Fungus Rhizopus

Catharanthus roseus) [9]. Maytansine (3) is an ansa macrolyde isolated from Maytenus ovatus [10], and rhizoxin (4) is an antitumor macrolide isolated from the fungus Rhizopus chinensis [11]. Another very important tubulin interactive anti-cancer agent is colchicine (6), and this compound binds to a different binding site of tubulin but is also used in anti-cancer therapy. 

Drechsel H, Metzger J, Freund S, Jung G, Boelaert JR, Winkelmann G (1991) Rhizoferrin -a Novel Siderophore from the Fungus Rhizopus microsporus var. rhizopodiformis. Biol Metals 4 238... 

A practical technique for lactic acid fermentation of potato pulp has been developed (Oda et al., 2002). They screened 38 strains of the fungus Rhizopus oryzae either lactic acid or fumaric acid and ethanol were formed, and the ratio differed among the strains tested. Saito et al. (2003) studied the effect of pectinolytic enzymes on lactic acid fermentation of potato pulp by different Rhizopus oryzae NRRL 395 and NBRC 4707 strains. When a commercial preparation of pectinase was added to potato pulp inoculated with fungal spores and incubated for 7 days, both strains effectively produced larger amounts of lactic acid and ethanol. These data indicated that the fermentation of potato pulp depends on the degradation of pectic substances in NRRL 395 and NBRC 4707. Saito et al. (2006) evaluated the potato pulp obtained in different seasons and found pectin content to be dependent on the dates of extraction. 

Oda, Y, Saito, K., Yamauchi, H., Mori, M. (2002). Lactic acid fermentation of potato pulp by Ihe fungus Rhizopus oryzae. Curr. Microbiol., 45, 1. ... 

Biobased polymers from renewable materials have received increased attention recently. Lactate is a building block for bio-based polymers. In the United States, production of lactic acid is greater than 50,000 metric tons/yr and projected to increase exponentially to replace petroleum-based polymers. Domestic lactate is currently manufactured from corn starch using the filamentous fungus Rhizopus oryzae and selected species of lactic acid bacteria. The produced lactic acid can then be polymerized into polylactic acid (PLA) which has many applications (Hatti-Kaul et al., 2007). However, so far, no facility is built to use biomass derived sugars for lactic acid production. More research needs to be done to develop microbes using biomass derived sugars for lactate production. 

Partida-Martinez LP, Hertweck C. A gene cluster encoding rhi-zoxin biosynthesis in Burkholderia rhizoxina , the bacterial en-dosymbiont of the fungus Rhizopus microsporus. ChemBioChem. 2007 8 41-45. 

Figure 10 Rhizoxin, a polyketide from bacterial endosymbionts of the pathogenic fungus Rhizopus microsporus.

Scherlach K, Partida-Martinez LP, Dahse HM, Hertweck C. Antimitotic rhizoxin derivatives from a cultured bacterial endosym-biont of the rice pathogenic fungus Rhizopus microsporus. J. Am Chem. Soc. 2006 128 11529-11536. 

The lipase from the fungus Rhizopus niveus accepts a variety of protected dipeptide heptyl esters (33) and hydrolyzes the ester function in high yields at pH 7 and 37 °C without damaging the urethane protecting groups and the peptide bonds. The N- and C-terminal amino acid can vary over a wide range, but, with increasing steric bulkiness and hydrophobicity of the amino acids, especially the C-terminal one, the reaction rates decrease. 

Lactic acid is a major end product from fermentation of a carbohydrate by lactic acid bacteria (Tormo and Izco, 2004). However, lactic acid can be produced commercially by either chemical synthesis or fermentation. The chemical synthesis results in a racemic mixture of the two isomers whereas during fermentation an optically pure form of lactic acid is produced. However, this may depend on the microorganisms, fermentation substrates, and fermentation conditions. Lactic acid can be produced from renewable materials by various species of the fungus Rhizopus. This has many advantages as opposed to bacterial production because of amylolytic characteristics, low nutrient requirements, and the fungal biomass, which is a valuable fermentation by-product (Zhan, Jin, and Kelly, 2007). 

Rhizoxin D is a 16-membered macrolide isolated from the fungus Rhizopus chinensis Rh-2 and it showed remarkable antimitotic properties. Rhizoxin D was synthesized from four subunits and the final step involved the Stille coupling of the oxazole fragment with an iodolactone [17]. 

The Hep-esters proved to be chemically stable during the removal of the N-terminal Z-, Boc- and the Aloe-group from the dipeptides 21. The selective removal of the Hep-esters was achieved by a lipase-catalyzed hydrolysis. From several enzymes investigated, a biocatalyst isolated from the fungus Rhizopus niveus was superior to the others with respect to substrate tolerance and reaction rate. The enzyme accepts a variety of Boc-, Z- and Aloc-protected dipeptide Hep-esters as substrates and hydrolyzes the ester functions in high yields at pH 7 and 37 °C... 

Early experiments concerned the enzymatic hydrogenation of fumaric acid to succinic acid, catalyzed by either yeast 24,55 or enzyme extracts from yeast cells56. Much later, strains of Escherichia coli, Aerobacter aerogenes and Aerobacter cloacae were shown to have the same ability 57,58. An interesting mixed culture fermentation has been developed, where the fungus Rhizopus chinensis produces fumaric acid from glucose and a selected E. coli converts the previously formed fumaric acid into succinic acid58. 

In 1950 Peterson and Murray observed the first microbial 11-hydroxylation, namely, the llo-hydroxylation of progesterone with the fungus, Rhizopus arrhizus. The culture was isolated from the air when an agar plate was exposed on a window sill (P-721). Shortly thereafter, Rhizopus nigricans was found to llo-hydroxylate progesterone in high yield. The first publication of this work in extensowzs in a U. S. 

The process was simplified in 1952 when Petersen and Murray described a direct hydroxylation at C-11 catalysed by the fungus Rhizopus arrhizus. Although this oxidation produced the 1 la-hydroxysteroid, inversion of the configuration of the hydroxyl group is relatively straightforward. The process can reasonably be credited with reviving interest in the application... 

Liao W, Liu Y, Frear C, Chen S. Co-production of frimaric acid and chitin from a nitrogen-rich lignoceUulosic material - dairy manure - using a pelletized filamentous fungus Rhizopus oryzae ATCC 20344. BioresourTechnol 2008 99 5859-66. 

Liao W, LiuY, Frear C, Chen S. A new approach of peUet formation of a filamentous fungus- Rhizopus oryzae. Bioresour Technol 2007 98 3415-23. 

Tempeh, a popular fermented food eaten as a meat substitute, is made in a solid-state fermentation bioreactor by cultivating the fungus Rhizopus oUgosporus on cooked soybeans. The fungus binds the soybeans into compact cakes that are fried and packaged to sell to the public. 

Matthews et al. have determined the structure of the extracellular proteolytic enzyme, thermolysin, to 2.3 A resolution. This enzyme of molecular weight 37 500 contains one zinc and four calcium ions, and is interesting because of its imusual heat stability. The active site contains a zinc atom tetrahedrally co-ordinated to His-142, His-146, Glu-166, and a water molecule, and in this way resembles carboxypeptidase A. The precise details of the co-ordination of the calcium ions are not reported. However, it is of interest that two have a centre-to-centre distance of 3.8 A and are located within an interior region of the protein, surrounded by carbonyl and carboxylate groups. Loss of calcium does not hinder proteolysis at room temperature, but the enzyme is no longer heat stable. Preliminary X-ray data are also reported for the acidic protease from the fungus Rhizopus chinensis. ... 

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