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In Situ Generated Metal Nanoparticles by Bioreduction Method
Published in Peerawatt Nunthavarawong, Sanjay Mavinkere Rangappa, Suchart Siengchin, Mathew Thoppil-Mathew, Antimicrobial and Antiviral Materials, 2022
Basa Ashok, Natarajan Rajini, Paramasivan Sivaranjana, Anumakonda Varada Rajulu
The antibacterial activity of the nanocomposite films and fabrics was examined by the standard disc method adopting the procedure described elsewhere [29]. The method is described in brief in the following lines. Initially, the nutrient agar medium was made by mixing 5 g of sodium chloride, 5 g of peptone, 3 g beef extract in 1 liter of distilled water. This agar medium was then sterilized and subsequently transferred to Petri dishes, which were then kept in a Laminar air flow chamber. The agar was then allowed to solidify. Then, the bacterial culture (50 μL) was spread on the media and inoculated. Subsequently, circular discs of the nanocomposite films and fabrics with in situ generated MNPs were placed on the inoculated medium and incubated at 37 °C for 48 hours in the incubation chamber. The formed clear zones indicating the inhibition of bacteria by the nanocomposite specimens were photographed. In each case, the diameter of the inhibition (clear) zone was measured using Image software.
Improving properties of recycled coarse aggregate (RCA) by biomineralization method
Published in Konstantinos Papadikis, Chee S. Chin, Isaac Galobardes, Guobin Gong, Fangyu Guo, Sustainable Buildings and Structures: Building a Sustainable Tomorrow, 2019
Z.W. Liu, C.S. Chin, J. Xia, V. Achal
Three bacterial strains were chosen in this research. Lysinibacillus fusiformis (LF) was isolated from sludge and identified based on 16S rRNA gene sequencing and sequences were deposited in GenBank under accession number MN097919. Bacillus megaterium de Bary (BM) (ATCC 25300) and Sporosarcina pasteurii (SP) (ATCC 11859) were procured from American Type Culture Collection (ATCC), United States. The bacteria were subcultured in nutrient agar medium (Figure 1(a)) and nutrient broth media (Figure 1(b)). The media contained 1 g of “Lab-Lemco” powder, 2 g of yeast extract, 5 g of peptone and 10 g NaCl dissolved into 1 L distilled water. The spectrophotometer was used to measure the optical density (OD) value at 600 mm, which can be used to judge the concentration of the bacteria solution. In the research, bacteria were cultured in 30 °C until the OD600 arrived 0.6 trans-1 and then centrifuged bacteria solution in 20 °C and 6000 rpm to divide the bacteria cells and medium.
Ultrapure Water and Bacteria
Published in Tadahiro Ohmi, Ultraclean Technology Handbook, 2017
Table 2 shows the incubation results of bacteria in ultrapure water. For this incubation, three types of media were prepared: medium A for heterotrophic bacteria and medium B and medium C for autotrophic bacteria. The composition of each is as follows: Medium A, nutrient agar: 0.5% meat extract, 0.5% peptone, 1.3% agar, and pH 7.1 ± 0.1. This medium is diluted to ½ and 110. In each case, however, the agar content is 1.3%.Medium B, Winogradsky medium: 0.1% (NH4)2SO4, 0.1% K3PO4, and 1.3% agar.Medium C, Czapek-Dox medium: 0.1% K2HPO4, 0.05% MgSO4·7Ag, 0.2% NaNO3, 0.05% KCl, 0.001% FeSO4, and 1.3% agar. No sucrose is added.
Synthesis, molecular modeling, and biomedical applications of oxovanadium(IV) complexes of Schiff bases as a good SARS-CoV-2 inhibitor
Published in Inorganic and Nano-Metal Chemistry, 2022
Mohammad Nasir Uddin, Zainul Abedin Siddique, Jabunnisa Akter, Md. Saifur Rahman, Wahhida Shumi, Munira Nasiruddin
Nutrient agar (NA) medium consists of beef extract (3 g), peptone (5 g), NaCl (0.5 g), agar (15 g) in1000 mL distilled water. NB medium used for assessing the microbial growth against the test compounds was prepared without agar. NA slants were prepared and sterilized in autoclave for the purpose. About 24-h-old culture of each bacterial pathogen was inoculated in freshly prepared slants in a test tube at 35 ± 2 °C for 24 h. After optimizing the bacterial growth in culture, slants were kept in polythene bags, properly tied, and preserved as stock culture at 10 °C. To prepare bacterial suspension, 10 mL of NB medium was taken in a screw-cap test tube for each of the bacterial isolates. After sterilization and cooling, one loop of freshly prepared culture (24 h old) was transferred into liquid culture medium and mixed properly. Then 100 L of test compounds (0.1%) was added in each of the test tubes separately. After that, 100 µL of stock bacterial suspension was mixed properly in each test tube and inoculated at 35 ± 2 °C for 3, 6, 9, 12, 18, 21, and 24 h. After a specific incubation period, the growth of bacterial isolates was determined through optical density (OD) using 1 cm cubed at 600 nm against control or blank for each of the time intervals. The absorbance was measured at least three times and the mean value of the absorbance was calculated. Control or blank test tube was prepared for each of the time intervals.
Influence of aeration rate and reactor shape on the composting of poultry manure and sawdust
Published in Journal of the Air & Waste Management Association, 2019
Waqas Qasim, Byeong Eun Moon, Frank Gyan Okyere, Fawad Khan, Mohammad Nafees, Hyeon Tae Kim
Colony-forming units (CFU) of mesophilic and thermophilic bacteria were determined by the spread plate technique (Prescot, Harley, and Kleon 1996). Nutrient agar was used as a growth medium. One gram of each sample was suspended in 99 mL of physiological solution and then homogenized using a magnetic stirrer for 30 min. Dilution series (from 10−3 to 10−8) were made from the prepared suspensions. One milliliter of each sample from the above-mentioned dilution was placed into a Petri dish and spread up and down using a “hockey stick.” The Petri dishes were incubated at 37 °C for 48 hr for the growth of mesophilic bacteria and at 55 °C for 48 hr for the growth of thermophilic bacteria. The CFU of mesophilic and thermophilic bacteria were counted using a digital colony meter, and the results were expressed as CFU of mesophilic and thermophilic bacteria per gram of compost.
Removal of tetrachloroethene from polluted air by activated sludge
Published in Environmental Technology, 2019
Agnieszka Tabernacka, Ewa Zborowska, Katarzyna Pogoda, Marcin Żołądek
In the first stage of research PCE elimination efficiency was in the range 70–84%. Increase in the pollution loading rate did not affect the process efficiency (Table 2). The total number of bacteria decreased, while the number of bacteria capable of contaminant degradation has increased approximately twice. The highest number of bacteria active in contaminant degradation was observed on day 35 (Figure 2), while the total number of bacteria was low. The reason for the atypical results of the study is the method of determination of the bacteria number. It is typical for bacteria that they grow better on media containing similar nutrients to those present in their natural environment. Nutrient agar medium (used for the determination of the total number of bacteria) is not favourable for bacteria living in heavily polluted sites. This phenomenon is sometimes observed in very contaminated soil or in technological systems containing bacteria adapted to biodegradation of specific pollutants.