Erythritol production by Moniliella megachiliensis using nonrefined glycerol waste as carbon source.

UNLABELLED: The number of naphtha plants is being reduced due to a worldwide shift in energy sources. Consequently, a shortage of chemical materials heavily dependent on naphtha-oil, especially C4 compounds such as butene and butane-diol, is an urgent issue in chemical manufacturing. Erythritol is a rare C4 compound produced by fermentation processes using glucose as the carbon source. Since erythritol is considerably more expensive than hydrocarbons derived from naphtha-oil, a reduction in its cost is critical. We found that Moniliella megachiliensis, a highly osmotolerant yeast strain, can utilize nonrefined glycerol waste derived from palm oil or beef tallow and convert it to erythritol. Cell growth on glycerol was almost the same as on glucose, and the cells could grow in up to 300 mg ml(-1) glycerol. When 200 mg ml(-1) nonrefined glycerol was supplied, the yield of erythritol from the glycerol was approx. 60%, which is slightly higher than that obtained using glucose. The cost of glycerol waste is considerably lower than that of glucose. Thus, the conversion of glycerol waste into valuable erythritol, proposed here, is attractive and promising from the viewpoint of ensuring a supply of C4 hydrocarbons and utilizing a waste natural resource. SIGNIFICANCE AND IMPACT OF THE STUDY: A shortage of C4 hydrocarbon depending much on naptha-oil has become urgent problem due to rapid reduction of naphtha plants together with global energy revolution. Erythritol, obtained by fermentation, is a rare C4 polyol that can be converted to C4 hydrocarbons. Erythritol is considerably expensive than hydrocarbons, a reduction in cost is critical issue. To meet this, we proposed to utilize low-cost glycerol waste from bio-diesel fuel as a carbon source. Moniliella megachiliensis successfully converted glycerol waste to erythritol. This proposal is promising to obtain C4 hydrocarbon substitute, and concomitantly to dispose a large amount of glycerol waste discharged.

Efficient selection of genomic clones from a female chicken bacterial artificial chromosome library by four-dimensional polymerase chain reactions.

A bacterial artificial chromosome (BAC) library consisting of 49,152 genomic clones was constructed from partially HindIII-digested female chicken embryo genomic DNA using the pBAC-Lac vector and maintained in 512 96-well plates. The mean insert size was approximately 150 kb, and the total library was estimated to contain about 3.2 times coverage of the diploid genome. In order to screen this library by the PCR, 296 BAC clone DNA samples were prepared: one sample each from 8 superpools (64 plates per superpool) and 36 samples of four-dimensionally (4-D) mixed clones from each superpool. A BAC clone of interest was selected by two-step PCR. First, 8 DNA samples representing superpools were subjected to PCR with a set of primers to amplify a part of the genomic sequence of interest. Second, 36 4-D DNA samples from the superpool that contained BAC clone(s) of interest were subjected to PCR with the same set of primers. The second step identified a plate and a well containing the BAC clone of interest. Selection of target BAC clone(s) from the whole library with the above procedure can be achieved within 1 to 4 d without using a radioactive probe. This procedure was applied successfully in the selection of BAC clones for Wpkci, chPKCI/HINT, ZOV3, and 17beta-HSD genes.

Inhibitory effects of triterpenoids and sterols on human immunodeficiency virus-1 reverse transcriptase.

Fifty-five triterpenoids consisting of 19 tetracyclic, 32 pentacyclic, and 4 incompletely cyclized triterpenoids, and 2 sterols, mostly isolated from various plant and fungal materials, were examined for their inhibitory effects on a purified human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. Twenty triterpenoids and one sterol showed inhibitory effects with 50% inhibition concentration (IC50) values less than 5.0 microM. Among these cycloartenol ferulate (IC50 = 2.2 microM), 24-methylenecycloartanol ferulate (1.9 microM), lupenone (2.1 microM), betulin diacetate (1.4 microM), and karounidiol 29-benzoate (2.2 microM) inhibited most effectively. Some of the triterpenoids and sterols may be potential new lead compounds to find still more potent HIV-1 reverse transcriptase inhibitors.

PP-R, 7-(2-hydroxyethyl)-monascorubramine, a red pigment produced in the mycelia of Penicillium sp. AZ.

A red pigment was extracted and purified from the mycelia of a newly isolated strain of Penicillium sp., Penicillium sp. AZ, which produced a soluble violet pigment PP-V, 12-carboxyl-monascorubramine, in the culture fluid. The red pigment, PP-R, was determined by FAB-MS and 1H and 13C NMR to be a novel compound, 7-(2-hydroxyethyl)-monascorubramine.

Production and structural analysis of PP-V, a homologue of monascorubramine, produced by a new isolate of Penicillium sp.

A fungal strain newly isolated from soil has been found to produce a violet water-soluble pigment (PP-V) in high quantity when cultured in a medium consisting of soluble starch and citrate buffer. Glucose repressed the production of this pigment. PP-V has the molecular formula C23H25NO6 revealed by HR-FAB mass spectroscopy and has been shown to be composed of an isoquinoline skeleton, a n-octanoyl group, and a 2-propenoic acid group by NMR. In conclusion, PP-V is a novel compound, 3-(9a-methyl-3-octanoyl-2,9-dioxo-2,7,9,9a-tetrahydro-furo[3,2-g]isoquinolin-6-yl)acrylic acid; a homologue of monascorubramine in which the 1-propenyl group is converted to a 2-propenoic acid group.

Biosynthesis of PP-V, a monascorubramine homologue, by Penicillium sp. AZ.

The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by 13C-labeling studies. The [1-13C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-13C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin.