1
|
Devant M, Pérez A, Medinyà C, Riera J, Grau J, Fernández B, Prenafeta-Boldú FX. Effect of decreasing dietary crude protein in fattening calves on the emission of ammonia and greenhouse gases from manure stored under aerobic and anaerobic conditions. Animal 2022; 16:100471. [PMID: 35245785 DOI: 10.1016/j.animal.2022.100471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/15/2022] Open
Abstract
Dietary strategies can potentially help to reduce nitrogen (N) emissions and decrease the environmental impact of beef production. This study aimed to evaluate the effects of dietary crude protein (CP) concentration on animal performance, N excretion, and manure N volatilisation of finishing Holstein animals. In a first study, 105 Holstein bulls (BW 344 ± 2.6 kg; age 252 ± 0.9 days) were allocated to eight pens to evaluate the effect of two treatments (medium (M) and low (L), which contained CP 14.5% and 12% on a DM basis, respectively) on performance, and results confirmed that dietary CP decrease did not impair animal growth. In a second study, N excretion study, 24 Holstein heifers (BW 310 ± 5.3 kg; age 251 ± 1.4 days) were distributed randomly depending on the initial BW to three treatments (high (H), M, and L, which contained CP 17%, 14.5% and 12% on a DM basis, respectively). Based on N excretion, urinary N excretion was greater (P < 0.001) in H than in M and L diets, but no differences in faecal N excretion were observed among treatments. A third study with in vitro assays under aerobic and anaerobic conditions was designed to analyse gaseous emissions (volatilisation of N and carbon, C) during the storage stage of manure. Manure, faecal and urine samples, mixed at a ratio of 1:1 (wet weight), were collected during the N excretion study (manure-H, manure-M, manure-L). Under aerobic conditions, manure-M and manure-L showed a delay of 4-5 days in manure ammonia emission compared with manure-H (P < 0.01). Total N content was lower (P < 0.01) in manure-L compared with manure-M and manure-H, but N volatilisation (percentage relative to initial N) in manure-L and manure-M was greater (P < 0.01) than in manure-H. In contrast, the anaerobic N volatilisation was 20 times greater in manure-M and 10 times greater in manure-H compared with manure-L. Under aerobic and anaerobic conditions, the emission of C, as C-CO2 and C-CH4, was greater in manure-L than in manure-H and manure-M. Therefore, the decrease of dietary CP concentration from 17% to 14.5% and 12% is an efficient strategy to reduce urinary N excretion by 40%, without impairing performance, and also to reduce manure N losses through ammonia volatilisation under anaerobic conditions. However, a dietary CP content of 14.5% resulted in less environmental impact than a CP content of 12.8% when also considering manure emissions under aerobic or anaerobic conditions.
Collapse
Affiliation(s)
- M Devant
- IRTA - Institut de Recerca i Tecnologies Agroalimentàries, Torre Marimon, 08140 Caldes de Montbui, Spain.
| | - A Pérez
- Corporación Alimentaria Guissona, S.A., 25210 Guissona, Lleida, Spain
| | - C Medinyà
- Nutrición Animal S.L., 08650 Sallent, Barcelona, Spain
| | - J Riera
- Nanta S.A., 28760 Tres Cantos, Madrid, Spain
| | - J Grau
- Setna Nutrición Animal SAU, 28521 Rivas Vaciamadrid, Madrid, Spain
| | - B Fernández
- IRTA - Institut de Recerca i Tecnologies Agroalimentàries, Torre Marimon, 08140 Caldes de Montbui, Spain
| | - F X Prenafeta-Boldú
- IRTA - Institut de Recerca i Tecnologies Agroalimentàries, Torre Marimon, 08140 Caldes de Montbui, Spain
| |
Collapse
|
2
|
Prenafeta-Boldú FX, Burgos L, Noguerol J, Mercader M, Soler J, Fernández B. Solar drying in the vineyard: a sustainable technology for the recovery of nutrients from winery organic waste. Water Sci Technol 2020; 82:27-38. [PMID: 32910790 DOI: 10.2166/wst.2020.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The present study describes a pilot-scale experimental validation of a forced-convection greenhouse solar dryer, combined with a biofilter, for controlled atmospheric emissions. This set-up was applied to the dewatering of sewage sludge from a biological plant that treated process wastewater in a commercial Mediterranean winery. Experiments were performed after the harvest, from September onwards, during the peak generation of sludge. The average drying rate during the first 10 days of operation ranged from 1.17 to 2.24 kg m-2 d-1, depending on the measurement method, during which the water content of the sludge was reduced from 90% down to 67%. Biofiltration was quite inefficient against greenhouse gases (methane and dinitrous oxide), and direct emissions during the drying process were on average 57 g CO2-eq m-2 d-1. Ammonia and volatile organic compounds were removed with average efficiencies of 71% and 35%, but ammonia losses through volatilization represented less than 2% of the initial nitrogen content. The sludge was dried further during November, to the lowest possible water content of 14%. Both the intermediate and final sludge dried materials were characterized for their agronomical value as organic fertilizers.
Collapse
Affiliation(s)
- F X Prenafeta-Boldú
- GIRO Program, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain E-mail:
| | - L Burgos
- GIRO Program, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain E-mail:
| | - J Noguerol
- GIRO Program, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain E-mail:
| | - M Mercader
- Bodegas Torres, Familia Torres, Carrer de Miquel Torres i Carbó 6, E08720, Vilafranca del Penedès, Barcelona, Catalonia, Spain
| | - J Soler
- EMA Depuració i Enginyeria de l'Aigua, S.L. Avda. Sant Jordi 176, E17800 Olot, Girona, Catalonia, Spain
| | - B Fernández
- GIRO Program, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain E-mail:
| |
Collapse
|
3
|
Rodríguez-Abalde Á, Guivernau M, Prenafeta-Boldú FX, Flotats X, Fernández B. Characterization of microbial community dynamics during the anaerobic co-digestion of thermally pre-treated slaughterhouse wastes with glycerin addition. Bioprocess Biosyst Eng 2019; 42:1175-1184. [DOI: 10.1007/s00449-019-02115-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/20/2019] [Accepted: 03/25/2019] [Indexed: 11/25/2022]
|
4
|
Ruiz-Sánchez J, Guivernau M, Fernández B, Vila J, Viñas M, Riau V, Prenafeta-Boldú FX. Functional biodiversity and plasticity of methanogenic biomass from a full-scale mesophilic anaerobic digester treating nitrogen-rich agricultural wastes. Sci Total Environ 2019; 649:760-769. [PMID: 30176486 DOI: 10.1016/j.scitotenv.2018.08.165] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/12/2018] [Accepted: 08/12/2018] [Indexed: 06/08/2023]
Abstract
The effect of ammonia on methanogenic biomass from a full-scale agricultural digester treating nitrogen-rich materials was characterized in batch activity assays subjected to increasing concentrations of total ammonia N. Acetotrophic and methanogenic profiles displayed prolonged lag phases and reduced specific activity rates at 6.0 gN-TAN L-1, though identical methane yields were ultimately reached. These results agreed with the expression levels of selected genes from bacteria and methanogenic archaea (qPCR of 16S rRNA and mrcA cDNA transcripts). Compound-specific isotope analysis of biogas indicated that ammonia exposure was associated to a transition in methanogenic activity from acetotrophy at 1.0 gN-TAN L-1 to intermediate and complete hydrogenotrophy at 3.5 and 6.0 gN-TAN L-1. Such pattern matched the results of 16S-Illumina sequencing of genes and transcripts in that predominant methanogens shifted, along with increasing ammonia, from the obligate acetotroph Methanosaeta to the hydrogenotrophic Methanoculleus and the poorly understood methylotrophic Methanomassiliicoccus. The underlying bacterial community structure remained rather stable but, at 6.0 gN-TAN L-1, the expression level increased considerably for a number of ribotypes that are related to potentially syntrophic genera (e.g. Clostridium, Bellilinea, Longilinea, and Bacteroides). The predominance of hydrogenotrophy at high ammonia levels clearly points to the occurrence of the syntrophic acetate oxidation (SAO), but known SAO bacteria were only found in very low numbers. The potential role of the identified bacterial and archaeal taxa with a view on SAO and on stability of the anaerobic digestion process under ammonia stress has been discussed.
Collapse
Affiliation(s)
- J Ruiz-Sánchez
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain
| | - M Guivernau
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain
| | - B Fernández
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain
| | - J Vila
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain; Department of Microbiology, University of Barcelona, UB. Av. Diagonal, 643, E08028, Barcelona, Catalonia, Spain
| | - M Viñas
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain
| | - V Riau
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain
| | - F X Prenafeta-Boldú
- GIRO, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, E08140 Caldes de Montbui, Barcelona, Catalonia, Spain.
| |
Collapse
|
5
|
Ruiz-Sánchez J, Campanaro S, Guivernau M, Fernández B, Prenafeta-Boldú FX. Effect of ammonia on the active microbiome and metagenome from stable full-scale digesters. Bioresour Technol 2018; 250:513-522. [PMID: 29197774 DOI: 10.1016/j.biortech.2017.11.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 05/20/2023]
Abstract
Four full-scale anaerobic digesters with a long history of stable operation were characterized in terms of active microbiome and metagenome. Isotopic fractionation of biogas demonstrated that acetotrophy was rather prevalent in reactors operated at <3 gTAN L-1 while hydrogenotrophy was predominant at >6 gTAN L-1, suggesting that syntrophic acetate oxidizing bacteria (SAOB) played a significant role in the latter. These results were generally coherent with the observed active bacterial and archaeal communities but no known SAOB were observed. Metagenome descriptions yielded 73 assembled population genomes, of which only 7 could be assigned at the species level. Gene annotation and association to relevant metabolic pathways indicated that the phyla Chloroflexi and Bacteroidales might encompass new, currently undescribed, SAOB/formate producing species that would metabolize acetate via the glycine cleavage system. The predominant hydrogenotrophic counterpart at a high ammonia content belonged to the genus Methanoculleus, which could also grow on acetate to a certain extent.
Collapse
Affiliation(s)
- J Ruiz-Sánchez
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain.
| | - S Campanaro
- Department of Biology, University of Padua, Via U.Bassi 58/b 35121, Padua, Italy
| | - M Guivernau
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
| | - B Fernández
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
| | - F X Prenafeta-Boldú
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
| |
Collapse
|
6
|
Calderer M, Martí V, de Pablo J, Guivernau M, Prenafeta-Boldú FX, Viñas M. Effects of enhanced denitrification on hydrodynamics and microbial community structure in a soil column system. Chemosphere 2014; 111:112-119. [PMID: 24997907 DOI: 10.1016/j.chemosphere.2014.03.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 02/19/2014] [Accepted: 03/01/2014] [Indexed: 06/03/2023]
Abstract
Enhanced heterotrophic denitrification by adding glucose was investigated by means of a soil column experiment which simulated the groundwater flow. The carbon-to-nitrogen ratio was the main factor determining denitrification potential under experimental conditions. The influence of stimulated denitrification on the autochthonous microbial community was investigated by quantitative PCR (qPCR), and denaturing gradient gel electrophoresis (DGGE). The qPCR detection of the nosZ genes encoding nitrous oxide reductase, and the comparison of the abundances of 16S rRNA genes revealed that the addition of glucose enhanced denitrification leading to an increase in both the total eubacteria and, in particular, in the ratio of denitrifying bacteria, which represented the 21% of the total native eubacteria on the basis of nosZ/16S rRNA gene ratio. Microbial community profiling by DGGE indicated that ribotypes closely related to the genera Acidovorax and Hydrogenophaga (Comamonadaceae family) became enriched in the soil column. The effects of biomass occurrence in the column system on soil hydrodynamics, assessed by tracer studies, revealed a reduction of porosity and a significant increase of dispersivity that could be caused by the appearance of new functional microbial biomass in the aquifer material under enhanced denitrifying conditions. The importance of investigating the microbial growth in relation to the hydrodynamic effects, during enhanced denitrification, has been revealed in the column system experiments associated with the bioremediation. Combining microbial characterisation and hydrodynamic data in a soil column system permits us to gain an insight to the limiting factors of different stimulation strategies that can be applied in the field.
Collapse
Affiliation(s)
- M Calderer
- CTM Technological Centre, Environmental Technology Area, Plaça de la Ciència, No. 2, E-08243 Manresa, Spain.
| | - V Martí
- CTM Technological Centre, Environmental Technology Area, Plaça de la Ciència, No. 2, E-08243 Manresa, Spain; Technical University of Catalonia, Department of Chemical Engineering (UPC, ETSEIB), Av. Diagonal, No. 647, E-08028 Barcelona, Spain
| | - J de Pablo
- CTM Technological Centre, Environmental Technology Area, Plaça de la Ciència, No. 2, E-08243 Manresa, Spain; Technical University of Catalonia, Department of Chemical Engineering (UPC, ETSEIB), Av. Diagonal, No. 647, E-08028 Barcelona, Spain
| | - M Guivernau
- IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Spain
| | - F X Prenafeta-Boldú
- IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Spain
| | - M Viñas
- IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Spain
| |
Collapse
|
7
|
Palatsi J, Illa J, Prenafeta-Boldú FX, Laureni M, Fernandez B, Angelidaki I, Flotats X. Long-chain fatty acids inhibition and adaptation process in anaerobic thermophilic digestion: batch tests, microbial community structure and mathematical modelling. Bioresour Technol 2010; 101:2243-2251. [PMID: 20015641 DOI: 10.1016/j.biortech.2009.11.069] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 11/11/2009] [Accepted: 11/16/2009] [Indexed: 05/26/2023]
Abstract
Biomass samples taken during the continuous operation of thermophilic anaerobic digestors fed with manure and exposed to successive inhibitory pulses of long-chain fatty acids (LCFA) were characterized in terms of specific metabolic activities and 16S rDNA DGGE profiling of the microbial community structure. Improvement of hydrogenotrophic and acidogenic (beta-oxidation) activity rates was detected upon successive LCFA pulses, while different inhibition effects over specific anaerobic trophic groups were observed. Bioreactor recovery capacity and biomass adaptation to LCFA inhibition were verified. Population profiles of eubacterial and archaeal 16S rDNA genes revealed that no significant shift on microbial community composition took place upon biomass exposure to LCFA. DNA sequencing of predominant DGGE bands showed close phylogenetic affinity to ribotypes characteristic from specific beta-oxidation bacterial genera (Syntrophomonas and Clostridium), while a single predominant syntrophic archaeae was related with the genus Methanosarcina. The hypothesis that biomass adaptation was fundamentally of physiological nature was tested using mathematical modelling, taking the IWA ADM1 as general model. New kinetics considering the relation between LCFA inhibitory substrate concentration and specific biomass content, as an approximation to the adsorption process, improved the model fitting and provided a better insight on the physical nature of the LCFA inhibition process.
Collapse
Affiliation(s)
- J Palatsi
- GIRO Technological Centre, Rambla Pompeu Fabra, Barcelona, Spain
| | | | | | | | | | | | | |
Collapse
|
8
|
Prenafeta-Boldú FX, Ballerstedt H, Gerritse J, Grotenhuis JTC. Bioremediation of BTEX Hydrocarbons: Effect of Soil Inoculation with the Toluene-Growing Fungus Cladophialophora Sp. Strain T1. Biodegradation 2004; 15:59-65. [PMID: 14971858 DOI: 10.1023/b:biod.0000009973.53531.96] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The biodegradation of a mixture of benzene, toluene, ethylbenzene, xylene, (BTEX) and methyl-tert-butyl ether (MTBE) was studied in soil microcosms. Soil inoculation with the toluene-metabolising fungus Cladophialophora sp. strain T1 was evaluated in sterile and non-sterile soil. Induction of biodegradation capacity following BTEX addition was faster in the soil native microflora than in axenic soil cultures of the fungus. Toluene, ethylbenzenes, and the xylenes were metabolized by the fungus but biodegradation of benzene required the activity of the indigenous soil microorganisms. MTBE was not biodegraded under the tested environmental conditions. Biodegradation profiles were also examined under two pH conditions after a long term exposure to BTEX. At neutral conditions the presence of the fungus had little effect on the intrinsic soil biodegradation capacity. At an acidic pH, however, the activity of the indigenous degraders was inhibited and the presence of Cladophialophora sp. increased significantly the biodegradation rates of toluene and ethylbenzene. Comparison of the BTEX biodegradation rates measured in soil batches combining presence and absence of indigenous degraders and the fungal inoculum indicated that no severe antagonism occurred between the indigenous bacteria and Cladophialophora sp. The presence of the fungal inoculum at the end of the experiments was confirmed by PCR-TGGE analysis of small subunits of 18S rDNA.
Collapse
Affiliation(s)
- F X Prenafeta-Boldú
- Centraalbureau voor Schimmelcultures, Institute of the Royal Netherlands Academy of Arts and Sciences, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
9
|
Prenafeta-Boldú FX, Vervoort J, Grotenhuis JTC, Van Groenestijn JW. Substrate interactions during the biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) hydrocarbons by the fungus Cladophialophora sp. strain T1. Appl Environ Microbiol 2002; 68:2660-5. [PMID: 12039717 PMCID: PMC123968 DOI: 10.1128/aem.68.6.2660-2665.2002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2001] [Accepted: 03/06/2002] [Indexed: 11/20/2022] Open
Abstract
The soil fungus Cladophialophora sp. strain T1 (= ATCC MYA-2335) was capable of growth on a model water-soluble fraction of gasoline that contained all six BTEX components (benzene, toluene, ethylbenzene, and the xylene isomers). Benzene was not metabolized, but the alkylated benzenes (toluene, ethylbenzene, and xylenes) were degraded by a combination of assimilation and cometabolism. Toluene and ethylbenzene were used as sources of carbon and energy, whereas the xylenes were cometabolized to different extents. o-Xylene and m-xylene were converted to phthalates as end metabolites; p-xylene was not degraded in complex BTEX mixtures but, in combination with toluene, appeared to be mineralized. The metabolic profiles and the inhibitory nature of the substrate interactions indicated that toluene, ethylbenzene, and xylene were degraded at the side chain by the same monooxygenase enzyme. Our findings suggest that soil fungi could contribute significantly to bioremediation of BTEX pollution.
Collapse
Affiliation(s)
- F X Prenafeta-Boldú
- Division of Industrial Microbiology. Subdepartment of Environmental Technology, Wageningen University, 6700 EV Wageningen, The Netherlands.
| | | | | | | |
Collapse
|
10
|
Prenafeta-Boldú FX, Luykx DM, Vervoort J, de Bont JA. Fungal metabolism of toluene: monitoring of fluorinated analogs by (19)F nuclear magnetic resonance spectroscopy. Appl Environ Microbiol 2001; 67:1030-4. [PMID: 11229888 PMCID: PMC92691 DOI: 10.1128/aem.67.3.1030-1034.2001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We used isomeric fluorotoluenes as model substrates to study the catabolism of toluene by five deuteromycete fungi and one ascomycete fungus capable of growth on toluene as the sole carbon and energy source, as well as by two fungi (Cunninghamella echinulata and Aspergillus niger) that cometabolize toluene. Whole cells were incubated with 2-, 3-, and 4-fluorotoluene, and metabolites were characterized by (19)F nuclear magnetic resonance. Oxidation of fluorotoluene by C. echinulata was initiated either at the aromatic ring, resulting in fluorinated o-cresol, or at the methyl group to form fluorobenzoate. The initial conversion of the fluorotoluenes by toluene-grown fungi occurred only at the side chain and resulted in fluorinated benzoates. The latter compounds were the substrate for the ring hydroxylation and, depending on the fluorine position, were further metabolized up to catecholic intermediates. From the (19)F nuclear magnetic resonance metabolic profiles, we propose that diverse fungi that grow on toluene assimilate toluene by an initial oxidation of the methyl group.
Collapse
Affiliation(s)
- F X Prenafeta-Boldú
- Division of Industrial Microbiology, Wageningen University, 6700 EV Wageningen, the Netherlands.
| | | | | | | |
Collapse
|
11
|
Tan NC, Prenafeta-Boldú FX, Opsteeg JL, Lettinga G, Field JA. Biodegradation of azo dyes in cocultures of anaerobic granular sludge with aerobic aromatic amine degrading enrichment cultures. Appl Microbiol Biotechnol 1999; 51:865-71. [PMID: 10422231 DOI: 10.1007/s002530051475] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A prerequisite for the mineralization (complete biodegradation) of many azo dyes is a combination of reductive and oxidative steps. In this study, the biodegradation of two azo dyes, 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (4-sulfophenylazo-salicylic acid; MY10), was evaluated in batch experiments where anaerobic and aerobic conditions were integrated by exposing anaerobic granular sludge to oxygen. Under these conditions, the azo dyes were reduced, resulting in a temporal accumulation of aromatic amines. 4-Aminophenol (4-AP) and aniline were detected from the reduction of 4-PAP. 5-Aminosalicylic acid (5-ASA) and sulfanilic acid (SA) were detected from the reduction of MY10. Subsequently, aniline was degraded further in the presence of oxygen by the facultative aerobic bacteria present in the anaerobic granular sludge. 5-ASA and SA were also degraded, if inocula from aerobic enrichment cultures were added to the batch experiments. Due to rapid autoxidation of 4-AP, no enrichment culture could be established for this compound. The results of this study indicate that aerobic enrichment cultures developed on aromatic amines combined with oxygen-tolerant anaerobic granular sludge can potentially be used to completely biodegrade azo dyes under integrated anaerobic/aerobic conditions.
Collapse
Affiliation(s)
- N C Tan
- Wageningen University and Research Center, Department of Agricultural, Environmental and System Technology, The Netherlands.
| | | | | | | | | |
Collapse
|