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1.
A newly isolated strain, MU-2, which produces very high -fructofuranosidase activity, was identified asAspergillus japonicus. For enzyme production by the strain, sucrose at 20% (w/v) was the best carbon source and yeast extract at 1.5 to 3% (w/v) the best nitrogen source. Total enzymatic activity and cell growth were at maximum after 48 h, at 1.57×104 U/flask and 0.81 g dry cells/flask, respectively. The optimum pH value of the enzymatic reaction was between 5.0 and 5.5 and the optimum temperature 60 to 65°C. The enzyme produced 1-kestose (O--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) and nystose (O--d-fructofuranosyl-(21)--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) from sucrose by fructosyl-transferring activity. The strain was found to be very useful for industrial production of -fructofuranosidase.  相似文献   

2.
Maximum production of extracellular -amylase activity inHalobacterium halobium was at 40°C in a medium containing 25% (w/v) NaCl, 1% (w/v) soluble starch and 1% (w/v) peptone, in presence of 0.1mm ZnSO4 after 5 days in shaking cultures. The amylase had optimal activity at pH 6.5 in the presence of 1 to 3% (w/v) NaCl at 53°C.S. Patel, N. Jain and D. Madamwar are with the Post Graduate Department of Biosciences, Sadar Patel University, Vallabh Vidyanagar-388120, India.  相似文献   

3.
Summary Cladosporium resinae QM 7998 produced high activities of extracellular and constitutive -glucosidase when grown on a variety of sugars or cellulose. Starch and ribose induced enzyme synthesis several fold.Cladosporium resinae could utilize agricultural waste residues for growth and -glucosidase production. The initial pH of the medium had a marked effect on enzyme prowduction and optimum pH was between 4.0 and 5.0 depending on the assay method. Mixed culturing ofC. resinae with yeasts, viz.Saccharomyces cerevisiae andCandida utilis, increased the -glucosidase production while that with other fungi decreased the enzyme yield. The- glucosidase preparation fromC. resinae significantly increased the saccharification of rice and wheat straw (untreated or delignified) withTrichoderma reesei QM 9414 cellulase preparation.
Résumé Cladosporium resinae QM 7998 produit des concentrations élevées de -glucosidase tant extracellulaire que constitutive lorsqu'elle croît sur une variété de sucres ou sur la cellulose. On a trouvé que l'amidon et le ribose augmentent de plusieurs fois la quantité d'enzyme synthétisée.Cladosporium resinae peut utiliser des résidus agricoles pour sa croissance et pour la production de -glucosidase. Le pH initial du milieu exerce un effet marqué sur la production d'enzyme et le pH optimum est compris entre 4.0 et 5.0 selon les conditions de l'essai. La croissance mixte deCladosporium resinae avec diverses levures, notammentSaccharomyces cerevisiae etCandida utilis, augmente la production de -glucosidase tandis que celle avec d'autres moisissures diminue le rendement en enzyme. La -glucosidase deCladosporium resinae augmente de manière significative la saccharification des pailles de riz et de froment (non-traitées ou délignifiées) traités par la cellulase deTrichoderma reesei QM 9414.
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4.
The production of -glucosidase by Aspergillus terreus was investigated in liquid shake cultures. Enzyme production was maximum on the 7th day of growth (2.18 U/ml) with the initial pH of the medium in the range of 4.0–5.5. Cellulose (Sigmacell Type 100) at 1.0% (wt/vol) gave maximum -glucosidase activity among the various soluble and insoluble carbon sources tested. Potassium nitrate was a suitable nitrogen source for enzyme production. Triton X-100 at 0.15% (vol/vol) increased the enzyme levels of A. terreus. The test fungal strain showed an ability to ferment glucose to ethanol.  相似文献   

5.
An isolate from a Hong Kong soil sample which produced -amylase was identified as a thermotolerant strain ofBacillus circulans with a growth range of 35 to 55C. The -amylase was stable at 45°C for 30 min but lost half of its activity after 30 min at 50°C. Maximum specific activity of -amylase (36.2 units/mg protein) in the culture broth was detected after 36 h of cultivation at 45°C in a medium containing soluble starch, beef extract, coconut water and inorganic salts.  相似文献   

6.
Summary The production of -carotene by the biomass ofRhodotorula strain var.glutinis, during the stationary phase of growth and in non-proliferating conditions was assayed. When the cells were transferred to distilled water, the fraction of -carotene produced increased from 130 to 630 g per gram of dried cells.  相似文献   

7.
Pectolytic enzymes play an important role in food processing industries and alcoholic beverage industries. These enzymes degrade pectin and reduce the viscosity of the solution so that it can be handled easily. These enzymes are mainly synthesized by plants and microorganisms. Aspergillus niger is used for industrial production of pectolytic enzymes. This fungus produces polygalacturonase, polymethylgalacturonase and pectinlyase. This review mainly concerns with the production of pectolytic enzymes using different carbon sources. It also deals with the effect of operating parameters such as temperature, aeration rate, agitation and type of fermentation on the production of these enzymes.  相似文献   

8.
Wild strains of Rhodotorula glutinis and R. rubra were investigated concerning their carotenoid production, proportion of beta-carotene and cell mass yield. R. glutinis NCIM 3353 produced 2.2 mg carotenoid/l in 72 h; and the amount of beta-carotene was 14% (w/w) of the total carotenoid content (17 microg/g cell dry weight). It was subjected to mutagenesis using UV radiation for strain improvement. Out of 2,051 isolates screened, the yellow coloured mutant 32 produced 120-fold more beta-carotene (2,048 microg/g cell dry weight) than the parent culture in 36 h, which was 82% (w/w) of the total carotenoid content. Mutant 32 was grown on different carbon and nitrogen sources. The best yield of beta-carotene (33+/-3 mg/l) was obtained when glucose and yeast extract were supplied as carbon and nitrogen sources, respectively. Divalent cation salts further increased the total carotenoid content (66+/-2 mg/l) with beta-carotene as the major component (55+/-2%, w/w).  相似文献   

9.
Growth at 25°C and pH 5.50 favour the production of-glucosidase. De-fatted oilseed flour and Tween 80 enhanced the production of-glucosidase, Lactose, gentibiose, gentibiose-acetate, laminarabiose and xylobiose induced-glucosidase activity. Precipitation of the culture filtrate with (NH4)2SO4 resulted in 26-fold purification with 67% recovery. The optimum pH and temperature for activity were 5.0 to 5.4 and 55°C respectively. The enzyme was stable at 40°C with half-life at 12 h at 50°C. TheK m andV max for the hydrolysis ofp-nitrophenyl--d-glucoside at 40°C H 5.0 are 0.28mm and 0.60 U/mg protein, respectively.  相似文献   

10.
Bacterial Flocculation and Production of Poly-β-Hydroxybutyrate   总被引:1,自引:1,他引:0       下载免费PDF全文
Experiments with a number of bacteria isolated from activated sludge have shown that flocculation is independent of the presence of poly-beta-hydroxybutyrate (PHB) in the cells. Several strains gave flocculent growth without any PHB detectable. Other strains, producing PHB in varying amounts, utilized this compound as an endogenous substrate, and after its disappearance the floc structure remained unchanged. The PHB content of various samples of activated sludge was found to be negligible.  相似文献   

11.
A 4.5 litre photobioreactor was developed and used to produce 13 C-labelled b-carotene by feeding 13 CO2 to growing ells of the marine alga Dunaliella salina. Three runs were carried out using different feeding regimes producing b-carotene containing 40, 56 and 76 Atom% 13 C. Approximately 145 mg b-carotene was recovered from each run. Incorporation of 13 C into b-carotene ranged from 1.4 to 2.8%. The labelled b-carotene produced would allow multiple tracer experiments for the study of human carotenoid metabolism. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   

12.
Summary Preliminary data for production of -malic acid from calcium acetate byPaecilomyces varioti is presented. Shake flask cultures with free cells and with cells immobilised in calcium alginate beads gave comparable results, acid concentrations of approximately 8 g/l being produced after 5 days from a medium containing 4% w/w of calcium acetate. A packed bed reactor, operated as an extended batch with product recycle, produced maximum acid concentrations of 32.6 g/l, equivalent to 73% of the maximum theoretical yield, after 3 days. Evidence obtained indicated that spores were more active than mycelia in the production of malic acid.  相似文献   

13.
Summary The reaction conditions for the enzymatic production of l-cystathionine were optimized, using the two kinds of cystathionine -synthase, types I and II, which are abundant in cell-free extracts of Erwinia carotovora (IFO 3830) and Bacillus sphaericus (IFO 3526), respectively. Under the optimal conditions, 178 and 184 mM l-cystathionine (40 and 41 g per liter of the reaction mixture) were synthesized with conversion ratios of 89 and 92% with the Erwinia and Bacillus enzymes, respectively.Recipient of a JSPS Fellowship for Japanese Junior Scientists  相似文献   

14.
Cultured malt broth of Fusarium poae has a strong fruity odor mainly due to lactones: γ penta-, γ hexa-, γ hepta-, γ octa-, γ nona-, γ deca-, γ undeca-, γ dodeca-, cis-6-dodecen-4-olide and δ decalactones. They were identified after gas chromatography and mass spectrometry by comparison of retention data and odors with those of authentic samples. cis-6-Dodecen-4-olide is the most abundant lactone (2 mg/liter) and is responsible for the predominant canned peach-like aroma.  相似文献   

15.
β-Poly-L-malate (PMA) is synthesized by plasmodia of Physarum polycephalum during growth and secreted into the culture medium. There it is degraded to L-malate after growth has ceased. Its concentration is highest in cell nuclei, where it probably performs a plasmodium-specific function.  相似文献   

16.
Summary A recombinantEscherichia coli strain harboring the PHB biosynthesis genes fromAlcaligenes eutrophus was used to produce poly--hydroxybutyrate (PHB) by pH-stat fedbatch culture. Initial glucose concentration for optimal growth was found to be 20g/L from a series of flask cultures. A final PHB concentration of 88.8 g/L could be obtained after 42 hrs of cultivation.  相似文献   

17.
Method for production of deuterated -carotene for the bioavailability studies of vitamin A has been developed using Spirulina platensis in culture. Suspension cultures of Spirulina in heavy water (99.4% D2O) medium produced maximum biomass and -carotene in 28 to 30 days. Of the total carotenoids, lutein constituted 30 to 35% while -carotene was about 24%. MS showed that 60 to 65% H atoms in -carotene were deuterated. 100% replacement of H atom with deuterium was achieved by preventing exchange with atmospheric moisture. The medium could be used in several cycles for metabolic labelling of carotenoids whereby the cost of production is reduced.  相似文献   

18.
The presence of multiple types of β-galactosidases in a commercial enzyme preparation from Bacillus circulans ATCC 31382 and differences in their transgalactosylation activity were investigated. Four β-galactosidases, β-Gal-A, β-Gal-B, β-Gal-C, and β-Gal-D, which were immunologically homologous, were isolated and characterized. The N-terminal amino acid sequences of all of the enzymes were identical and biochemical characteristics were similar, except for galactooligosaccharide production. β-Gal-B, β-Gal-C, and β-Gal-D produced mainly tri- and tetra saccharides at maximum yields of 20–30 and 9–12%, while β-Gal-A produced trisaccharide with 7% with 5% lactose as substrate. The Lineweaver-Burk plots for all of the enzymes, except for β-Gal-A, showed biphasic behavior. β-Gal-A was truncated to yield multiple β-galactosidases by treatment with protease isolated from the culture broth of B. circulans. Treatment of β-Gal-A with trypsin yielded an active 91-kDa protein composed of 21-kDa and 70-kDa proteins with characteristics similar to those for β-Gal-D.  相似文献   

19.
20.
Summary The transfer of cytoplasms of various Triticum and Aegilops species to a hexaploid triticale (Rosner) has been attempted using 30 alloplasmic lines and a euplasmic line of common wheat as cytoplasmic donors. The average rate of F1 hybrid production (seed setting rateXgermination rate) following an ordinary method of crossing is only 0.09%, whereas this rate is increased to 3.1% by use of embryo culture. The first backcross of the F1 plants with triticale pollen is again difficult, the hybrid production being 0.9%. Further backcrosses proceed smoothly in most cases. As a consequence, the following seven cytoplasms have been transferred to triticale: T. dicoccum, T. aestivum, Ae. squarrosa, Ae. cylindrica, Ae. juvenalis, Ae. ovata and Ae. speltoides. None of these alien cytoplasms causes more meiotic instability than does the triticale's own cytoplasm. Two cytoplasms of T. dicoccum and T. aestivum, both belonging to the B plasma type, have no effect upon any of triticale's characters. Two D type cytoplasms of Ae. squarrosa and Ae. cylindrica cause about 50% reduction of male fertility but exert no other remarkable effects. This fact suggests a partial functional compensation of the effect of a 1D chromosome upon interacting with D cytoplasm by a rye chromosome substituting for it in triticale. A D2 cytoplasm of Ae. juvenalis causes earlier heading and complete male sterility, accompanied by some reduction of growth vigor. An M0 type cytoplasm of Ae. ovata and an S type cytoplasm of Ae. speltoides cause a great heading delay, complete male sterility, and severe reduction of vigor. From the viewpoint of triticale breeding, none of these cytoplasms appears superior to the triticale's own cytoplasm. However, from the viewpoint of genetics, the hexaploid triticale is an effective tester for differentiating the B, S, and D plasma types.Contribution No. 466 from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan  相似文献   

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