| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1084-1 | ||||
Resumo:Soil microorganisms play an essential role in glyphosate degradation, offering a natural approach to mitigate the environmental impact of this widely used herbicide and promote sustainable agricultural practices. This study aimed to assess the tolerance and utilization of glyphosate as a nutritional source by fungal isolates from agricultural soil and their potential for phosphate solubilization in vitro. Fungal isolates were obtained from coffee crop soil using selective media (Saboraud, BDA, and DYGS) in plates supplemented with commercial glyphosate (60 mM) and incubated at 30 °C for 7 days. Subsequently, the isolates were grown in a liquid medium containing increasing concentrations of glyphosate in distilled water (120, 300, and 480 mM) for 5 days at 30 °C and 150 rpm. The most tolerant strains were further assessed for their ability to use glyphosate as the sole nutritional source of carbon and phosphorus at concentrations of 10, 30, 60, and 120 mM in CDA C- and CDA P- medium, incubated for 15 days at 30 °C. Growth was determined by measuring colony diameter and calculating the tolerance index. The isolates were also tested for their phosphate solubilization capacity and classified based on solubilization index (SI) high (> 1.24), medium (> 1.13 ≤ 1.24), or low (≤ 1.13). A total of 37 filamentous soil fungi were isolated from the selective media. Among them, 12 strains tolerate the highest tested glyphosate concentration (480 mM). These strains were selected to evaluate the utilization of glyphosate as a nutritional source. In the CDA C- test, all strains displayed tolerance index values from 50 to 85,5% at 10 mM of glyphosate, while in the CDA P- test tolerance index values ranged from 38 to 98,4%. However, the growth rates of all strains decreased as the glyphosate concentration in the medium increased in both tests. At 120 mM, the tolerance index varied from 0 to 15,4%, observing the inhibition of 3 strains in the CDA C- test and 4 strains in the CDA P- test. Also, the phosphate solubilization capacity of the 37 isolates was classified as 13 strains with high SI, 10 strains with medium SI, and 14 with low SI. The ability of these isolates to use glyphosate as a nutrient source offers promising prospects for addressing soil bioremediation. Additionally, the high solubilization index of phosphate observed among the isolates highlights their potential for promoting plant growth. By harnessing the biotechnological potential of these fungi, we can take significant strides toward achieving a more environmentally friendly and productive agricultural system. Palavras-chave: Bioremediation, Glyphosate, Plant growth promotion, Soil microorganisms, Sustainable agriculture Agência de fomento:UENF, FAPERJ, FAPES, IFRJ, CAPES, CNPq | |||||