Eco. Env. & Cons. 28 (3) : 2022; pp. (1544-1560) Copyright@ EM International ISSN 0971–765X Kinetic Indices of Enzyme Activity used as Sensitive Biomarkers to Monitor Mine Spoil Genesis in Chronosequence Coal Mine Overburden Spoil Payal Agrawal, Jitesh Kumar Maharana and Amiya Kumar Patel* Department of Biotechnology and Bioinformatics Sambalpur University, At/po- Jyoti Vihar, Burla 768 019, Odisha, India (Received 21 July, 2021; Accepted 15 November, 2021) ABSTRACT Mine spoil genesis mostly focuses on careful consideration of enzyme activities and kinetics parameters to elucidate microbial mediated biotransformation and nutrient cycling including their link with the variation in physicochemical properties, microbial community dynamics and landscape ecology as the functional determinants of ecosystem function. The relative distribution of microbial populations exhibited progressive increase in different age series coal mine overburden spoil over time. The kinetic parameters of amylase, invertase, protease, urease, phosphates and dehydrogenase activities were determined to assess the metabolic response in different age series coal mine spoil. Gradual increase in Vmax and decline in Km of enzyme activities representing the quality and affinity of enzymes correlated well with the shift in microbial community composition over time. Besides, the shift in catalytic efficiency (Vmax/Km) has greater significance as early and sensitive indicators of the changes in soil properties influencing microbial community dynamics across the sites. The enzyme activity and kinetic parameters correlated well the changes in physicochemical properties over time across the sites. PCA and RDA analysis can able to discriminate six different age series coal mine overburden spoil and nearby NF soil into independent clusters based on the variability in physicochemical properties, microbial community structure, enzyme activities and kinetic parameters. The study suggested that the kinetic indices of enzyme activities can be used as reliable ecological biomarkers to monitor the progress of mine spoil genesis. Key words: Mine spoil, Microbial community structure, Enzyme activity, Enzyme kinetics, Mine spoil genesis. Introduction Enzymes are primarily derived from soil microbes either as extracellular secretions and/or products from lysed cells. Enzymes are biological entities that catalyses biochemical reactions influencing the rate limiting steps involved in various biotransformation reactions of available nutrients. Enzyme activities provide integrative relationships between biological and biochemical soil attributes and proposed as early and sensitive indicators of the changes medi- ated by anthropogenic activities. Enzyme activities contributed by proliferating microbes play an im- portant role in the decomposition and mineraliza- tion of soil organic matter, which provides insight into microbial community dynamics ad activities. Therefore, the rationale of estimating enzyme activi- ties is prerequisite to establish correlation with soil quality status and microbial activities useful for the periodic assessment of mine spoil genesis. The biochemical properties are responsive to small changes in microbial activities due to their in- DOI No.: http://doi.org/10.53550/EEC.2022.v28i03.063