RESUMO
Chitinase production by a terrestrial Streptomyces sp. ANU 6277 was studied under sub-merged fermentation. Chitinase production started after 24 h of incubation and reached maximum levels after 60 h of cultivation. A high level of chitinase activity was observed in the culture medium with pH 6 at 35ºC. Culture medium amended with 1 percent chitin was found to be suitable for maximum production of chitinase. An optimum concentration of colloidal chitin for chitinase production was determined. Studies on the influence of additional carbon and nitrogen sources on chitinase production revealed that starch and yeast extract served as good carbon and nitrogen sources to enhance chitinase yield.Chitinase was purified from crude enzyme extract by single step gel filtration by Sephadex G-100. Purified chitinase of the strain exhibited a distinct protein band near 45 kDa by means of SDS-PAGE.
Assuntos
Meios de Cultura , Biossíntese de Proteínas , Quitinases/análise , Quitinases/biossíntese , Streptomyces/enzimologia , Streptomyces/isolamento & purificação , Ativação Enzimática , Métodos , MétodosRESUMO
Chitinase production by a terrestrial Streptomyces sp. ANU 6277 was studied under sub-merged fermentation. Chitinase production started after 24 h of incubation and reached maximum levels after 60 h of cultivation. A high level of chitinase activity was observed in the culture medium with pH 6 at 35°C. Culture medium amended with 1% chitin was found to be suitable for maximum production of chitinase. An optimum concentration of colloidal chitin for chitinase production was determined. Studies on the influence of additional carbon and nitrogen sources on chitinase production revealed that starch and yeast extract served as good carbon and nitrogen sources to enhance chitinase yield. Chitinase was purified from crude enzyme extract by single step gel filtration by Sephadex G-100. Purified chitinase of the strain exhibited a distinct protein band near 45 kDa by means of SDS-PAGE.
RESUMO
An attempt was made to study the bioactive compounds from a terrestrial Streptomyces sp. ANU 6277 isolated from laterite soil. Four active fractions were recovered from the solvent extracts obtained from the culture broth of five day-old strain. Three bioactive compounds were purified and identified as 3-phenylpropionic acid, anthracene-9,10-quinone and 8-hydroxyquinoline. The components of the partially purified fourth active fraction were analyzed by gas chromatography-mass spectrometry and identified as benzyl alcohol, phenylethyl alcohol and 2H-1, 4-benzoxazin-3 (4H)-one. Four active fractions were screened for antimicrobial activity against Gram-positive and Gram-negative bacteria, and fungi including phytopathogenic, toxigenic and dermatophytic genera. Among these metabolites, 8-hydroxyquinoline exhibited strong antibacterial and antifungal activity as compared to 3-phenylpropionic acid and anthracene-9,10-quinone.
Assuntos
Antraquinonas/química , Oxiquinolina/química , Fenilpropionatos/química , Streptomyces/química , Antraquinonas/isolamento & purificação , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Oxiquinolina/isolamento & purificação , Fenilpropionatos/isolamento & purificação , Microbiologia do Solo , Streptomyces/isolamento & purificaçãoRESUMO
The strain ANU 6277 was isolated from laterite soil and identified as Streptomyces sp. closely related to Streptomyces albidoflavus cluster by 16S rRNA analysis. The cultural, morphological and physiological characters of the strain were recorded. The strain exhibited resistance to chloramphenicol, penicillin and streptomycin. It had the ability to produce enzymes such as amylase and chitinase. A bioactive compound was isolated from the strain at stationary phase of culture and identified as 3-phenylpropionic acid (3-PPA) by FT-IR, EI-MS, 1H NMR and 13C NMR spectral studies. It exhibited antimicrobial activity against different bacteria like Bacillus cereus, B. subtilis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, P. flourescens, Staphylococcus aureus and some fungi including Aspergillus flavus, A. niger, Candida albicans, Fusarium oxysporum, F. udum and Penicillium citrinum. The antifungal activity of 3-PPA of the strain was evaluated in in vivo and in vitro conditions against Fusarium udum causing wilt disease in pigeon pea. The compound 3-PPA is an effective antifungal agent when compared to tricyclozole (fungicide) to control wilt caused by F. udum, but it exhibited less antifungal activity than carbendazim.
