Hirsutellone F, a dimer of antitubercular alkaloids from the seed fungus Trichoderma species BCC 7579.

[structure: see text] Hirsutellone F (7), a novel alkaloid dimer, was isolated together with known monomers, hirsutellones A (1), B (2), and C (3), from the seed fungus Trichoderma sp. BCC 7579. The structure of 7 was elucidated by spectroscopic analysis. Studies on biomimetic chemistry, using the dimer 7, suggested that compound 8 (17,1'-dehydrohirsutellone B) should be the precursor for all hirsutellones.

Isolation and in vitro cultivation of the insect pathogenic fungus Cordyceps unilateralis.

Cordyceps unilateralis, a fastidious insect pathogenic fungus, was found to produce red naphthoqinones, which possess anti-malarial activity. A method for the isolation and in vitro cultivation of this fungus was, therefore, developed in this study. Ascospores from ant cadavers were used as starting materials, and their secondary spores were allowed to germinate first on PDA for 2 d. Secondary spores were then transferred to Grace's Insect Cell Medium + 2 mM glutamine and 10% fetal bovine serum, incubated for 7 d, after which the formation of mycelia was stimulated by transfer to potato dextrose broth. As a result, the growth of C. unilateralis from the steps of secondary spore germination, blastospore formation and mycelial growth was successfully completed for the first time.

Production of red pigments by the insect pathogenic fungus Cordyceps unilateralis BCC 1869.

Production of red pigments (naphthoquinones) by the insect pathogenic fungus Cordyceps unilateralis BCC 1869 was investigated in this study. Cultivation conditions, including temperature, intitial pH of medium, and aeration, were optimised to improve the yield of total naphthoquinones in shake-flask culture of C. unilateralis. The highest yield of total naphthoquinones (3 g L-1) was obtained from a 28-day culture grown in potato dextrose broth with an initial pH of 7.0, at 28 degrees C with shaking-induced aeration at 200 rpm. An extraction process for isolation of the targeted naphthoquinone, 3,5,8-trihydroxy-6-methoxy-2-(5-oxohexa-1,3-dienyl)-1,4-naphthoquinone (3,5,8-TMON), from a culture of C. unilateralis, was also developed. The yield of 3,5,8-TMON obtained was about 1.2 g L-1 or 40% of total naphthoquinones. The stability of 3,5,8-TMON was very high, even upon exposure to strong sunlight (70,000 lx), high temperature up to 200 degrees C, and acid and alkali solutions at concentrations of 0.1 M.

Isolation and characterization of novel strains of Pseudomonas aeruginosa and Serratia marcescens possessing high efficiency to degrade gasoline, kerosene, diesel oil, and lubricating oil.

Bacteria possessing high capacity to degrade gasoline, kerosene, diesel oil, and lubricating oil were screened from several areas of Hokkaido, Japan. Among isolates, two strains, WatG and HokM, which were identified as new strains of Pseudomonas aeruginosa and Serratia marcescens species, respectively, showed relatively high capacity and wide spectrum to degrade the hydrocarbons in gasoline, kerosene, diesel, and lubricating oil. About 90-95% of excess amount of total diesel oil and kerosene added to mineral salts media as a sole carbon source could be degraded by WatG within 2 and 3 weeks, respectively. The same amount of lubricating oil was 60% degraded within 2 weeks. Strain HokM was more capable than WatG in degrading aromatic compounds in gasoline. This strain could also degrade kerosene, diesel, and lubricating oil with a capacity of 50-60%. Thus, these two isolates have potential to be useful for bioremediation of sites highly contaminated with petroleum hydrocarbons.