Se ha investigado, a escala de laboratorio, el proceso de biolixiviación de un concentrado de cobre utilizando microorganismos termófilos moderados como una alternativa al proceso de fundición convencional; asimismo se han evaluado las condiciones experimentales óptimas para la extracción de cobre en términos de densidad de pulpa, pH y tamaño de partículas del concentrado cuprífero. La experimentación se llevó a cabo en un biorreactor de 5 l de capacidad. Y utilizando dos especies de Sulfobacillus. Los resultados mostraron que, después de 12 días, más del 80% del cobre se puede extraer del concentrado de calcopirita. Las condiciones óptimas para la extracción del metal fueron: una densidad de pulpa del 5% (p/v), un pH inicial de 1 y un tamaño de partícula (d80) de 45 µm. Los resultados de esta investigación contribuirán al diseño, por parte de la Compañía Iranian Babak Copper (IBCCO), de una planta industrial de biolixiviación en tanques de una capacidad anual de 50.000 t de cátodo de cobre.

More than 70% of heat resistance enzymes, such as lipase, cutinase, cellulase, Alpha amylase, L-aspartas, are being used in industries which are producing by thermophillic microorganisms. The purpose of this research is Isolation, molecular identification of thermophillic bacteria from the soil of hotest area in Iran and measuring extracellular enzymes activities and kinetics. According to the sampling principles, taking sample from the soil is done from the 5 cm depth of the soil and it became isolated and identified by using ribotyping stub. According to standard methods, the enzyme activities of isolated stub were measured and analyzed. Licheniformis was identified in in ribotyping of the isolated sample. This bacterium had produced the highest amount of cellulase which was 17.5 u/ml, after 72 hours, while pH was equal to 8. As well, the highest amount of protease production was done under alkaline conditions. The asparaginase and lipase activity levels in the isolated Bacillus licheniformis are 4 and 19 enzyme units per ml respectively at 55 °C, while pH is equal to 8. Bacillus licheniformis strain extracted from Gandome Beryan area is an appropriate source of heat-resistant extracellular enzymes with suitable enzyme activity level which can be used in various industries.

As a resistant and toxic polycyclic aromatic hydrocarbon (PAHs), phenanthrene is largely distributed in aquatic and terrestrial environments with adverse biological consequences. Mineralization of this toxic component via bioremediation has been vastly studied in recent years and might lead to new hope in the economic clean-up of this contaminant. The aim of this study was the isolation and identification of phenanthrene degrading bacteria from petroleum polluted environments and the assessment of their growth kinetics. Soil samples were collected from the oil-polluted sites of Darkhouvin oilfield, Iran. Bacterial isolates capable of degrading phenanthrene were characterized genetically and morphologically. Optimal level of environmental parameters including pH, time, temperature, nitrogen and phosphate source, and phenanthrene concentration were determined using Taguchi method. The results showed that different bacterial genera were isolated in which Bacillus mojavensis and Lysinibacillus sphaericus were identified as phenanthrene degrading isolates. Isolated strains showed hemolytic activity and deceased surface tension values. The optimal condition was determined as 45 °C, pH 7, nitrate 1 µg/mL, sodium phosphate 0.3 µg/mL, and on the fifth day of culturing for B. mojavensis, which showed prominent activity in phenanthrene biodegradation. In this study, the ability of native strains on the biodegradation of phenanthrene in soil was investigated. The findings suggest that isolated biosurfactant generating bacteria could biodegrade phenanthrene in optimum conditions.

The rise of multidrug-resistant (MDR) pathogens, particularly Acinetobacter baumannii, poses a significant threat to global health due to its resistance to multiple antibiotics, biofilm-forming capacity, and associated poor clinical outcomes. This study aimed to evaluate the antibacterial and antibiofilm efficacy of 1,3,4-oxadiazole against A. baumannii, focusing on biofilm-related challenges and gene expression. A one-step, high-yield method was used to synthesize the 1,3,4-oxadiazoles. Thirteen A. baumannii isolates were collected from clinical samples and assessed for biofilm formation using microtiter plate assays. Antimicrobial susceptibility was determined via the Kirby-Bauer disk diffusion method, while the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 1,3,4-oxadiazole were evaluated following CLSI guidelines. PCR was used to detect the presence of biofilm-associated (bap) gene. The inhibitory effect of 1,3,4-oxadiazole on biofilm formation and bap gene expression (using RT-qPCR) was assessed, alongside cytotoxicity testing on the A549 lung cancer cell line. Among eight selected clinical isolates, 100% were MDR, exhibiting high resistance to gentamicin, ciprofloxacin, and imipenem. Biofilm assays classified the isolates as strong, moderate, or weak producers, with the presence of the bap gene significantly associated with biofilm formation (p < 0.05). MIC and MBC values of 1,3,4-oxadiazole ranged from 7.81–31.25 µg/ml and 7.81–62.5 µg/ml, respectively. Sub-MIC concentrations significantly inhibited biofilm formation (43–79% reduction) and downregulated bap expression (log2-fold change: 0.24–4.13). Cytotoxicity analysis confirmed no significant effects on A549 cells at 15.62 and 7.81 µg (p = 0.085). 1,3,4-Oxadiazole exhibits significant antibacterial and antibiofilm properties against MDR A. baumannii, effectively targeting biofilm-associated genes and demonstrating a favorable safety profile. These findings highlight the potential of 1,3,4-oxadiazole as a promising candidate for combating MDR infections and biofilm-related complications.

Background: Rotaviruses are widely distributed throughout the world and cause serious water-borne infections in infants, children, adults, and individuals with weakened immune systems. These viruses enter environmental waters via wastewater discharge and pose a serious risk to public health. Objectives: The purpose of the present study is to monitor human rotavirus levels in Ahvaz's water and wastewater treatment systems. Methods: This study used the grab sampling method to collect 60 samples from two water treatment systems (including raw water inlet points, filtration outlet, and clean water tank outlet) and 48 samples from the influent and effluent of a wastewater treatment system in Ahvaz city. Water samples were concentrated with a 0.2-µm membrane filter cartridge and polyethylene glycol in a centrifuge, while wastewater samples were concentrated with both pellet and two-phase methods. For rotavirus detection, RNA isolation, complementary DNA (cDNA) synthesis, and amplification were performed with RVA primer by reverse transcription polymerase chain reaction (RT-PCR). The genotyping of rotavirus was performed using the multiplex nested reverse transcription polymerase chain reaction (MN-RT-PCR). Results: Out of the total samples collected, rotavirus was identified in 45 samples (41.66%) using RT-PCR. The efficiency of water treatment plant systems was 75%, and the efficiency of wastewater treatment plant systems in removing rotavirus was 60%. There was no significant difference between the rotaviruses identified in the influent and effluent samples of wastewater in different months of the year (P = 0.626). The most abundant genotypes identified were G9 and G10, with frequencies of 40% and 5%, respectively. Conclusions: The results showed that the water and wastewater treatment systems in Ahvaz are not efficient in eliminating rotaviruses. Therefore, continuous monitoring of human rotaviruses in water and wastewater to assess the efficiency of treatment systems and identify circulating genotypes for the appropriate design of human vaccines is recommended. There is also a need to use more appropriate processes for the removal of infectious viruses, such as ozone disinfection.