Antarctic krill carbohydrate content was followed during 1983—84 Eighth Polish Antarctic Expedition. The Admiralty Bay (King George Island) was th area of study. The following average values of three estimated fractions were obtained: 3.77 +- 1.51%, 0.47 +- 0.34% and 3.30 +- 1.33% for total, TCA-soluble and TCA-insoluble carbohydrates, respectively. Percentage contribution of the estimated fractions to dry weight varied seasonally (1.48—7.41%, 0.15—1.83%, and 1.28—6.28%, respectively). The carbohydrate content showed a clearcut cycle of changes over the calender year, with a minimum in autumn-winter and a maximum in spring-summer.

Salinity has adverse effects on plants and is one of the causes of environment degradation. Plants have developed many defensive mechanisms, protecting them from sodium chloride (NaCl), including accumulation of osmoprotective compounds, which maintain osmotic balance, protect cell structure and enzymes. In the current study, we investigated the effects of salinity resulting from a range of sodium chloride concentrations (from 0 to 400 mM) on the growth of common duckweed (Lemna minor L.) and yellow lupin (Lupinus luteus L.). Increasing concentration of sodium chloride decreased the area of common duckweed leaves. At the highest applied salt concentration, the decrease of leaf area was associated with leaf chlorosis. In yellow lupin, the increasing sodium chloride concentration inhibited root and stem elongation. The highest tested NaCl concentration of 400 mM completely stopped elongation of yellow lupin shoots. The content of cyclitols and soluble carbohydrates in plant tissues was evaluated as well. Cyclitols (D -chiro -inositol and D -pinitol), as well as soluble carbohydrates (glucose, fructose and sucrose) were detected in common duckweed tissues. Yellow lupin seedlings also contained cyclitols - D -pinitol, myo -inositol and D -chiro -inositol - and soluble carbohydrates - glucose, galactose and sucrose. The content of osmoprotectants in plant tissues, especially sucrose and cyclitols, increased with increasing concentration of sodium chloride in the soil. The results indicate that the content of cyclitols and soluble carbohydrates in plant tissues can be an indicator of plant response to salinity stress.

Girdling was applied to 5-year-old potted beech individuals of early, intermediate and late phenological forms to block assimilate export from leaves. Phloem severance caused accumulation of soluble carbohydrates and starch in leaves and increased the C/N ratio. While the hexose content increased continuously until the end of the experiment, the sucrose and starch contents peaked earlier, depending on the plant's phenological features. Different rates of chlorophyll degradation and H2O2 and TBARS (thiobarbituric acid-reactive substances) production in different phenological forms implied that phloem girdling was the source of oxidative stress and, depending on the phenological form, accelerated leaf senescence to different degrees. The variable rate of the increase in soluble carbohydrate and starch content, characteristic of the different phenological forms, had different modifying effects on the antioxidant activity in leaves. Compared with the early phenological form, the late form was characterized by a smaller increase in H2O2 and TBARS content and delayed and slowed chlorophyll and carotenoid degradation. In conjunction with the larger increase in the activity of antioxidant enzymes (catalase, ascorbate peroxidase and superoxide clismutase) induced by carbohydrate accumulation and slower carotenoid degradation, these changes led to the late form having greater resistance to oxidative stress and slower senescence.

Plants adapt to extremely low temperatures in polar regions by maximizing their photosynthetic efficiency and accumulating cryoprotective and osmoprotective compounds. Flowering plants of the family Poaceae growing in the Arctic and in the Antarctic were investigated. Their responses to cold stress were analyzed under laboratory conditions. Samples were collected after 24 h and 48 h of cold treatment. Quantitative and qualitative changes of sugars are found among different species, but they can differ within a genus of the family Poaceae. The values of the investigated parameters in Poa annua differed considerably depending to the biogeographic origin of plants. At the beginning of the experiment, Antarctic plants were acclimatized in greenhouse characterized by significantly higher content of sugars, including storage reserves, sucrose and starch, but lower total protein content. After 24 h of exposure to cold stress, much smaller changes in the examined parameters were noted in Antarctic plants than in locally grown specimens. Total sugar content and sucrose, starch and glucose levels were nearly constant in P. annua, but they varied significantly. Those changes are responsible for the high adaptability of P. annua to survive and develop in highly unsupportive environments and colonize new regions.

The aim of this paper is to show the basic principles of the anaerobic digestion process. All the stages of degradation, such as hydrolysis, acidogenesis, acetogenesis and methanogenesis are characterized. Biodegradable organic matter consists of three main types of substances: carbohydrates, proteins and lipids; the metabolic pathways of their decomposition are described. The last part of the paper presents the co-digestion process, its benefits and technological parameters required to make that process attractive from an economical and environmental point of view.

With the improvement of people’s living standards and rapid economic development, the incidence of diabetes mellitus (DM) is increasing in most parts of the world. DM presents an important potential threat to human health. In the present study, a model of diabetes in female mice was established, and fasting blood glucose was detected at week 4, after which the biochemical profiles were evaluated by histopathological analysis. The success rate of modeling in the normal control (NC) group and the low/ middle/high-dose streptozotocin (STZ) group were 0, 0, 25% and 60%, respectively. In the middle-dose and high-dose STZ groups, the liver index was increased significantly compared with the NC group (p<0.05). The blood biochemical indicators of total cholesterol and low density lipoprotein cholesterol in three STZ injection groups were as follows: alanine aminotransferase and aspartate transaminase in middle- and high-dose STZ groups, high-density lipoprotein cholesterol and serum creatinine in the high-dose STZ group, and blood urea nitrogen in the middle-dose STZ group were significantly increased (p<0.05). The level of total triglycerides was lower, obviously, in the high-dose STZ group than in the NC group (p<0.05). The mice showed marked steatosis, green-dyed fiber tissue coloring in varying degrees, and the contour of the hepatic lobules basically disappeared in STZ injection groups. The results suggest that to establish a diabetes model for female ICR mice, the optimum dose of STZ is 100 mg/kg.

Nanotechnology has been widely applied in agriculture, and understanding of the mechanisms of plant interaction with nanoparticles (NPs) as environmental contaminants is important. The aim of this study was to determine the effects of foliar application of cobalt oxide (Co3O4) NPs on some morpho-physiological and biochemical changes of canola (Brassica napus L.) leaves. Seeds were sown in plastic pots and grown under controlled conditions. Fourteen-day-old seedlings were sprayed with different concentrations of Co3O4 NPs (0, 50, 100, 250, 500, 1000, 2000, and 4000 mg L-1) at weekly intervals for 5 weeks. Growth parameters of the shoot (length, fresh and dry weights) were stimulated by low concentrations of Co3O4 NPs (50 and 100 mg L-1) and repressed by higher concentrations. Similar trends were observed in photosynthetic pigment contents. The results indicated that high concentrations of Co3O4 NPs increased lipoxygenase (LOX) activity and the malondialdehyde (MDA), hydrogen peroxide (H2O2), and dehydroascorbate (DHA) contents, but reduced the membrane stability index (MSI), ascorbate (ASC), and glutathione (GSH). Despite the increase of antioxidant capacity (DPPH) and the accumulation of nonenzymatic antioxidants (total flavonoids and flavonols) and osmolytes (proline, glycine betaine (GB) and soluble sugars) at high concentrations of Co3O4 NPs, the growth and photosynthesis were reduced. The defence system activity did not seem to be sufficient to detoxify reactive oxygen species (ROS). Altogether, high concentrations of Co3O4 NPs showed a phytotoxic potential for canola as an oilseed crop.