Screening of rare actinomycetes isolated from natural wetland ecosystem (Fetzara Lake, northeastern Algeria) for hydrolytic enzymes and antimicrobial activities (original) (raw)

Characterization of Bioactive Actinomycetes Isolated from Kadolkele Mangrove Sediments, Sri Lanka

Polish Journal of Microbiology

Exploring untapped microbial potentials in previously uncharted environments has become crucial in discovering novel secondary metabolites and enzymes for biotechnological applications. Among prokaryotes, actinomycetes are well recognized for producing a vast range of secondary metabolites and extracellular enzymes. In the present study, we have used surface sediments from ‘Kadolkele’ mangrove ecosystem located in the Negombo lagoon area, Sri Lanka, to isolate actinomycetes with bioactive potentials. A total of six actinomycetes were isolated on modified-starch casein agar and characterized. The isolates were evaluated for their antibacterial activity against four selected bacterial strains and to produce extracellular enzymes: cellulase, amylase, protease, and lipase. Three out of the six isolates exhibited antibacterial activity against Staphylococcus aureus, Escherichia coli, and Bacillus cereus, but not against Listeria monocytogenes. Five strains could produce extracellular cel...

Actinomycetes of Howz Soltan Lake and their metabolite diversity in Iran

Saline environments are largely unexplored sources for actinomycetes with the potential to produce biologically active secondary metabolites. A total of 34 actinomycete strains from water, sediments and mostly rhizosphere (82%) were collected from different sites of Howz Soltan Lake in Iran. Based on phylogenetic analysis, the isolated strains belonged to the genera Streptomyces, Nocardia and Saccharomonospora. Among the isolated actinomycetes, several strains had valuable biotechnological applications such as growth inhibition of human tumor cells. The results of cytotoxic assay revealed strain act9 having the most potent extract (19.716 ± 5.72 µg/ml) against the MDA-MB-231 human breast cancer cell. Also 38% of the strains had an antimicrobial activity against some pathogenic and nonpathogenic microorganisms. The ethyl-acetate extract of act18 showed the most antibacterial effect against Staphylococcus aureus, MRSA, and was further analyzed by GC/MS. Ar-tumerone (26.41%) and Butyl ...

Isolation and Screening of Actinomycetes for Bioactive Compounds from the Marine Coast of South- Gujarat Region

Abstract-Actinomycetes are the most economically and biotechnologically valuable prokaryotes able to produce wide range of bioactive secondary metabolites. Around 23 000 bioactive secondary metabolites produced by microorganisms have been reported and over 10 000 of these compounds are produced by Actinomycetes, representing 45% of all bioactive microbial metabolites discovered. Studies have shown that Actinomycetes isolated from the marine environment are metabolically active and have adapted to life in the sea. As marine environmental conditions are extremely different from terrestrial ones and also most potential source for isolation of Actinomycetes ,marine soil is collected from less unscreened west- coast area of Arabian sea (Tithal) and Salt pan region of Charwada , Valsad district of South- Gujarat region. A Physical and Chemical pretreatment of collected marine soil samples resulted into good isolation of 17 species belonging to the Actinomycetes group. These isolates were screened for the production of bioactive compounds including enzymes such as amylase, gelatinase , caseinase, lipase and urease. & antibacterial compounds. However, of the 17 isolates obtained only four isolates namely ACT-2, ACT-8, ACT-10 and ACT-11 showed significant antibacterial activity against both tested gram-positive and gram-negative bacteria.

Isolation, Characterization and Screening of Marine Actinomycetes for Bioactive Compounds

Marine ecosystem is a wide source for industrially important microorganism. Among the marine microorganisms, actinomycetes are a group of bacteria that are widely distributed. They have characteristics in common to both bacteria and fungi and yet they possess sufficient distinctive features to classify them into a separate category. The present study reports bioprospecting of marine actinomycetes. Our findings suggest potential of these isolated actinomycetes as industrially and biotechnologically important enzymes.

Diversity and antibacterial activity of actinomycetes from wetland soil

The South Pacific Journal of Natural and Applied Sciences, 2010

Diversity of soil actinomycetes isolated from various regions of a wetland was analysed. The strains were assigned under 11 genera according to their morphological and biochemical characteristics. They are: Nocardia, Pseudonocardia, Streptomyces, Micromonospora, Rhodococcus, Actinosynnema, Nocardiodes, Kitasatospora, Gordona, Intrasporangium and Streptoalloteichus. Around 55% of the identified strains are Nocardioform actinomycetes. Screening for their antibacterial activities revealed that 96% of the isolated strains showed different degrees of inhibition potential against 12 test pathogenic bacteria (including various serotypes of Salmonella, Vibrio cholerae, Bacillus subtilis and Escherichia coli). Of these about 41% of strains showed antagonism towards Bacillus subtilis. The Nocardioform actinomycetes exhibited antibacterial activity against 9 out of 12 test organisms. The least antibacterial potential was exhibited by Gordona, Rhodococcus, Micromonospora and Kitasatospora. The ...

Screening of antibacterial producing actinomycetes from sediments of the caspian sea

International journal of molecular and cellular medicine, 2013

Actinomycetes are interesting as a main producer of secondary metabolites and industrial antibiotics from marine environments. A total of 44 strains of actinomycetes were isolated from Caspian Sea sediments at a depth of 5-10 m. Preliminary screening was done using cross-streak method against 2 gram-positive and 4 gram-negative pathogen bacteria. The most potent strains MN2, MN3, MN38, MN39, MN40, MN41, and MN44 were used to extract the antibacterial substances. The antibacterial activities were performed using Kirby-Bauer disk diffusion method. Potent actinomycetes were screened for hydrolytic exoenzymatic activities (amylase and protease). All of the 24 isolates were active against at least to one of the test organisms. The MN38 strain showed activity against Staphylococcus aureus (20.0±0.5mm), Bacillus subtilis (27.0±0.2 mm), and Escherichia coli (20.0±0.3 mm). The MN39 strain was also active against E. coli (23.0±0.4mm), B. subtilis (23.0±0.2mm), Klebsiella pneumonia (24±0.1mm),...