Ghaffar Imania, Hussain Ali, Hasan Ali, Deepanraj Balakrishnan
Applied and Environmental Microbiology Laboratory, Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Applied and Environmental Microbiology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan.
Chemosphere. 2023 Apr;320:137921. doi: 10.1016/j.chemosphere.2023.137921. Epub 2023 Jan 19.
The recent surge in industrialization has intensified the accumulation of various types of organic and inorganic pollutants due to the illegal dumping of partially and/or untreated wastewater effluents in the environment. The pollutants emitted by several industries pose serious risk to the environment, animals and human beings. Management and diminution of these hazardous organic pollutants have become an incipient research interest. Traditional physiochemical methods are energy intensive and produce secondary pollutants. So, bioremediation via microalgae has appeared to be an eco-friendly and sustainable technique to curb the adverse effects of organic and inorganic contaminants because microalgae can degrade complex organic compounds and convert them into simpler and non-toxic substances without the release of secondary pollutants. Even some of the organic pollutants can be exploited by microalgae as a source of carbon in mixotrophic cultivation. Literature survey has revealed that use of the latest modification techniques for microalgae such as immobilization (on alginate, carrageena and agar), pigment-extraction, and pretreatment (with acids) have enhaced their bioremedial potential. Moreover, microalgal components i.e., biopolymers and extracellular polymeric substances (EPS) can potentially be exploited in the biosorption of pollutants. Though bioremediation of wastewaters by microalgae is quite well-studied realm but some aspects like structural and functional responses of microalgae toward pollutant derivatives/by-products (formed during biodegradation), use of genetic engineering to improve the tolerance of microalgae against higher concentrations of polluatans, and harvesting cost reduction, and monitoring of parameters at large-scale still need more focus. This review discusses the accumulation of different types of pollutants into the environment through various sources and the mechanisms used by microalgae to degrade commonly occurring organic and inorganic pollutants.
近期工业化的激增,由于部分和/或未经处理的废水被非法倾倒到环境中,加剧了各种有机和无机污染物的积累。多个行业排放的污染物对环境、动物和人类构成了严重风险。对这些有害有机污染物的管理和减少已成为新的研究热点。传统的物理化学方法能耗大且会产生二次污染物。因此,通过微藻进行生物修复似乎是一种生态友好且可持续的技术,可抑制有机和无机污染物的不利影响,因为微藻能够降解复杂的有机化合物,并将其转化为更简单且无毒的物质,而不会释放二次污染物。甚至一些有机污染物在混合营养培养中可被微藻用作碳源。文献调查表明,对微藻使用最新的改性技术,如固定化(在藻酸盐、角叉菜胶和琼脂上)、色素提取和预处理(用酸),提高了它们的生物修复潜力。此外,微藻成分,即生物聚合物和胞外聚合物(EPS),有可能用于污染物的生物吸附。尽管微藻对废水的生物修复是一个研究得相当充分的领域,但仍有一些方面需要更多关注,比如微藻对污染物衍生物/副产物(在生物降解过程中形成)的结构和功能反应、利用基因工程提高微藻对更高浓度污染物的耐受性、降低收获成本以及大规模参数监测。本综述讨论了不同类型污染物通过各种来源在环境中的积累,以及微藻用于降解常见有机和无机污染物的机制。