Isolation and characterization of cellulase-producing aeorobic bacterial £ora in the intestine of omnivorous tilapia (Oreochromis mossambica) and phytophagous Chinese grass carp (Ctenopharyngodon idella) have been carried out using selective carboxymethylcellulose-agar (CMC-agar) medium. The cellulolytic activity was measured both qualitatively and quantitatively. It was found that the ability of di¡erent strains in degrading cellulose varies within a wide range. Among the strains isolated from the gut of each test ¢sh, TM1 and CI3 isolated from O. mossambica and C. idella, respectively exhibited maximum cellulolytic activity (67.02 and 35.8 U mL À1 respectively). Pure cultures of these strains were selected for morphological, physiological and biochemical characterization. On the basis of these tests, the isolated strains were identi¢ed as Bacillus circulans (TM1) and Bacillus megaterium (CI3). Both the strains are rod-shaped, motile and show better temperature (15^42 1C) and pH (5^11) tolerance. The selected strains were further quantitatively assayed for amylase and protease activities. Maximum amylase and protease activities were exhibited by TM1 and CI3 respectively. Information generated from the present study might contribute towards better-feed formulation incorporating plant ingredients.

It was found that the bioactive compound, dibutyl phthalate, was produced by a new soil isolate Streptomyces albidoflavus 321.2. Once this active compound was recovered by ethyl acetate from the fermented broth, being possible to isolate 13.4 mg/l, it was purified by paper, silica gel column, thin layer and gas chromatography. Structure was determined by analysing UV, IR and GC-MS spectra. During analysis, such active compound showed strong activity against gram-positive and gram-negative bacteria, as well as unicellular and filamentous fungi. The antimicrobial activity of the compound was reversed by the amino acid proline. No acute toxicity was observed.

Partial characterization of a cubic Bacillus phage. Can. J. Microbiol. 24: 986--993. Phage Bam35 is an icosahedron of about 63 nm in diameter. It has a double capsid with spikes at the vertices, and a tail which seems to appear upon nucleic acid ejection. The phage contains DNA and, probably, lipids which seem to be located in the inner coat. The phage is Bacillus-specific, UV- and lipase-resistant, and sensitive to heat, chloroform, and ether. The latent period is 50 min and the burst size is 39. Page Bam35 belongs to a new virus group which includes a phage of B. anthracis and four phages of gram-negative bacteria harboring drug-resistance plasmids.

Purpose The study aims to search for potent cellulase producer from the gut of Gryllotalpa africana as well as to characterize and determine the effect of the purified enzyme on the cellulosic waste materials. Methods The potent cellulolytic strain was identified through morphological, biochemical, physiological, and molecular characterization like 16S rRNA and fatty acid methyl ester profile. After the optimization of cellulase production, the enzyme was purified through DEAE-Sepharose column chromatographic separation. The molecular weight of the purified enzyme was determined by SDS-PAGE analysis. The purified enzyme was characterized in terms of its activity and its effect on cotton fiber, and sawdust was also studied. Result The selected potent strain GAC 16.2 was identified as Acinetobacter junii that was capable to produce enhanced cellulase (112.38 ± 0.87 U/ml) at standardized optimum fermentation conditions. The molecular weight of the purified enzyme was determined as 55 kDa. The utmost activity of the purified enzyme was detected pH 7.0, temperature 50 °C, and in the presence of metal ions like Mg2+ and Mn2+. The substantive degradation of cotton fiber and sawdust has been observed in a reasonably short period. Conclusion Purified cellulase from the selected isolate A. junii GAC16.2, a gut isolate of G. africana, has the potentiality to degrade cellulosic substances. This property can make the isolate a potent candidature for industrial application, as well as an effective biotechnological tool for environmental monitoring through cellulosic waste management.

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Antibiotic resistance has led to the search for more effective antimicrobial agents among plant materials that can serve as source and template for the synthesis of new antimicrobial drugs. The current study aims to analyses the oil, extracted from the leaves of Crotalaria pallida for its physicochemical and antimicrobial properties. Leaf oil was extracted by petroleum ether (40-60 • C) and its fatty acid constituents were isolated as a mixture after saponification. Mixture of fatty acid was purified by TLC and characterized by IR, GC and GC-MS analysis by converting them into their FAME. MIC of the oil against the Gram positive and Gram negative bacteria was determined by agar diffusion method. Nineteen fatty acids were identified by gas-liquid chromatography followed by GC-MS. It was found that unsaturated fatty acids were present in greater amounts than saturated fatty acids. Most predominating unsaturated and saturated fatty acids were linolenic acid (34.06 ± 0.23%) and palmitic acid (24.47 ± 0.22%) respectively. The acid value (19.63 ± 0.22) and saponification value (109.08 ± 2.87) were also estimated to evaluate the quality of the oil. The oil showed good antimicrobial activities against Gram-positive bacteria, Bacillus subtilis as well as Gram-negative bacteria, Escherichia coli and Acinetobacter junii.

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