Simultaneous bioremediation of diesel-contaminated soil and water ecosystems using mixed culture of Acinetobacter baumannii IITG19 and Providencia vermicola IITG20

ABSTRACT

Diesel degradation and bacterial growth were investigated in soil, marine water, and freshwater ecosystems using Acinetobacter baumannii IITG19, Providencia vermicola IITG20, and their mixed culture. Both bacteria were found to be effective in all three ecosystems, with the best degradation occurring in freshwater. Acinetobacter baumannii IITG19 showed higher degradation (59%, 62%, and 76%) than Providencia vermicola IITG20 (31%, 57%, and 67%) in soil, marine water, and freshwater, respectively. Alkanes showed higher degradation than naphthenes and aromatics for both strains. The mixed culture showed higher diesel degradation efficiency than individual strains in all ecosystems. The overall degradation was similar in soil and marine water (66%), while freshwater showed the highest degradation of 81%. In the presence of the mixed culture, the degradation of alkanes was more than 90%. Bacterial growth was highest in freshwater and lowest in soil for both bacteria and the mixed culture. Metabolite analysis confirmed alcoholic degradation for alkanes and cyclo-alcoholic degradation for naphthenes. The degradation rate for mixed culture was higher than that of both the individual strains. The mixed culture had highest degradation rate constant in freshwater at 0.11 day⁻¹ followed by that in marine ecosystem at 0.078 day⁻¹. The rate constant was lowest for soil ecosystem at 0.066 day^−1. Thus the mixed culture showed effectiveness in all three ecosystems, with its highest effectiveness observed in the freshwater ecosystem.

GRAPHICAL ABSTRACT

KEYWORDS:

• Bioremediation
• diesel degradation
• degradation kinetics
• mixed bacterial culture
• environmental ecosystems

Acknowledgements

Authors acknowledge the instrumental facility provided by the Central instrumental facility, and Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Compliance with ethical standards

This article does not contain any studies with animals performed by any of the authors.

Author contributions

Rahul Kumar was involved in conceptualization, performing experiments, analysing experimental data, and writing original draft of manuscript. Mahuya De was involved in conceptualization, resources, supervision, and editing of manuscript. Both authors read and approved the final manuscript.

Data availability statement

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.