Register      Login
Soil Research Soil Research Society
Soil, land care and environmental research
RESEARCH ARTICLE

Enzyme activity, microbial biomass and community structure in a long-term restored soil under semi-arid conditions

I. F. Torres A B , F. Bastida A , T. Hernández A , J. Albaladejo A and C. García A
+ Author Affiliations
- Author Affiliations

A Centro de Edafología y Biología Aplicada del Segura, CEBAS-CSIC Campus Universitario de Espinardo, Aptdo. de Correos 164, Espinardo 30100 Murcia, Spain.

B Corresponding author. Email: iftorres@cebas.csic.es

Soil Research 53(5) 553-560 https://doi.org/10.1071/SR14297
Submitted: 26 March 2014  Accepted: 27 March 2015   Published: 17 August 2015

Abstract

Our aim was to evaluate the long-term influences of urban organic amendments on the enzymes involved in the carbon cycle under semi-arid conditions, including changes in the biomass and structure of the microbial community. A soil was restored 24 years ago with an organic amendment based on domestic organic waste. Organic amendment was applied to soil in order to increase the content of total organic carbon (TOC) by 0.5% and 1.5% with respect to the original TOC content. Enzyme isoform composition was studied by using zymographic techniques based on protein extraction, separation by gel electrophoresis and further enzyme-specific, in-gel staining. Total cellulose and β-glucosidase activities, microbial biomass estimated by phospholipid-fatty acid analysis and the number of isoforms of each enzyme showed increases related to the initial amount of organic amendment and the consequent development of vegetation. The information obtained by enzyme activity assays may be improved by the use of zymographic techniques, which allow the investigation of the variety of isoforms of each enzyme. This information could improve the understanding of the relationship between the microbial community and carbon cycling in restored areas.

Additional keywords: C cycling, isoform variety, microbial biomass and community, PFLA, semi-arid conditions, soil restoration, zymography.


References

Acosta-Martínez V, Cruz L, Sotomayor-Ramírez D, Pérez-Alegría L (2007) Enzyme activities as affected by soil properties and land use in a tropical watershed. Applied Soil Ecology 35, 35–45.
Enzyme activities as affected by soil properties and land use in a tropical watershed.Crossref | GoogleScholarGoogle Scholar |

Albaladejo J, Castillo V, Diaz E (2000) Soil loss and runoff on semiarid land as amendment with urban solid refuse. Land Degradation & Development 11, 363–373.
Soil loss and runoff on semiarid land as amendment with urban solid refuse.Crossref | GoogleScholarGoogle Scholar |

Albaladejo J, Lopez J, Boix-Fayos C, Barbera GG, Martinez-Mena M (2008) Long-term effect of a single application of organic refuse on carbon sequestration and soil physical properties. Journal of Environmental Quality 37, 2093–2099.
Long-term effect of a single application of organic refuse on carbon sequestration and soil physical properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtl2hsL7M&md5=9fee938d0090124564fac5ec6c32e06bCAS | 18948462PubMed |

Allison S (2006) Soil minerals and humic acids alter enzyme stability implications for ecosystem processes. Biogeochemistry 81, 361–373.
Soil minerals and humic acids alter enzyme stability implications for ecosystem processes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtFGqur%2FP&md5=baffee17647bea9fe31019cd932a2e3fCAS |

Balloni W, Favilli F (1987) Effects of agricultural practices on the physical, chemical and biochemical properties of soils: Part I. Effect of some agricultural practices on the biological soil fertility. In ‘Scientific basis for soil protection in the European Community’. (Eds H Barth, PL Hermite) pp. 161–175. (Elsevier: London)

Bardgett RD, Hobbs PJ, Frostegard A (1996) Changes in soil fungal: bacterial biomass ratios following reductions in the intensity of management of an upland grassland. Biology and Fertility of Soils 22, 261–264.
Changes in soil fungal: bacterial biomass ratios following reductions in the intensity of management of an upland grassland.Crossref | GoogleScholarGoogle Scholar |

Bastida F, Moreno JL, Garcia C, Hernandez T (2007) Addition of urban waste to semiarid degraded soil: long-term effect. Pedosphere 17, 557–567.
Addition of urban waste to semiarid degraded soil: long-term effect.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXht1Cnt77N&md5=8dbd43a5ee4d5ae21d6565aab16d99a4CAS |

Bastida F, Kandeler E, Hernández T, García C (2008) Long-term effect of municipal soild waste amendment on microbial abundance and humus-associated enzyme activities under semiarid conditions. Microbial Ecology 55, 651–661.
Long-term effect of municipal soild waste amendment on microbial abundance and humus-associated enzyme activities under semiarid conditions.Crossref | GoogleScholarGoogle Scholar | 17768652PubMed |

Bastida F, Torres IF, Hernández T, Bombach P, Richnow HH, García C (2013) Can the labile carbon contribute to carbon immobilization in semiarid soils? Priming effects and microbial community dynamics. Soil Biology & Biochemistry 57, 892–902.
Can the labile carbon contribute to carbon immobilization in semiarid soils? Priming effects and microbial community dynamics.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhslaqu7fJ&md5=5917d345ade0714720846a09a5629992CAS |

Bending G, Turner MK, Rayns F, Marx M-C, Wood M (2004) Microbial and biochemical soil quality indicators and their potential for differentiating areas under contrasting agricultural management regimes. Soil Biology & Biochemistry 36, 1785–1792.
Microbial and biochemical soil quality indicators and their potential for differentiating areas under contrasting agricultural management regimes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXnslKhtbw%3D&md5=a5b001622159747e3f7a48d64eb6a609CAS |

Bligh EG, Dyer WJ (1959) A rapid method for total lipid extraction and purification. Canadian Journal of Biochemistry and Physiology 37, 911–917.
A rapid method for total lipid extraction and purification.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaG1MXhtVSgt70%3D&md5=471441e1edd99d722996ba9745506014CAS | 13671378PubMed |

Brockway DG, Outcalt KW, Wilkins RN (1998) Restoring long leaf pine wiregrass ecosystems: plant cover, diversity and biomass following long-rate hexazinone application on Florida sandhills. Forest Ecology and Management 103, 159–175.
Restoring long leaf pine wiregrass ecosystems: plant cover, diversity and biomass following long-rate hexazinone application on Florida sandhills.Crossref | GoogleScholarGoogle Scholar |

Burns RG (1983) Extracellular enzyme-substrate interactions in soil. In ‘Microbes in their natural environment’. (Eds JH Slater, R Wittenbury, JWT Wimpenny) pp. 249–298. (Cambridge University Press: London, UK)

Cañizares R, Benitez E, Ogunseitan OA (2011) Molecular analyses of β-glucosidase diversity and function in soil. European Journal of Soil Biology 47, 1–8.
Molecular analyses of β-glucosidase diversity and function in soil.Crossref | GoogleScholarGoogle Scholar |

Carpenter-Boggs L, Kennedy AC, Reganold JP (1998) Use of phospholipid fatty acids utilization patterns to track microbial community succession in developing compost. Applied and Environmental Microbiology 64, 4062–4064.

Criquet S (2002) Measurement and characterization of cellulose activity in sclerophyllous forest litter. Journal of Microbiological Methods 50, 165–173.
Measurement and characterization of cellulose activity in sclerophyllous forest litter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xjtl2is7g%3D&md5=fe777f6011c3604fed9eda060a519a6bCAS | 11997167PubMed |

Criquet S, Tagger S, Vogt G, Le Petit J (2002) Endoglucanase and β-glycosidase activities in an evergreen oak litter: annual variation and regulating factors. Soil Biology & Biochemistry 34, 1111–1120.
Endoglucanase and β-glycosidase activities in an evergreen oak litter: annual variation and regulating factors.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xlt1Oitrw%3D&md5=24e33aeeeda9b62b71d16d6a0e43238aCAS |

De Luca TH, Keeney DR (1993) Soluble anthrone-reactive carbon in soils: effect of carbon and nitrogen amendments. Soil Science Society of America Journal 57, 1296–1300.
Soluble anthrone-reactive carbon in soils: effect of carbon and nitrogen amendments.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXns1equg%3D%3D&md5=23f5e9a7efb7bb3f6e107cec5c27abdaCAS |

Deng SP, Tabatabai MA (1994) Cellulase activity of soils. Soil Biology & Biochemistry 26, 1347–1354.
Cellulase activity of soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXmt12rsbs%3D&md5=206c6062b5ce7ce288f0831e5b09564cCAS |

Di Nardo C, Cinquegrana A, Papa S, Fuggi A, Fioretto A (2004) Laccase and peroxidase isoenzymes during leaf litter decomposition of Quercus ilex in a Mediterranean ecosystem. Soil Biology & Biochemistry 36, 1539–1544.
Laccase and peroxidase isoenzymes during leaf litter decomposition of Quercus ilex in a Mediterranean ecosystem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXnslKhtr0%3D&md5=5e5290c0bbc1cb68b7e2c23579a4cdefCAS |

Dick WA, Tabatabai MA (1993) Significance and potential uses of soil enzymes. In ‘Soil microbial ecology. Application in agricultural and environmental management’. (Ed. FB Metting Jr) pp. 95–127. (Marcel Dekker: New York)

Dick RP, Sandor JA, Eash NS (1994) Soil enzyme activities after 1500 years of terrace agriculture in the Colca Valley, Peru. Agriculture, Ecosystems & Environment 50, 123–131.
Soil enzyme activities after 1500 years of terrace agriculture in the Colca Valley, Peru.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXmsl2ksrw%3D&md5=5f689520b7e75c406790090d536ab5d2CAS |

Dungait JAJ, Kemmit SJ, Michallon L, Guo S, Wen Q, Brookes PC, Evershed RP (2011) Variable responses of the soil microbial biomass to trace concentrations of 13C-labelled glucose, using 13C-PLFA analysis. European Journal of Soil Science 62, 117–126.
Variable responses of the soil microbial biomass to trace concentrations of 13C-labelled glucose, using 13C-PLFA analysis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXisVGgt7o%3D&md5=afce223bc65dd22c7620b45788a04b15CAS |

Dutta T, Sahoo R, Sengupta R, Ray SS, Bhattacharjee A, Ghosh S (2008) Novel cellulases from an extremophilic filamentous fungi Penicillium citrinum: production and characterization. Journal of Industrial Microbiology & Biotechnology 35, 275–282.
Novel cellulases from an extremophilic filamentous fungi Penicillium citrinum: production and characterization.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXks1Gjurk%3D&md5=46c0f09d7a1b1f337db25f35c4d0ee6eCAS |

Falkowski P, Scholes RJ, Boyle E, Canadell J, Canfield D, Elser J, Gruber N, Hibbard K, Högberg P, Linder S, Mackenzie FT, Moore B, Pedersen T, Rosenthal Y, Seitzinger S, Smetacek V, Steffen W (2000) The global carbon cycle: a test of our knowledge of earth as a system. Science 290, 291–296.
The global carbon cycle: a test of our knowledge of earth as a system.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXnsVGisrg%3D&md5=504e224d6cbb381abc95671833c1b2c8CAS | 11030643PubMed |

Frostegård A, Bååth E, Tunlid A (1993) Shifts in the structure of soil microbial communities in limed forests as revealed by phospholipid fatty acid analysis. Soil Biology & Biochemistry 25, 723–730.
Shifts in the structure of soil microbial communities in limed forests as revealed by phospholipid fatty acid analysis.Crossref | GoogleScholarGoogle Scholar |

García C, Hernández T, Costa F (1994) Microbial activity in soils under Mediterranean environmental conditions. Soil Biology & Biochemistry 26, 1185–1191.
Microbial activity in soils under Mediterranean environmental conditions.Crossref | GoogleScholarGoogle Scholar |

García C, Hernandez T, Costa F (1997) Potential use of dehydrogenase activity as an index of microbial activity in degraded soils. Communications in Soil Science and Plant Analysis 28, 123–134.
Potential use of dehydrogenase activity as an index of microbial activity in degraded soils.Crossref | GoogleScholarGoogle Scholar |

García-Álvarez A, Ibañez JJ (1994) Seasonal fluctuations and crop influence on microbiota and enzyme activity in fully developed soils of central Spain. Arid Soil Research and Rehabilitation 8, 161–178.
Seasonal fluctuations and crop influence on microbiota and enzyme activity in fully developed soils of central Spain.Crossref | GoogleScholarGoogle Scholar |

Grayston SJ, Prescott CE (2005) Microbial communities in forest floors under four tree species in coastal British Columbia. Soil Biology & Biochemistry 37, 1157–1167.
Microbial communities in forest floors under four tree species in coastal British Columbia.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXisFGruro%3D&md5=e08cca9f0af04e22feaee057b5e27b41CAS |

Harris RF, Karlen DL, Mulla DJ (1996) A conceptual framework for assessment and management of soil quality and health. In ‘Methods for assessing soil quality’. (Eds JS Doran, AJ Jones) (SSSA, Inc.: Madison, WI, USA)

Hoffmann VG, Pallauf J (1965) Eine kolorimetrische Methode zur Bestimmung der Saccharase-Aktivität von Böden. Journal of Plant Nutrition and Soil Science 110, 193–201.

Imam SH, Greene RV, Hockridge ME (1993) Zymographic analyses of carboxymethylcellulases secreted by the bacterium from wood-boring marine shipworms. Biotechnology Techniques 7, 579–584.
Zymographic analyses of carboxymethylcellulases secreted by the bacterium from wood-boring marine shipworms.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXitlykur0%3D&md5=701895222bf6fcaf0b9c6f731c388ae2CAS |

Johnson JL, Temple EL (1964) Some variables affecting the measurements of catalase activity. Soil Science Society of America Journal 28, 207–209.
Some variables affecting the measurements of catalase activity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF2cXktFCnsLs%3D&md5=46e7311c41b104766203c5d847dafa52CAS |

Khalili B, Nourbakhsh F, Nili N, Khademi H, Sharifnabi B (2011) Diversity of soil cellulase isoenzymes is associated with soil cellulase kinetic and thermodynamic parameters. Soil Biology & Biochemistry 43, 1639–1648.
Diversity of soil cellulase isoenzymes is associated with soil cellulase kinetic and thermodynamic parameters.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXnsVeqsLg%3D&md5=25776bc9eb427001db0cd69e8c04b343CAS |

Kim K, Brown KM, Harris PV, Langston JA, Cherry JR (2007) A proteomics strategy to discover β-glucosidases from Aspergillus fumigatus with two-dimensional page in-gel activity assay and tandem mass spectrometry. Journal of Proteome Research 6, 4749–4757.
A proteomics strategy to discover β-glucosidases from Aspergillus fumigatus with two-dimensional page in-gel activity assay and tandem mass spectrometry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtlaktbrL&md5=90c98ac33632f03c13606dfd778fabd7CAS | 18020405PubMed |

Knight TR, Dick RP (2004) Differentiating microbial and stabilized β-glucosidase activity relative to soil quality. Soil Biology & Biochemistry 36, 2089–2096.
Differentiating microbial and stabilized β-glucosidase activity relative to soil quality.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXos1ejtr8%3D&md5=8657bdfd91cae0e20567349c72cee1ceCAS |

Lacks SA, Springhorn SS (1980) Renaturation of enzymes after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The Journal of Biological Chemistry 255, 7467–7473.

Liang YC, Si J, Nikolic M, Peng Y, Chen W, Jiang Y (2005) Organic manure stimulates biological activity and barley growth in soil subject to secondary salinization. Soil Biology & Biochemistry 37, 1185–1195.
Organic manure stimulates biological activity and barley growth in soil subject to secondary salinization.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXisFGrurk%3D&md5=4b5f0651054e0d0924cd50f30dec8b63CAS |

Lucas-Borja ME, Candel D, Jindo K, Moreno JL, Andrés M, Bastida F (2012) Soil microbial community structure and activity in monospecific and mixed forest stands, under Mediterranean humid conditions. Plant and Soil 354, 359–370.
Soil microbial community structure and activity in monospecific and mixed forest stands, under Mediterranean humid conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XlvFWgurg%3D&md5=86eebfec78fe5369763e5c5feb783a33CAS |

Nazir A, Soni R, Saini HS, Kaur A, Chadha BS (2010) Profiling differential expression of cellulases and metabolite footprints in Aspergillus terreus. Applied Biochemistry and Biotechnology 162, 538–547.
Profiling differential expression of cellulases and metabolite footprints in Aspergillus terreus.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXmvFCmsLw%3D&md5=cf912bba2c908dd098db36feaec201a0CAS | 19779865PubMed |

Nelson N (1944) A photometric adaptation of the Somogyi method for the determination of glucose. The Journal of Biological Chemistry 153, 375–380.

Parr JF, Papendick RI (1997) Soil quality, relationship and strategies for sustainable dryland farming system. Annals of Arid Zone 36, 181–191.

Perissol C, Roux M, Le Petit J (1993) Succession of bacteria attached to evergreen oak leaf surfaces. European Journal of Soil Biology 29, 167–176.

Petersen SO, Henriksen K, Mortensen GK, Krogh PH, Brandt KK, Sorensen J, Madsen T, Petersen J, Gron C (2003) Recycling of sewage sludge and household compost to arable land: fate and effects of organic contaminants, and impact on soil fertility. Soil & Tillage Research 72, 139–152.
Recycling of sewage sludge and household compost to arable land: fate and effects of organic contaminants, and impact on soil fertility.Crossref | GoogleScholarGoogle Scholar |

Pramanik P, Chung YR (2011) Changes in fungal population of fly ash and vinasse mixture during vermicomposting by Eudrilus eugeniae and Eisenia fetida: Documentation of cellulase isozymes in vermicompost. Waste Management 31, 1169–1175.
Changes in fungal population of fly ash and vinasse mixture during vermicomposting by Eudrilus eugeniae and Eisenia fetida: Documentation of cellulase isozymes in vermicompost.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXkvVKgurg%3D&md5=4e806b66532545acc28c49962394db61CAS | 21277188PubMed |

Rinnan R, Baath E (2009) Differential utilization of carbon substrates by bacteria and fungi in Tundra soil. Applied and Environmental Microbiology 75, 3611–3620.
Differential utilization of carbon substrates by bacteria and fungi in Tundra soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXntlSgs7k%3D&md5=b7a3b1361c33fcdaf7d5600fc6275acaCAS | 19363072PubMed |

Ros M, Hernández MT, García C (2003) Soil microbial activity after restoration of a semiarid soil by organic amendments. Soil Biology & Biochemistry 35, 463–469.
Soil microbial activity after restoration of a semiarid soil by organic amendments.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXhvFGrt70%3D&md5=98f12468129ec6d37a645679fe828684CAS |

Schimel J (1995) Ecosystem consequences of microbial diversity and community structure. In ‘Arctic and alpine biodiversity: Patterns, causes, and ecosystem consequences’. (Eds FS Chapin, C Korner) (Springer-Verlag: Berlin)

Schimel J, Bennett J (2004) Nitrogen mineralization: challenges of a changing paradigm. Ecology 85, 591–602.
Nitrogen mineralization: challenges of a changing paradigm.Crossref | GoogleScholarGoogle Scholar |

Sims JR, Haby VA (1971) Simplified colorimetric determination of soil organic matter. Soil Science 112, 137–141.
Simplified colorimetric determination of soil organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXkvFOls70%3D&md5=e62e8532d3315e760f9ed2179218a068CAS |

Sinsabaugh RS (1994) Enzymatic analysis of microbial pattern and process. Biology and Fertility of Soils 17, 69–74.
Enzymatic analysis of microbial pattern and process.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXmtVSnsLk%3D&md5=c659be6ffe2d52a1de3c964657363b02CAS |

Sinsabaugh RL (2010) Phenol oxidase, peroxidase and organic matter dynamics of soil. Soil Biology & Biochemistry 42, 391–404.
Phenol oxidase, peroxidase and organic matter dynamics of soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtVaqt74%3D&md5=d973190c6b6849b77a986dc003b8396bCAS |

Sinsabaugh RL, Antibus RK, Linkins AE (1991) An enzymic approach to the analysis of microbial activity during plant litter decomposition. Agriculture, Ecosystems & Environment 34, 43–54.
An enzymic approach to the analysis of microbial activity during plant litter decomposition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3MXlsFOrur4%3D&md5=fa68f96ae35dbbd1d835f7e3dff97b03CAS |

Sinsabaugh RL, Gallo ME, Lauber CL, Waldrop M, Zak DR (2005) Extracellular enzyme activities and soil carbon dynamics for northern hardwood forests receiving simulated nitrogen deposition. Biogeochemistry 75, 201–215.
Extracellular enzyme activities and soil carbon dynamics for northern hardwood forests receiving simulated nitrogen deposition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtFynt7zM&md5=76ec2e872818843ab5354772cd5e8445CAS |

Smith LJ, Papendick RI (1993) Soil organic matter dynamics and crop residue management. In ‘Soil microbial ecology. Applications in agricultural and environmental management’. (Eds FB Metting Jr) pp. 65–94. (Marcel Dekker: New York)

Soil Survey Staff (1998) ‘Keys to Soil Taxonomy.’ 8th edn (USDA-ARS: Washington, DC)

Sonia KG, Chadha BS, Badhan AK, Saini HS, Bhat MK (2008) Identification of glucose tolerant acid active β-glucosidases from thermophilic and thermotolerant fungi. World Journal of Microbiology & Biotechnology 24, 599–604.
Identification of glucose tolerant acid active β-glucosidases from thermophilic and thermotolerant fungi.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXksVaktb4%3D&md5=71137cf2cca34b73fadcd74bcc1c47d6CAS |

Stott DE, Andrews SS, Liebig MA, Wienhold BJ, Karlen DL (2010) Evaluation of beta-glucosidase activity as a soil quality indicator for the soil management assessment framework. Soil Science Society of America Journal 74, 107–119.
Evaluation of beta-glucosidase activity as a soil quality indicator for the soil management assessment framework.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXis12qsA%3D%3D&md5=4504ad6141a03dc5104cdd96126f6084CAS |

Stursova M, Sinsabaugh RL (2008) Stabilization of oxidative enzymes in desert soil may limit organic matter accumulation. Soil Biology & Biochemistry 40, 550–553.
Stabilization of oxidative enzymes in desert soil may limit organic matter accumulation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtlajsL7E&md5=f216364fb0780ebaa77958eeae664860CAS |

Tabatabai MA (1982) Soil enzymes. In ‘Methods of soil analysis. Part 2. Chemical and microbiological properties’. 2nd edn. (Eds AL Page, RH Miller, DR Keeney) pp. 903–947. (American Society of Agronomy, Soil Science Society of America: Madison, WI, USA)

Trasar-Cepeda C, Leirós MC, Gil-Sotres F (2008) Hydrolytic enzyme activities in agricultural and forest soils. Some implications for their use as indicators of soil quality. Soil Biology & Biochemistry 40, 2146–2155.
Hydrolytic enzyme activities in agricultural and forest soils. Some implications for their use as indicators of soil quality.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVSjtrjI&md5=057ba7b64db9d0a60f6a4a8e738a9b7eCAS |

Trevors JT, Mayfield CI, Inniss WE (1982) Measurement of electron transport system (ETS) activity in soil. Microbial Ecology 8, 163–168.
Measurement of electron transport system (ETS) activity in soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXhsFyntQ%3D%3D&md5=20447a5b85e4899ab8694ed08f360794CAS | 24225810PubMed |