, ion traffic, and formation of multicellular structures. All cellular anti-stress mechanisms depend on genes whose products are directly involved in counteracting the effects of stressors, or are regulators. The latter proteins monitor and modulate gene activity. Biomethanation depends on the concerted action of at least three groups of microbes, the methanogens being one of them. Their anti-stress mechanisms are briefly discussed in this Chapter from the standpoint of their role in biomethanation with emphasis on their potential for optimizing bioreactor performance. Bioreactors usually contain stressors that come with the influent, or are produced during the digestion process. If the stressors reach levels above those that can be dealt with by the anti-stress mechanisms of the microbes in the bioreactor, the microbes will die or at least cease to function. The bioreactor will malfunction and crash. Manipulation of genes involved in the anti-stress response, particularly those pertinent to the synthesis and regulation of the Hsp70(DnaK) and Hsp60 molecular machines, is a promising avenue for improving the capacity of microbes to withstand stress, and thus to continue biomethanation even when the bioreactor is loaded with harsh waste. The engineering of methanogenic consortia with stress-resistant microbes, made on demand for efficient bioprocessing of stressor-containing effluents and wastes, is a tangible possibility for the near future. This promising biotechnological development will soon become a reality due to the advances in the study of the stress response and anti-stress mechanisms at the molecular and genetic levels.
Collapse
Affiliation(s)
- Everly Conway de Macario
- Wadsworth Center, Division of Molecular Medicine, New York State Department of Health, Department of Biomedical Sciences, School of Public Health, The University at Albany, Albany, New York 12201-0509, USA.
| | | |
Collapse
|
16
|
McHugh S, Carton M, Mahony T, O'Flaherty V. Methanogenic population structure in a variety of anaerobic bioreactors. FEMS Microbiol Lett 2003; 219:297-304. [PMID: 12620635 DOI: 10.1016/s0378-1097(03)00055-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The methanogenic community structures of six anaerobic sludges were examined using culture-independent techniques. The sludges were obtained from full-scale and laboratory-scale bioreactors, treating a variety of low- and high-strength, simple and complex wastewaters at psychrophilic (10-14 degrees C), mesophilic (37 degrees C) and thermophilic (55 degrees C) temperatures. Amplified rDNA restriction analysis identified 18 methanogenic operational taxonomic units in the six samples. 16S rRNA gene sequencing and phylogenetic reconstruction demonstrated that five separate groups of methanogens were represented with Methanosaeta-like species dominant in all sludges, but particularly in samples from a psychrophilic bioreactor treating low-strength synthetic sewage (75% of all clones detected).
Collapse
Affiliation(s)
- Sharon McHugh
- Microbial Ecology Laboratory, Microbiology Department, National University of Ireland, Galway, Ireland
| | | | | | | |
Collapse
|
17
|
Leclerc, Delbes, Moletta, Godon. Single strand conformation polymorphism monitoring of 16S rDNA Archaea during start-up of an anaerobic digester. FEMS Microbiol Ecol 2001; 34:213-220. [PMID: 11137601 DOI: 10.1111/j.1574-6941.2001.tb00772.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
A laboratory-scale continuously mixed anaerobic digester was inoculated with a mix of anaerobic sludge and fed with glucose. The start-up strategy was progressive and chemical analyses were done to evaluate digester performance from day 1 to day 107. In parallel, Archaeal community dynamics were monitored by SSCP analysis of the V3 region of 16S rDNA genes and further characterized by partial sequencing of 16S rDNA genes. At day 1 the inoculum contained at least five distinct Archaeal peaks close to known methanogenic species. The dominant peak was very close to Methanosaeta concilli, the remaining species being members of the Methanobacteriales and Methanomicrobiales. A rapid shift of the Archaeal population was observed during the experiment. At day 21 Methanobacterium formicicum, which was not detected at day 1, became the dominant methanogenic species in the bioreactor and remained so until the end of the experiment.
Collapse
Affiliation(s)
- Leclerc
- Laboratoire de Biotechnologie de l'Environnement, Institut National de la Recherche Agronomique, Avenue des Etangs, 11100, Narbonne, France
| | | | | | | |
Collapse
|
18
|
|
19
|
Rocheleau, Greer, Lawrence, Cantin, Laramee, Guiot. Differentiation of methanosaeta concilii and methanosarcina barkeri in anaerobic mesophilic granular sludge by fluorescent In situ hybridization and confocal scanning laser microscopy. Appl Environ Microbiol 1999; 65:2222-9. [PMID: 10224023 PMCID: PMC91320 DOI: 10.1128/aem.65.5.2222-2229.1999] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/1998] [Accepted: 02/17/1999] [Indexed: 11/20/2022] Open
Abstract
Oligonucleotide probes, designed from genes coding for 16S rRNA, were developed to differentiate Methanosaeta concilii, Methanosarcina barkeri, and mesophilic methanogens. All M. concilii oligonucleotide probes (designated MS1, MS2, and MS5) hybridized specifically with the target DNA, but MS5 was the most specific M. concilii oligonucleotide probe. Methanosarcina barkeri oligonucleotide probes (designated MB1, MB3, and MB4) hybridized with different Methanosarcina species. The MB4 probe specifically detected Methanosarcina barkeri, and the MB3 probe detected the presence of all mesophilic Methanosarcina species. These new oligonucleotide probes facilitated the identification, localization, and quantification of the specific relative abundance of M. concilii and Methanosarcina barkeri, which play important roles in methanogenesis. The combined use of fluorescent in situ hybridization with confocal scanning laser microscopy demonstrated that anaerobic granule topography depends on granule origin and feeding. Protein-fed granules showed no layered structure with a random distribution of M. concilii. In contrast, a layered structure developed in methanol-enriched granules, where M. barkeri growth was induced in an outer layer. This outer layer was followed by a layer composed of M. concilii, with an inner core of M. concilii and other bacteria.
Collapse
Affiliation(s)
- Rocheleau
- Environmental Bioengineering Group, Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, Canada H4P 2R2
| | | | | | | | | | | |
Collapse
|
20
|
Sekiguchi Y, Kamagata Y, Nakamura K, Ohashi A, Harada H. Fluorescence in situ hybridization using 16S rRNA-targeted oligonucleotides reveals localization of methanogens and selected uncultured bacteria in mesophilic and thermophilic sludge granules. Appl Environ Microbiol 1999; 65:1280-8. [PMID: 10049894 PMCID: PMC91175 DOI: 10.1128/aem.65.3.1280-1288.1999] [Citation(s) in RCA: 322] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
16S rRNA-targeted in situ hybridization combined with confocal laser scanning microscopy was used to elucidate the spatial distribution of microbes within two types of methanogenic granular sludge, mesophilic (35 degrees C) and thermophilic (55 degrees C), in upflow anaerobic sludge blanket reactors fed with sucrose-, acetate-, and propionate-based artificial wastewater. The spatial organization of the microbes was visualized in thin sections of the granules by using fluorescent oligonucleotide probes specific to several phylogenetic groups of microbes. In situ hybridization with archaeal- and bacterial-domain probes within granule sections clearly showed that both mesophilic and thermophilic granules had layered structures and that the outer layer harbored mainly bacterial cells while the inner layer consisted mainly of archaeal cells. Methanosaeta-, Methanobacterium-, Methanospirillum-, and Methanosarcina-like cells were detected with oligonucleotide probes specific for the different groups of methanogens, and they were found to be localized inside the granules, in both types of which dominant methanogens were members of the genus Methanosaeta. For specific detection of bacteria which were previously detected by whole-microbial-community 16S ribosomal DNA (rDNA)-cloning analysis (Y. Sekiguchi, Y. Kamagata, K. Syutsubo, A. Ohashi, H. Harada, and K. Nakamura, Microbiology 144:2655-2665, 1998) we designed probes specific for clonal 16S rDNAs related to unidentified green nonsulfur bacteria and clones related to Syntrophobacter species. The probe designed for the cluster closely related to Syntrophobacter species hybridized with coccoid cells in the inner layer of the mesophilic granule sections. The probe for the unidentified bacteria which were clustered with the green nonsulfur bacteria detected filamentous cells in the outermost layer of the thermophilic sludge granule sections. These results revealed the spatial organizations of methanogens and uncultivated bacteria and their in situ morphologies and metabolic functions in both mesophilic and thermophilic granular sludges.
Collapse
Affiliation(s)
- Y Sekiguchi
- Department of Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan.
| | | | | | | | | |
Collapse
|
21
|
Daffonchio D, De Biase A, Rizzi A, Sorlini C. Interspecific, intraspecific and interoperonic variability in the 16S rRNA gene of methanogens revealed by length and single-strand conformation polymorphism analysis. FEMS Microbiol Lett 1998; 164:403-10. [PMID: 9682489 DOI: 10.1111/j.1574-6968.1998.tb13116.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Thirty-seven strains of mesophilic and thermophilic methanogenic Archaea, belonging to 30 species, were analyzed by length polymorphism (LP) and single-strand conformation polymorphism (SSCP) of an amplified 300-bp fragment of the 16S rRNA gene (Escherichia coli positions 9-331) including the variable regions V1 and V2, LPs and SSCPs were detected between species and between strains of the same species (Methanobacterium formicicum). LPs were found in Mb. formicicum DSMZ 3637, Mb. ivanovii DSMZ 2611, Mb. wolfei DSMZ 2970, Methanosarcina barkeri DSMZ 800, and Methanosaeta concilii DSMZ 3671, suggesting the presence of polymorphic 16S rRNA genes in the genome. We propose that LP and SSCP analysis of the 16S rRNA gene could be of practical help for strain identification.
Collapse
Affiliation(s)
- D Daffonchio
- Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche (DISTAM), Università degli Studi di Milano, Italy.
| | | | | | | |
Collapse
|
22
|
Sørensen AH, Ahring BK. An improved enzyme-linked immunosorbent assay for whole-cell determination of methanogens in samples from anaerobic reactors. Appl Environ Microbiol 1997; 63:2001-6. [PMID: 9143130 PMCID: PMC168490 DOI: 10.1128/aem.63.5.2001-2006.1997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An enzyme-linked immunosorbent assay was developed for the detection of whole cells of methanogens in samples from anaerobic continuously stirred tank digesters treating slurries of solid waste. The assay was found to allow for quantitative analysis of the most important groups of methanogens in samples from anaerobic digesters in a reproducible manner. Polyclonal antisera against eight strains of methanogens were employed in the test. The specificities of the antisera were increased by adsorption with cross-reacting cells. The reproducibility of the assay depended on the use of high-quality microtiter plates and the addition of dilute hydrochloric acid to the samples. In an experiment on different digester samples, the test demonstrated a unique pattern of different methanogenic strains present in each sample. The limited preparatory work required for the assay and the simple assay design make the test well suited for routine analysis of large numbers of samples and thus for process surveillance during operation of biogas digesters.
Collapse
Affiliation(s)
- A H Sørensen
- Institute of Environmental Science and Engineering, Technical University of Denmark, Lyngby, Denmark
| | | |
Collapse
|
23
|
Conrad R. Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO). Microbiol Rev 1996; 60:609-40. [PMID: 8987358 PMCID: PMC239458 DOI: 10.1128/mr.60.4.609-640.1996] [Citation(s) in RCA: 360] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Production and consumption processes in soils contribute to the global cycles of many trace gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and climate. Soil microbial processes contribute substantially to the budgets of atmospheric trace gases. The flux of trace gases between soil and atmosphere is usually the result of simultaneously operating production and consumption processes in soil: The relevant processes are not yet proven with absolute certainty, but the following are likely for trace gas consumption: H2 oxidation by abiontic soil enzymes; CO cooxidation by the ammonium monooxygenase of nitrifying bacteria; CH4 oxidation by unknown methanotrophic bacteria that utilize CH4 for growth; OCS hydrolysis by bacteria containing carbonic anhydrase; N2O reduction to N2 by denitrifying bacteria; NO consumption by either reduction to N2O in denitrifiers or oxidation to nitrate in heterotrophic bacteria. Wetland soils, in contrast to upland soils are generally anoxic and thus support the production of trace gases (H2, CO, CH4, N2O, and NO) by anaerobic bacteria such as fermenters, methanogens, acetogens, sulfate reducers, and denitrifiers. Methane is the dominant gaseous product of anaerobic degradation of organic matter and is released into the atmosphere, whereas the other trace gases are only intermediates, which are mostly cycled within the anoxic habitat. A significant percentage of the produced methane is oxidized by methanotrophic bacteria at anoxic-oxic interfaces such as the soil surface and the root surface of aquatic plants that serve as conduits for O2 transport into and CH4 transport out of the wetland soils. The dominant production processes in upland soils are different from those in wetland soils and include H2 production by biological N2 fixation, CO production by chemical decomposition of soil organic matter, and NO and N2O production by nitrification and denitrification. The processes responsible for CH4 production in upland soils are completely unclear, as are the OCS production processes in general. A problem for future research is the attribution of trace gas metabolic processes not only to functional groups of microorganisms but also to particular taxa. Thus, it is completely unclear how important microbial diversity is for the control of trace gas flux at the ecosystem level. However, different microbial communities may be part of the reason for differences in trace gas metabolism, e.g., effects of nitrogen fertilizers on CH4 uptake by soil; decrease of CH4 production with decreasing temperature; or different rates and modes of NO and N2O production in different soils and under different conditions.
Collapse
Affiliation(s)
- R Conrad
- Max-Planck-Institut für terrestrische Mikrobiologie, Marburg, Germany
| |
Collapse
|
24
|
Zellner G, Macario AJL, de Macario EC. Microbial subpopulations in the biofilm attached to the substratum and in the free flocs of a fixed-bed anaerobic bioreactor. Appl Microbiol Biotechnol 1996. [DOI: 10.1007/bf00166243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
25
|
Harmsen HJ, Kengen HM, Akkermans AD, Stams AJ, de Vos WM. Detection and localization of syntrophic propionate-oxidizing bacteria in granular sludge by in situ hybridization using 16S rRNA-based oligonucleotide probes. Appl Environ Microbiol 1996; 62:1656-63. [PMID: 8633864 PMCID: PMC167940 DOI: 10.1128/aem.62.5.1656-1663.1996] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In situ hybridization with fluorescent oligonucleotides was used to detect and localize microorganisms in the granules of two lab-scale upflow anaerobic sludge blanket reactors that had been fed for several months with either sucrose or a mixture of volatile fatty acids. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Bacteria, Archaea, specific phylogenetic groups of methanogens, and two syntrophic propionate-oxidizing strains, MPOB and KOPROP1. Cells of the syntrophic strain KOPROP1 were not detected in either type of sludge granules. Hybridizations of the sucrose-fed granules showed an outer layer of mainly bacterial microcolonies with different morphologies. More inwards of these granules, a layer of different methanogenic microcolonies mixed with large colonies of the syntrophic strain MPOB could be detected. The MPOB colonies were intertwined with hydrogen- or formate-consuming methanogens, indicating their syntrophic growth. The granules fed with volatile fatty acids showed an outer layer of mainly bacteria and then a thick layer of Methanosaeta-like methanogens mixed with a few bacteria and a layer of methanogens mixed with syntrophic MPOB microcolonies. The centers of both sludge types consisted of large cavities and methanogenic microcolonies. These results indicate a juxtapositioning of syntrophic bacteria and methanogens and provide additional evidence for a layered microbial architecture of anaerobic granular sludge.
Collapse
Affiliation(s)
- H J Harmsen
- Department of Microbiology, Wageningen Agricultural University, The Netherlands
| | | | | | | | | |
Collapse
|
26
|
Schmidt JE, Ahring BK. Granulation in thermophilic upflow anaerobic sludge blanket (UASB) reactors. Antonie Van Leeuwenhoek 1995; 68:339-44. [PMID: 8821789 DOI: 10.1007/bf00874144] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The state of the art for thermophilic UASB reactors is discussed focusing on the start-up of UASB reactors, the influence of the waste water composition and temperature on the development and maintenance of thermophilic granules, and the microbial composition and structure of thermophilic granules.
Collapse
Affiliation(s)
- J E Schmidt
- Department of Environmental Science and Engineering, Technical University of Denmark, Lyngby
| | | |
Collapse
|
27
|
Comparative composition and characteristics of methanogenic granular sludges treating industrial wastes under different conditions. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0922-338x(95)90616-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Impact of the reactor hydrodynamics and organic loading on the size and activity of anaerobic granules. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0923-0467(94)87028-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
29
|
Sanchez JM, Arijo S, Mu�oz MA, Mori�igo MA, Borrego JJ. Microbial colonization of different support materials used to enhance the methanogenic process. Appl Microbiol Biotechnol 1994. [DOI: 10.1007/bf00939040] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
30
|
Ahring BK, Schmidt JE, Winther-Nielsen M, Macario AJ, Conway de Macario E. Effect of medium composition and sludge removal on the production, composition, and architecture of thermophilic (55 degrees C) acetate-utilizing granules from an upflow anaerobic sludge blanket reactor. Appl Environ Microbiol 1993; 59:2538-45. [PMID: 8368841 PMCID: PMC182317 DOI: 10.1128/aem.59.8.2538-2545.1993] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A thermophilic upflow anaerobic sludge blanket (UASB) reactor degrading acetate was started by applying published methods (W. M. Wiegant and A. W. A. de Man, Biotechnol. Bioeng. 28:718-77, 1986) for production of granules dominated by Methanothrix spp. The reactor was inoculated with thermophilic digested sludge. No granules were observed during the first 7 months of start-up of the UASB reactor. However, after the concentrations of potassium, phosphate, ammonium, and magnesium in the medium were gradually increased, granules developed, indicating that there was a critical concentration of one or more of the ions required for production of granules from the starting material. After several years of stable operation, the effect of removing 60% of the granular sludge was investigated. Immunologic qualitative and quantitative studies showed that removal of the granular sludge resulted in an increase in the number of the predominant methanogens, antigenically related to Methanosarcina thermophila TM-1 and Methanosarcina mazeii S-6, and Methanobacterium thermoautotrophicum delta H and GC1. These changes were accompanied by modifications of the microanatomy of the granules, as demonstrated histochemically and immunohistochemically. The results indicated that different catabolic pathways dominated in different regions of the granules, i.e., acetate oxidation in the middle of the granules, where there is a low acetate concentration, and an aceticlastic reaction in the outer surfaces, with a high acetate concentration. The results also showed that removal of granules from a UASB reactor which has been under steady-state operation for a long period can improve the reactor's performance via formation of denser and larger granules with improved microbial activities.
Collapse
Affiliation(s)
- B K Ahring
- Department of Biotechnology, Technical University of Denmark, Lyngby
| | | | | | | | | |
Collapse
|
31
|
Rintala J, Lepistö S, Ahring B. Acetate Degradation at 70°C in Upflow Anaerobic Sludge Blanket Reactors and Temperature Response of Granules Grown at 70°C. Appl Environ Microbiol 1993; 59:1742-6. [PMID: 16348950 PMCID: PMC182154 DOI: 10.1128/aem.59.6.1742-1746.1993] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anaerobic acetate degradation at 70°C and at 55°C (as a reference) was studied by running laboratory upflow anaerobic sludge blanket (UASB) reactors inoculated with mesophilic granular sludge. In UASB reactors fed with acetate-containing media (3 g of chemical oxygen demand [COD] per liter, corresponding to 47 mM acetate) approximately 50 days was needed at 70°C and less than 15 days was needed at 55°C to achieve an effluent COD of 500 to 700 mg/liter. In the UASB reactors at both 70 and 55°C up to 90% of the COD was removed. Batch assays showed that sludges from two 70°C UASB reactors, one run at a low effluent acetate concentration and the other run at a high effluent acetate concentration, exhibited slightly different responses to temperatures in the range from 37 to 70°C. Both 70°C sludges, as well as the 55°C sludge, produced methane at temperatures of 37 to 73°C. The 55°C sludge exhibited shorter lag phases than the 70°C sludges and higher specific methane production rates between 37 and 65°C.
Collapse
Affiliation(s)
- J Rintala
- Water and Environmental Engineering, Tampere University of Technology, P.O. Box 600, SF-33101 Tampere, Finland, and The Anaerobic Microbiology/Biotechnology Group, Department of Biotechnology, The Technical University of Denmark, DK-2800 Lyngby, Denmark
| | | | | |
Collapse
|
32
|
Ohtsubo S, Mitsuyoshi Kanno, Hiroyoshi Miyahara, Shuhei Kohno, Yosuke Koga, Isao Miura. A sensitive method for quantification of aceticlastic methanogens and estimation of total methanogenic cells in natural environments based on an analysis of ether-linked glycerolipids. FEMS Microbiol Ecol 1993. [DOI: 10.1111/j.1574-6941.1993.tb00015.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
33
|
Bhatti ZI, Furukawa K, Fujita M. Treatment performance and microbial structure of a granular consortium handling methanolic waste. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0922-338x(93)90012-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
34
|
van Lier JB, Grolle KC, Stams AJ, Conway de Macario E, Lettinga G. Start-up of a thermophilic upflow anaerobic sludge bed (UASB) reactor with mesophilic granular sludge. Appl Microbiol Biotechnol 1992; 37:130-5. [PMID: 1368497 DOI: 10.1007/bf00174217] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- J B van Lier
- Department of Environmental Technology, Wageningen Agricultural University, The Netherlands
| | | | | | | | | |
Collapse
|
35
|
|
36
|
Schmidt JE, Macario AJ, Ahring BK, Conway de Macario E. Effect of magnesium on methanogenic subpopulations in a thermophilic acetate-degrading granular consortium. Appl Environ Microbiol 1992; 58:862-8. [PMID: 1575487 PMCID: PMC195346 DOI: 10.1128/aem.58.3.862-868.1992] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The effects of Mg2+ on thermophilic (55 degrees C) granules grown on acetate in 0.2-liter upflow anaerobic sludge blanket reactors were studied. The methanogens in the granules were identified and counted by using antibody probes and the antigenic fingerprinting method. Packets of large coccoidal cells antigenically related to Methanosarcina thermophila TM-1 were scarce in the absence of Mg2+ but increased with increasing Mg2+ concentrations up to 30 mM; Methanosarcina packets immunologically related to Methanosarcina barkeri R1M3 showed a similar trend, and their numbers increased up to 100 mM Mg2+. The number of single cells antigenically related to TM-1, R1M3, and Methanosarcina mazei S-6 were scarce at low Mg2+ concentrations but increased drastically at 30 and 100 mM Mg2+. The number of rod-shaped bacteria antigenically related to Methanobacterium thermoautotrophicum GC1 and delta H was highest with no Mg2+ present, and their numbers decreased with increasing concentrations of the cation. These quantitative data, obtained by counting cells in suspensions made from disrupted granules, were confirmed by microscopic observation of the methanogenic subpopulations in thin histologic sections of the granules.
Collapse
Affiliation(s)
- J E Schmidt
- Department of Biotechnology, Technical University of Denmark, Lyngby
| | | | | | | |
Collapse
|