Open Access Original Research Article

Evaluation of Inhibition of Fungal Spore Germination by Rhizospheric Bacterial Extracts

Asma Benslim, Samia Mezaache-Aichour, Nora Haichour, Sami Chebel, Mohamed Mihoub Zerroug

Annual Research & Review in Biology, Page 1-7
DOI: 10.9734/ARRB/2016/31228

Aims: This work aims to evaluate the anti-germinative activity of bacterial extracts. These bacteria were already characterized for their antagonistic capacity in vitro against telluric phyto-pathogens fungi: Fusarium oxysporum f.sp. albedinis (Foa), Fusarium solani var. coeruleum (Fsc) and  Phytophthora infestans (Pi), causing Bayoud, dry rot and mildew diseases respectively. 

Methodology: The OD of bacterial cultures is measured in order to determine the microbial charge producing the anti-germination substances, then centrifuged, filtered. A volume of spore suspension of determined concentration is added to a determined volume of the bacterial filtrates. After incubation, for 24 hours at room temperature the inhibition of spore germination is observed under a microscope using a Malassez cell.

Results: The results showed that these bacterial filtrates are able of inhibiting fungal spore germination, among these filtrates XI35 ' one, gave a total inhibition (100%) on both of the tested fungi Foa and Fsc, while on Pi it only gave 16.66% of inhibition.

Conclusion: The bacterial filtrates were more active against mitosporic fungi, than oomycetes.

Open Access Original Research Article

Antimicrobial Activity of Potato Rhizospheric Pseudomonas chlororaphis subsp. aureofaciens from Sétif Algeria

Samia Mezaache-Aichour, Nora Haichour, Jane Nicklin, Mohamed M. Zerroug

Annual Research & Review in Biology, Page 1-7
DOI: 10.9734/ARRB/2016/31651

Aims: This study was assessed to demonstrate the antimicrobial activity in vitro of an identified fluorescent Pseudomonas strain characterized for its capacity to produce phenazine compounds.

Methodology: First Pseudomonas chlororaphis subsp aureofaciens was inoculated on Nutrient Broth supplemented with Yeast Extract (NBY) and with glucose at a final concentration of 2%, after incubation the filtered culture was acidified with HCl to pH 2. The solution was extracted twice with the same volume of ethyl-acetate. The organic supernatants were combined, dried over anhydrous Na2SO4, and evaporated to dryness. The crude extract was resuspended in methanol and tested for antimicrobial activity. Antimicrobial activity was determined (i) by disc diffusion technique for bacteria and (ii) using serial dilution technique in soft PDA for fungi. Secondly the antifungal activity of the bacterial strain was tested against several phytopathogenic fungi in dual culture.

Results: The studied strain has an important activity against the phytopathogenic bacteria and fungi tested. Among the tested fungi Fusarium oxysporum f. sp. albedinis is the most sensitive to the actions of this Pseudomonas, where the inhibition rate reached 77.78%. The less sensitive one was Pythium ultimum with a rate of 55.56%. While for pathogenic bacteria only Salmonella enteridis was sensitive to the tested strain.

Conclusion: Pseudomonas chlororaphis subsp aureofaciens showed appreciable antagonistic activity, in vitro, against special forms of Fusarium oxysporum and the tested phytopathogenic bacteria.

Open Access Original Research Article

Characterization of anti-Listeria innocua. F Bacteriocins Produced by Lactococcus lactis ssp raffinolactis Isolated from Algerian Camel Milk

Achour Chergui, Ahcene Hakem, Nacima Meguenni, Ghenima Aiche Iratni, Samira Bouzida, Yacine Titouche, Karim Houali

Annual Research & Review in Biology, Page 1-9
DOI: 10.9734/ARRB/2016/31767

Aims: Our work is focused on the characterization of anti-Listeria innocua. F bacteriocins produced by lactic acid bacteria belonging to the genus Lactococcus isolated from camel milk.

Methodology: We tested the bacteriocins activities by diffusion wells method, followed by protease inactivation. The antibacterial peptides are extracted by adsorption/desorption method and then separated on a PAGE-SDS and their activity is detected by the zymogram technique. On the other hand, genetic characterization of these molecules was realized by the plasmid curing using two antibiotics, Rifampicin and Novobiocin. The cure is checked by extraction of the plasmids followed by a migration on an agarose gel. The Bac-mutants obtained underwent testing activity by well diffusion method and by zymogram technique, using as a positive control, wild strains Bac+.

Results: Lactococcus lactis ssp raffinolactis gave inhibition zones against  Listeria innocua F strain with a diameter of 16 mm as well as by the zymogram has inhibition zones between 5 and 10 Kda. Bacteriocins produced are sensitive to the proteases used. The disappearance of the zones of inhibition after the plasmid treatment confirms the plasmid location of the genetic clusters bacteriocins. After cure of the plasmids, it is indicated that the genes for immunity to the parental bacteriocins are also carried by the same plasmid and therefore co-transcribed with genes encoding the bacteriocin. Finally, our work is completed by the determination of CMI of bacteriocins extracts; the value found is 7.14 IU/ml.

Conclusion: Bacteriocins produced are sensitive to trypsin and pepsin, two proteolytic enzymes most commonly used to confirm the protein nature of bacteriocins and gave a protein pattern and a zone of inhibition of 9.26 KDa. This MW is situated between 5 to 10 KDa and it is corresponding to sub-class IIa of bacteriocins. The Minimal inhibitory concentration of bacteriocin was 7.14 IU/ml.

Open Access Original Research Article

New Appearance of Phytophthora palmivora as a Pathogen of the Olive Trees in Sidi Kacem Region (Morocco)

S. Msairi, M. Chliyeh, K. Selmaoui, A. Mouria, A. Ouazzani Touhami, R. Benkirane, A. Douira

Annual Research & Review in Biology, Page 1-7
DOI: 10.9734/ARRB/2016/31427

This study aims to study and evaluate the presence and geographical distribution of Phytophthora palmivora, the causal agent of the olive trees wilting in Morocco. In 2015 surveys, carried out in Sidi Kacem region, made it possible to note the presence of olive trees showing symptoms of dieback. The diseased samples were taken from these trees in order to determine the causative agent of the disease. P. palmivora was isolated and the Koch’s postulate was verified. The pathogenicity of one isolate, selected among other isolates was studied. After five months of inoculation, this isolate proved able to induce different types of symptoms in olive plants: growth reduction in the vegetative and the root parts and the number of Leaves and buds. Sometimes the newly formed buds dry up. The values of the growth parameters are very low in the inoculated seedlings, the number of leaves, branches and buds are respectively 101, 12 and 13.5. On the other hand, these values are respectively 338.66, 29.83 and 11.83 in the control plants, the root mass of the Inoculated seedlings is also very low (13.1 g) versus 75.1 g for the control seedlings. The fungus was found in different parts of the inoculated olive plants: roots, stems and dried out buds.

Open Access Original Research Article

Influence of Treatment Parameters on Symptom Relief in Individuals with Vitamin B12 Deficiency

Patricia A. Kornic, Margaret M. J. Harty, Joshua A. Grant

Annual Research & Review in Biology, Page 1-8
DOI: 10.9734/ARRB/2016/31711

Objective: Ever-growing numbers of displeased vitamin B12 deficiency patients are joining online support groups seeking help. The current study attempted to assess, quantitatively, several of the concerns of these patients.

Methods: A survey was developed, advertised and administered to 204 vitamin B12 deficiency patients through the online research website The survey assessed the impact, on symptoms, of discrete, historical, epochs of B12 treatment characterized by a) type of B12 used, b) administration route, c) dosage, d) frequency and e) additional supplements. The final sample consisted of data from 192 individuals.

Findings: B12 injections were associated with greater mean symptom improvement than oral supplements. However, the combination of injections and additional oral cobalamin resulted in the greatest improvement. There were no differences observed for the form of cobalamin used. Compared to daily (DLY) or weekly (WKLY) injections, monthly (MNTH) or every two to three month (MNTH+) injections were associated with less symptom improvement. While additional oral B12 improved the effectiveness of daily, weekly and monthly injections, it was insufficient to ‘rescue’ the ineffectiveness of MNTH+ injections. Lastly, folate intake, but not iron, was associated with greater symptom improvement.

Conclusions: Patient’ symptom reports suggest that oral supplements are not as effective as B12 injections. This is in contrast to previous work that relied primarily on biomarker change as a proxy for effectiveness, suggesting more research is necessary. The frequency of injections perceived as most effective by patients was far in excess of that often prescribed, suggesting under-treatment may be occurring. Taken together, further investigation with more definitive tests and the inclusion of patient reports is necessary.