Nonequilibrium as a source of unmixing

The intermediates, U and V, of a simple model reaction system (the so-called Brusselator) are shown to have both uniform and patterned steady states in a membrane. The patterned distribution of U and V has the symmetry of hexagons in the plane and is stable for B #62; B_m, B being the controlled concentration of one of the parametric species. The uniform solution is stable for B < B_c, and, since B_c #62; B_m, the increase and subsequent decrease of B over an interval that includes (B_m,B_c) can produce a hysteresis in which the transitions from mixed (i.e. uniform) to unmixed (i.e. hexagonlly patterned) states happen quite suddenly at the two critical values. Since the transfer or reactive properties of the membrane might be different in the two states, this model provides a bistable membrane element that might have prototypical value in a theory of biochemical control.     

Micro-algae as a source of protein

About five decades ago, the mass production of certain protein-rich micro-algae was considered as a possibility to close the predicted so called "protein gap". Comprehensive analyses and nutritional studies have demonstrated that these algal proteins are of high quality and comparable to conventional vegetable proteins. However, due to high production costs as well as technical difficulties to incorporate the algal material into palatable food preparations, the propagation of algal protein is still in its infancy. To date, the majority of micro-algal preparations are marketed as health food, as cosmetics or as animal feed.     

Microbial lipids as a source of biofuel

This review presents the main directions and experimental data aimed at searching for active producers of lipids among different species of microorganisms and ways to optimize the lipidogenesis process in the most promising stains. It was shown that enzymatic processes can be directed by maintaining the necessary cultivation conditions. The influence on the growth, development, and biochemical activity of the microbial medium composition and temperature and the aeration and oxidation reduction conditions was considered. Changes in these factors affected the biosynthetic activity of microorganisms and lipidogenic yeasts and the composition of synthesized lipids. The ability of lipidogenic yeasts, as well as the relatively rapid ability of changing the amount and composition of lipids by direct cultivation, leads to the conclusion that lipids obtained by microbial synthesis can be a source of commercial raw materials for biofuel.     

Kappaphycus alvarezii as a source of bioethanol

The present study describes production of bio-ethanol from fresh red alga, Kappaphycus alvarezii. It was crushed to expel sap - a biofertilizer - while residual biomass was saccharified at 100 °C in 0.9 N H₂SO₄. The hydrolysate was repeatedly treated with additional granules to achieve desired reducing sugar concentration. The best yields for saccharification, inclusive of sugar loss in residue, were 26.2% and 30.6% (w/w) at laboratory (250 g) and bench (16 kg) scales, respectively. The hydrolysate was neutralized with lime and the filtrate was desalted by electrodialysis. Saccharomyces cerevisiae (NCIM 3523) was used for ethanol production from this non-traditional bio-resource. Fermentation at laboratory and bench scales converted ca. 80% of reducing sugar into ethanol in near quantitative selectivity. A petrol vehicle was successfully run with E10 gasoline made from the seaweed-based ethanol. Co-production of ethanol and bio-fertilizer from this seaweed may emerge as a promising alternative to land-based bio-ethanol.     

Northern berries as a source of carotenoids

Carotenoids are bioactive substances in human diet. The aim of the study was to determine β-carotene and xanthophylls in four berries species. An HPLC gradient elution system were used for separation and quantification of the carotenoids. The highest total carotenoid content among the berries studied was found in cloudberry (2840 μg/100g dw), followed by blueberry (2140 μg/100 g). All berries had lutein but it was a predominant carotenoid in blueberry. The highest β-carotene levels were found in cloudberry (83% of total Car content). Cranberry and cowberry were the poorest sources of carotenoids. Our data will be included in the regional database of resources with the increased nutritional value.     

Agricultural animals as a source of yersiniosis

The role of agricultural animals as the sources of infection was studied. 8 Yersinia strains were isolated from 83 samples taken from cattle. Yersinia were isolated from feces, udder washings and milk. In the examination of 63 samples obtained from sheep the infective agent was isolated from feces in 6 cases. 6 Yersinia strains were isolated from 92 fecal samples taken from pigs. Y. enterocolitica were isolated from sick animals. The isolated strains were classified with serovars 03, 058, 08 and 09. In the foci of animal infection thus revealed antibodies to various Yersinia strains were detected in the blood sera of the animal-tending personnel, which indicates the professional character of the spread of this infection among humans. The infection is probably transferred by the contact and alimentary routes.     

Transgenic plants as a source of polyhydroxyalkanoates

Polyhydroxyalkanoates (PHAs) make a large class of biodegradable biopolymers that are naturally synthesized by numerous microorganisms. These biopolymers could be an alternative to commonly used plastics based on petroleum. Production of PHAs in bioreactors using microorganisms is not widely applied due to its unprofitability. Using transgenic plants for this purpose may be cheaper and more environmental friendly because the biosynthesis of PHAs in plants is based only on water, mineral salts, CO₂ and light. Additionally, plants are not capable of degrading PHAs as bacteria do, and extraction of PHAs from plant tissues is not always necessary. The main objective of this work is a review of possibilities of PHA biosynthesis in transgenic plants and presentation of general information on properties and potential application possibilities of these biopolymers. The possibility of syntheses and accumulation of PHA in several transgenic plants has been studied for some years. Many experiments were performed on model plant Arabidopsis thaliana, however, the research has also revealed a great potential of transgenic crop plants such as camelina (Camelina sativa), tobacco (Nicotiana tabacum) or sugarcane (Saccharum officinarum) as a good sources of PHAs. The highest level of PHAs accumulation in plants was achieved in transgenic A. thaliana (up to 40% of the dry weight of the leaf), and among crop plants in C. sativa (up to 20% of the dry weight of the seed). Increasing knowledge on PHAs permits expansion of the possibilities of these biopolymers use even at a low level of their accumulation in plant tissues.     

Endosymbiosis as a source of immune innovation

Some years ago, Lynn Margulis proposed to envision symbiosis as a source of evolutionary innovation. Here we revisit this concept in the context of insect nutritional endosymbiosis, and discuss recent data suggesting that host–endosymbiont coevolution has led to the selection of innovative strategies towards endosymbiont maintenance and control by the host immune system.