Biodegradation Kinetics of Diethyl Phthalate by Three Newly Isolated Strains of Pseudomonas

Khadka, Sujan; Nshimiyimana, Jean Bosco; Zou, Piao; Koirala, Niranjan; Li, Xiong

doi:10.1016/j.sciaf.2020.e00380

Cited by 14 publications

(5 citation statements)

References 42 publications

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“…Genomic DNA of isolated Bacillus species was extracted by phenol-chloroform assay, and DNA amplification of the 16S rRNA gene was performed by the primer sets: 8F (5′-AGAGTTTGATCCCTCAG-3′) and 1492R (5′-GGTTACCTTGTTACGACTT-3′) [ 22 , 34 , 37 , 38 ]. PCR amplification conditions were as follows: 30 cycles of denaturation at 98°C for 10 seconds and annealing at 55°C for 5 seconds with final elongation at 72°C for 1 min.…”

Section: Methodsmentioning

confidence: 99%

Detection of Bacillus Species with Arsenic Resistance and Plant Growth Promoting Efficacy from Agricultural Soils of Nepal

et al. 2022

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Arsenic contamination in soil and water is one of the major environmental problems in multiple countries including Nepal imposing a serious threat to the ecosystem and public health. Many soil bacteria can detoxify arsenic, including genus Bacillus. With an objective to gauge the plant growth-promoting activities of arsenic-resistant Bacillus species, 36 samples (soil, rice, cauliflower, and beans) were collected from the Terai region of Nepal. For selective isolation of Bacillus species, each sample was heated at 80°C for 15 min before the inoculation into nutrient agar (NA). Following the standard protocol, arsenic-resistant Bacillus species were screened using NA supplemented with 100 ppm sodium arsenate and sodium arsenite. Among 158 randomly selected isolates, only five isolates were able to tolerate sodium arsenite concentration up to 600 ppm. Notably, all five isolates were able to produce indole acetic acid (IAA), a plant hormone, and solubilize phosphate. Based on biochemical analysis and 16S rRNA gene sequencing, isolates N4-1, RW, KR7-12, Bhw1-4, and BW2-2 were identified as B. subtilis subsp. stercosis, B. flexus, B. licheniformis, B. cereus, and B. flexus, respectively. To the best of our knowledge, this is the first study showing the presence of arsenic-resistant B. flexus in Nepalese soil with plant growth-promoting traits. Possible utilization of these Bacillus strains could facilitate the novel bioremediation pathway to reduce the toxic effect of arsenic from the soil and water in the Terai region of Nepal.

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Section: Methodsmentioning

confidence: 99%

Detection of Bacillus Species with Arsenic Resistance and Plant Growth Promoting Efficacy from Agricultural Soils of Nepal

et al. 2022

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“…DNA denaturation (30 cycles) at 98 °C for 10 seconds, primer annealing at 55 °C for 5 s, and elongation at 72 °C for 1 min were performed during the PCR. Amplification of the 16S rRNA gene was performed using the following universal primer sets: 8F (5′-AGAGTTTGATCCCTCAG-3′) and 1492R (5′-GGTTACCTTGTTACGACTT-3′) [ 41 , 42 , 43 ]. By loading 7 μL of each PCR product with 2 μL of loading dye into the wells of 0.8% agarose gel containing 2 μL/mL EtBr (ethidium bromide), the amplified DNA fragments were separated using gel electrophoresis.…”

Section: Methodsmentioning

confidence: 99%

Screening and characterization of potent poly glutamic acid producing Bacillus sp. isolated from Kinema, water and soil samples

Thapa

Khadka

et al. 2021

Heliyon

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Microbially produced gamma poly glutamic acid (γ–PGA) is a commercially important biopolymer with many applications in foods and various other substances and are abundantly used in different parts of the world. With an aim to study the potent γ–PGA producing Bacillus species, a total of 47 different samples ( Kinema , soil, and water) were randomly collected from different locations across the country, and Bacillus sp. were selectively isolated, screened, and characterized by performing physiological, biochemical, morphological, and 16S rRNA gene sequencing. The microbial production of γ–PGA was assayed with the selected isolates on the PGA medium and the metabolite obtained was recovered by ethanol precipitation method and further characterized by thin-layer chromatography (TLC). Thermotolerance (25–60 °C), pH tolerance (4–9), and NaCl tolerance (1–9%) tests were performed to optimize the bacterial growth and γ–PGA production and its viscosity were measured by Ostwald's viscometer. Out of 145 randomly selected colonies, 63 isolates were Gram-positive, rods, and endospore producers and were presumptively confirmed as genus Bacillus. Higher growth of γ–PGA producers were reported in 22 isolates and was found at optimum conditions such as temperature (30–37 °C), pH (6.5–7), incubation time (3 days), and NaCl concentration (3%) and γ–PGA thus produced was further verified by TLC with the retention factor (RF) value 0.27. The potent isolates were closely similar to Bacillus subtilis subsp . stercoris , Bacillus cereus , Bacillus paranthracis, and Bacillus licheniformis etc . Based on the findings of the study, B . licheniformis is the most potent γ–PGA producing Bacillus sp. which can further be used for the commercial production of γ–PGA. To the best of our knowledge, there is yet no published research from Nepal showing the production of the γ–PGA although microbially produced γ–PGA are the major constituents in some popular foods in particular communities of the country.

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“…Further confirmation of Pseudomonas sp. was carried out by using cetrimide agar medium and following the standard microbiological procedures that included colonial morphology, Gram staining, and a series of standard biochemical tests (indole, methyl red, Voges-Proskauer, citrate utilization, urease, oxidative/fermentative, catalase, oxidase, triple sugar iron, mannitol fermentation, and motility) [28,29].…”

Section: Sample Processing and Identification Of Isolatesmentioning

confidence: 99%

Clinical Specimens are the Pool of Multidrug- resistant Pseudomonas aeruginosa Harbouring oprL and toxA Virulence Genes: Findings from a Tertiary Hospital of Nepal

Chand

Khadka

Sharma

et al. 2021

Emergency Medicine International

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The multidrug- or extensively drug-resistant (MDR/XDR) Pseudomonas aeruginosa carrying some virulence genes has become a global public health threat. However, in Nepal, there is no existing report showing the prevalence of oprL and toxA virulence genes among the clinical isolates of P. aeruginosa. Therefore, this study was conducted for the first time in the country to detect the virulence genes (oprL and toxA) and antibiotic susceptibility pattern of P. aeruginosa. A total of 7,898 clinical specimens were investigated following the standard microbiological procedures. The antibiotic susceptibility testing was examined by the modified disc diffusion method, and virulence genes oprL and toxA of P. aeruginosa were assessed using multiplex PCR. Among the analyzed specimens, 87 isolates were identified to be P. aeruginosa of which 38 (43.68%) isolates were reported as MDR. A higher ratio of P. aeruginosa was detected from urine samples 40 (45.98%), outpatients’ specimens 63 (72.4%), and in patients of the age group of 60–79 years 36 (41.37%). P. aeruginosa was more prevalent in males 56 (64.36%) than in female patients 31 (35.63%). Polymyxin (83.90%) was the most effective antibiotic. P. aeruginosa (100%) isolates harboured the oprL gene, while 95.4% of isolates were positive for the toxA gene. Identification of virulence genes such as oprL and toxA carrying isolates along with the multidrug resistance warrants the need for strategic interventions to prevent the emergence and spread of antimicrobial resistance (AMR). The findings could assist in increasing awareness about antibiotic resistance and suggest the judicious prescription of antibiotics to treat the patients in clinical settings of Nepal.

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Biodegradation Kinetics of Diethyl Phthalate by Three Newly Isolated Strains of Pseudomonas

Cited by 14 publications

References 42 publications

Detection of Bacillus Species with Arsenic Resistance and Plant Growth Promoting Efficacy from Agricultural Soils of Nepal

Detection of Bacillus Species with Arsenic Resistance and Plant Growth Promoting Efficacy from Agricultural Soils of Nepal

Screening and characterization of potent poly glutamic acid producing Bacillus sp. isolated from Kinema, water and soil samples

Clinical Specimens are the Pool of Multidrug- resistant Pseudomonas aeruginosa Harbouring oprL and toxA Virulence Genes: Findings from a Tertiary Hospital of Nepal

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