On the vertical distribution of microorganisms in lake Baikal during spring deep-water renewal

The vertical distribution of microorganisms during spring deep-water renewal in Lake Baikal was studied. The downward advection of trophogenic waters was found to create conditions for the extensive growth of microorganisms capable of decomposing and mineralizing organic carbon, nitrogen, and phosphorus in deep water layers. These processes occur annually at spring thermal bars near the underwater slope of Lake Baikal, whereas in its pelagic zone, the deep intrusions of waters rich in organic material are observed only in the years when enhanced deep-water renewal is accompanied by a high spring yield of phytoplankton.     

Effect of ascorbic acid on production of nitric oxide by leukocytes

The effect of ascorbic acid on suspensions of blood formic elements was studied by the ESR method. It was shown that incubation of a suspension of formic blood elements in the presence of ascorbic acid leads to the appearance of nitric oxide, which is produced by leukocytes and partially probably by thrombocytes. The formation of nitric oxide is evidenced by the appearance of nitrosyl complexes heme-NO. In this case, hemoglobin of erythrocytes serves as a natural trap for nitric oxide.     

Influence of neurotensin on behavior of rats with lesions in serotonergic neurons

After serotonergic lesion by administration of 5,7-dihydroxytryptamine into the dorsalis raphe nucleus, effects of neurotensin microinjections into the caudate nucleus and substantia nigra on rat behavior were compared. Serotonergic lesions resulted in motivated excitement of rats manifested as an increase in the number of intersignal motor reactions during realization and, particularly, extinction of thirst conditioned reflex. Neurotensin microinjections into the caudate nucleus facilitated extinction of the conditioned reflex both in operated and control rats, but such microinjection into the substantia nigra facilitated this process only in operated animals. Neurotensin did not change conditioned reflex realization in both groups of animals but decreased emotional excitement of rats in the "open field". The behavioral effects of neurotensin in operated rats are connected with normalization of motivational and emotional states of animals and may be explained by recovery of interaction between the dopamine- and serotonergic systems. It is suggested that the mechanisms of this normalizing effects of neurotensin at the levels of the caudate nucleus and substantia nigra are different and are associated preferentially with its action either on dopamine- or serotonergic structures.     

High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

Background

Short rotation coppice willow is a potential lignocellulosic feedstock in the United Kingdom and elsewhere; however, research on optimising willow specifically for bioethanol production has started developing only recently. We have used the feedstock Salix viminalis × Salix schwerinii cultivar 'Olof' in a three-month pot experiment with the aim of modifying cell wall composition and structure within the stem to the benefit of bioethanol production. Trees were treated for 26 or 43 days with tension wood induction and/or with an application of the cellulose synthesis inhibitor 2,6-dichlorobenzonitrile that is specific to secondary cell walls. Reaction wood (tension and opposite wood) was isolated from material that had received the 43-day tension wood induction treatment.

Results

Glucan content, lignin content and enzymatically released glucose were assayed. All measured parameters were altered without loss of total stem biomass yield, indicating that enzymatic saccharification yield can be enhanced by both alterations to cell wall structure and alterations to absolute contents of either glucan or lignin.

Conclusions

Final glucose yields can be improved by the induction of tension wood without a detrimental impact on biomass yield. The increase in glucan accessibility to cell wall degrading enzymes could help contribute to reducing the energy and environmental impacts of the lignocellulosic bioethanol production process.     

Identification of Ca(2+)-activated Mg(2+)-dependent ATP-hydrolase activity of membrane microsomal fraction of loach embryo (Misgurnus fossilis L.)

The functional confirmation of availability of Ca2+ transport initially-active systems in the embryo cells of loach Misgurnus fossilis L. has been obtained. Using thapsigargin, the specific inhibitor of endoplasmic reticulum of Ca2+, Mg(2+)-ATPase, this enzyme activity was divided into thapsigargin-sensitive (actually endoplasmic reticulum Ca2+, Mg(2+)-ATPase) and thapsigargin-insensitive (plasma membrane Ca2+, Mg(2+)-ATPase) constituents. The Ca(2+)-independent Mg(2+)-dependent ATPase activity makes above 39.7% of the common Ca2+, Mg(2+)-ATPase activity of embryo loach. The periodic changes of Ca2+, Mg(2+)-ATPase activity (except for the changes of plasma membrane Ca2+, Mg(2+)-ATPase activity) were found out, which coincide with periodic [Ca2+]i oscillations during the synchronous divisions of loach blastomers embryos.     

The early life history of two sympatric New Zealand octopuses: eggs and paralarvae of Octopus huttoni and Pinnoctopus cordiformis

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female.     

Quantitative isolation of microbial DNA from the different types of soils of natural and agricultural ecosystems

A novel procedure was developed for direct quantitative isolation of microbial DNA from soil. This technique was used to evaluate microbial DNA pools in soils of contrasting types (chernozems and brown forest soils) under different anthropogenic loads. A strong correlation was found between microbial biomass and DNA contents in soils of different types (R2 = 0.799). The ratio of soil CO2 emission rate to the amount of extractable DNA in the soil was shown to reflect physiological state of the soil microbial community; this ratio can be used as an ecophysiological parameter similarly to the metabolic quotient qCO2.