Summary: Large amount of drilling waste associated with the expansion of the O rinoco O il B elt ( OOB ), the biggest proven reserve of extra‐heavy crude oil ( EHCO ) worldwide, is usually impregnated with EHCO and highly salinized water‐based drilling fluids. Oxidative exoenzymes ( OE ) of the lignin‐degrading enzyme system ( LDS ) of fungi catalyse the oxidation of a wide range of toxic pollutants. However, very little evidences on fungal degradation or biotransformation of EHCO have been reported, which contain high amounts of asphaltenes and its biodegradation rate is very limited. The aims of this work were to study the ability of P estalotiopsis palmarum BM ‐04 to synthesize OE , its potential to biotransform EHCO and to survive in extreme environmental conditions. Enzymatic studies of the LDS showed the ability of this fungus to overproduce high amounts of laccase ( LACp ) in presence of wheat bran or lignin peroxidase ( LIPp ) with EHCO as sole carbon and energy source (1300 U mgP ⁻¹ in both cases). FT ‐ IR spectroscopy with A ttenuated T otal R eflectance ( ATR ) analysis showed the enzymatic oxidation of carbon and sulfur atoms in both maltenes and asphaltenes fractions of biotreated EHCO catalysed by cell‐free laccase‐enriched OE using wheat bran as inducer. UV ‐visible spectrophotometry analysis revealed the oxidation of the petroporphyrins in the asphaltenes fraction of biotreated EHCO . Tolerance assays showed the ability of this fungus to grow up to 50 000 p.p.m. of EHCO and 2000 mM of NaCl . These results suggest that P . palmarum BM ‐04 is a hopeful alternative to be used in remediation processes in extreme environmental conditions of salinity and EHCO contamination, such as the drilling waste from the OOB .

The composition, abundance and distribution of macroplastics (MAPs) and microplastics (MPs) in the Vinces and Los Tintos rivers were determined in three sites (Pueblo Nuevo, Santa Marianita, Los Tintos) from the low basin in the coastal province of Guayas, Ecuador. MAPS were recorded by visual census, covering a total distance of 140 m, and MPs were extracted in the intertidal sediments via density separation using a saturated NaCl solution, and these were counted using a stereomicroscope. A total of 940 plastic items were identified. The predominant debris was plastic with 85.2%, followed by manufactured materials and metals. The Vinces River contained the highest abundance of plastic in the locality of Pueblo Nuevo. The most abundant plastic was MPs. The most common MAPs were plastic bags (23%), food packaging (17%) and foamed plastic (8%). MP size classes quantified between 0.15 and 2.52 mm in intertidal, very fine sandy sediment and decreased in abundance with increasing grain size. The most common MPs were fibres (65.2%) (black (43.8%) and blue (25.8%)), and their distribution has a high correlation with population density and water flow direction: Santa Marianita 5.55 g⁻¹, Pueblo Nuevo 7.39 g⁻¹, Los Tintos 8.17⁻¹. A significant abundance of fibres was identified in Pueblo Nuevo. The plastic spatial distribution revealed major plastic pollution in areas where recreational and tourism activities have been developed. Therefore, we recommend implementing awareness campaigns by educating businesses, residents and tourists on managing solid waste (especially plastic) and wastewater. Our results can serve as a baseline for future plastic monitoring in the area.

Existen evidencias de contaminación por metales pesados en el Estero Salado, localizado en la ciudad de Guayaquil, provincia del Guayas, en la costa de Ecuador. Con la finalidad de identificar organismos bioindicadores de contaminación por metales pesados, se estudió la concentración de Cd y Pb en agua, sedimento, hojas de mangles como Rhizophora racemosa, Avicennia germinans, Conocarpus erectus y Laguncularia racemosa, y gasterópodos como Littorina varia y Cerithidea mazatlanica, que se encontraban a nivel del Puente Portete en el Estero Salado. Las muestras fueron analizadas por espectrofotometría de absorción atómica de flama. Los valores de Cd y Pb en agua y sedimento superaron a los límites permisibles establecidos en las normas ecuatoriana y canadiense. Los gasterópodos L. varia y C. mazatlanica demostraron ser los mejores bioindicadores de contaminación al acumular en sus tejidos blandos 2,45±0,49 mg kg-1 de Pb y 1,49±0,67 mg kg-1 de Cd, respectivamente. Los mangles no acumularon en sus hojas Cd y Pb por la baja biodisponibilidad en el sedimento

(1) Background: This research examines the contamination levels of cadmium (Cd) and lead (Pb) in sugarcane and its derived products in Ecuador, addressing the significant issue of heavy metal pollution in the country’s agricultural lands. The primary aim of this study was to quantify the concentrations of Cd and Pb in sugarcane and the products derived from it, which are available to the Ecuadorian market. (2) Methods: Samples of the most-cultivated sugarcane varieties in the country, including ECU-01, ECU-02, Cenicaña (CC85-92), and Ragnar, were obtained. To ascertain the source of contamination in the derived products, the brands of panela, white sugar, and brown sugar that are most widely consumed in the country were selected. An atomic absorption spectrophotometry analysis was performed with a graphite furnace. (3) Results: All cane varieties presented Cd and Pb contamination. The variety with the highest levels of heavy metals was Ragnar, with average values of 4.32 mg kg⁻¹ of Pb and 0.15 mg kg⁻¹ of Cd. In the derived products, Pb was found to exceed the maximum limits stipulated in national and international regulations (0.5 mg kg⁻¹) in panela (2.3 mg kg⁻¹) and white sugar (1.6 mg kg⁻¹) sold by one of the brands. (4) Conclusions: It was found that lead (Pb) contamination is directly linked to the use of contaminated sugarcane as a raw material, along with bleaching agents.

FITOTOXICIDAD DE HAP, CRUDOS EXTRA PESADOS Y SUS FRACCIONES EN Lactuca sativa : UNA INTERPRETACIÓN INTEGRAL UTILIZANDO UN ÍNDICE DE TOXICIDAD MODIFICADO