Antimicrobial Activity of <i>Ramalina conduplicans</i> Vain. (Ramalinaceae)

Abstract

Article InformationThe members of the genus Ramalina (Ramalinaceae) are fruticose lichens growing on various types of substrata. The present study was conducted with an aim of determining antimicrobial activity of Ramalina conduplicans Vain. The powdered lichen material was extracted sequentially using petroleum ether, ethyl acetate and ethanol. The solvent extracts were screened for antibacterial activity by Agar well diffusion assay against 15 bacteria which included reference strains and isolates from burn, dental caries and urinary tract infections. Poisoned food technique was performed to determine antifungal effect of solvent extracts against fungal isolates from anthracnose of chilli, foot rot of finger millet and mouldy grains of sorghum. Usnic acid, Salazinic acid and Sekikaic acid were detected in the lichen. The solvent extracts were shown to exhibit dose dependent inhibitory activity against test bacteria. Ethyl acetate extract inhibited reference bacterial strains to higher extent. Among solvent extracts, only ethanol extract inhibited all urinary tract bacteria. S. aureus isolates from burn were inhibited to higher extent when compared to S. mutans isolates from dental caries. The solvent extracts exhibited varied inhibitory activity against test fungi. Ethyl acetate extract inhibited Alternaria sp., Aspergillus flavus and Sclerotium rolfsii to higher extent while Colletotrichum capsici and Helminthosporium sp. were inhibited to higher extent by petroleum ether and ethanol extract respectively. The observed inhibitory potential of solvent extracts of R. conduplicans could be ascribed to the presence of secondary metabolites. The lichen can be used in the treatment of bacterial infections and to manage plant pathogenic fungi.

Radical Scavenging, Antimicrobial and Insecticidal Efficacy of <i>Parmotrema cristiferum</i> and <i>Dirinaria applanata</i>

“…Hence, alternatives to several synthetic fungicides currently in use are needed. It has been shown that lichen and lichen forming fungi exhibit marked antifungal activity against a wide range of phytopathogenic fungi (Shahi et al, 2001;Oh et al, 2006;Wei et al, 2008;Goel et al, 2011;Tiwari et al, 2011;Kambar et al, 2014a). In the present study, we screened the potential of extract of P. cristiferum and D. applanata to inhibit fungi.…”

Antimicrobial activity of selected corticolous macrolichens

“…The study of Vivek et al (2014a) showed the inhibitory effect of three Parmotrema species against Gram positive and Gram negative bacteria. Similarly, studies by Karthikaidevi et al (2009), Karagöz et al (2009), Ranković et al (2010), Paudel et al (2012), Pavithra et al (2013), Kekuda (2014), Kambar et al (2014a) and Anjali et al (2015) showed the antimicrobial efficacy of lichens. …”

“…Vivek et al (2014b) found antifungal effect of extract of three Parmotrema species against Sclerotium rolfsii (isolate from foot rot of finger millet) and Helminthosporium sp., Alternaria sp., and Aspergillus flavus isolated from moldy grains of sorghum. In a study by Kambar et al (2014a) and Kekuda et al (2014), marked inhibition of Colletotrichum capsici was exhibited by extracts of macrolichens. Vinayaka et al (2014) showed the potential of extract of Usnea pictoides to inhibit the mycelial growth of F. oxysporum f.sp.…”

“…The use of these chemicals is associated with certain drawbacks such as resistance development in fungi, high cost and adverse effects on non-target organisms (including humans). Natural products including extracts and purified metabolites from lichens are considered to be alternative strategies for prevention and control of fungal diseases (Wei et al, 2008;Park et al, 2008;Shukla et al, 2011;Goel et al, 2011;Kambar et al, 2014a).…”

“…Lichens growing on the barks of tress are known as corticolous lichens. In India, >70% lichens are ., 2007; Kambar et al, 2014a). Barks of a number of trees support the growth of epiphytic ., 2012; Kambar et al,…”