Determination of enzymatic activities using a miniaturized system as a rapid method to assess soil quality

Abstract

SummarySoil quality determination requires the analysis of a number of soil attributes using different approaches. In recent years, one of the most promising approaches has been the determination of enzymatic activities. Generally, only a few enzymes have been analysed and related to other soil properties such as total carbon, nitrogen content or microbial biomass carbon. The aim of this work was to investigate the possible use of the API ZYM strip, a semi-quantitative miniaturized system that determines 19 enzymatic activities, to study soil quality. To this end, we tested the system in different soil types, including albic Arenosols, mollic Leptosols, rendzic Leptosols, haplic Leptosols and calcaric Regosols. Fresh samples were sieved through a 2-mm sieve in the field and soil extracts were prepared by mixing 2-20 g (depending on the soil horizon characteristics) from each sample with 2-20 ml of sterile water. Next, 65-μl aliquots of the supernatant extract were placed into each API ZYM microtube and were incubated at 37• C for 16 hours. Our results show important qualitative and quantitative differences among the different soil types studied, with soil characteristics and biological properties correlating with biochemical information. The results provide useful information not only to determine soil quality, but also to assess changes in the soil environment. As a whole, our results suggest that the use of the API ZYM system could prove most useful in soil environmental studies. Finally, some suggestions are presented, including modifications to the system that could improve its application in this field.

Evaluation of Non-Conventional Biological and Molecular Parameters as Potential Indicators of Quality and Functionality of Urban Biosolids Used as Organic Amendments of Agricultural Soils

“…Also included are enzyme activity monitoring systems that allow the establishment of "fingerprints" or activity enzyme "profiles" such as the API ZYM ® system. As well, the establishment of indices of functional diversity and microbial activity, such as the Shannon index (H') and synthetic enzymatic index (SEI) is also important for their potential contribution as indicators of quality and agronomic functionality of biosolids before and after being applied as soil improvers [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Only U.S.A. regulation stipulates that the agronomic speed of application cannot be exceeded [41]; to protect the quality of groundwater or surface water, nitrogen must be regulated through an agronomic rate approach, which requires an estimate of the need for N from the crop and the availability of N in biosolids [41,42].…”

“…One of these enzymatic assays is the API ZYM ® system which has been used in environmental matrices with complex biochemical processes e.g., soils, compost, activated sludge and sediments [34][35][36][37][38][39]44]. This system provides rapid and semi-quantitative information on the hydrolytic activity of 19 enzymes associated with the biodegradation of lipids, proteins, carbohydrates, and nucleic acids [34,36,39]. Therefore, the importance of monitoring a wide range of enzymes involved in various biochemical processes such as those occurring in biosolids is emphasized.…”

Assessing soil quality of gleyed paddy soils with different productivities in subtropical China

“…Soil quality is complex and its proper evaluation requires determining a large number of properties (Boluda et al, 2014). Many soil scientists have agreed to establish a minimum data set (MDS) to reduce the analysis costs because of its capacity to adequately represent the total data set (Qi et al, 2009;Rahmanipour et al, 2014).…”

API ZYM assay to evaluate enzyme fingerprinting and microbial functional diversity in relation to soil processes

“…The API ZYM strips were covered and incubated at 37°C for 4 h. After that, one drop (30 μl) of the commercial reagents ZYM A and ZYM B (bioMérieux) was added to all the microcupules to develop chromogenic substrates. The colour reactions were read after 5 min, and a numerical value ranging from 0 to 5 was assigned according to the colour chart provided by the manufacturer, as already reported (Tiquia 2002;Bending et al 2002;Shemekite et al 2014;Boluda et al 2014). In an equivalence scale of readings according to Baldrian et al (2011), 0 is 0 nanomoles substrate hydrolysed, 1 is 5 nanomoles substrate hydrolysed, 2 is 10 nanomoles substrate hydrolysed, 3 is 20 nanomoles substrate hydrolysed, 4 is 30 nanomoles substrate hydrolysed, and 5 is higher or equal to 40 nanomoles substrate hydrolysed.…”

“…The API ZYM assay includes 19 enzymatic reactions involved in the breakdown of peptides, phosphomonoesters, lipids, mucopolysaccharides, polysaccharides, chitin, cellulose, starch, and galactans (Bending et al 2002). This assay has been used for evaluating the enzyme activity in soil (Bending et al 2002;Boluda et al 2014) and composts (Tiquia 2002;Shemekite et al 2014). Moreover, this enzymatic kit could be transported in the field and be rapidly used for a biochemical evaluation of soil and forming factors or ecosystem perturbations.…”