جستجوی مقالات مرتبط با کلیدواژه « antibiotics » در نشریات گروه « محیط زیست »

Potatoes and carrots are one of the major tuber crops in the world with high exposure to various pests and diseases, especially soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. In recent years, several reports relating to the spread of this disease in different parts of Northwest Iran have been published, but so far, no effective solution has been found. Due to the high prevalence of this disease in the region, the use of chemical pesticides, new antibiotics and safe antimicrobial compounds such as herbal extracts and essential oils appears to be necessary. The current research was conducted to assess the antibacterial effects of the three antibiotics Oxytetracycline, Dihydrostreptomycin and Chloramphenicol, in addition to thyme and mint essential oils, as well as neem aqueous and alcoholic extracts on the causal agent of the soft rot disease. Copper oxychloride pesticide was used as the control to compare the efficiencies of the compounds and extracts. The antibacterial effects on soft rot-inducing bacteria were analyzed using the agar gel diffusion and disc diffusion methods in three replicates by applying completely randomized design, and the results were analyzed in the SPSS software. The results showed that among the antibiotics the highest inhibition effect belonged to oxytetracycline. This antibiotic with its inhibitory halo diameter of 43 mm and percentage inhibition of 47.77% showed better performance than all other treatments, whereas copper oxychloride pesticide even at the highest concentration (5000mg/L), the inhibitory halo diameter was 13 mm and the inhibitory effect was 14.77%. Among the essential oils and extracts, the thyme essential oil with the inhibitory halo diameter of 27 mm and percentage inhibition of 30% was the highest among the natural compounds.

Silver nanoparticles (AgNPs) with antimicrobial and anticancer properties have been widely used in a variety of fields. This research investigated the antimicrobial effects and toxicity of AgNPs synthesized using the extract of the medicinal plant lemon balm, Melissa officinalis L., on 3 cancer cell lines (A549, MCF-7, and HeLa). AgNPs were biologically synthesized using the extract of M. officinalis. After physical and chemical evaluation, the anti-bacterial properties of the synthesized nanoparticles were evaluated in Escherichia coli and Staphylococcus aureus. Finally, the inhibitory effect of synthesized nanoparticles was assessed by the MTT assay on 3 cancer cell lines. With an average size of 17 nm, the nanoparticles synthesized by M. officinalis L. extract had a significant inhibitory and lethal effect on 2 bacteria. The findings indicated that the synthesized nanoparticles had more inhibitory and bactericidal effects on S. aureus as a gram-positive bacterial strain. The MBC of nanoparticles synthesized by M. officinalis extract was 500 μg/mL for S. aureus and 700 μg/mL for E. col. At a concentration of 50 g/mL, the synthesized AgNPs showed more than 50% inhibitory effect on different cell lines. Our results demonstrate that medicinal plants can be used in the successful synthesis of biological AgNPs. The synthesized AgNPs can be utilized as effective medicinal agents in the management of several cancers due to their coating made of effective secondary metabolites and the release of silver ions (Ag+).

The present study aims at phytoremediation of Lemna gibba L. in aqueous solutions with different concentrations of TC and Degradation Products (DPs). It also tries to determine whether there are differences in TC, ETC, EATC, and ATC levels, accumulated by Lemna gibba L. Exposure concentrations of 50, 100, and 300 ppb have been selected for TC and DPs, showing that the highest TC50, TC100, and TC300 concentrations in the plant have been 23.5.1, 80.1.9, and 274 ppb, respectively, while the highest ETC50, ETC100, and ETC300 have proven to be 39.5.9, 47.8.4, and 168.4 ppb, respectively. The highest EATC50, EATC100, and EATC300 concentrations in the plant have been 45.3.3; 65.0 and 173.0 ppb, respectively, whereas the highest ATC50, ATC100, and ATC300 concentrations in Lemna gibba L. have been 34.7.7, 39.6.2, and 114.6 ppb, respectively. TC, ETC, EATC, and ATC concentrations in Lemna gibba L. have increased with the increase of initial TC, ETC, EATC, and ATC concentration.

For small cheese-making factories, with no effluent treatment plants, whey can be a serious problem and the landfarming technique represents an alternative for its disposal. However, whey may contain antibiotic residues at the Maximum Residue Limits. Therefore, in this work, we evaluated the phytotoxic effect of different concentrations of five antibiotics (enrofloxacin, kanamycin, oxytetracycline, penicillin and tylosin) on the germination frequency and root elongation of five Argentine crops: sunflower (Helianthus annuus), corn (Zea mays), soybean (Glycine max), sorghum (Sorghum bicolor), and wheat (Triticum aestivum). We concluded that the antibiotic concentrations currently allowable for the dairy industry (Maximum Residue Limits) are a potential risk for S. bicolor, corn and G. max crops. Results showed that 0.10 mg/l of enrofloxacin affected sorghum, 0.15 mg/l of kanamycin affected corn and G. max, 0.004 mg/l of penicillin affected corn, G. max and S. bicolor, and that 0.05 mg/l of tylosin affected G. max. Therefore, dumping whey contaminated with antibiotic residues on the soil is not recommended.

This study investigated the occurrence and removal of 12 antibiotics (ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, nalidixic acid, azithromycin, clarithromycin, roxithromycin, lincomycin, novobiocin, sulfamethoxazole, trimethoprim) at four sewage treatment plants (STPs): two STPs in Kyoto, Japan and two STPs in Beijing, China. The STPs differed in design and operation conditions, utilized a variety of secondary treatment processes. The antibiotics were frequently detected in influents and effluents, and ranged from ng/L up to lower μg/L. In influent, clarithromycin (1.1–1.6 μg/L) and levofloxacin (3.6–6.8 μg/L) were detected in the highest concentration in Japanese and Chinese STPs, respectively. The overall elimination of the antibiotics were differed between STPs and ranged from negative to >90%. These data demonstrate that there are detectable levels of antibiotics are discharging from STPs, and only some of these antibiotics are being removed in a significant proportion by STPs. It was also observed that biological nutrient removal based sewage treatment processes (anaerobic–anoxic–oxic: A2O; and anoxic–oxic: AO) have relatively higher antibiotics removal efficiencies than oxidation ditch (OD) processes.

Whey protein is a byproduct of dairy industry, where cheese and casein are manufactured.This is the major protein content which is loss during the formation of yogurt and cheese. If this is added to the diet then that can enhance the nutritioal value for the diet, which will be very usefull. In this study we try to find it out that the whey protein has the antibiotic effect, that much better than the antibiotic generally found in market. But this is not as much as better than the tetracyclin. But better than the common antibiotics like amoxicillin. So from the study we can conclude that the antibiotic which is used to provide strength against the different types of microrganism and also have the nutritional effect co that it can be use as a great nutritional element in future for the general house hold use and for the sport industry also.

The Streptomycetes are gram positive bacteria with a filamentous form that present in a wide variety of soil including composts, water and plants. The most characteristic of Streptomycetes is the ability to produce secondary metabolites such as antibiotics. They produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin and chloramphenicol. Another characteristic of Streptomycetes is making of an extensive branching substrate and aerial mycelium.Carbon and nitrogen sources, oxygen, pH, temperature, ions and some precursors can affect production of antibiotics. This review also addresses the different methods to study the antimicrobial activity of Streptomyces sp. Because of increasing microbial resistance to general antibiotics and inability to control infectious disease has given an impetus for continuous search of novel antibioticsall the word.