Journal of Microbiology and Biotechnology

1-5

Authors: P Ellaiah

During our continuous search for antibiotic producing actinomycetes, a variant of Streptomyces species was isolated from soils of Andhra Pradesh in India. The morphological, cultural, physiological and biochemical characters were studied, compared to known species and identified as a new variant of Streptomyces noursei and designated as Streptomyces noursei var saccharicus. The antibiotic activity of the strain was tested against both Gram-positive and Gram-negative bacteria as well as fungi and yeasts. INTRODUCTION Since the isolation of actinomycin in 1940 and streptomycin in 1944 by Waksman, the actinomycetes have received tremendous attention of the scientists. Soils, composts and fodders are common sources of actinomycetes. Waksman [1] recognized a few natural substrates as ideal sources for the isolation of actinomycetes and other streptomycetes. The nature of a Streptomyces colony is an important property in characterizing a culture. Krainsky [2] used the structure, size, shape and texture of the colony as one of the major diagnostic criteria. According to Pridham and Lyons [3] and International Subcommittee [4], the best way to handle streptomycete classification nomenclature and identification is through application of the genus-species-subspecies concept. The majority of antibiotic producing actinomycetes found in these species led to growing economic importance of these organisms which resulted in the isolation and description of numerous new species. It is reported that the only genus Streptomyces, the member of Actinomycetales accounts for approximately 93% producing secondary metabolites [5]. The present communication deals with the isolation and characterization of an antibiotic producer from soils.

1-6

Authors: Mustafa Baloch

Nowadays, natural treatment of bacterial diseases using substances which are herbal is of utmost importance. In the present study effects of three antibacterial medicinal plants in south of Iran against the separated Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli from Clinical samples and standard strains was investigated. Hydro-alcoholic extracts of Ziziphora tenuior, Origanum Vulgare and Mentha longifolia were prepared after being dried at shade. In the following the antibacterial activity of the extracts against separated Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli from clinical samples of the Shiraz hospitals and standard samples using disk agar diffusion method was investigated and the drug resistance in the studied samples was conducted using the standard Kirby-Bauer method. The growth of the all studied Staphylococcus aureus and Escherichia coli was stopped by hydro-alcoholic extracts of Mentha longifolia, Ziziphora tenuior and Origanum Vulgare but Pseudomonas aeruginosa showed growth zone of inhibition only against Origanum Vulgare. From statistical viewpoint Origanum Vulgare had also the most antimicrobial effect against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in the all studied samples (P<0.05). Extracts of Mentha longifolia, Origanum Vulgare and Ziziphora tenuior have a potent antibacterial effect against the gram-positive and gram-negative. But on the nosocomial pathogen, Pseudomonas aeruginosa, only Origanum Vulgare has growth inhibitory effect.

1-4

Authors: Barge VU

Chromatography, although primarily a separation technique, is most employed in chemical analysis in biotech plant is SEC which is very powerful technique for protein purification, polymer characterization etc. As the principal advantage of SEC is its gentle non-interaction with the sample, enabling high preservation of biological activity, so SEC has lot of importance in biotech industry. In this review the basic theory, principle & applications of SEC in biotech industry are included.