Bioaugmentation and biostimulation: a potential strategy for environmental remediation

Abstract

As the world is heading towards rapid urbanization and technological advancements, more undesirable and unwanted activities by human is raising major environmental issues like global warming, imbalance in soil ecological processes leading to lower agricultural yield, drastic climate change, etc. Predominantly, among all, xenobiotic recalcitrant compounds are indiscriminately being disposed in the environment causing significant hazard owing to its high stability and complexity. However, there are several methods for disposing such materials but the most efficient and significant disposal strategy is said to be bioremediation. This biological approach of remediation can be executed through introduction of efficient microbial strains (bioaugmentation) or by addition of rate limiting nutrients to the soil (biostimulation) to enhance the remediation process significantly. Existing literatures provide a broad landscape of the efficiency of some of the microbial strains and a few of the rate limiting nutrients in remediation of the toxic, highly complex and resistant contaminants but lacks information regarding their degree of efficiency and eco-friendliness in comparison with those of other disposal strategies. This review extensively focuses on a comparative discussion on different strategies of bioremediation to remediate the environment from the toxic, hazardous waste with the goal of building a less-toxic, stable and a healthy environment.

Microbial Degradation of Rubber: Actinobacteria

“…Biomimicry can improve the degradation process through introduction of efficient microbial strains (bio-augmentation) or by addition of nutrients to the soil (bio-stimulation) [ 139 ]. Bioaugmentation is a technique for improving the degradative capacity of contaminated areas through introduction of specific competent strains or consortia of microorganisms (autochthonous or allochthonous wild type or genetically modified microorganisms, GEMs) [ 140 ].…”

“…Bio-stimulation refers to the addition of growth-rate limiting nutrients like phosphorus, nitrogen, oxygen, electron donors to severely polluted sites for the enhancing the indigenous biomass activity to degrade the hazardous and toxic contaminants [ 139 ]. The primary advantage of bio-stimulation is that bioremediation will be undertaken by already present native microorganisms that are well-suited to the subsurface environment and are well distributed spatially within the subsurface [ 142 ].…”

Advances in Bioremediation Agents and Processes for Removal of Persistent Contaminants From Environment

“…Bioaugmentation is the process of introducing specific microbial strains or consortia into contaminated environments with the aim of increasing the ability of the existing microbial population for degradation [33]. This targeted approach lessens the need for external inputs like chemical supplements while promoting the microbial diversity that is already present in the environment.…”

Nutrient depletion is the main limiting factor in the crude oil bioaugmentation process

“…Foreign microorganisms have been applied widely, but the efficiency depends on the competitiveness with indigenous microorganisms, predators and various abiotic factors ( Zeneli et al, 2019 ;Tribedi et al, 2018 ). The toxicity of a high concentration of hydrocarbons, the limitation in nutrient sources, low numbers of the principal oil degraders in the sediment and seawater, and by-products of degradation to the bacterial community can affect the rate and effectiveness of natural biodegradation ( Ossai et al, 2020 ).…”