1 Plant Archives Vol. 20, Supplement 2, 2020 pp. 2509-2516 e-ISSN:2581-6063 (online), ISSN:0972-5210 MICROORGANISM BASED BIOSENSORS TO DETECT SOIL POLLUTANTS Rabiu Garba Ahmad and Vineet Kumar* Department of Biotechnology, School of Bioengineering and Biosciences, LFTS, Lovely Professional University, Phagwara, Punjab- 144111, India *Author for correspondence email: vineetkumar22@gmail.com Abstract Biosensors play a vital role in the field of environmental biotechnology. Biosensors are devices that can be used for analysis which include a biological sensing element integrated with a physical transducer to generate a signal. The signal produced is proportional to the concentration of analyte. Microorganisms can also be used as response element to obtain biosensor. Biosensor has many applications that include environmental monitoring of toxic chemicals or compounds that may affect the ecosystems as well as the life and development of humans. In this review, use of various types of microorganisms to obtain electrochemical, optical and other biosensors for pollutants detections have been discussed. Applications of biosensors for monitoring environmental pollutants such as polychlorinated biphenyls, nitrogenous compounds, pesticides as well as aromatic hydrocarbons are also addressed. Overall, the use of biosensor could serve as an alternative and a promising technology that can be used effectively for the detection and hence remediation of toxic pollutants in the environment as well as the industrial waste contaminated soil. Keywords: Sensor, Biosensor, Environmental pollution, Soil. Introduction Pollution causes a very serious change in the environment and the ecology. However, alternative arrangements of power generation energy resources and reserve in India are discussed (Kumar et al., 2019). It also has an effect on the economic growth of the area (Segura et al., 2017). Anthropogenic activities are one of the causative agents of environmental hazard faced globally. Both developing and developed countries are suffering from industry-based pollutant (Jarque et al., 2016). Human activities related to industrial production of day-to-day use goods, medicines, agricultural products are major source of pollutants into the environment. These pollutants such as trace element ions, toxic gas causes pollutants in air, water, soils that are harmful to the life and human development (Renella and Giagnoni, 2016; Kumar and Dwivedi, 2018a; Kumar and Kumar et al. 2018b; Kumar et al., 2018c; Kumar and Dwivedi, 2018d; Kumar et al., 2018e). Because of the increasing public awareness and strict regulation of environmental issues, monitoring of environmental pollutants related to soil, water as well as air has become necessary. Pollutants from petroleum sources due to leaking on the ground, underground storage, and spillage while transportation of petroleum products and such waste from related industries are serious soil pollutants. These kinds of pollutants are very costly to be decontaminated. Just like petroleum-based pollutants, overall methods for remediating the polluted sites by mixture of pollutant like lake water attracts more attention (Alamri, 2009). To overcome these challenges, remedial actions need to be done with a high frequency and accuracy (Geetha et al., 2013, Kumar and Pathak, 2019f; Kumar et al., 2019g; Siddique and Kumar, 2018h; Siddique et al., 2018i; Pathak et al., 2017j; Prakash and Kumar, 2017k; Kumar and Mandal, 2014L). To detect initial pollutant level and whether a remedial method is removing pollutants from contaminated water and soil we require accurate sensing technique, procedures and sensors. Many sensing techniques have been used for the detection of environmental monitoring; however, the techniques that have been used have some drawbacks. In a recent development, the use of biosensor serves as a promising technology that can be used for continuous detection of pollutants in the environment. Biosensors in combinations with some new technologies related to nanomaterial, molecular biology as well as microfluidic has many applications for environmental monitoring. They include real time detection of pesticides, and other environmental toxic chemicals (Dorst et al., 2010; Pakshirajan et al., 2015; Timur et al., 2015). Use of microorganisms for the detection of soil pollutant is low cost effective approach and hence has been discussed in detail. Sensors to Detect Environmental Pollutants Sensors, term has been derived from Latin word “Sentire” which means to observe or perceive. Biotechnology play an important role regarding the monitoring as well as treatment of environmental pollutants prevailing in contaminated air, water, and soil. Among the different biosensing approaches available currently some are well established and few are new (Kumar et al., 2014m; Kumar et al., 2014n; Kumar, 2013o; Kumar and Dwivedi, 2015p; Gogia et al., 2014q; Kumar, 2014r; Kumar et al., 2012s). Overall the reliability regarding the performances of most of these sensors is under scrutiny. This is difficult due to challenges observed regarding sample isolation and processing in a complex environment. Continuous efforts are being made to design wearable accurate personalized sensor for robust human use Different sensor types for monitoring of environmental pollutants are categorized. The employment of these sensors depends upon the type of analyte to be detected as well as the transducer to be used (Dorst et al., 2010; Pakshirajan et al., 2015; Timur et al., 2015; Çevik et al., 2016; Lei et al., 2006). Biosensor integrates biological sensing elements namely, enzymes, nucleic acids, proteins, and microorganisms with transducer to generate a signal, which is proportional to the analyte concentration under investigation. In biosensor, transducer has the responsibility of producing a response that is measurable which includes potential, current as well as absorption via electrochemical or optical process by the action of the transducer that alter the