Sugarcane glycoproteins are required to the production of an active UDP-glucose dehydrogenase byXanthomonas albilineans

In vitro enzymatic assay of UDP-glucose dehydrogenase fromXanthomonas albilineans requires the addition of a protease inhibitors cocktail to cell-free extracts, since bacterial proteases rapidly hydrolyses the enzyme in solution. The addition of low amounts of 8-azaguanine and chloramphenicol to the culture medium do not impede the production of the dehydrogenase that requires concentrations higher than 0.3 mM of both antimetabolites to inhibit its synthesis. Glycoproteins from sugarcane, the natural host of the bacterium, also assure the production of the active enzyme by inhibiting bacterial proteases.     

Production of L-carnitine by secondary metabolism of bacteria

The increasing commercial demand for L-carnitine has led to a multiplication of efforts to improve its production with bacteria. The use of different cell environments, such as growing, resting, permeabilized, dried, osmotically stressed, freely suspended and immobilized cells, to maintain enzymes sufficiently active for L-carnitine production is discussed in the text. The different cell states of enterobacteria, such as Escherichia coli and Proteus sp., which can be used to produce L-carnitine from crotonobetaine or D-carnitine as substrate, are analyzed. Moreover, the combined application of both bioprocess and metabolic engineering has allowed a deeper understanding of the main factors controlling the production process, such as energy depletion and the alteration of the acetyl-CoA/CoA ratio which are coupled to the end of the biotransformation. Furthermore, the profiles of key central metabolic activities such as the TCA cycle, the glyoxylate shunt and the acetate metabolism are seen to be closely interrelated and affect the biotransformation efficiency. Although genetically modified strains have been obtained, new strain improvement strategies are still needed, especially in Escherichia coli as a model organism for molecular biology studies. This review aims to summarize and update the state of the art in L-carnitine production using E. coli and Proteus sp, emphasizing the importance of proper reactor design and operation strategies, together with metabolic engineering aspects and the need for feed-back between wet and in silico work to optimize this biotransformation.     

Suprabenthic euphausiids and mysids from the South Shetland Islands and the Bransfield Strait, Southern ocean (BENTART-95 cruise)

During the austral summer 1995, the suprabenthic assemblages from 24 stations (45–649 m water depth) located around the South Shetland Islands and in the Bransfield Strait were sampled with a Macer-GIROQ sled. The purpose of this paper is to describe the structure of two main crustacean groups (euphausiids and mysids) in the near-bottom water layers sampled by the sled and to focus on the life history of two dominant mysid species from these areas (Mysidetes posthon and Antarctomysis maxima). The distribution and the main factor structuring populations in the investigated area are discussed.     

Emerging conflicts for the environmental use of water in high-valuable rangelands. Can livestock water ponds be managed as artificial wetlands for amphibians?

Continental freshwater, irrespective of its origin, natural or artificial, may contribute significantly to biodiversity conservation. Because of the decline of natural aquatic habitats, an increasing concern exists about the role of water ponds as spots of biological richness. Amphibians are strongly at risk since the loss of aquatic habitats, among other factors, causes the isolation of their populations. The implementation of livestock ponds as artificial wetlands may be an effective measure for enhancing amphibian decaying communities. This policy assumes that managing ponds for wildlife conservation purposes joins livestock welfare requirements, but this hypothesis has not been specifically studied. The purpose of this research is to evaluate this premise in the Urbasa-Andia Natural Park, a high-valuable environmental area that holds a relevant amphibian community and has an extended grazing history. We analyse the relationship between the amphibian assemblages present and the design and attributes of a variety of drinking points previously chosen by embodying a high environmental heterogeneity of water resources. The results of this study indicate that the quality of the water stored varies largely along the season, degrading severely in summer because of the wading of animals (in unfenced ponds) and the low water recharge. The contamination, caused by increased enteric microorganisms and dissolved N, is likely to affect livestock more severely than amphibian populations, since the sensitive breeding stage of many amphibians occurs before the loss of water quality. Although the quality of the water is essential, and mammals (wild and domestic) have an influence on it, other factors that are less considered by environmental managers emerge as main drivers of amphibian assemblages, such as hydroperiod, predator occurrence and the environmental quality of the surrounding habitat.     

Endostatin gene therapy enhances the efficacy of IL-2 in suppressing metastatic renal cell carcinoma in mice

We investigated whether the administration of IL-2 combined with endostatin gene therapy was able to produce additive or even synergistic immunomodulatory activity in a mouse model of metastatic renal carcinoma. Renca cells were injected into the tail vein of BALB/c mice. After 24 h, the animals were randomly divided into four groups (5 mice/group). One group of mice was the control, the second group received treatment with 100,000 UI of Recombinant IL-2 (Proleukin, Chiron) twice a day, 1 day per week during 2 weeks (IL-2), the third group received treatment with a subcutaneous inoculation of 3.6 × 10⁶ endostatin-producing cells, and the fourth group received both therapies (IL-2 + ES). Mice were treated for 2 weeks. In the survival studies, 10 mice/group daily, mice were monitored daily until they died. The presence of metastases led to a twofold increase in endostatin levels. Subcutaneous inoculation of NIH/3T3-LendSN cells resulted in a 2.75 and 2.78-fold increase in endostatin levels in the ES and IL-2 + ES group, respectively. At the end of the study, there was a significant decrease in lung wet weight, lung nodules area, and microvascular area (MVA) in all treated groups compared with the control group (P < 0.001). The significant difference in lung wet weight and lung nodules area between groups IL-2 and IL-2 + ES revealed a synergistic antitumor effect of the combined treatment (P < 0.05). The IL-2 + ES therapy Kaplan–Meier survival curves showed that the probability of survival was significantly higher for mice treated with the combined therapy (log-rank test, P = 0.0028). Conjugated therapy caused an increase in the infiltration of CD4, CD8 and CD49b lymphocytes. An increase in the amount of CD8 cells (P < 0.01) was observed when animals received both ES and IL-2, suggesting an additive effect of ES over IL-2 treatment. A synergistic effect of ES on the infiltration of CD4 (P < 0.001) and CD49b cells (P < 0.01) was also observed over the effect of IL-2. Here, we show that ES led to an increase in CD4 T helper cells as well as cytotoxic lymphocytes, such as NK cells and CD8 cells, within tumors of IL-2 treated mice. This means that ES plays a role in supporting the actions of T cells.     

The Bet Collector

The Bet Collector (Kubrador), Jeffrey Jeturian, director; 2006, 101 minutes, DVD; in Tagalog, with English subtitles. Distributed by Global Film Initiative, San Francisco, CA.