Characterization of the Biocidal Spectrum of Extracellular Filtrates of Microcystis aeruginosa

Abstract

The effect of dichloromethane (DCM) and ethyl acetate (EA) extract of a cyanobacterium, Microcystis aeruginosa was evaluated against unicellular cyanobacteria and the phytopathogenic fungus Rhizoctonia solani. Fractionation of the filtrate showed the presence of five spots of different Rf values on silica gel coated plates indicating the presence of a number of compounds in the extract. A marked reduction in growth (52%) of the fungus was recorded on the plates supplemented with cyanobacterial extract, indicating the involvement of anti-fungal metabolite(s). The extract did not show any negative influence on seed germination and growth of seedlings of wheat, rice and mung, emphasizing the suitability of the compound for use in agriculture.

Antifungal activity of the cyanobacterium Microcystis aeruginosa against mycotoxigenic fungi

“…Shrivastava (2014) found that M. aeroginosa methanolic extract significantly inhibited the mycelial growth of Aspergillus fumagatus, Candida albicans and Rhizoctonia solani. Jaiswal et al (2011) revealed that M. aeruginosa dichloromethane and ethyl acetate extracts had antifungal activity against the phytopathogenic fungus Rhizoctonia solani. Perveen and Alwathani (2013) found that methanol extract M. aeroginosa showed antifungal activity against Fusarium sp., F. oxysporum, F. solani and A. flavus, while acetone had antifungal against F. solani.…”

“…and F. oxysporum. Kamble et al (2012) revealed that the diethyl ether extract of M. aeroginosa had the largest inhibition zone against S. cerevisiae and C. albicans on the agar.…”

“…No available studies measured MIC of extracts, fractions, sub-fractions and pure compounds from M. aeruginosa, whereas other organisms were studied. Jassbi et al (2013) indicated that Hexadecanoic acid methyl ester from a red algae Hypneaflagelli formis and two brown algae Cystoseiramyrica and Sargassum boveanum had antimicrobial activity against E. coli, K. pneumonia, S. typhi, S. aureus, S. epidemidis, B. subtilis, A. niger and C. albicans with MIC values ranged from 3 to 45.5 μg ml -1 . Al-Rekabi (2011) reported that Oscillatoria irrigua aqueous fraction had antifungal activity against A. flavus with MIC value 1.25 mg ml -1 .…”

Biological activity of entomopathogenic actinomycetes against lepidopteran insects (Noctuidae: Lepidoptera)

“…The scale bar indicates the evolutionary distance value between the sequences.functionality. Similarly, Frisvad (1989),Arasu et al (2008) andJaiswal et al (2011) demonstrated the efficiency of extracellular secondary metabolites from bacteria, fungi and actinomycetes as biocidal compounds. Recently,Omura (2011) has reviewed the wide range of microbial metabolites isolated and identified by his research group, most of which have been obtained as extracellular metabolites from bacterial, fungus and actinomycete isolates.…”

Antibacterial Activity of Methanolic Extracts from Lyngbya truncicola and Pseudanabaena sp.

“…Antimicrobial effects are demonstrated as visible zones of growth inhibition. Bacterial biological tests cover various bacteria such as: Micrococcus luteus, Bacillus subtilis, B. cereus and Escherichia coli, which are frequently used to detect antibiotic residues in food (Jaiswal et al, 2011).…”