Pileggi Marcos, Pileggi Sônia A V, Sadowsky Michael J
Laboratory of Environmental Microbiology, Biological Science and Health Institute, Department of Structural and Molecular Biology, and Genetics, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil.
The Biotechnology Institute, Department of Soil, Water, and Climate, Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN, USA.
Heliyon. 2020 Dec 24;6(12):e05767. doi: 10.1016/j.heliyon.2020.e05767. eCollection 2020 Dec.
There is high demand for herbicides based on the necessity to increase crop production to satisfy world-wide demands. Nevertheless, there are negative impacts of herbicide use, manifesting as selection for resistant weeds, production of toxic metabolites from partial degradation of herbicides, changes in soil microbial communities and biogeochemical cycles, alterations in plant nutrition and soil fertility, and persistent environmental contamination. Some herbicides damage non-target microorganisms via directed interference with host metabolism and via oxidative stress mechanisms. For these reasons, it is necessary to identify sustainable, efficient methods to mitigate these environmental liabilities. Before the degradation process can be initiated by microbial enzymes and metabolic pathways, microorganisms need to tolerate the oxidative stresses caused by the herbicides themselves. This can be achieved via a complex system of enzymatic and non-enzymatic antioxidative stress systems. Many of these response systems are not herbicide specific, but rather triggered by a variety of substances. Collectively, these nonspecific response systems enhance the survival and fitness potential of microorganisms. Biodegradation studies and remediation approaches have relied on individually selected strains to effectively remediate herbicides in the environment. Nevertheless, it has been shown that microbial communication systems that modulate social relationships and metabolic pathways inside biofilm structures among microorganisms are complex; therefore, use of isolated strains for xenobiotic degradation needs to be enhanced using a community-based approach with biodegradation pathway integration. Bioremediation efforts can use omics-based technologies to gain a deeper understanding of the molecular complexes of bacterial communities to achieve to more efficient elimination of xenobiotics. With this knowledge, the possibility of altering microbial communities is increased to improve the potential for bioremediation without causing other environmental impacts not anticipated by simpler approaches. The understanding of microbial community dynamics in free-living microbiota and those present in complex communities and in biofilms is paramount to achieving these objectives. It is also essential that non-developed countries, which are major food producers and consumers of pesticides, have access to these techniques to achieve sustainable production, without causing impacts through unknown side effects.
基于增加作物产量以满足全球需求的必要性，对除草剂的需求量很大。然而，除草剂的使用存在负面影响，表现为对耐药杂草的选择、除草剂部分降解产生有毒代谢物、土壤微生物群落和生物地球化学循环的变化、植物营养和土壤肥力的改变以及持续的环境污染。一些除草剂通过直接干扰宿主代谢和氧化应激机制损害非靶标微生物。出于这些原因，有必要确定可持续、有效的方法来减轻这些环境负担。在微生物酶和代谢途径启动降解过程之前，微生物需要耐受除草剂本身引起的氧化应激。这可以通过一个复杂的酶促和非酶促抗氧化应激系统来实现。这些反应系统中的许多不是除草剂特异性的，而是由多种物质触发的。总体而言，这些非特异性反应系统提高了微生物的生存和适应潜力。生物降解研究和修复方法依赖于单独选择的菌株来有效修复环境中的除草剂。然而，已经表明，调节微生物生物膜结构内社会关系和代谢途径的微生物通讯系统很复杂；因此，需要使用基于群落的方法并整合生物降解途径来加强使用分离菌株进行异源生物降解。生物修复工作可以使用基于组学的技术来更深入地了解细菌群落的分子复合体，以实现更有效地消除异源生物。有了这些知识，改变微生物群落以提高生物修复潜力而不造成更简单方法未预期的其他环境影响的可能性就增加了。了解自由生活微生物群以及复杂群落和生物膜中存在的微生物群落动态对于实现这些目标至关重要。对于作为主要粮食生产国和农药消费国的不发达国家来说，能够获得这些技术以实现可持续生产而不通过未知的副作用造成影响也至关重要。
