Growth characteristics of haploid and diploid Hansenula polymorpha yeasts on methanol in continuous culture

The rate of growth and the yield of biomass of a Hunsenula polymorpha homozygous diploid strain ML-3 X ML-3 were nearly identical with those of the parent haploid culture ML-3. The two cultures were eliminated from the fermenter at D = 0.20 to 0.21 h-1. In contrast, a heterozygous diploid strain ML-3 X VKM 1397 could grow at D = 0.23 to 0.25 h-1 and its biomass yield reached 38% while the yields of the haploid and homozygous diploid strains were 35 to 36%. The pH of the medium had the same effect on the three cultures: a change in the pH from 4.0 to 3.5 and then to 3.0 did not influence the yield of biomass; a further pH drop to 2.5 made the cells be eliminated from the fermenter.     

Comparative Characteristics of the Chemical Composition of Some Brown Algae from the White and Yellow Seas

Russian Journal of Bioorganic Chemistry - Brown algae represent a valuable source of various biologically active compounds. Their accumulation is influenced by many environmental factors. The...     

Investigation of erythrocyte shape, plasma membrane fluidity and conformation of haemoglobin haemoporphyrin under the influence of long-term space flight

The investigation of long-term space flight (SF) effect on the blood cells function is of great importance for modern space biology and medicine. We established that the number of discocytes decreased in the period of early rehabilitation after long-term SF. After SF plasma membrane fluidity and phospholipid content decreased and cholesterol content increased. After SF the amount of haemoglobin decreased and the parameters characterizing haemoglobin haemoporyphyrin (HH) conformation changed. We suppose that erythrocyte shape, membrane fluidity and HH conformation are among factors affecting oxygen transfer during and after space flight.     

Effect of tumor necrosis factor DNA on immune response to DNA immunization against herpes simplex virus

A study was made of the adjuvant effect of the mouse tumor necrosis factor alpha (mTNF alpha) on DNA immunization against the herpes simplex virus type 1 (HSV1). The HSV1 gD gene (pDNAgD) served as an immunogen; mTNF alpha or its gene cloned in an eukaryotic expression vector (pDNAmTNF) were used to modulate the immune response. Double immunization with pDNAgD led to a sixfold increase in the in vitro T-cell response, a high (1:2000) titer of anti-HSV1 antibodies (including virus-neutralizing antibodies), an increase in IgG2a/IgG1 (suggesting a shift of the immune response to the Th1 type), and no change in CD4/CD8 T-cell ratio. A single injection of mTNF alpha along with inactivated HSV1 allowed a twice higher antibody titer and a fourfold higher T-cell response as compared with immunization with HSV1 alone. Double immunization with both pDNAgD and pDNAmTNF increased the titer of anti-HSV1 antibodies and the T-cell response by factors of 8 and 1.5, respectively, as compared with immunization with pDNAgD alone. However, the protective effect was significantly lower with the two plasmids than with pDNAgD (73 vs. 100%). Thus, DNA immunization with pDNAgD induced both B- and T-cell responses and completely protected mice from a lethal doze of HSV1. The adjuvant properties of mTNF alpha and pDNAmTNF need further investigation.     

Carbon and Nitrogen Mineralization of Lead Treated Soils in the Eastern Mediterranean Region,Turkey

The aim of this study was to determine the first effect of lead on microbial activity in soil. The study was carried out in the soil samples from four different radish (Raphanus sativus L. var. radicula, Brassicaceae) fields along the highway in a district (Kadirli, Osmaniye) of the Eastern Mediterranean Region, Turkey. After the calculation of Pb contents, the Pb amounts of the soil samples were brought up to 50 and 100 mg Pb kg^?1 by treatment with Pb(NO ₃ ) ₂ , and the samples for the carbon and the nitrogen mineralization were incubated under controlled conditions (28°C, constant moist). The carbon mineralization was determined by a CO ₂ respiration method for 30 days. The nitrogen mineralization was observed in vitro for 6 weeks. The untreated group was statistically different from the 50 and 100 mg Pb kg^?1 treatments in the aspect of the C(CO ₂ ) outlet during mineralization (P ≤ 0.05), but difference between the 50 and 100 mg Pb kg^?1 treatments was not significant. NH ₄ -N and NO ₃ -N contents of each soil were shown differences between across treatments. Based on these results, it is possible to conclude that the addition of 50 and 100 mg Pb kg^?1 provided a toxic effect threshold for the microbial activity into 30 days.     

Incidence of mycoflora and mycotoxins in some edible fruits and seeds of forest origin

Twelve fungi namelyAlternaria alternata, Aspergillus flavus, A niger, A ochraceus, Actinomucor repens, Capnodoium spp., Curvularia lunata, Fusarium pallidoroseum, F solani, F verticillioides, Penicillium citrinum and Rhizopus stolonifer were recorded from samples ofAegle marmelos, Aesculus indica, Buchanania lanzan andPinus gerardiana. In case ofPrunus amygdalus only Rstolonifer was recorded. A significant variation in pattern of mycoflora incidence was observed in terms of source and season. Fungal infestation in most of the substrates was found to be highest during monsoon. Aflatoxins were the most common mycotoxins elaborated by different isolates ofA flavus obtained fromA marmelos, B lanzan andP gerardiana. The amount of aflatoxins produced by the toxigenic isolates ofA flavus was in the range of traces to 0.9–26.0 μg/ml inA marmelos, 0.8–17.5 μg/ml inP gerardiana and 0.65–13.2 μg/ml inB lanzan. The percentage toxigenicity was comparatively lower in the isolates of other mycotoxigenic fungi. Aflatoxins were detected almost in all the samples analyzed for mycotoxin contamination. However, traces of zearalenone were detected inA marmelos. The concentration of aflatoxin B₁ was in the range of 0.13–0.75 μg/g inA marmelos, 0.09–0.60 μg/g inP gerardiana and 0.01–0.20 ug/g inB lanzan. Mycotoxins were not detected inAesculus indica andPrunus amygdalus.     

Alterations of Antioxidant and Oxygen Transport Properties of Blood in Adenocarcinoma-Bearing Mice during Chemotherapy

The influence of murine intestinal adenocarcinoma on the antioxidant status and hemoglobin content in the blood was analyzed. Murine adenocarcinoma was accompanied with a decrease of the nonprotein thiol concentration and an increase in ceruloplasmin. A conformational change in the globin molecule but not in the heme group was revealed in the hemoglobin molecule. The changes in the protein appear to be caused by nonspecific damage that results from the processes of peroxidation.