Facultad de Ingeniería, Universidad Autónoma de Yucatán, Av. Industrias No Contaminantes por Anillo Periférico Norte S/n. Apdo. Postal 150 Cordemex. Cd, Mérida, Yucatán, Mexico.
Instituto Tecnológico de Conkal, Avenida Tecnológico S/n Apdo, Postal 97345, Conkal, Yucatán, Mexico.
Ecotoxicol Environ Saf. 2020 Sep 1;200:110734. doi: 10.1016/j.ecoenv.2020.110734. Epub 2020 May 25.
Microorganisms' role in pesticide degradation has been studied widely. Insitu treatments of effluents containing pesticides such as biological beds (biobeds) are efficient biological systems where biomixture (mixture of substrates) and microorganisms are the keys in pesticide treatment; however, microbial activity has been studied poorly, and its potential beyond biobeds has not been widely explored. In this study, the capacity of microbial consortium and bacteria-pure strains isolated from a biomixture (soil-straw; 1:1, v/v) used to treat agricultural effluents under real conditions were evaluated during a bioremediation process of five pesticides commonly used Yucatan Mexico. Atrazine, carbofuran, and glyphosate had the highest degradations (>90%) using the microbial consortium; 2,4-D and diazinon were the most persistent (DT = 8.64 and 6.63 days). From the 21 identified bacteria species in the microbial consortium, Pseudomonas nitroreducens was the most abundant (52%) according to identified sequences. For the pure strains evaluation 2,4-D (DT = 9.87 days), carbofuran (DT = 8.27 days), diazinon (DT = 8.80 days) and glyphosate (DT = 8.59 days) were less persistent in the presence of the mixed consortium (Ochrobactrum sp. DGG-1-3, Ochrobactrum sp. Ge-14, Ochrobactrum sp. B18 and Pseudomonas citronellolis strain ADA-23B). Time, pesticide, and strain type were significant (P < 0.05) in pesticide degradation, so this process is multifactorial. Microbial consortium and pure strains can be used to increase the biobed efficiency by inoculation, even in the remediation of soil contaminated by pesticides in agricultural areas.
微生物在农药降解中的作用已得到广泛研究。原位处理含有农药的废水，如生物床（biobeds），是一种有效的生物系统，其中生物混合物（基质混合物）和微生物是农药处理的关键；然而，微生物活性的研究还很不完善，其在生物床之外的潜力也尚未得到广泛探索。在这项研究中，评估了从用于处理农业废水中的生物混合物（土壤-秸秆；1:1，v/v）中分离出的微生物联合体和细菌纯菌株在五种常见农药的生物修复过程中的能力。在墨西哥尤卡坦使用微生物联合体处理农业废水中时，莠去津、克百威和草甘膦的降解率最高（>90%）；2,4-D 和敌敌畏是最持久的（DT = 8.64 和 6.63 天）。在微生物联合体中，根据鉴定的序列，假单胞菌硝化还原菌是最丰富的（52%）。对于纯菌株的评估，2,4-D（DT = 9.87 天）、克百威（DT = 8.27 天）、敌敌畏（DT = 8.80 天）和草甘膦（DT = 8.59 天）在混合联合体存在下的持久性降低（Ochrobactrum sp. DGG-1-3、Ochrobactrum sp. Ge-14、Ochrobactrum sp. B18 和 Pseudomonas citronellolis 菌株 ADA-23B）。时间、农药和菌株类型对农药降解有显著影响（P < 0.05），因此这是一个多因素过程。微生物联合体和纯菌株可通过接种用于提高生物床的效率，即使在修复农业区受农药污染的土壤时也是如此。
