Rhizopus species

Lipases can be classified into groups that reflect their specificity. The common lipases include non-specific lipases that do not discriminate between the position or the type of the fatty acid on the triacylglycerol (e.g., lipase from Candida cylindracea) and 1,3-specific lipases that act only at the sn-l and sn-3 positions of the triacylglycerol (e.g., lipases from Aspergillus niger and Rhizopus species). In addition, some lipases are specific for a specific fatty acid type (e.g., lipase from Geotrichum candidum). 

L-Menthol (+D-men-thyl acetate) D, L-Menthyl acetate Penicillium species, Rhizopus species, Trichoderma species Refreshing, cooling, peppermint... 

The three-dimensional structures of human pancreatic lipase and Rhizo-mucormiehei lipase have recently been elucidated [141-143]. Among the lipases purified from different sources—mammals, bacteria, fungi, and plants—the fungal lipases from Rhizopus species exhibit a remarkably broad pH zone of stability and activity, extending from pH 3 to 9. 

The stability of pectate and pectin depolymerizing enzymes produced by Mucor puriformis, Rhizopus sexualis, R. stolonifer, Botrytis cinerea, Aureobasidium pullulans, Trichosporon pullulans, and Cryptococcus albidus var. albidus in sulphite liquor has been studied in relation to the breakdown of sulphited strawberries. Marked breakdown of fruit occurred only when pectolytic activity could be detected in the liquor for more than two weeks using a viscometric assay. Of the fungi tested, Rhizopus species produced enzymes that were the most stable in sulphite liquor. For each of the Mucor and Rhizopus species tested, the stability of poly-D-galacturonases in sulphite liquor was very similar for extracts of infected fruit and culture filtrates. It was suggested that sulphite labile (=acid labile) and sulphite stable (=acid stable) forms of the poly-D-galacturonases are present. 

Two other proteases have been commercialized by Sigma and used for such experiments. They both are extracts from fungi protease from. Rhizopus species (type XVIII), EC 3.4.23.6, optimum pH 3 and protease from Aspergillus saitoi (type XIII), EC 3.4.23.18, optimum pH 2.8. Several others were purified or overexpressed by groups developing the approach. 

Type XVIII Rhizopus species P, R, and H W, K, E, E, E Crude culture extract... 

Antifungal activity on most postharvest fimgi, e.g., Altemaria, Fusarium, and Rhizopus species. 

Fumaric acid can be produced by Rhizopus, Mucor, Cmninghamella, and Circinella species, among which, several Rhizopus species nigricans, arrhizus, oryzae, md formosa) are the best-producing strains, yielding fumaric acid under both aerobic and anaerobic conditions. 

Rhizopus species tend to grow on the walls and on the stirrer of the reactor, and sometimes, clumps are formed. As a result, the fermentation can suffer from oxygen limitation, especially when calcium fumarate is present. One way to minimize oxygen mass... 

Another way to improve morphology of Rhizopus species utilizes immobilization techniques for the possibility of a continuous operation mode for fumaric acid production and to reduce oxygen transfer problems. ... 

The properties of glucoamylase activities occurring in a number of strains of Klebsiella (Aerobacter) aerogenes and Rhizopus species have been investigated. 

A lytic activity that degrades the cell walls of a Rhizopus species has been found in culture filtrates of a Bacillus species. The lytic activity was separated (by ion-exchange chromatography) into two fractions one of the fractions was identified as a protease, whereas the other liberated material containing 2-amino-2-deoxyhexose from Rhizopus cell walls and was also active on glycolated chitosan. 

The structure of one of the carbohydrate moieties of an a-amylase from a Rhizopus species has been determined. Six o-mannosyl residues and a 2-acetamido-2-deoxy-D-gIucosyl residue were released on digestion of a glyco-peptide in turn with a-o-mannosidase and -D-2-acetamido-2-deoxyglucosidase. The structure (5) was proposed on the basis of the results of enzymic hydrolysis, methylation, partial acetolysis, and Smith degradation. 

A Bacillus species synthesizes two activities that degrade the cell walls of Rhizopus species one of them, a chitosanase, is active towards glycolchitosan and chitosan. The activity of the enzyme (mol. wt. 3.1 x 10, p7 8,30, pH optimum 5.6, temperature optimum 40 °C) was destroyed by sulphydryl reagents, but it was restored by either reduced glutathione or cysteine. The enzyme appears to act by an f>/ (7o-mechanism. 

Intracellular and extracellular pullulanases accelerated the hydrolysis of waxy corn starch by the glucoamylase of a Rhizopus species, but they are less active towards non-waxy corn starch. ... 

Hydroxylation of 21-carbon compounds at Cn has been achieved microbiologically and offers an attractive method, in combination with chemical synthesis, for the large-scale preparation of adrenocortical hormones. Progesterone, compound S, and desoxycorticosterone have been converted to their lla-hydroxylated analogs by a fungus of the Rhizopus species and by Aspergillus niger, whereas Streptomyces fradiae converts compound S to compound F. 

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