摘要:

A relatively new type of molecular markers are di-, tri- or tetranucleotide repeats, also called microsatellites which can be amplified by the polymerase chain reaction. Microsatellites as a marker system are especially useful for self-pollinating crops due to their high level of polymorphism based on varying numbers of repeats in different lines/accessions at one locus. The ability to detect a much higher level of polymorphism with microsatellites in eukaryotes than with RFLP markers are demonstrated in the work. For applications of microsatellites, the relatively low level of amplification of DNA fragments from homeologous loci is more than compensated by the higher level of polymorphism when compared to RFLP. The chromosomal and chromosome arm assignment of such markers is a valuable prerequisite for their application in breeding as a second generation markers in marker assisted selection.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818855

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

The gaseous plant hormone ethylene affects somatic embryogenesis in various ways depending on the species or explants used. Inclusion of ethylene action inhibitors, namely silver ions in culture media increased somatic embryogenesis in some species. Large scale (bioreactor) yields of somatic embryos were less than these from flask cultures. Ethylene depletion from the bioreactors due to aeration is considered as a possible reason for the decrease in somatic embryogenesis. Ethylene is discussed as a physiological marker related to embryogenic potential. Wound ethylene evolved after transformation experiments might have some inhibitory role on transformation but results are contradictory. Ethylene plays different roles in long term storage (low and ambient temperatures) of embryogenic cultures. Use of transgenic technology in ethylene biosynthesis reduction is discussed as a way to understanding ethylene role in somatic embryogenesis.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818856

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Protein changes in roots of winter wheat were investigated on the 3rdand 8thday after a rapid temperature shift-down from 25° C to 4° C. Proteins were labelled during the last 12 hours before harvesting using L-[14C] aminoacid mixture and were analyzed by scintillation counting, one- and two dimensional gel electrophoresis and fluorography. The total uptake of the label was about 10 times lower in the treated plants of both series. A prominent band with molecular mass of 43±3 kDa and an isoelectric point between pH 6.8–7.4 was observed on the 3rdday after treatment. The obtained results suggest a transient expression of the 43 kDa protein(s) and may be an indication for its involvement in the development of the cold stress response.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818857

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Crude cellulolytic enzyme preparation was isolated from the culture supernatant of Tricho- derma reesei M7by ammonium sulfate precipitation (80% saturation). An endo-1,4-β-D-glucanase (EC 3.2.1.4) from the multicomponent cellulolytic complex of Trichoderma reesei M7was purified for further investigations and biotechnological applications. The endoglucanase active fraction F-II-III-II was isolated in a molecular homogeneous form by a simple three-step chromatographic procedure on Sephadex G-75, DEAE Sephadex A-50 and PBE 94 columns. The homogeneity of the purified enzyme was assessed by gel filtration chromatography on Superose 12 column, SDS-PAGE and analytical isoelectric focusing. The optimum pH and temperature values were estimated to be 5.0 and 60°C (for the crude cellulolytic preparation) and 6.0 and 60°C (for the purified endoglucanase), respectively. The homogeneous protein corresponded to a relative molecular mass and pi value of 51 kDa and 5.82, respectively. The predominant products of the enzymatic hydrolysis of cellulosic substrates by crude enzyme preparation were identified as glucose, xylose and cellobiose. The biotechnological potential of the purified endoglucanase preparation will be investigated further.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818858

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

We have established the interdependence between the air flow rate, lactose assimilation and cell protein synthesis during batch cultivation of Kluyveromyces marxianus var. lactis MC5 strain in a nutrient medium containing cheese whey ultrafiltrate with varying lactose concentrations (40.0 g/L, 78.0 g/L, 124.0 g/L), (NH4)2HPO4- 6.0 g/L, yeast extract - 5.0 g/L, pH=5.0, at 29 °C in bioreactors ABR 02M (2.0 L), Bulgaria, and MBR AG (15.0 L), Switzerland. Maximum lactose conversion has been achieved by maintaining dynamic control on the air flow rate throughout the process. The outcome of the fermentation process has been determined by the efficiency factor Yx/s, which is 0.79 for the ABR 02M system, and 0.9 for MBR AG.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818859

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Fungal strain Humicola lutea 120–5 was immobilized in poly[hydroxyethylmethacrylate (HEMA)-ethyleneglycoldimethacrylate (EDMA)] gel. Immobilized cells were cultivated in column and airlift bioreactors with different height to diameter (H/D) ratio for acid proteinases production during batch and repeated-batch processes. Influence of aeration rate in the bioreactors on enzyme production was studied. Optimal conditions for maximum proteinases production were obtained during repeated batch cultivation of immobilized cells (IC) in an airlift bioreactor with H/D=4 and aeration rate of 6 wm.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818860

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Extracellular β-galactosidase from Aspergillus orizae H 26–10–7 has been purified by procedures including ultrafiltration, precipitation with ethyl alcohol and ion-exchange chromatography on DEAE-cellulose as a result of which specific activity of 93 units/mg protein, purification of 18.2-fold and yield of 39.6% have been obtained. Some enzyme characteristics have been determined: molecular weight - 102 kD; Km- 1,61 mM for o-nitrophenyl-β-D-galactopyranoside and 69.36 mM for lactose; temperature and pH-optimum of activity - 60°C and pH 4.75 for both substrates. The enzyme preserves 80% of its activity at pH 5 and temperature of 55°C in the course of 6 hours. On the basis of these properties β-galactosidase from A. oryzae has been recommended for lactose hydrolysis in whey.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818861

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

228 patients clinically diagnosed as superficial fungus infections (115 scaly ringworm of the scalp, 13 black dot, 9 favus, 9 kerion, 48 tinea corporis, 18 tinea cruris, 9 onychomycosis, 5 tinea pedis and 2 tinea barbae) were examined mycologically. 30 cases with T. Violaceum infection were examined immunologically. T. violaceum was the most common dermatophyte (45.6%), T. rubrum (5.3%), T. schoenleinii (4.8), T. mentagrophytes (3.5%) and E. floccosum (1.8%). In 30 cases with T. violaceum infection there was a significant decrease in Erosette particularly in chronic cases. The helper/suppressor ratio of T-lymphocytes (detected by monoclonal antibodies) in patients was 0.99:1 while in control cases it was 1.6:1. There was a marked increase in IgM and IgG but not in IgA levels. The C3cfraction of the complement showed a slight decrease and C4 a marked decrease in comparison with the control.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818862

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

In this study, the actions of Pseudomonas phospholipase C (EC 3.1.4.3) were investigated with respect to their toxicity and effect on blood coagulation. Phospholipase C (P. fluoresces) is an effective inhibiter of thromboplastin and probably uses this enzyme as a therapeutic or prophylactic agent in thrombosis and other forms of intravascular coagulation. Phospholipase C (P. fluorescens) purified by us caused significant loss in the procoagulant activity of thromboplastin. Gram-negative phospholipase C with subtoxic or weakly toxic doses inhibited blood coagulation in rabbits for up to 60–180 min after i.v. infusion of the enzyme.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818863

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

The causative rabbit haemorrhagic disease viral antigen (RHDV) was purified by sucrose and caesium chloride density gradients. The viral fractions were characterised by a haemagglutination test and a dodecylsulfat polyacrilamide gel electrophoresis (SDS-PAGE). Different migration patterns were observed after sucrose and caesium chloride (CsCl) density gradient centrifugations.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818864

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor