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Evaluation of Food and Food Contaminants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
Enzyme activities have been indicated as soil properties suitable for use in the evaluation of the degree of alteration of soils in both natural and agroecosystems. Soil microbial properties have a strong correlation with soil health. Some research has already suggested the favorable effects of conservation, tillage practices, and organic fertilizers on soil enzyme activities.247 The activity of dehydrogenase is considered an indicator of the oxidative metabolism in soils and thus of the microbiological activity, because it is exclusively intracellular and, theoretically, can function only within viable cells. Urease catalyzes the hydrolysis of urea to CO2 and NH3, which is of specific interest because urea is an important N fertilizer. Urease is released from living and disintegrated microbial cells, and in the soil it can exist as an extracellular enzyme absorbed on clay particles or encapsulated in humic complexes. Phosphatases catalyze the hydrolysis of both organic phosphate (P) esters and anhydrides of phosphoric acid into inorganic P. Phosphatase activity may originate from the plant roots (and associated mycorrhiza and other fungi), or from bacteria.250
Soils with Biological Problems
Published in Manorama K.C. Thampatti, Problem Soils, 2023
Soil enzyme activity: Yet another factor that indicates soil biological activity is soil enzymes. Soil enzymes control the rate of organic matter decomposition and release of plant available nutrients. Enzymes are specific to a substrate and have active sites that bind with the substrate to form a temporary complex. The enzymatic reaction releases a product, which can be a nutrient contained in the substrate. Absence or suppression of soil enzymes prevents or reduces processes that can affect plant nutrition. Poor enzyme activity can result in an accumulation of chemicals that are harmful to the environment; some of these chemicals may further inhibit soil enzyme activity.
Factors Responsible for Spatial Distribution of in Soil
Published in Suhaib A. Bandh, Javid A. Parray, Nowsheen Shameem, Climate Change and Microbial Diversity, 2023
Soil enzymes are a vast area of research. The soil enzymes’ importance and role could be seen on soil quality, productivity, and in soil biogeochemical reactions. Soil enzymes are directly or indirectly influenced by various factors belongs to physical, chemical, and biological characteristics of soil. The enzyme activities are directly correlated to management practices as well as environmental factors. The environmental factors not only distribute these soil enzymes spatially but the time of sampling and storage before assaying the enzyme activities is also an important factor. Temporal and spatial enzyme activity assay required the knowledge of factors controlling the enzymes activities. With advancement in molecular biology techniques, it is possible to work on enzyme coding genes, transcript products, and protein production. Soil enzyme profiling will help in management practices and therefore could be used to increase productivity. It could also be used to control soil pollution crested directly or indirectly by different anthropogenic activities. Biotic and abiotic stresses induced by climate change also affect the soil enzyme activity. Advance and strategic research is required to study the dynamics of enzyme activity. Further researches should be carried out to minimize or control the change in enzyme activities due to such stresses. By combining the molecular technique of quantitative PCR with measurement of activities of soil enzymes, soil chemistry, and analyzing microbial community using next generation sequencing methods, a most probable future research could be conducted to avail knowledge related to soil enzyme distribution and activity. The most important challenge for assaying enzyme activity is the time, which should be considered during sampling and data analyzing. In addition to adequate protocols, it is required to collect data of accurate definition based on spatial before generating any conclusion on the spatial factors for enzymatic activity.
Enhancement of phytoextraction efficiency coupling Pteris vittata with low-dose biochar in arsenic-contaminated soil
Published in International Journal of Phytoremediation, 2023
Zhou-Yu Liu, Rui Yang, Xue-Ying Xiang, Li-Lu Niu, Dai-Xia Yin
It had been reported that biochar has a great labile fraction of carbon, which can be used as an energy source by soil microorganisms (Lehmann et al.2011). The mineralization of soil organic matter (SOM) is an considerable microbially-mediate process by which carbon and other nutrients are converted from organic into inorganic forms (Nannipieri et al.2012). Besides, pH increase induced by biochar addition is another factor, increasing proton amounts, and thus increase microbial biomass and bacteria abundance (Lehmann et al.2011). Soil pH is one of the main factors driving changes in soil enzyme activity (Zhang D et al.2022). Significant positive correlation was observed between pH and CAT activities in the rhizosphere (p < 0.05, Table S2). It had been found that the changes in environmental pH greatly affect the respiration and metabolism (Srinivasan and Mahadevan 2010). CAT activity is an important indicator of soil redox capability associated with soil biochemical processes, such as soil energy and nutrient transformation (Zhang G et al.2020), which may alter As behavior in soil and uptake by plants (Yang X et al.2022).
Effects of the promoting bacterium on growth of plant under cadmium stress
Published in International Journal of Phytoremediation, 2023
Deng Yang, Mingbo Zuo, Yueli Chen, Yuan Liu, Yueqing He, Haoming Wang, Xiaoxiao Liu, Jing Xu, Minjuan Zhao, Yuanyuan Shen, Ying Liu, Gao Tianpeng
Soil enzyme activity is closely related to soil properties, soil type, and environmental conditions, and it has been widely used as an indicator of soil quality and fertility (Aponte et al. 2020). Inoculation of plant growth promoting bacteria can accelerate the decomposition of soil organic compounds and provide substrates for enzymatic reactions, thus increasing soil enzyme activity (Saia et al. 2015). Inoculation with PGPR can also effectively promote soil nutrient uptake by plants (Damodharan et al. 2018). Khan et al. (2023) showed that inoculation with B. cepacia CS8 not only helped to promote plant growth but also improved the contaminated soil. The inhibition of soil enzyme activity caused by increased heavy metal biotoxicity in this study may be due to the reaction of metal ions with sulfhydryl groups of enzymes, or chelation with substrates or with enzyme-substrate reactions (Tang et al. 2020). In this study, inoculation with strain ZG7 or planting sugar beet. significantly increased the activity of all four soil enzymes. The study also showed that sucrase, urease, catalase and neutral phosphatase activities were better and more stable in the presence of both strain ZG7 and sugar beet compared to other treatments (Figure 5). This is in agreement with previous studies that inoculated strains help to increase soil enzyme activity (Lin et al. 2021; Abdelkrim et al. 2020; Li et al. 2019; Bai et al. 2020). The possible reason is that plant root secretions and beneficial microorganisms contribute to soil enzyme activity (Lin et al. 2021).Therefore, it is suggested that inoculation of plant growth promoting bacteria in mining areas can be used as biofertilizer to improve soil enzyme activity and reduce soil pollution by Cd, which is of great significance for agricultural development around mining areas.
Leaching of Heavy Metals and Enzymatic Activities in Un-inoculated and Inoculated Soils with Yeast Strains
Published in Soil and Sediment Contamination: An International Journal, 2020
Kouchou Aziza, El Ghachtouli Naïma, Rais Naoual, Derraz Khalid, Ijjaali Mustapha, Bahafid Wifak
Since soil enzyme activities are known to play essential roles in organic matter mineralization and decomposition of C, N, P, and S nutrients in soils, they could be positively affected by the organic matter (Jordan et al. 1995). Thus, we studied the correlations between enzymatic activities and the physicochemical properties of the soil, in particular soil organic matter. The results are shown in Table 6.