Rhizopus arrhizus

Other species such as Rhizopus arrhizus and Rhizopus stolonifer also produce some sulphone by oxidation of a sulphoxide, albeit in low yields (less than 10%)163. 

ATCC 9245), Cunninghamella sp. (NRRL 5695), and Rhizopus arrhizus (ATCC 11145) produced the 6-glucopyranose conjugate [59]. The structures of the related starting and transformed molecules are shown in Fig. 8. 

Schemes Microbial transformation of the 5,ll-dimethyl-5ff-indolo[2,3-lt]quinoline to its 9-hydroxy derivative in the presence of Rhizopus arrhizus [60]...

Peczyfiska-Czoch W et al. (1996) Microbial transformation of azacarbazoles X re-gioselective hydroxylation of 5,ll-dimethyl-5ff-indolo[2,3-l)]quinoline, a novel DNA topoisomerase 11 inhibitor, hy Rhizopus arrhizus. Biotechnol Lett 18(2) 123-128... 

Fumaric acid, a metabolite of many fungi, lichens moss and some plants, and mainly used as the diacid component in alkyd resins, is produced commercially to some extent by fermentation of glucose in Rhizopus arrhizus yet productivity improvements appear essential for the product to be an option for replacing its petrochemical production by catalytic isomerization of maleic acid. 

Rhizopus sp., Thamnidium elegans) 4-0-sulfate conjugation Rhizopus arrhizus) [131]... 

Byrne GS, Ward OP, Effect of nutrition on pellet formation by Rhizopus arrhizus, Biotechnol Bioeng 33 912—914, 1989. 

In every case the information provided has been obtained by collating public domain sources of information, but unfortunately very often little data is available, particularly on commercial aspects, even for products that have proved to be big successes. Thus microbial biotransformations for steroid modification, particularly stereoselective hydroxylations, such as the use of Rhizopus arrhizus to convert progesterone into antiinflammatory and other dmgs via 11- -hydroxyprogestrone, have proved to be very successful. However, comparatively little useful information exists from public domain sources, despite (or perhaps because) a market of hundreds of millions /a exists for such microbially transformed steroids (cortisone, aldosterone, prednisolone and prednisone etc.) produced by microbial hydroxylation and dehydrogenation reactions coupled with complimentary chemical steps. 

Several hydroxylation biotransformations have been conunercialised, such as steroid hydroxylation, e.g. the 11-bf-hydroxylation of progesterone by Rhizopus arrhizus, 6-... 

Kinetic optical resolution of racemic alcohols and carboxylic acids by enzymatic acyl transfer reactions has received enormous attention in recent years56. The enzymes generally employed are commercially available lipases and esterases, preferentially porcine liver esterase (PLE) or porcine pancreatic lipase (PPL). Lipases from microorganisms, such as Candida cylindracea, Rhizopus arrhizus or Chromobacterium viscosum, are also fairly common. A list of suitable enzymes is found in reference 57. Standard procedures are described in reference 58. Some examples of the resolution of racemic alcohols are given39. 

Lactic acid Rhizopus arrhizus WEBL 0501 (Zhang et al., 2007)... 

Huang L.P., Jin, B., Lant, (2005a). Direct fermentation of potato starch wastewater to lactic acid by Rhizopus oryzae and Rhizopus arrhizus. Biopro. Biosyst. Eng. 27. 229-238. 

Jin, B., Huang, L. R, Lant, R. (2003). Rhizopus arrhizus - a producer for simultaneous saccharification and fermentation of starch waste materials to L(+)-lactic acid. Biotechnol. Lett., 25, 1983-1987. 

Zhang, Z. Y, Jin, B., Kelly, J. M. (2007). Production of lactic acid and byproducts from waste potato starch by Rhizopus arrhizus role of nitrogen sources. World J. Microbiol. BiotechnoL, 23,229-236. 

The biotechnological production of flavour compounds is particularly focused on esters and lactones. Lipase from Mucor miehei is the most widely studied fungal lipase [30-35]. Esters of acids from acetic acid to hexanoic acid and alcohols from methanol to hexanol, geraniol and citronellol have been synthesised using lipases from Mucor miehei, Aspergillus sp., Candida rugosa, Rhizopus arrhizus and Trichosporum fermentans [32-37]. 

Figu re 1.4 Normalized reaction rate as function of water activity for the esterification of dodecanol with decanoic acid catalyzed by Rhizopus arrhizus lipase at three different concentrations 20mM (O), 200mM ( ) and 800mM ( ) of each substrate. Data obtained from Ref. [26]. 

For the screening, 25 microbial cultures, obtained from the University of Mississippi Department of Pharmacognosy culture collection, were used. Microbial bioconversion studies of sarcophine (45) showed that it can be metabolized by several fungi species. Preparative-scale fermentation with Absidia glauca American-type culture collection (ATCC) 22752, Rhizopus arrhizus ATCC 11145, and R. stolonifer ATCC 24795 resulted in the isolation... 

In response to the success of microbially mediated cleanup of metal-contaminated waters, some commercial bioremediation products such as BIOCLAIM, AlgaSORB, and BIO-FIX are available. More detailed descriptions are provided by Brierley (1990). BIOCLAIM and BIO-FIX use immobilized bacterial preparations while AlgaSORB utilizes a nonviable algae matrix for metal removal. In addition to these products, there are several proposed proprietary processes including the use of immobilized Rhizopus arrhizus biomass for uranium recovery (Tsezos, McCready Bell, 1989). A froth flotation method for enhanced contact between biomass and contaminated water has been proposed by Smith, Yang Wharton (1988). 

CATALYSIS WITH IMMOBILIZED ENZYMES HYDROLYSIS AND ESTERIFICATION BY RHIZOPUS ARRHIZUS... 

The dedd cells of the mycelium of Rhizopus arrhizus constitute d naturally immobilized lipdse very active in organic solvents. This immobilized enzyme was used for hydrolysis and synthesis of ester bonds triglycerides hydrolysis, and interesterification, esters and glycerides synthesis. More recently, the catalytic system has been applied in drug synthesis to the resolution of racemic esters with a good enantioselectivity. 

In the case of Rhizopus arrhizus. primary alcohols have a good reactivity when they are not too much sterically hindered, but secondary alcohols are less reactive and tertiary... 

Rhizopus arrhizus (ATCC 24563) is a filamentous fungus, known to be producer of an exocellular lipase. According to the culture medium and especially to the carbon and nitrogen sources the lipolytic activity can remain bound to the cells. 

Operational stability of Rhizopus arrhizus mycelium on continuous hydrolysis of triglycerides... 

Rhizopus arrhizus dead mycelium was found to be very active in organic solvents as a naturally immobilized lipase. Triglycerides hydrolysis and interesterification, esters and glycerides synthesis, natural flavour esters preparation and racemic mixtures resolution in pharmaceutical drugs synthesis are among the successfully designed processes, each of one with a specific reactional medium. 

G, Bell, J.A. Blain, J.D.E. Patterson, C.E.L. Shaw and R. Todd, Ester and glyceride synthesis by Rhizopus arrhizus mycelia. Ferns Microbiol. Lett., 3, 1978,223-225. 

Fumaric acid Rhizopus arrhizus, Rhizopus nigricans Plastics and food industries... 

Mucor plumbeus Rhizopus arrhizus various fungal strains... 

---