Enzymatic defense of Cyperus brevifolius in hydrocarbons stress environment and changes in soil properties

Abstract

Hydrocarbons or crude oil contamination of soil is still a burning problem around the globe. The herbs competent that are to survive in hydrocarbons contaminated habitats have some adaptive advantages to cope up with the adverse situations prevailing in that environment. In the present study, the adaptive response of Cyperus brevifolius in the heavily polluted soil with crude oil has been investigated in terms of survivability, changes in productivity, antioxidants, phytochemicals and functional group pro files of the plant species. Besides, changes in enzymes, beneficial bacterial population and physico-chemical conditions of contaminated soil were also studied during 60 days of experimental trials. The results showed significant enhancement in activities of soil dehydrogenase, urease, alkaline phosphatase, catalase, and amylase whereas reduction in cellulase, polyphenol oxidase and peroxidase activities. There was a significant increase in nitrogen fixing, phosphate and potassium solubilizing bacterial population, improvement in physico-chemical conditions and a decrease in total oil and grease (TOG) levels. Besides there was significant variations in the productivity parameters and antioxidant profiles of Cyperus brevifolius in hydrocarbons stress condition suggesting enzymatic defense of the herb. The fourier-transform infrared (FT-IR) analysis indicated uptake and metabolism of some hydrocarbon components by the experimental plant from the hydrocarbons polluted soil.

Understanding Biochemical Defense of Leucas Aspera in Crude Oil Polluted Habitat and Changes in Soil Properties

“…The shifting in pH towards less acidic condition after plant's treatment could be attributed to the mineralization of oil components in soil. It has been suggested that introduction of plants in contaminated soil enhances the microbial activities which further accelerate the mineralization process in soil (Chakravarty and Deka 2021).The present nding on pH deviation agrees the report of Ukaegbu-Obi and Omeh (2014) who have pointed out that mineralization of crude oil components is responsible for reduction in soil acidity thereby con rming the biodegradation of hydrocarbons in the contaminated soil. Similarly, the soil conductivity and water holding capacity values have also increased signi cantly in T3 when compared with the initial level (T1).…”

“…Again, methods of Johnson and Temple (1964) were used to measure the activity of catalase enzyme. Alkaline Phosphatase activities were analyzed by employing the method of Tabatabai and Bremner (1969) whereas polyphenol oxidase and peroxidase were measured by the standard protocols of Bach et al (2013) and German et al (2011).The total population of nitrogen xing, phosphate and potassium solubilizing bacteria in the soil samples were enumerated in Jensen's medium, Pycovskaya's and Aleksandrow agar respectively following serial dilutions technique as outlined by Chakravarty and Deka (2021).…”

“…The methods of Hagerman (2002) and Jay et al (1975) were employed respectively for estimation of total phenol and avonoid contents of the plant extracts. The productivity parameters of L. aspera were analyzed before and completion of the experimental trials in terms of Leaf area index (LAI), estimation of chlorophyll and dry biomass employing the methods outlined by Chakravarty and Deka (2021).…”

“…Nevertheless, better adaptability, robust growth after establishment, presence of brous and extensive root systems (Cook and Hesterberg 2013) con rms the suitability of herbs and grasses against the crude oil pollutants when compared with trees. There are numbers of report regarding the better adaptive response of grasses/herbs in crude oil polluted soil as against the tree seedlings or saplings (Chakravarty and Deka 2021, Ali et al 2013, Basumatary et al 2012a and accordingly several workers have established them as the suitable candidates for phytoremediation practices (Adesodun et al 2010, Salazar andPignata 2014).…”

Microbiological Study in Petrol-Spiked Soil

“…They are used to construct models for the assessment of potential soil fertility [ 28 , 77 , 78 , 79 , 80 ]. Due to their ability to signalize changes triggered under the pressure of stress factors, they also perfectly mirror the effects of pollutants on soil [ 81 , 82 , 83 ]. Among the soil enzymes, dehydrogenases prove best in reflecting the rate of changes in the soil environment.…”