ISSN 2736-1756
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-008, May, 2019. © International Scholars Journals
Full Length Research Paper
Effects of different light treatments on the natural transformation of Synechocystis sp. strain PCC 6803
Zongjuan Long, Jiaohong Zhao, Jingsong Zhang, Lanzhen Wei, Quanxi Wang and Weimin Ma*
College of Life and Environment Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234, People’s Republic of China.
Accepted 16 March, 2019
Abstract
Although many factors that affect the frequency of natural transformation of the unicellular cyanobacterium Synechocystis have been extensively reported, little is known regarding the effects of changes in the spectral quality and intensity of light on its natural transformation. The frequency of natural transformation was significantly enhanced or inhibited by the treatments with low light (LL) or high light (HL) under the incubation condition of cells and DNA before plating and/or on the plates in comparison with that by the treatment with growth light (GL); the changes in the spectral quality of light did not remarkably affect the transformation efficiency of Synechocystis. Further, the lengths of the appearance time of transformants were shortened or retarded by HL or LL illumination when cells and DNA were incubated on the plates relative to that by GL illumination. Further, the transformation efficiency of Synechocystis was closely associated with the permeability of the cell membranes. Treatment with LL significantly enhances the frequency of natural transformation whereas HL illumination remarkably shortens the appearance time of Synechocystis transformants. These phenomena can be extensively applied to future studies according to the specific demands of the transformation experiments. Possible mechanisms underlying these phenomena are discussed.
Key words: Appearance time of transformants, light treatments, natural transformation, Synechocystis, transformation efficiency.
Jiaohong Zhao, Lanzhen Wei, Quanxi Wang and Weimin Ma*, Jingsong Zhang, Zongjuan Long
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-004, May, 2019. © International Scholars Journals
Full Length Research Paper
Multi-drug resistance in Acinetobacter baumannii strains isolated from clinical specimens from three hospitals in Tehran-Iran
Sepideh Mostofi1, Reza Mirnejad2* and Faramaz Masjedian3
1Department of Biology, North Tehran Azad University, Tehran, Iran.
2Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
3Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Accepted 23 March, 2019
Abstract
The aim of this study is to investigate multi-drug resistance in A. baumannii strains that was isolated from clinical samples of three highly large hospitals in Tehran-Iran. This descriptive-cross sectional study was performed in three large hospitals in Tehran on 70 samples of Acinetobacter which were isolated from patients during April to November 2010. After identifying the species level by using culture and biochemical methods, in order to determine sensitivity of 50 isolates of A. baumannii to 13 antibiotics, standard methods according to CLSI guidelines were performed. In this study, resistance to three or more of three classes of antibiotics multidrug resistance was defined. In this study, 50 A. baumannii strains, 12 A. lwoffii strains and other Acinetobacter species were isolated from patients. The majority of isolates were from blood specimens. Isolates of A. baumannii showed the highest resistance to cefepime, ceftazidime, aztreonam, norfloxacin, ofloxacin, ciprofloxacin and amikacin. Tobramycin and meropenem considered as effective drugs in this study. Multi-drug resistance in these strains was respectively 55.4%. Multi-drug resistant Acinetobacters are growing and considered as important threat for hospitalized patients, so change in consumption patterns of antibiotics and control of hospital infections seems to be necessary.
Key words: Acinetobacter baumannii, nosocomial infection, multi-drug resistance, antibiogram.
Sepideh Mostofi, Reza Mirnejad* and Faramaz Masjedian
Research Article
A simplified system without purification for selection of aptamers against Vibrio alginolyticus
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-005, May, 2019. © International Scholars Journals
Full Length Research Paper
A simplified system without purification for selection of aptamers against Vibrio alginolyticus
Jumin Hao, Jiang Zheng*, Xuemin Tang, Qingpi Yan, Yubao Li and Zhongbao Li
Fisheries College of Jimei University, Key Laboratory of Science and Technology for Aquaculture and Food Safety in Fujian Province University, Xiamen 361021, China.
Accepted 22 March, 2019
Abstract
We have explored a simplified system without purification for systematic evolution of ligands by exponential enrichment (SELEX) against Vibrio alginolyticus to select single-stranded DNA ligands (aptamers) from a random 82-nt library. The DNA content was quantified by agarose gel electrophoresis and follow-up image analyses with the BandScan 5.0 software. Anti-digoxigenin/HRP system was used to determine the binding activity of aptamers for V. alginolyticus. The results showed that the affinity of aptamers increased gradually with the increase of screening rounds, indicating that the lack of purification did not affect screening results but rather made SELEX screening much more convenient and significantly increased the efficiency.
Key words: Aptamers, purification, systematic evolution of ligands by exponential enrichment (SELEX), Vibrio alginolyticus.
Jumin Hao, Jiang Zheng*, Qingpi Yan, Yubao Li and Zhongbao Li, Xuemin Tang
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-005, May, 2019. © International Scholars Journals
Full Length Research Paper
Insecticidal effect of diatomaceous earth against Callosobruchus maculates under laboratory conditions
Golnaz Shams1*, Mohammad Hassan Safaralizadeh2 and Sohrab Imani1
1Department of Entomology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
2Department of Plant Protection, College of Agriculture, University of Urmia, Urmia, Iran.
Accepted 23 March, 2019
Abstract
Laboratory experiments were carried out in order to evaluate the insecticidal effect of diatomaceous earth against adults of Callosobruchus maculatus (F.) and Sitophilus granarius (L.), two important stored grain pests in darkness (30°C and 65% RH). Wheat and cowpea were treated with the diatomaceous earth formulation Silicosec® (Biofa, Germany), at five concentrations determined with preliminary tests and compared with untreated wheat and cowpea as control. Dead adults were counted 24, 36 and 48 h later. Results showed that increasing the concentration of Silicosec® and days after treatment (DAT) significantly increased the mortality rates of adults to above 90% in both experiments. Regarding Lc50 and Lc95 values, it was observed that C. maculatus adults are more susceptible to Silicosec® than S. granarius. The results showed that these two pests could be controlled successfully with diatomaceous earth.
Key words: Callosobruchus maculatus, diatomaceous earth, Silicosec®, Sitophilus granarius, stored grains, cowpea, wheat.
Mohammad Hassan Safaralizadeh and Sohrab Imani, Golnaz Shams*
Research Article
Identification of lipase producing thermophilic bacteria from Malaysian hot springs
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-005, May, 2019. © International Scholars Journals
Full Length Research Paper
Identification of lipase producing thermophilic bacteria from Malaysian hot springs
H. Zuridah1,2*, N. Norazwin1, M. Siti Aisyah1, M. N. A. Fakhruzzaman1 and N. A. Zeenathul3
1Faculty of Health Sciences, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia.
2Pharmogenomic Centre (PROMISE), Faculty of Pharmacy, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia.
3Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia.
Accepted 19 March, 2019
Abstract
Lipase enzyme is an important group of biocatalyst for biotechnological application. One of the major industrial microorganism is the Bacillus species which are in abundance in the hot springs. The aim of this research was to isolate and characterize lipase producing bacteria from five hot springs in Malaysia. Eight bacterial strains from five hot springs were characterized by both biochemical and molecular techniques. Four strains were lipase producing thermophilic bacteria (coded as A1, A3, A4 and A14). The presence of lipase enzyme was confirmed by an orange fluorescence halos around the bacteria in rhodamine B olive oil agar plate. Based on molecular analysis, A1, A3 and A4 were assigned to the Bacillus and Geobacillus sp., and isolate A14 is found to be a nucleoside permease gene from Anoxybacillus flavithermus WK1.
Key words: Lipase enzyme, rhodamine B olive oil, polymerase chain reaction (PCR), hot springs, thermophilic bacteria.
N. Norazwin, M. Siti Aisyah, M. N. A. Fakhruzzaman and N. A. Zeenathul, H. Zuridah*
Research Article
Osmoadaptation and plant growth promotion by salt tolerant bacteria under salt stress
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (5), pp. 001-009, May, 2019. © International Scholars Journals
Full Length Research Paper
Osmoadaptation and plant growth promotion by salt tolerant bacteria under salt stress
Aisha Waheed Qurashi* and Anjum Nasim Sabri
Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-i-Azam Campus, Lahore, Pakistan.
Accepted 16 March, 2019
Abstract
Establishment of biofilm, production of exopolysacharides (EPS) and accumulation of endogenous osmolytes under varying stress conditions are significant strategies adopted by bacterial strains for their successful survival in plant rhizosphere. Our studies focus on determining the osmoadaptation strategies used by two native salt-tolerant strains Oceanobacillus profundus (Pmt2) and Staphylococcus saprophyticus (ST1) and their plant growth promoting abilities. The ability of these strains to be used as inoculants for Lens esculenta Var. masoor 93 under salt stress was tested in the laboratory. We found that unlike the bacterial growth, biofilm formation, exopolysaccharide production and endogenous osmolyte (proline and glycine betaine) accumulation increased at higher salt stress. Biofilm formation and endogenous osmolytes increased with increasing salt concentrations. The maximum increase in EPS accumulation was observed at maximum NaCl stress for ST1. Bacterial inoculation improved growth parameters and endogenous osmolytes accumulation of plants under salt stress compared to noninoculated control plants. The ST1 strain in this work efficiently produced biofilm and exopolysacharide and accumulated osmolytes in response to NaCl stress. It could be speculated that these strategies reverse the detrimental effects of high osmolarity in soil and helpful for improving crop under salt stress.
Key words: Biofilm, exopolysaccharide, endogenous osmolytes, Lens esculenta, salinity.
Anjum Nasim Sabri, Aisha Waheed Qurashi*