MINI-REVIEW Successive use of microorganisms to remove chromium from wastewater Amina Elahi 1 & Iqra Arooj 2 & Dilara A. Bukhari 3 & Abdul Rehman 1 Received: 30 January 2020 /Revised: 28 February 2020 /Accepted: 9 March 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Heavy metal pollution is a direct consequence of the extensive utilization of heavy metals in various industrial processes. The persistence and nondegradability of heavy metals cause them to bioaccumulate in nature, and when they come in direct contact with the pristine environment, they not only contaminate it severely but also pose dire consequences to the health of all living forms on earth, including humans. Chromium (Cr) is one of the heavy metals which has been extensively used in various industrial processes such as mining, alloy manufacturing, tanning of hides and skins, pigment production, etc. However, it is regarded as a priority pollutant due to its highly toxic, teratogenic, mutagenic, and carcinogenic nature, and the U.S. Environmental Protection Agency (EPA) also categorized it into group “A” human carcinogen. In contrast to water-soluble hexavalent chromium (Cr 6+ ), its reduced form, trivalent chromium (Cr 3+ ), is relatively benign and readily precipitated at environmental pH. Thus, bioremediation of Cr 6+ through microorganisms including bacteria, yeast, and algae provides a prom- ising approach to decontaminate a metal-polluted environment. This review describes an overview of the microbial reduction of Cr 6+ , resistance mechanism, and the antioxidant profiling exhibited by these microorganisms when exposed to Cr 6+ . It also describes the pilot-scale study of the successive use of bacterial, fungal, and algal strains and the subsequent use of microbially purified water for the cultivation of plant growth. Multiple metal-resistant microorganisms are a good bioresource for green chemistry to eradicate environmental Cr 6+ . Key Points • Hexavalent chromium (Cr 6+ ) is highly toxic for living organisms including humans. • Microbial Cr resistance is mediated at the genetic, proteomic, and molecular levels. • Successive use of microorganisms is the best strategy to exterminate Cr 6+ from the environment. Keywords Cr toxicity . Cr resistance strategies . Antioxidant enzymes . Microorganisms . Cr bioremediation Introduction Industrial globalization and rapid technological advance- ments, raising the standards of living and being vital to meet the needs of the modern age, also inflict serious damage to the environment. Industries indiscriminately are releasing large quantities of toxic waste materials in solid, liquid, and gaseous forms directly into the ecosystem. The hazardous waste mate- rials contain toxic heavy metals, metalloids, and organic pol- lutants that collectively inflict severe damage to the soil and water systems. Among all the contaminants released, heavy metal pollution is a matter of concern globally as it poses a serious threat to the environment and leads to global health issues. Heavy metal pollution aggravated the situation because Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00253-020-10533-y) contains supplementary material, which is available to authorized users. * Abdul Rehman rehman.mmg@pu.edu.pk 1 Department of Microbiology and Molecular Genetics, University of the Punjab, New Campus, Lahore 54590, Pakistan 2 Department of Microbiology and Molecular Genetics, The Women University, Multan, Pakistan 3 Department of Zoology, Government College University, Lahore, Pakistan Applied Microbiology and Biotechnology https://doi.org/10.1007/s00253-020-10533-y