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In vitro Characterisation of Endophytic Fungi Strains from Lantana camara Leaves Displaying Antifungal Activity Against Phytophthora colocasiae
Mbouobda Hermann Desire,
Muyang Rosaline Forsah,
Djeuani Astride Carole,
Djou Tchinda Ismael,
Fotso
Issue:
Volume 5, Issue 6, December 2019
Pages:
87-93
Received:
31 August 2019
Accepted:
4 October 2019
Published:
21 November 2019
Abstract: Colocasiae esculenta is an important tropical tuber crop susceptible to attack by many diseases. The most devastative among these is Taro leaf blight cause by the pathogen Phytophthora colocasiae. The pathogen can cause rapid complete defoliation and crop destruction and under some circumstances, the disease can attack harvested corms and cause heavy losses during storage. Endophytes constitute an important source of bioactive secondary metabolites and enzymes. Based on their phytochemical properties, they can be used as a source of antifungal agent for the treatment of some infectious diseases. In order to evaluate the impact of endophytes on plant defence, in vitro evaluation of the growth effect of endophytic fungi against P. colocasiae was conducted in dual culture, after isolating and screening endophytic fungi from L. camara leaves for their production of some extracellular enzymes (amylases, lipases, laccases, protease and cellulose) and some secondary metabolites (tannins, saponins, phenols, cardiac glycoside) using standard procedures. In-vitro culture techniques with Potato Dextrose Agar (PDA) as culture medium were used to isolate endophytes from L. camara leaf tissues. Isolate identification was done using macroscopic and microscopic characteristics. These isolates were then tested in vitro to evaluate their morphological growth effect against P. colocasiae via the dual culture. Five endophytic fungi were isolated from Lantana camara leaves and coded L1, L2, L3, L4 and L5. The L2, L3 and L5 strains were filamentous and showed coenocytic hyphae which bore some structures’ called conidiosphores identified as Cladosporium sp. L1 strain was filamentous fungi having clamp connections hyphae (bridge-like growth) above hyphal septa and brown sclerotia. L4 strain showed very tiny interwoven and tightly parked mycelia. As enzyme activities, all the strains were found to produce amylase and not protease. L1, L3 and L4 were able to synthesis laccase while L5 produced cellulose and lipase. For the secondary metabolites, all the strains were able to produced tannins and cardiac glycoside but they did not synthesis saponins. L1, L2 and L4 strains were able to produced phenol. In dual culture, the growth of the pathogen decreased the growth rate of the endophytes. L2 strain grew normally by forming an arc around P. colocasiae growth while L3 and L5 strains induced the pathogen to grow on the opposite side of P. colocasiae. Concerning L1 and L4 strains, there were no effect. Based on the antifungal activities against P colocasiae, these strains L2 and L3 could be used for biological control of taro life blight.
Abstract: Colocasiae esculenta is an important tropical tuber crop susceptible to attack by many diseases. The most devastative among these is Taro leaf blight cause by the pathogen Phytophthora colocasiae. The pathogen can cause rapid complete defoliation and crop destruction and under some circumstances, the disease can attack harvested corms and cause hea...
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Study on the Optimization of Extraction Technology of Anemonin from Pulsatilla chinensis and Its Inhibitory Effect on Alternaria panax
Xue Fang,
Jinlei Liu,
Lirui Yang,
Xiangguo Li
Issue:
Volume 5, Issue 6, December 2019
Pages:
94-102
Received:
21 October 2019
Accepted:
14 November 2019
Published:
21 November 2019
Abstract: Background: The main antibacterial component of Pulsatilla chinensis is anemonin, which has strong antibacterial effect, so it is studied. The Pulsatilla chinensis is one of the diseases that are difficult to solve in the growth of ginseng, but chemical control not only causes harm to the environment, but also has residues on ginseng itself. Pulsatilla is a good medicinal plant. It will have a certain effect on the prevention and treatment of ginseng disease, and it can do no residue, no harm to ginseng. Objective: This experiment can provide effective data support for the prevention and treatment of Pulsatilla chinensis. Method: In this experiment, Pulsatilla Chinensis was used as experimental materials to extract plant by reflux, ultrasonic extraction methods, the content of anemonin in each single factor experiment was determined by HPLC. According to the content, the response surface analysis method was used to find the best extraction process, and the mycelium growth rate method was further used to determine the antifungal effect of Alternaria panax. Results: The EC50 value of P. Chinensis extract to A. panax was methanol extract < acetone extract < ethanol extract in order from small to large; The optimum extraction conditions of anemonin, the effective component of P. Chinensis methanol extract, were as follows: methanol volume fraction 87%, extraction time 2 h, solid-liquid ratio 20 (V: m), the optimum extraction amount was 3.760 μg·g-1.
Abstract: Background: The main antibacterial component of Pulsatilla chinensis is anemonin, which has strong antibacterial effect, so it is studied. The Pulsatilla chinensis is one of the diseases that are difficult to solve in the growth of ginseng, but chemical control not only causes harm to the environment, but also has residues on ginseng itself. Pulsat...
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Effectiveness of Coriandrum sativum Extract as Antimicrobial by Applying on Six Bacterial Strains
Faroug Bakheit Mohamed Ahmed,
Abd El-Mohymen Jaber Alla
Issue:
Volume 5, Issue 6, December 2019
Pages:
103-106
Received:
23 September 2019
Accepted:
27 November 2019
Published:
7 December 2019
Abstract: The study aimed to detect the antibacterial activity of coriander extract via investigation of six types of bacteria; three gram-positive reference strain were (Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212), whilst three gram-negative reference strains were (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 13311 and Pseudomonas aeruginosa ATCC 27853). All bacterial strains were stored in Brain Heart Infusion (BHI) broth with 20% (v/v) glycerol at 280°C. Prior to susceptibility testing, each strain was inoculated on BHI agar to ensure optimal growth and purity plating suitable. Four different concentrations (12.5%, 25%, 50% and 100%) of the oil were dissolved in dimethyl sulfoxide (DMSO) in triplicates using nutrient agar medium. In general, our study revealed that the coriander oil appeared higher influence on the positive gram strain rather than negative gram strain; this might be due to the gram positive strains are more sensitive and potential of hydrophobic essential oils to disrupt the bacterial cell membrane. The results showed that all tested concentrations of coriander oil as antibacterial activity against gram positive and gram negative bacteria; Salmonella typhimurium and Enterococcus fecalis respectively were appeared resistance at the concentrations 12.5%. In addition the concentration 100% inflicted the highest antibacterial activities. The most susceptible bacteria strains was Staphylococcus aureus with highest inhibition zone values (33mm) at concentration 25% and 100% (40mm).
Abstract: The study aimed to detect the antibacterial activity of coriander extract via investigation of six types of bacteria; three gram-positive reference strain were (Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212), whilst three gram-negative reference strains were (Escherichia coli ATCC 25922, Salmonell...
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