Vaishnav Anukool, Kumar Roshan, Singh Harikesh Bahadur, Sarma Birinchi Kumar
Department of Biotechnology, GLA University, Mathura 281406, India; Agroecology and Environment, Agroscope (Reckenholz), Zürich 8046, Switzerland.
National Centre for Biological Sciences (TIFR-NCBS), Bengaluru 560065, India.
Sci Total Environ. 2022 Jun 20;826:154170. doi: 10.1016/j.scitotenv.2022.154170. Epub 2022 Feb 25.
Incessant release of nitrile group of compounds such as cyanides into agricultural land through industrial effluents and excessive use of nitrile pesticides has resulted in increased nitrile pollution. Release of nitrile compounds (NCs) as plant root exudates is also contributing to the problem. The released NCs interact with soil elements and persists for a long time. Persistent higher concentration of NCs in soil cause toxicity to beneficial microflora and affect crop productivity. The NCs can cause more problems to human health if they reach groundwater and enter the food chain. Nitrile degradation by soil bacteria can be a solution to the problem if thoroughly exploited. However, the impact of such bacteria in plant and soil environments is still not properly explored. Plant growth-promoting rhizobacteria (PGPR) with nitrilase activity has recently gained attention as potential solution to address the problem. This paper reviews the core issue of nitrile pollution in soil and the prospects of application of nitrile degrading bacteria for soil remediation, soil health improvement and plant growth promotion in nitrile-polluted soils. The possible mechanisms of PGPR that can be exploited to degrade NCs, converting them into plant useful compounds and synthesis of the phytohormone IAA from degraded NCs are also discussed at length.
通过工业废水将氰化物等含腈基化合物不断释放到农田中，以及腈类农药的过度使用，导致了腈污染的增加。作为植物根系分泌物释放的腈类化合物（NCs）也加剧了这一问题。释放出的NCs与土壤元素相互作用并长期存在。土壤中持续较高浓度的NCs会对有益微生物群产生毒性，并影响作物产量。如果NCs进入地下水并进入食物链，会给人类健康带来更多问题。如果能充分利用土壤细菌对腈的降解作用，可能是解决这一问题的办法。然而，这类细菌在植物和土壤环境中的影响仍未得到充分研究。具有腈水解酶活性的植物促生根际细菌（PGPR）最近作为解决该问题的潜在方案受到关注。本文综述了土壤中腈污染的核心问题，以及腈降解细菌在腈污染土壤修复、改善土壤健康和促进植物生长方面的应用前景。还详细讨论了PGPR降解NCs、将其转化为植物有用化合物以及从降解的NCs合成植物激素IAA的可能机制。
