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Introduction
Published in Debabrata Das, Debayan Das, Biochemical Engineering, 2019
Microorganisms require different nutrients for their growth and development (Table 1.3). The essential nutrients include macronutrients (required in large quantities) and micronutrients (required in trace amounts), vitamins (required as cofactors), and water. These nutrients perform several functions that aid in their growth. Water helps in the soaking up of nutrients and for the elimination of waste products. In the laboratory conditions, microorganisms are grown in a culture media that comprises all these essential nutrients. Specialized media are developed for isolating and identifying organisms, testing their antibiotic sensitivity, distinguishing one species from another, etc. (Table 1.4). The nutritional requirement of each organism depends on the natural habitat from which it is isolated. For example, organisms growing in deep-sea sediments require complete depletion of oxygen from its surrounding environment for their growth and survival, while the organisms growing in saline soils require high salt conditions.
Isolation of Extremely Thermophilic, Fermentative Archaebacteria from Deep-Sea Geothermal Sediments
Published in Donald L. Wise, Bioprocessing and Biotreatment of Coal, 2017
To become familiar with the type of organisms described by the Zillig/Stetter group, prior to our first cruise to this site, we obtained sediment samples from a submarine volcanic spring near Pozzuoli, Italy. We were able to isolate two different strains that were both new to the present systematic scheme of thermophilic archaebacteria. Our strain NS-C [52] grows optimally at 88°C above a pH of 7 and reduces elemental sulfur to H2 S. It is a strictly anaerobic heterotroph which is insensitive to free oxygen, however, at a lower temperature range where no growth occurs (i.e., below 50°C). It cannot be grouped into the “thermoacidophiles” [27] and resembles morphologically and by its G + C content Sulfolobus [53], although it is not autotrophic or aerobic. By the absence of muramic acid and the type of antibiotic sensitivity found, it appears to belong to the archaebacteria.
Salmonids (Salmonidae)
Published in John A Plumb, Health Maintenance Of Cultured Fishes, 1994
Where A. salmonicida is enzootic, the disease will likely manifest itself sooner or later, regardless of preventive measures. When it does appear, chemotherapy is necessary to reduce mortalities and to help fish overcome the infection. Sulfamerazine® had previously been used to treat furunculosis42 but is no longer available because of the manufacturer’s withdrawal of its label for fish application. Although oxytetracycline (Terramycin®) is an FDA-approved drug for furunculosis, many of the presently isolated A. salmonicida are resistant to it. When Terramycin®-sensitive isolates are encountered, it is recommended that this drug be incorporated into the diet so that fish receive 50 to 80 mg/kg of body weight daily. Terramycin® is fed 10 to 14 d and requires a 21-d withdrawal period before slaughter. The potentiated sulfonamide Romet-30®, applied at 50 mg/kg of fish daily for 5 d, is also FDA-approved for furunculosis with a 42-d withdrawal period.46 Oxolinic acid is used extensively in European salmonid culture at 10 mg/kg body weight daily. Before chemotherapy is applied, it is strongly recommended that antibiotic sensitivity be determined for a particular isolate of A. salmonicida because of the potential for antibiotic resistance. Antibiotics should not be used indiscriminately for long periods of time or at less than recommended concentrations, because these practices will lead to increased drug resistance by the pathogen. To illustrate the importance of this problem, Inglis and Richards41 reported that between 1989 and 1991 53% of the A. salmonicida isolates from salmon were resistant to oxy tetracycline and 43% were resistant to oxolinic acid.
Antibacterial activity of Blumea axillaris synthesized selenium nanoparticles against multidrug resistant pathogens of aquatic origin
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Jyoti Prakash Dash, Lopamudra Mani, Sukanta Kumar Nayak
Antibiotic sensitivity assay study revealed the multidrug resistance pattern among the primary and secondary aquatic pathogens. All the pathogens were found to be resistant to a minimum of five antibiotics and the resistance pattern among the pathogens is shown in Table 1. All the bacteria were found to be resistant toward ampicillin, erythromycin and novobiocin. Apart from these antibiotics, both P. aeruginosa and E. coli isolates were resistant toward tetracyclin, oxytetracycline and bacitracin. Similarly all bacteria, except Aeromonas species, P. aeruginosa, and E. coli isolates showed resistance toward co-trimoxazole and tetracycline. On the other hand both the virulent and moderately virulent A. hydrophila pathogens were resistant to ampicillin, erythromycin, novobiocin, vancomycin, and co-trimoxazole. Aeromonas species also showed a similar type of resistance pattern against ampicillin, erythromycin, novobiocin, vancomycin, and bacitracin.
Microbe-EDTA mediated approach in the phytoremediation of lead-contaminated soils using maize (Zea mays L.) plants
Published in International Journal of Phytoremediation, 2021
Saiqa Menhas, Kashif Hayat, Nabeel Khan Niazi, Pei Zhou, Jochen Bundschuh, Muhammad Naeem, Muhammad Farooq Hussain Munis, Xijia Yang, Hassan Javed Chaudhary
The presence of C. sakazakii in inoculated plants and its absence in non-inoculated plants was confirmed upon completion (45 days) of the experiment using previously described method of Luo et al. (2011). After plant harvesting, fresh tissues of root and shoot was selected followed by serial washing with autoclaved distilled water before surface-sterilization. A 0.1 mL sample of the autoclaved distilled water used in the final rinse was streaked onto LB media to verify the efficacy of sterilization. After surface sterilization, the tissue was triturated in 10 mL of sterile PBS (phosphate-buffered saline) after cutting. Proper dilutions (0.1 mL bacterial culture) were plated onto LB medium and incubated at 28 °C for 2–14 days. Emerging colonies of C. sakazakii strain were identified by their morphological characteristics; gram staining and antibiotic sensitivity.
Zinc oxide nanoparticles inhibit bacterial biofilm formation via altering cell membrane permeability
Published in Preparative Biochemistry & Biotechnology, 2021
Tanvir Kaur, Chayanika Putatunda, Ashish Vyas, Gaurav Kumar
The antibiogram were prepared in order to detect and monitor trends, if present any, in patterns of antibacterial resistance. The Mueller Hinton agar (MHA) plates were surface swabbed with a bacterial suspension of the respective test organism and left to dry for a few minutes. Then using sterilized forceps, the various selected antibiotic disks were carefully placed over MHA plates and incubated at 37 °C for 24 hours. A confluent growth on MHA plates was viable enough for taking readings and thus interpreting the antibiogram. The inhibition zones around the disks were carefully measured (in mm) at eye level and compared with the reference zone diameter for each antibiotic as enlisted per CLSI (Clinical and Laboratory Standards Institute) guidelines, 2020.[32] The millimeters as obtained for each zone of inhibition were categorized as Sensitive (S), Intermediate (I) and Resistant (R). The antibiotic sensitivity testing (AST) was performed in triplicates.