Open Access Original Research Article

Antifungal Activity of Pseudomonas frederiksbergensis CMAA 1323 Isolated from the Antarctic Hair Grass Deschampsia antarctica

Itamar S. Melo, Wallace R. Souza, Leonardo J. Silva, Suikinai N. Santos, Marcia R. Assalin, Tiago D. Zucchi, Sonia C. N. Queiroz

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/BMRJ/2016/25314

Aims: Epiphytic bacteria, isolated from Deschampsia antarctica, were screened for their potential to inhibit the plant pathogen Botrytis cinerea, the causal agent of gray mold disease of strawberry pseudofruits. This phytopathogenic fungus is more active and the disease is more serious in temperate climate where the temperatures are lower.

Methodology: The approach involved the isolation and characterization of bacteria from the phyllosphere of D. antarctica and the evaluation of their antifungal activity.

Results: A total of 56 bacterial strains were isolated and only one of them, identified by the sequencing of 16S rDNA gene, as Pseudomonas frederiksbergensis CMAA 1323, inhibited the mycelial growth and the conidial germination of the fungus. Its ethyl acetate extract also inhibited the mycelial growth. Analysis of the bioactive fraction by using liquid chromatography coupled to a mass spectrometry (LC-MS) revealed the presence of cyclo(Pro-Val), a compound belonging to the class of diketopiperazines (DKPs).

Conclusion: These findings support the potential use of the psychrophilic bacterium P.  frederiksbergensis as promising antifungal agent, and highlight the need for more studies with this bacterium in the biological control of plant pathogenic fungi.

Open Access Original Research Article

Bacillus thuringiensis Strains Isolated from Agricultural Soils in Mali Tested for Their Potentiality on Plant Growth Promoting Traits

Adounigna Kassogué, Amadou Hamadoun Dicko, Diakaridia Traoré, Rokiatou Fané, Fernando Hercos Valicente, Amadou Hamadoun Babana

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/BMRJ/2016/24785

Aims: To screen of the multiple plant growth promoting activities of some Bacillus thuringiensis strains isolated from Malian Agricultural soils and evaluate their ability to improve maize seed germination and seedling vigor in vitro.

Study Design: Strains of Bacillus thuringiensis (Bt) used in this study belong to collection of the Laboratory of Research in Microbiology and Microbial Biotechnology (LaboREM-Biotech) isolated from different agricultural soils of Mali.

Methodology: Different tests, namely: Phosphate solubilization, Siderophore production, Indol acetic acid cellulase and chitinase production tests were performed to confirm the PGP characteristic of the insecticidal B. thuringiensis strains screened. In vitro test was performed in the laboratory to confirm the capacity of these bacteria to enhance maize germination and seedling vigor.

Results: All tested Bacillus strains solubilize efficiently insoluble phosphate, but BtI4" showed the highest clearance zone around its colony. In this study, except in BtI4’, the siderophore production was significantly elevated in the other Bt strains tested. Only BtD5 was able to produce Indol acetic acid. Contrary, except BtD5, all the isolates produce chitinase and cellulase.  Exept IAA, the isolate BtI4" produce all the tested compounds and showed the highest % seed germination and seedling vigor. 

Conclusion: In the current study, plant growth promotion analysis of three B. thuringiensis strains from Malian agricultural soils were assessed in relation with maize seed germination and seedling vigor. These tested Bt strains showed several plant growth-promoting characteristics. These activities may allow the use of these isolates for plant growth promotion. Future work will address the applications of the selected bacteria in biocontrol and plant growth promotion. Insect pest biocontrol, enhancement of plant nutrition and production of phytohormon are the mechanisms involved.

Open Access Original Research Article

Sequence Analysis of Three Genes of Mycoplasma bovis Isolates from Egyptian Cattle and Buffaloes

Sabry Eissa, Yousreya Hashem, Abo-Shama U. H., Mona Shaker

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/BMRJ/2016/25014

The present study concerned with phylogentic analysis of three genes (gapA, p 40 pseudogene and uvrC) related to adhesion and virulence of Mycoplasma bovis (M. bovis) in cows and buffaloes. In this study, 625 milk samples were collected from clinical and subclinical mastitis in cows and buffaloes in two Egyptian Governorates Fayoum (south of Cairo Governorate) and Dakahlia (south of Cairo Governorate) for the detection of M. bovis infection by isolation and PCR. Mycoplasma infection was higher in cows (31.6%) than buffaloes (14.3%) suffered from clinical mastitis at Fayoum. The incidence of clinical mastitis in cows (20%) is higher than that in buffaloes (10%) at Dakahlia. Concerning subclinical cases, the incidence was higher at Dakahlia (30.19% and 38.3%) than Fayoum (20.6% and 12%) in cows and buffaloes respectively. Phylogentic analysis of nucleotides and amino acids of gapA gene showed 100% identity of the two isolates. The study proved that p40 gene is present in bovine as pseudogene and its protein did not expressed. The amino acids of uvrC gene of our field isolates showed 50 a.a substitutions. In conclusion M. bovis isolate isolated in the current study had identical gapA gene in both cow and buffalo in DNA and amino acid sequences (aa), whereas uvrC gene showed 50 aa substitutions in which could affect the antigenicity and p40 gene showed no protein expression and present in bovine as pseudogene.

Open Access Original Research Article

Phytochemistry and in-vitro Antimicrobial Evaluation of Phragmanthera incana (Schum.) Balle Extracts on Selected Clinical Microorganisms

O. T. Ogunmefun, A. B. Saba, T. R. Fasola, F. C. Akharaiyi, O. A. Oridupa

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/BMRJ/2016/18324

Aims: Phragmanthera incana, an African mistletoe hemi-parasitic plant growing on cocoa (Theobroma cacao) and kolanut (Cola nitida) trees was screened for antimicrobial and phytochemical activities due to their ethno medicinal claims as remedies for gastro intestinal tract infections, wound, diarrhoea, dysentery and skin infections. 

Methodology: The antimicrobial activities of hexane, methanol, chloroform, ethyl acetate and aqueous extracts of P. incana obtained from cocoa (Theobroma cacao) and kolanut  (Cola nitida)  trees were tested in vitro against five Gram negative and two Gram positive pathogenic bacteria; and three pathogenic fungi species using agar well diffusion technique. Qualitative and quantitative phytochemicals of the plants were determined by chemical methods.

Results: Phytochemical screening of P. incana on cocoa and kolanut trees showed the presence of phytochemicals quality and quantity assessments. Varying degrees of inhibitory activities was observed with the solvent extracts of P. incana from cocoa and kolanut trees on test bacteria species while the test fungi species were resistant to all the extracts.

Conclusion: This study showed that the methanol and ethyl acetate extracts of Phragmanthera incana had more antibacterial activities than other solvents. Antifungal activity was not exhibited by the five extracts of P. incana harvested from the two host plants used. Proteus mirabilis and P. aerugiosa commonly known for their resistant activities to most conventional antibiotics were inhibited by some of the extracts of P. incana in this study.

Open Access Original Research Article

Comparative Evaluation of Biological Activities, Bioautography and Spot Screening of Boiled and Macerated Extracts of Medicinal Plants against Zoonotic Pathogens

Rabia Ilyas, Saiqa Andleeb, Muhammad Babar, Rozina Ghulam Mustafa, Irsa Shafique, Atiya Zafar, Shaukat Ali

Microbiology Research Journal International, Page 1-13
DOI: 10.9734/BMRJ/2016/24654

Aims: There is an escalating requirement for the development of novel drugs for the treatment of zoonotic diseases. Herbal plants have always been the best source of therapeutic agents.

Study Design: Biological activities of medicinal plants.

Place and Duration of Study: Microbial Biotechnology laboratory, Department of Zoology, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan, between 12 Feb, 2014 and 29 June, 2015.

Methodology: In current research work biological properties of various extracts of medicinal plants i.e. Atropa acuminate, Atropa belladonna and Morus nigra were investigated. Extracts were prepared through both maceration and boiling extraction methods. Antibacterial activity against zoonotic pathogens such as Serratia odorifera, Enterobacter amnigenus, Shigella flexneri, Salmonella Typhimurium and Pseudomonas aeruginosa was assessed using agar well diffusion method. DPPH free radical scavenging method was used to measure antioxidant potential. Total phenolic and flavonoid contents were estimated.

Results: It was found that boiling extracts showed maximum antibacterial activity against all tested pathogens. The results of antioxidant potential revealed the maximum activity in root extracts of A. belladonna and all extracts of M. nigra while A. acuminata showed lowest scavenging activity. Phytochemical analysis indicated the existence of alkaloids, flavonoids, quinones, phenols, tannins, terpenoides, glycosides, steroids and carbohydrates. Thin layer chromatography (TLC) also mentioned the presence of phytochemical constituents. TLC- developed plates have showed the maximum presence of both antioxidant constituents and flavonoids contents in all boiling extracts of Z. armatum. Bio-autobiography by agar overlying assay indicated the significant inhibition of tested pathogens.

Conclusion: The current study provides scientific confirmation supporting the therapeutic potency of these medicinal plants for medicinal uses and identifies gaps for future research to facilitate commercial utilization.

Open Access Review Article

Poly-β-hydroxybutyrate: A Biodegradable Polyester, Biosynthesis and Biodegradation

Monika Sharma, Harish Kumar Dhingra

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/BMRJ/2016/25430

Bioplastic can be degraded in nature with time and produce carbon dioxide as an end product. It reduces the environmental pollution created by synthetic plastic. Biodegradable plastic can be used to make plastic bags and also have application in medical field like in formation of bone implants. Poly-β-hydroxybutyrate is a microbial polymer formed inside the bacterial cell and commercially important in formation of biodegradable plastic. In this review we tried to summarized identification, biosynthesis, metabolism, biodegradability and applications of PHB. Information summarized in review can lead to design many experiments to increase production of bacterial polymer as valuable renewable products.