Screening for extracellular synthesis of silver nanoparticles by bacteria isolated from Al-Halfaya oil field reservoirs in Missan province, Iraq

Abstract

Abstract. Alshami HGA, Al-Tamimi WH, Hateet RR. 2022. Screening for extracellular synthesis of silver nanoparticles by bacteria isolated from Al-Halfaya oil field reservoirs in Missan province, Iraq. Biodiversitas 23: 3462-3470. Microorganisms that live in deep environments are thought to be adapted to the conditions of these environments and possess enzymatic systems that can be useful in scientific and commercial applications. The study aimed to isolate, identify, and screening of silver nanoparticles (AgNPs)-producing bacteria from five samples of produced water of the Al-Halfaya oil field reservoirs in Missan governorate, Iraq. The results revealed a total of 22 bacterial isolates were isolated and identified by morphological features and amplification of the 16S rDNA gene. The isolates are belonging to nine species, including Bacillus cereus strain DBA1.1, Bacillus thuringiensis strain MSP51, Neobacillus drentensis strain ROA042, Enterococcus faecalis strain 2674, Exiguobacterium mexicanum strain AB201, Klebsiella quasipneumoniae strain KP18-31, Klebsiella quasipneumoniae subsp. similipneumoniae strain 2437, Klebsiella pneumoniae strain IOB-L, and Acinetobacter lwoffii strain K34. The Gram-positive bacteria were the most dominant (55.56%), and the most frequent isolate was Klebsiella quasipneumoniae strain KP18-31 (63.64%). Six species out of nine species were recognized as AgNPs producing bacteria and B. cereus strain DBA1 was the best and most potent isolate in the synthesis of AgNPs. The phylogenetic tree was constructed depending on 16S rDNA gene sequences to determine the evolutionary relationship among the isolated bacteria.

Anti-biofilm and antibacterial activities of silver nanoparticles synthesized by using Pseudomonas aeruginosa

“…The soil samples were diluted with distilled water by taking 1 g of soil and dissolving it in a test tube containing 5 ml. From sterile distilled water, the samples were grown on the nutrient medium using a cotton swab and incubated at a temperature of 37 °C [13] .…”

Biosynthesis of Silver Nanoparticle by Using Bacillus Subtilis Bacteria and its Biofilm Activity

“…The soil samples were diluted with distilled water by taking 1 g of soil and dissolving it in a test tube containing 5 ml. From sterile distilled water, the samples were grown on the nutrient medium using a cotton swab and incubated at a temperature of 37°C [13] 2: Diagnosis of bacterial isolates Bacterial isolates were diagnosed based on phenotypic characteristics by observing the shape of the colonies growing on the nutrient agar plate, in addition to staining them with Gram stain and examining them under the microscope to reveal their shape and cell arrangement, and biochemical tests were performed [14]. The bacterial isolate was diagnosed using PCR technology based on the 16S rRNA gene and detecting the size of the bands formed when the gene was amplified using electrophoresis of the resulting DNA [15].…”

Molecular determination of the microbial diversity associated with vaginitis and testing their sensitivity to selected antimicrobials

“…There is growing evidence that connects enterococci to BV and AV. These bacteria were isolated from different environments, including produced water in oil fields (Alyousif et al 2020;Hamzah et al 2020;Aboud et al 2021;Alshami et al 2022;Alyousif et al 2022). One of the bacteria detected at a frequency of 1(4.2%) was Streptococcus agalactiae strain 149, a significant pathogen in AV and other human diseases.…”