A lipase of the fungus Rhizopus microsporus,UzLT-1 — A glycoprotein

Summary The molecule of the lipase of the fungusRhizopus microsporus UzLT-1 consists of protein and nonprotein moieties. The nonprotein moiety is formed by carbohydrates.The carbohydrate moiety is readily separated from the protein moiety, which suggested a noncovalent bond of the sugars with the protein fraction.Department of Microbiology of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 265–267, March–April, 1977.     

The lipase of the fungus Rhizopus microsporus,UZLT-1

1. An active lipase enzyme has been isolated from the culture liquid of the fungusRhizopus microsporus, UZLT-1, by precipitation with isopropanol, gel filtration on Sephadexes G-75 and G-150, and chromatography on CM-cellulose. Some properties of the purified enzyme (optimum pH, heat stability, influence of various ions) have been studied.     

The lipase of the fungus Rhizopus microsporus, UZLT-1

Summary 1. An active lipase enzyme has been isolated from the culture liquid of the fungusRhizopus microsporus, UZLT-1, by precipitation with isopropanol, gel filtration on Sephadexes G-75 and G-150, and chromatography on CM-cellulose. Some properties of the purified enzyme (optimum pH, heat stability, influence of various ions) have been studied.Department of Microbiology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 636–639, September–October, 1976.     

Antimitotic rhizoxin derivatives from a cultured bacterial endosymbiont of the rice pathogenic fungus Rhizopus microsporus

The potent antimitotic polyketide macrolide rhizoxin, the causal agent of rice seedling blight, is not produced by the fungus Rhizopus microsporus, as has been believed for over two decades, but by endosymbiotic bacteria that reside within the fungal mycelium. Here we report the successful isolation and large-scale fermentation of the bacterial endosymbiont ("Burkholderia rhizoxina") in pure culture, which resulted in a significantly elevated (10x higher) production of antimitotics. In addition to several known rhizoxin derivatives, numerous novel natural and semisynthetic variants were isolated, and their structures were fully elucidated. Cell-based assays as well as tubulin binding experiments revealed that methylated seco-rhizoxin derivatives are 1000-10000 times more active than rhizoxin and thus rank among the most potent antiproliferative agents known to date. Furthermore, more stable didesepoxy rhizoxin analogues were obtained by efficiently inhibiting a putative P-450 monooxygenase involved in macrolide tailoring.     

Lipoprotein lipase activity of the fungusRhizopus microsporus

A method is described for the isolation and purification of lipoprotein lipase activity from the culture liquid of the fungusRhizopus microsporus. Some properties of the homogeneous enzyme have been studied: molecular weight 43,000, pI 3.7.     

Purification and Characterization of a Chymosin from Rhizopus microsporus var. rhizopodiformis

Purification and characterization of a chymosin from Rhizopus microsporus var. rhizopodiformis were investigated in the present study. A newly isolated R. microsporus var. rhizopodiformis F518 produced a high level of milk-clotting activity (1,001 SU/mL). A chymosin from the fungus was purified 3.66-fold with a recovery yield of 33.2 %. The enzyme appeared as a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a molecular mass of 37.0 kDa. It was optimally active at 60 °C and was stable up to 40 °C. The purified enzyme was an acid protease with an optimum pH of 5.2 and retained 80 % of residual activity within pH 2.0–8.0. The inhibition of 96 and 100 % by pepstatin A at 0.01 and 0.02 mM, respectively, revealed that the enzyme is an aspartic protease. Thus, high milk-clotting activity of the chymosin with good stability will strengthen the potential use of the chymosin as a substitute for calf rennet in cheese manufacturing.     

Characterization of a β-glucanase produced by Rhizopus microsporus var. microsporus, and its potential for application in the brewing industry

Background  

In the barley malting process, partial hydrolysis of β-glucans begins with seed germination. However, the endogenous 1,3-1,4-β-glucanases are heat inactivated, and the remaining high molecular weight β-glucans may cause severe problems such as increased brewer mash viscosity and turbidity. Increased viscosity impairs pumping and filtration, resulting in lower efficiency, reduced yields of extracts, and lower filtration rates, as well as the appearance of gelatinous precipitates in the finished beer. Therefore, the use of exogenous β-glucanases to reduce the β-glucans already present in the malt barley is highly desirable.     

Production and application of amylases of Rhizopus oryzae and Rhizopus microsporus var. oligosporus from industrial waste in acquisition of glucose

Amylases from Rhizopus oryzae and Rhizopus microsporus var. oligosporus were obtained using agro-industrial wastes as substrates in submerged batch cultures. The enzymatic complex was partially characterised for use in the production of glucose syrup. Type II wheat flour proved better than cassava bagasse as sole carbon source for amylase production. The optimum fermentation condition for both microorganisms was 96 hours at 30°C and the amylase thus produced was used for starch hydrolysis. The product of the enzymatic hydrolysis indicated that the enzyme obtained was glucoamylase, only glucose as final product was attained for both microorganisms. R. oligosporus was of greater interest than R. oryzae for amylase production, taking into account enzyme activity, cultivation time, thermal stability and pH range. Glucose syrup was produced using concentrated enzyme and 100 g L^?1 starch in a 4 hours reaction at 50°C. The bioprocess studied can contribute to fungus glucoamylase production and application.     

Isolation of hispidin from a walnut-tree fungus and its antioxidant activity

An -styrylpyrone derivative — hispidin — has been isolated from a walnut-tree fungus. Its antioxidant activity has been studied inin vitro andin vivo experiments on animals of different ages.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 34–37, January–February, 1996. Original article submitted November 3, 1995.     

Preparation of immobilized lipases of the fungusRhizopus microsporus UzLT-1 and their properties

Summary It has been shown that adsorption on AE-cellulose partially protected by the palmitoyl residue is an effective method of immobilizing the lipases ofRhizopus microsporus. The kinetics of the lipases are characterized by substrate inhibition. Immobilization considerably increases the heat stability of the lipases.Institute of Microbiology, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute of Applied Enzymology, Vil'nyus. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 624–629, September–October, 1978.     

Preparation of adsorbed lipase and its properties

Summary 1. Under certain conditions, lipase immobilized on cellulose-based ion-exchange materials can be obtained. The best adsorbent is DEAE-cellulose.2. The optimum conditions for the immobilization of lipase on DEAE-cellulose are pH 8.0, time of contact with the support 15–20 min, temperature 10° C.3. The immobilized lipase (DEAE-cellulose-lipase) retains the main functional properties of the native enzyme.Department of Microbiology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 267–271, March–April, 1977.