Antimicrobial Activity of Cultivable Endophytic Fungi Associated with Hancornia Speciosa Gomes Bark

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Abstract

Introduction:

In this study, we evaluated the antimicrobial potential of cultivable endophytic fungi associated with Hancornia speciosaGomes stem bark.

Methods and Materials:

Plant samples were collected in rainy (July 2010) and dry (January 2011) seasons. In total, 116 endophytic fungi strains were isolated from 90 fragments (64.4% frequency of colonization). Higher fungi frequency was observed in the rainy season (84.4%). The strains were grouped into 14 species; the most frequent were Phoma cava(13.8%), Colletotrichum gloeosporioides(12.1%), and Lasiodiplodia theobromae(11.2%). Fungal diversity was similar in both the seasons. Among the 116 strains, 39 (33.6%) showed antimicrobial activity in preliminary screening. The ten most active isolates were subjected to semi-solid fermentation using rice or corn as substrates. Methanolic extracts were obtained from each fermentation medium and the minimum inhibitory (MIC) and minimum microbicide concentrations (MMC) were determined.

Results:

The best antimicrobial results (MIC < 100 µg/mL) were observed for fungi strains grown in rice medium: Aspergillus nigerFHS061 against Proteus mirabilis(MIC = 19 µg/mL) and Staphylococcus aureus(MIC = 39 µg/mL). These strains also showed good results when cultivated in corn medium against P. mirabilis(MIC = 78 µg/mL).

Conclusion:

Thus, the stem bark of H. speciosaharbors diverse endophytic fungi with antimicrobial potential.

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A Friendly Relationship between Endophytic Fungi and Medicinal Plants: A Systematic Review

Min Jia, Ling Chen, Hai-Liang Xin … (2016)

Endophytic fungi or endophytes exist widely inside the healthy tissues of living plants, and are important components of plant micro-ecosystems. Over the long period of evolution, some co-existing endophytes and their host plants have established a special relationship with one and another, which can significantly influence the formation of metabolic products in plants, then affect quality and quantity of crude drugs derived from medicinal plants. This paper will focus on the increasing knowledge of relationships between endophytic fungi and medicinal plants through reviewing of published research data obtained from the last 30 years. The analytical results indicate that the distribution and population structure of endophytes can be considerably affected by factors, such as the genetic background, age, and environmental conditions of their hosts. On the other hand, the endophytic fungi can also confer profound impacts on their host plants by enhancing their growth, increasing their fitness, strengthening their tolerances to abiotic and biotic stresses, and promoting their accumulation of secondary metabolites. All the changes are very important for the production of bioactive components in their hosts. Hence, it is essential to understand such relationships between endophytic fungi and their host medicinal plants. Such knowledge can be well exploited and applied for the production of better and more drugs from medicinal plants.