Effect of microbial elicitors on sclerotia biomass and carotenoid yield in surface cultures of Penicillium sp.PT95 / 生物工程学报

Six kinds of elicitors were prepared respectively from Neurospora crassa, Monascus purpureus, Sporobolomyces roseus, Rhodotorula rubra, Nocardia sp. N89 and Actinoplanes sp. A05. When Penicillium sp. PT95 was incubated in Czapek's agar plates containing appropriate amounts of elicitors, both its sclerotia biomass and carotenoid content accumulated in sclerotia were enhanced significantly (P < 0.01). Among tested elicitors, the elicitors from the fungi N. crassa, M. purpureus, S.-roseus and R. rubra were more effective than those from the actinomycetes Nocardia sp. N89 and Actinoplanes sp. A05; the elicitor from M. purpureus gave the highest carotenoid yield of 599 micrograms/plate, 2.76 times higher than that of control. Every one of elicitors except that from M. purpureus could increase significantly the proportion of beta-carotene in total carotenoids (P < 0.01).

SELECTION OF HIGH-YIELD CAROTENOID PRODUCING STRAIN BY LASER MUTAGENESIS OF PROTOPLAST OF PENICILLIUM SP. PT95 / 微生物学通报

A mutant strain L05 was screened from its parent strain Penicillium sp. PT95 by laser irradiation of protoplast. When LOS strain was incubated in Czapek' s agar plates for 20 d, both the sclerotia biomass and carotenoid content accumulated in sclerotia increased significantly compared with that of PT95 strain, and the increase rate reached respectively 98.6% and 28.3% . The carotenoid yield of L05 strain reached 381ug/plate, which was 2.54 times higher than that of PT95. The character of both sclerotia and carotenoid high productivity remained stable after three times of subculture. No sectored colony appeared during subculture.

STUDIES ON HARMFUL MICROBES IN RECIRCULATING WATER SYSTEM OF HEATING PIPELINE IN TAIYUAN / 微生物学通报

The microbial counts, type, as well as relationship between microbial counts and the temperature of water in reticulating water system of heating pipeline in Taiyuan were studied, which the main biofouling harmful microbes included slimeforming heterotrophic bacteria, sulfate reducing bacteria, iron bacteria and fungi, respectively. The results showed that the harmful microbes in water system were lower than that of control guideline during heating period, whereas the microbes were higher than that of control guideline, which would result in biofouling of water tube during non- heating period.