Lipid analysis of the plasma membrane and mitochondria of brewer's yeast.

The plasma membrane and mitochondria of bottom fermenting brewer's yeast obtained as a by-product of industrial beer production were isolated and the lipid fraction was analyzed. The phospholipid content accounted for 78 mg/g protein in the plasma membrane and 59 mg/g protein in the mitochondria. Major phospholipids in both preparations were phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine but their proportions differed significantly. In the plasma membrane phosphatidylinositol, and in the mitochondria phosphatidylcholine were present in the highest concentration (37 and 30%, respectively). The main classes of neutral lipids (triacylglycerols, ergosterol, squalene and steryl esters) were twice more abundant in the plasma membrane than in the mitochondria (61 and 33 mg/g protein, respectively). A characteristic of the neutral lipid composition of both organelles was the low content of ergosterol (12 and 7 mg/g protein, respectively) and a high content of squalene (25 and 22 mg/g protein). The main feature of the fatty acid composition of both organelles was the preponderance of saturated fatty acids (78 and 79%, respectively), among which palmitic acid was the principal one. The most expressed characteristics of lipid fractions of the analyzed plasma membranes and mitochondria, high concentration of squalene and preponderance of saturated fatty acids are the consequences of anaerobic growth conditions. The lack of oxygen had possibly the strongest effect on the lipid composition of the plasma membranes and mitochondria of bottom fermenting brewer's yeast.

Kidney length in healthy members of Balkan endemic nephropathy families.

BACKGROUND: Kidney size may differ between healthy members of Balkan endemic nephropathy (BEN) and non-BEN families. The present study was designed to elucidate this, in comparison with values for BEN patients. METHODS: A total of 71 BEN patients (34 males, 64.4 ± 12.0 years), 74 healthy BEN family members (39 males, 49.1 ± 12.2 years), and 59 non-BEN family members (19 males, 49.2 ± 12.3 years) were involved. We measured the longest craniocaudal length and minimal parenchymal thickness on each kidney of all examined subjects using ultrasound. RESULTS: No significant difference was found between the kidney length of healthy subjects from BEN (11.0 ± 0.8 cm) and non-BEN families (10.9 ± 0.8 cm), but kidneys were significantly longer than in BEN patients (9.9 ± 1.3 cm). Minimal parenchymal thickness was similar in all three groups. When subjects from each group were divided according to estimated glomerular filtration rate (eGFR), kidney length of the healthy groups was significantly longer than in BEN patients both in stage 1 (p =0.039) and stage 2 (p =0.044) of chronic kidney disease. The parental history of BEN was not associated with kidney dimensions, eGFR, or urinary excretion of albumin and alpha1-microglobulin. CONCLUSION: Kidneys of BEN patients were significantly shorter than in healthy members of both BEN and non-BEN families, but no difference was found in kidney length and parenchymal thickness between healthy members of BEN and non-BEN families. No significant association was found between parental history of BEN and kidney size and function either in BEN patients or in healthy members from BEN families. Hippokratia 2015; 19 (4): 304-308.

Cell lipids of the Candida lipolytica yeast grown on methanol.

Candida lipolytica yeast, grown on 1% methanol as the only carbon and energy source, synthesized 4.9% of dry cell mass as lipids, 52.3% of which were polar lipids. Polar lipids consisted mainly of phospholipids and sphingolipids as their minor components. The total long-chain bases content has been found to account only for 0.7% of the polar lipids. The long-chain bases composition determined by thin-layer and gas chromatography shows a preponderance of trihydroxy bases and a small amount of dihydroxy bases. The striking finding was the high content of 19-phytosphingosine (90.8% of total long-chain bases). Fatty acid (FA) composition of polar lipids was characterized by the relatively high concentration of unsaturated fatty acids (66.4% of total FA) and by the predominance of fatty acids with 16 carbon atoms (85.0% of total FA).

Isolation and chemical composition of the ceramide of the Candida lipolytica yeast.

Candida lipolytica yeast was grown batchwise on glucose medium. Ceramide was quantitatively isolated from sphingolipid fractions of total lipids by a combination of column chromatography and preparative thin-layer chromatography. Fatty acids and long-chain bases, obtained after acid methanolysis, were analyzed by gas-liquid chromatography. Fatty acid composition was characterized by predominance of fatty acids shorter than 20 carbon atoms (72.2% of total fatty acids) and by high concentration of fatty acids with 16 carbon atoms (43.3% of total fatty acids). The dominant fatty acids were h16:0 and 18:1. The major fatty acid with more than 20 carbon atoms was h24:0. Hydroxylated fatty acids quantitatively represented almost half of the total fatty acids. The ceramide contained an unusual long-chain base composition. Besides the well-known trihydroxy bases, 18- and 20-phytosphingosine, which is a common characteristic for yeast sphingolipids, a high proportion of more polar bases than the trihydroxy ones, was found. The structures of 4,5-dihydroxyicosasphinanine (1,3,4,5-tetrahydroxy-2-aminooctadecane) and 4,5-dihydroxyicosasphinganine (1,3,4,5-tetrahydroxy-2-aminoeicosane) were tentatively assigned to these bases. Their chromatographic properties were identical to those of synthetic bases.

Effect of growth phase on the content and composition of ceramides of the hydrocarbon-assimilating yeast Candida lipolytica.

Candida lipolytica yeast was grown batchwise on n-hexadecane as the carbon and energy source. Ceramides were quantitatively isolated from total lipids of exponential and stationary phase cells by a combination of column chromatography and preparative high-performance thin-layer chromatography. After acid methanolysis their composition was analyzed by gas-liquid chromatography. The ceramide content of the exponential phase cells was two times higher than the one of the stationary phase cells. The composition of long-chain base moiety of ceramides did not change significantly during the growth. In both growth phases 19-phytosphingosine was the major long-chain base. However, the fatty acid composition of ceramides changed greatly during the growth. In the exponential growth phase, ceramides contained predominantly fatty acids greater than 20 carbon atoms, while fatty acids shorter than 20 atoms predominated in ceramides of the stationary phase, 16:0 being the main one. In the exponential growth phase fatty acid moiety of ceramides was characterized by unusually high degree of unsaturation and relatively high proportion of odd-numbered fatty acids. However, the proportion of both, unsaturated and odd-numbered fatty acid decreased significantly in ceramides of the stationary phase. The unexpected finding was the absence of fatty acid hydroxylation of ceramides in the exponential phase cells and unusually low degree of hydroxylation in the stationary phase.

Microbial acetate oxidation in horizontal rotating tubular bioreactor.

The aim of this work was to investigate the possibility of conducting a continuous aerobic bioprocess in a horizontal rotating tubular bioreactor (HRTB). Aerobic oxidation of acetate by the action of a mixed microbial culture was chosen as a model process. The microbial culture was not only grown in a suspension but also in the form of a biofilm on the interior surface of HRTB. Efficiency of the bioprocess was monitored by determination of the acetate concentration and chemical oxygen demand (COD). While acetate inlet concentration and feeding rate influenced efficiency of acetate oxidation, the bioreactor rotation speed did not influence the bioprocess dynamics significantly. Gradients of acetate concentration and pH along HRTB were more pronounced at lower feeding rates. Volumetric load of acetate was proved to be the most significant parameter. High volumetric loads (above 2 g acetate l-1 h-1) gave poor acetate oxidation efficiency (only 17 to 50%). When the volumetric load was in the range of 0.60-1.75 g acetate l-1 h-1, acetate oxidation efficiency was 50-75%. At lower volumetric loads (0.14-0.58 g acetate l-1 h-1), complete acetate consumption was achieved. On the basis of the obtained results, it can be concluded that HRTB is suitable for conducting aerobic continuous bioprocesses.

Cerebrosides of Candida lipolytica yeast.

Candida lipolytica yeast was grown batchwise on glucose medium. Cerebrosides were isolated from the sphingolipid fraction of total lipids using column chromatography and separated into two compounds by high-performance thin-layer chromatography. Glucose was detected as the sole sugar constituent in cerebrosides. The fatty acid composition of cerebrosides was characterised by a predominance of saturated fatty acids and by a high proportion of fatty acids with 16 carbon atoms. The dominant fatty acid was h16:0. The principal long-chain base components of both cerebroside species were trihydroxy bases, 18- and 20-phytosphinosine. The unique characteristic of cerebrosides was the presence of a high proportion of sphingosine (one-fourth of the total long-chain bases), which is a common characteristic of mammalian sphingolipids and rarely occurs in yeast cerebrosides. The ceramide moiety profile of cerebrosides is similar to that of epidermal ceramides, which implies a possibility for their application in care cosmetics.

[A rare open injury of the rectum]. / Rijetka otvorena povreda rektuma.

Complicated injuries of the extraperitoneal part of the rectum, communicated with the injuries of sacrum, great injuries of the soft tissues following with abundant bleeding, are very difficult injuries. Above mentioned case, regarding to the way of the injury, good surgical treatment and good result, is out contribution in the treatment of the injuries of the sigmoid colon, rectum and anus.

The influence of carbon source on the level and composition of ceramides of the Candida lipolytica yeast.

Candida lipolytica yeast was grown batchwise on two different carbon sources, glucose and n-hexadecane. Free ceramides were quantitatively isolated from sphingolipid fractions of total lipids by a combination of column chromatography and preparative thin-layer chromatography. Their composition, after acid methanolysis, was analysed by gas-liquid chromatography. The ceramide content accounted for 2.6% of the total cell lipids in hexadecane-grown cells, which was 1.5 times higher than in glucose-grown cells. The fatty acid composition of ceramides was characterized by the predominance of fatty acids shorter than 20 carbon atoms and by high concentrations of fatty acids with 16 carbon atoms after growth on both carbon sources. The dominant fatty acid was hydroxylated 16:0 in the glucose-grown cells and 16:0 in the hexadecane-grown cells. The striking finding was the low degree of fatty acid hydroxylation and relatively high proportion of odd-numbered fatty acids in ceramide of the n-hexadecane-grown cells. The ceramides contained an unusual long-chain base composition. In hexadecane-grown cells more than 60% of the long-chain bases were C19 phytosphingosine. In glucose-grown cells more than one-half of the total long-chain bases were tetrahydroxy bases, 4,5-dihydroxysphinganine and 4,5-dihydroxyeicosasphinganine.

The barley protein degradation: Mechanism of protein solubilization during barley mashing with neutral proteinase.

Kinetics of protein solubilization during barley mashing with neutral proteinase were studied. By plotting the kinetics data in Foster-Niemann coordinates for barley concentration range of 10-30% linear relationships with high correlation coefficients (r >/= 0. 999) were obtained. The slopes of straight lines were very close to corresponding reciprocal initial insoluble nitrogen concentrations. Barley proteolytic inhibitors affected the ordinate intercept; by their addition the values of ordinate intercept decreased. The data suggest that the modified Foster-Niemann equation can be proposed to interpret kinetics of insoluble barley protein degradation. The proteolytic activity decay was studied as well. The enzyme decay was faster in buffer solution than during barley mashing, but in both cases first-order kinetics can be applied. A mathematical model describing protein solubilization and enzyme decay kinetics were developed. The results of computer simulation were in good agreement with experimental data.

[Personal experience in the care of thoracic war injuries 1992-1993]. / Nasa iskustva u zbrinjavanju ratnih povreda grudnog kosa u 1992-1993. godini.

The aim of this paper was to clear some dilemmas about the surgical treatment of chest injuries. In the period April 1992-December 1993 in the General Hospital of Foca 160 chest injuries were treated (71 penetrating and 89 unpenetrating injuries) that was 10.2% of the total number of injuries. The explosive injuries were 53.8% of cases and 46.2% sclopetary injuries. Those injuries dominated in 93 wounded and in 57 cases the injuries were associated. The isolated injuries were in 40% and combined ones in 60% of cases. Thirty five thoracotomies and 40 thorax drainages were done while on the rest of the wounded only surgical wound treatment was performed. The active immunization and antibiotic prophylaxis were performed on the wounded. The infection problem was present in one operated person and lethality rate was 4.4%. The treatment results were good due to the appropriate organization of the surgical service and timely primary specialist aid as well as sufficient quantity of blood and timely and adequate surgical procedure.

Partial purification and biochemical characterization of alkaline 5'-phosphodiesterase from barley malt sprouts.

An alkaline 5'-phosphodiesterase (5'-PDE) from barley (Hordeum distichum) malt sprouts was partially purified by thermal treatment and acetone precipitation to diminish phosphomonoesterase (PME) activity. 5'-PDE was purified 40-fold to a specific activity of 30 U mg(-1) protein with a final yield of about 32%. With synthetic substrate, the enzyme had an optimum pH of 8.9, maximum activity at 70 degrees C over 10 min, and a Km of 0.26 mM. The partially purified enzyme was activated by 10 mM Mg2+ up to 168% of the original activity, while Zn2+, Mn2+ and Cu2+ ions, chelating agent (EDTA) and NaN3 (1-10 mM), and 5'-ribonucleotides (1-5 mM) were inhibitory. Final enzyme preparation was stable over 8 d at 4 degrees C), at 70 degrees C for up to 120 min and without loss of activity over 90 d at -18 degrees C.

[The role of splenectomy in traumatic rupture of the spleen with comments on related material]. / Mjesto splenektomije kod traumatske rupture slezene uz komentar sopstvenog materijala.

The authors present their ten-year series of traumatic rupture of spleen. During the ten-year period 24 of such cases have been registered. In all ruptures of spleen the total splenectomy was performed, due to severe ruptures of capsule and parenchyma. In 87.5% the operations were done immediately. The delayed rupture of spleen was in three patients, without complications and mortality. The authors put the particular stress on fast and accurate diagnosis and note all methods of diagnosis, which can be used according to possibilities of Surgical Department. The authors suggest that the hesitation for laparatomy and that the splenectomy is justifiable operative method in traumatic rupture of spleen.

Bioprocess kinetics in a horizontal rotating tubular bioreactor.

A horizontal rotating tubular bioreactor (HRTB) is a plug flow bioreactor whose interior is provided with O-ring-shaped partition walls that serve as carriers for microbial biomass. During this investigation, microbial biomass was grown in suspension and on the bioreactor inner surface as a microbial biofilm with average mass that was considerably higher than suspended biomass. The dynamics of bioprocess in HRTB was studied by different combinations of process parameters (bioreactor rotation speed and mean residence time) and it was monitored by withdrawing the samples from five positions along the bioreactor. During this investigation it was also observed that mean residence time had a more pronounced effect on the bioprocess dynamics than bioreactor rotation speed. For the description of bioprocess kinetics in HRTB an unstructured kinetic model was established that defines biomass growth, product formations and substrate consumption rate by using a modified Monod (Levenspiel) model. This kinetic model defines changes in suspension and in microbial biofilm, and it shows relatively good agreement with experimental data.

Natural zeolite clinoptilolite increases the concentrations of sphingoid bases in the yeast Yarrowia lipolytica.

In the present paper, we studied the effect of natural zeolite clinoptilolite on sphingolipid metabolism in the yeast Yarrowia lipolytica. We also investigated if zeolite addition had any impact on cell shape and size, as well as on the pH alterations during the culture growth. High performance liquid chromatography analysis of sphingoid bases obtained by acid hydrolysis of complex sphingolipids from Y. lipolytica showed that their concentrations markedly rose upon the zeolite addition. The largest increase among the identified molecular species of sphingoid bases was seen in C18 phytosphingosine, whose levels rose 6.2-fold and 22.3-fold after culturing cells for 24 and 36 hours respectively in the presence of finely ground zeolite. pH measurements of the culture medium showed a similarity between pH profiles of control and zeolite-supplemented cells, suggesting that ion-exchange capacity was not probably responsible for the observed change in sphingolipid metabolism. Scanning electron microscopy revealed that zeolite affected cell size and shape. Y. lipolytica cells grown in the absence of zeolite were oval-shaped with an average cell size of 0.7-2.7 microns, whereas when cultured with zeolite, they were round-shaped and larger, having an average cell size of 1.3-2.9 microns.