The Application of Heating Effect in Breeding of Microorganism / 微生物学通报

Advances in mechanism and application of the heating effect in breeding of microorganism are reviewed in this paper. Heat produces mutagenesis effect and screening effect. Heating mutagenesis effect is occurred through the substitution of G-C base pair induced by heat, and heating screening effect produces higher forward mutation rate induced by other mutagens.

Isolation and Purification of Antibiotic from the Fermentation Broth of Micromonospora carbonacea JXNU-1 and Its Physical-chemical Properties / 微生物学通报

Based on the strain of Micromonospora carbonacea JXNU-1 with board-spectrum antimicrobial activity, the technology for the isolation and purification of antibiotic from the fermentation broth of the Micromonospora carbonacea, and its physical-chemical properties were studied. The results showed that, the antibiotic was stable under the condition of high temperature and alkali, but not in acid solution. After the pretreatment of centrifugation and filtration to remove the cells and lipids, the antibiotic was absorbed to negative exchange resin, and the impurity was excluded when 2 mol/L NaCl was used as primary eluent. The antibiotic could be eluted with 20% alcohol as eluent, and the eluting speed of the antibiotic was greatly accelerated as 2 mol/L NaCl was added into 20% alcohol as final eluent. Aqueous solution of the antibiotic was yielded from the alcohol-salt eluant by decompression concentration to wipe off alcohol and by dialysis to exclude salt. One active component was detected in antibiotic solution by paper chromatography, and theHPLC purity was over 99%. As the antibiotic shows positive color-forming reaction to Molish reagents, Benedict’s reagents and Diohenvlamine reagents, combined with the characteristics of absorption spectra, it is deduced that the antibiotic belongs to nucleoside antibiotics.

Isolation and Identification of a Strain of Micromonosporawith Broad-spectrum Antimicrobial Activity / 微生物学通报

A rare strain of actinomycetes, with broad-spectrum antimicrobial activity, was isolated from the soil samples from the farmland in the area of Yaohu lake in Nanchang. The information about the taxonomic identification, such as the morphology, physiological properties, cell components and 16S rRNA gene se-quences, suggested that the rare strain of actinomycetes was identified as Micromonospora carbonacea.