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J Kopecný

Publications and source records attributed to J Kopecný.

At least 19 recordsLinked to original sources
PubMed1998

Cellulolytic enzymes of rumen anaerobic fungi Orpinomyces joyonii and Caecomyces communis.

The rumen anaerobic fungi Orpinomyces joyonii A4 and Caecomyces communis JB1 were grown on microcrystalline cellulose (MC) and alfalfa hay. The cellular distribution of cellulases produced by these organisms was monitored. Fungal cultures were separated into extracellular, intracellular and cell wall fractions and assayed for endoglucanase (EG) and beta-glucosidase activity. In both fungal isolates, EG activity was the highest in the extracellular fraction regardless of the substrate used. The beta-glucosidase activity produced by O. joyonii was mainly found in the cell wall fraction. On the contrary, the same enzyme activity in C. communis predominated in the extracellular fraction. The polycentric isolate A4 more efficiently utilized both substrates, produced more short chain fatty acids (up to 31 mmol/l) and showed higher total levels of EG (2744 nmol glucose/h/ml) than the monocentric strain JB1. On the other hand, beta-glucosidase (9033 nmol glucose/h/ml) activity was the highest in cultures of C. communis grown on cellulose. In cultures of O. joyonii grown on MC, the production of yellow affinity substance (YAS) with similar properties compared with yellow substance from Clostridium thermocellum was observed. This compound increased the adsorption of fungal cellulases to MC the temperature and pH range tested.

Adsorption↗
PubMed1997

The effect of yellow affinity substance on cellulases of Ruminococcus flavefaciens.

Cellulolytic cultures of Ruminococcus flavefaciens produced a yellow affinity substance (YAS) with a strong affinity to microcrystalline cellulose (MC). YAS was bound to MC in the range of pH from 5 to 8 and at temperatures from 10 degrees C to 60 degrees C. The positive effect of YAS on adsorption of ruminococcal cellulases was demonstrated by comparing the adsorption behaviour of endoglucanases and cellobiohydrolases onto MC and YAS-treated MC. HPLC chromatography proved the presence of two yellow compounds with affinity to cellulose as well as to ruminococcal cellulases. Both YAS compounds were sensitive to oxidation. The observed YAS properties showed a close relation to YS of Clostridium thermocellum.

Adsorption↗
PubMed1996

The isolation and characterization of a rumen chitinolytic bacterium.

Chitinolytic bacteria were detected in faeces and digesta of wild and domesticated herbivores. The presence of chitinolytic bacteria in two cows was verified following enrichment culture of rumen fluid on colloidal chitin. In three other cows, direct counts on chitin agar showed that the numbers of these bacteria in the rumen fluid ranged from 5 x 10(4) to 2 x 10(8) ml-1. Most of these bacteria were Clostridium-like spore producers. The most typical strain, Clostridium sp. ChK5, was characterized further. This bacterium degraded colloidal chitin and produced mainly acetate, butyrate and lactate. Endochitinase and chitobiase were produced when chitin was the growth substrate. Endochitinase was also detected in cultures grown on N-acetylglucosamine and glucose. Optimal conditions for endochitinase activity were 37 degrees C and pH 4.5-6.1. The Michaelis constant (Km) for this enzyme was 19.3 mg ml-1. Strain ChK5 shows strong phenotypic similarity to Clostridium tertium.

Animals↗
PubMed1996

The effect of rumen chitinolytic bacteria on cellulolytic anaerobic fungi.

The polycentric anaerobic fungus Orpinomyces joyonii A4 was cultivated on microcrystalline cellulose alone and in association with the rumen chitinolytic bacterium Clostridium sp. strain ChK5, which shows strong phenotypic similarity to Clostridium tertium. The presence of strain ChK5 significantly depressed the solubilization of microcrystalline cellulose, the production of short-chain fatty acids (SCFA) and the release of endoglucanase by the fungus. Co-culture of the monocentric anaerobic fungus Neocallimastix frontalis strain RE1, Neocallimastix sp. strain G-1 and Caecomyces sp. strain SC2 with strain ChK5 also resulted in depressed fungal cellulolysis. Cell-free supernatant fluids from strain ChK5 inhibited the release of reducing sugars from carboxymethylcellulose by cell-free supernatant fluids from O. joyonii strain A4. Strain 007 of the cellulolytic anaerobe Ruminococcus flavefaciens was also shown to produce small amounts of soluble products upon incubation with colloidal chitin. Mixtures of culture supernates from this bacterium and from O. joyonii strain A4 showed cellulase activity that was less than that of the component cultures. It is suggested that the ability of some rumen bacteria to hydrolyse or transform chitin may be an important factor in the interactions between bacteria and fungi in the rumen.

Anaerobiosis↗
PubMed1996

Concentrations of polychlorinated biphenyls and chlorinated pesticides in human breast milk--a case study.

Concentrations of chlorinated pesticides (p,p'-DDE, lindane), hexachlorobenzene (HCB), sum of polychlorinated biphenyls (PCBs), and PCB congeners in breast milk during lactation and the distribution of the chlorinated compounds in fat tissue, blood serum and breast milk were pursued in five primi- or secundipara from the hinterland of a clinic of gynaecology and obstetrics in Brno in 1993. Capillary gas chromatography with ECD detection was used for the determination of the residues. The concentrations of HCB, lindane, p,p'-DDe, and sum of PCBs ranged from 42.5 to 238.4, from < 1.0 to 7.4 from 231.4 to 557.6, and from 661.3 to 2888.9 micrograms.kg-1 of milk fat, respectively. Seventeen PCB congeners were screened, of which 11 were identified in most of the milk samples (IUPAC numbers 28, 101, 118, 126, 128, 138, 153, 156, 170, 180, 194). Congeners 138, 153, 170, and 180 were the most abundant and their concentrations in microgram.kg-1 of milk fat ranged from 122.9 to 501.0 for 153, from 103.4 to 372.1 for 138, from 66.1 to 407.9 for 180, from 26.8 to 183.1 for 170, and from 10.0 to 41.7 for 118.

Adipose Tissue↗
PubMed1995

Pectinolytic enzymes of anaerobic fungi.

Pectinolytic enzymes of four rumen fungi have been described. Three fungal species were monocentric Neocallimastix spp. H15, JL3 and OC2, and one isolate was a polycentric strain of Orpinomyces joyonii, A4. They differed in degree of pectin degradation and utilization. Only the strain Neocallimastix sp. H15 and partially Orpinomyces joyonii A4 were able to utilize pectin to a higher extent. The most important pectinolytic activity in all these isolates represented pectin lyase (EC 4.2.2.10) and polygalacturonase (EC 3.2.1.15). Their specific activities were in the range of 100-900 and 10-450 micrograms galacturonic acid h-1 mg protein-1 for pectin lyase and polygalacturonase, respectively. Polygalacturonase, located mainly in the endocellular fraction, was inhibited by calcium ions and had the main pH optimum at pH 6.0. All strains produced pectate lyase (EC 4.2.2.2). None of the strains tested produced pectinesterase (EC 3.1.1.11).

Animals↗
PubMed1995

Interaction of the rumen fungus Orpinomyces joyonii with Megasphaera elsdenii and Eubacterium limosum.

The degradation and fermentation of microcrystalline cellulose were studied in monoculture of the polycentric anaerobic fungus Orpinomyces joyonii and in co-cultures with the rumen bacteria Megasphaera elsdenii and Eubacterium limosum. More than 25% of cellulose hydrolysis products (glucose and cellodextrins) were released by the fungus into the medium after 8 d of cultivation. These products were metabolized by bacteria in mixed cultures. In co-culture with the fungus M. elsdenii and E. limosum increased the extent of microcrystalline cellulose degradation by 10.12% and 7.96%, respectively. Biomass yield in co-cultures was increased by 89.9% and 59.4% for M. elsdenii and E. limosum. Y cellulose for fungus alone was 52.29 g dry matter mol-1 glucose. These values were 64.93 and 55.92 g mol-1 glucose unit in co-culture with M. elsdenii and E. limosum, respectively.

Anaerobiosis↗
PubMed1992

[DNA flow cytometry: perspective prognostic parameters in carcinoma of the uterine cervix].

We studied the relation between the 5-year disease free interval and the flow cytometric DNA content in a group of 55 patients treated by radiation for squamous cell carcinoma of the uterine cervix, stages Ib-IIIb (FIGO). The diploid DNA content was associated with a better prognosis, while prognostically unfavourable tumours tended to be aneuploid. The relation was statistically significant in the whole group (p = 0.016), in stage II disease (p = 0.003) and in the subgroup formed by the combination of stages I and II (p = 0.000). In stage III we did not prove the relation. Analysis of the survival function revealed also a better prognosis of diploid tumours (p = 0.041) in the whole group. The division into clearly diploid and non-diploid tumours seems to be more suitable for evaluation (p = 0.012). The difference between the prognostically favourable and unfavourable groups is expressed more clearly. We consider the flow cytometric DNA content a perspective prognostic parameter in squamous cell carcinoma of the uterine cervix. Its significance is apparent especially in patients treated by radiotherapy, because the size of the tumour cannot be assessed reliably in these cases.

Carcinoma, Squamous Cell↗
PubMed1989

Occurrence of conjugative amylolytic activity in rumen lactobacilli.

1,263 rumen strains of Lactobacilli were selected for the production of amylase and resistance to antibiotics. Out of 48 amylolytic Lactobacilli, in 17 strains, there was a cotransfer of the alpha amylase activity and resistance to tetracyclin with a transfer frequency of 10(-3) to 10(-7) ml-1 of the conjugative mixture. In strains No. 30, No. 36 and No. 49, plasmids with similar molecular weights as plasmids in corresponding transconjugants were detected. Similar protein pattern of the donors recipient of the L. lactis RN 1 and transconjugants obtained by PAGE proved the cotransfer of the amylase activity and antibiotic resistance.

Amylases↗
PubMed1989

[Intraperitoneal administration of high doses of cisplatin in advanced ovarian carcinoma].

42 patients with advanced ovarian carcinoma were treated with large doses of cis-DDP by the i.p. route. The toxic effects of platinum were reduced by the i.v. administration of thisulphate. Depending on age and the general condition of the patient, 200-270 mg cis-DDP were administered in one series. Ascites disappeared in 54.7% patients, partial remission of the tumour was achieved in 28.5%, complete histopathological remission confirmed by second look operation in 26.2% and in 21.4% the result was doubtful.

Adenocarcinoma↗
PubMed1989

[Granulosa cell tumor of the ovary; evaluation of therapeutic results].

In 1956-1985 in the Oncological Research Institute in Brno a total of 70 patients was treated on account of granulosa-cell tumours of the ovary. This accounts for 10% of all ovarian malignities treated in the Institute during this period. The initial treatment of all patients was surgery, i.e. abdominal hysterectomy with bilateral adnexectomy, performed in 54.5% of the patients, uni- or bilateral adnexectomy in 35.7%, supravaginal amputation of the uterus with adnexectomy in 7.1% and in 2.7% (two patients) exploratory laparotomy only. All patients had irradiation of the pelvic area, in recent years the area of external irradiation was extended with regard to the lymphographic finding. This examination has become an integral part of the pre-treatment routine examination of every single patient. Comprehensive treatment of the tumour comprised chemotherapy involving in a major number of patients an adjuvant chemotherapeutical regime of CVF (Cyclophosphamide, Vinblastin, Ftorouracil), later a MAFC regime (Methotrexate, Actinomycin D, Cyclohosphamide, Ftorouracil). In more advanced tumours or mixed tumours according to histopathological analysis, in recent years a chemotherapeutic regime of CAP is used (Cyclophosphamide, platinum, Adriblastina) or VAB (Vinblastin, Adriblastina, Bleomycin), or a combination of platinum, Vinblastin and Bleomycin. In the submitted group a recovery extending over five years has been recorded in 63.6%, 60.5% of the patients survive 10 years and 54.1% of the women 15 years. In stage I 5-year survival is 82.5%, in stage Ia 85.3%.

Adolescent↗
PubMed1988

Synergism of rumen microbial hydrolases during degradation of plant polymers.

In isolated mixture of exocellular enzymes of rumen bacteria Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and rumen fungus Neocallimastix frontalis, specific activities of cellulases, hemicellulases and glycosidases were determined. The highest specific activities were shown mostly for proteins of N. frontalis.

Animals↗