Enhanced nisin and pediocin production on whey supplemented with different nitrogen sources

Production of nisin and pediocin were followed, respectively, in Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B-5627 grown with lactose and four different nitrogen sources. Neither NH₄Cl nor glycine improved production of the bacteriocins. Both yeast extract and Casitone increased pediocin production from 55 BU ml^–1 to 195 BU ml^–1 and 185 BU ml^–1, respectively. Nisin increased from 21 BU ml^–1 to 74 BU ml^–1 and 59 BU ml^–1 with these nitrogen sources.     

The Granular Chloride Channel ClC-3 Is Permissive for Insulin Secretion

Insulin secretion from pancreatic β cells is dependent on maturation and acidification of the secretory granule, processes necessary for prohormone convertase cleavage of proinsulin. Previous studies in isolated β cells revealed that acidification may be dependent on the granule membrane chloride channel ClC-3, in a step permissive for a regulated secretory response. In this study, immuno-EM of β cells revealed colocalization of ClC-3 and insulin on secretory granules. Clcn3^−/− mice as well as isolated islets demonstrate impaired insulin secretion; Clcn3^−/− β cells are defective in regulated insulin exocytosis and granular acidification. Increased amounts of proinsulin were found in the majority of secretory granules in the Clcn3^−/− mice, while in Clcn3^+/+ cells, proinsulin was confined to the immature secretory granules. These results demonstrate that in pancreatic β cells, chloride channels, specifically ClC-3, are localized on insulin granules and play a role in insulin processing as well as insulin secretion through regulation of granular acidification.     

Genetic and molecular characterization reveals a unique nucleobase cation symporter 1 in Arabidopsis

Locus At5g03555 encodes a nucleobase cation symporter 1 (AtNCS1) in the Arabidopsis genome. Arabidopsis insertion mutants, AtNcs1-1 and AtNcs1-3, were used for in planta toxic nucleobase analog growth studies and radio-labeled nucleobase uptake assays to characterize solute transport specificities. These results correlate with similar growth and uptake studies of AtNCS1 expressed in Saccharomyces cerevisiae. Both in planta and heterologous expression studies in yeast revealed a unique solute transport profile for AtNCS1 in moving adenine, guanine and uracil. This is in stark contrast to the canonical transport profiles determined for the well-characterized S. cerevisiae NCS1 proteins FUR4 (uracil transport) or FCY2 (adenine, guanine, and cytosine transport).     

Genetic Analysis and Species Specific Amplification of the Artemisinin Resistance-Associated Kelch Propeller Domain in P. falciparum and P. vivax

Plasmodium falciparum resistance to artemisinin has emerged in the Greater Mekong Subregion and now poses a threat to malaria control and prevention. Recent work has identified mutations in the kelch propeller domain of the P. falciparum K13 gene to be associated artemisinin resistance as defined by delayed parasite clearance and ex vivo ring stage survival assays. Species specific primers for the two most prevalent human malaria species, P. falciparum and P. vivax, were designed and tested on multiple parasite isolates including human, rodent, and non- humans primate Plasmodium species. The new protocol described here using the species specific primers only amplified their respective species, P. falciparum and P. vivax, and did not cross react with any of the other human malaria Plasmodium species. We provide an improved species specific PCR and sequencing protocol that could be effectively used in areas where both P. falciparum and P. vivax are circulating. To design this improved protocol, the kelch gene was analyzed and compared among different species of Plasmodium. The kelch propeller domain was found to be highly conserved across the mammalian Plasmodium species.     

Patterns of characterization in folktales across geographic regions and levels of cultural complexity

Literary scholars are generally suspicious of the concept of universals: there are presently no candidates for literary universals that a high proportion of literary scholars would accept as valid. This paper reports results from a content analysis of patterns of characterization in folktales from 48 culture areas, aimed at identifying patterns of characterization that apply across regions of the world and levels of cultural complexity. The search for these patterns was guided by evolutionary theory and the findings are consistent with previous research on patterns of altruism, sex differences in mate preferences, sex differences in reproductive strategy, and differing emphases on male and female physical attractiveness. World literature, especially originally oral literature, represents a vast and neglected repository of information that researchers can use to more precisely map the contours of human nature. Jonathan Gottschall received his Ph.D. in English from Binghamton University and now teaches at St. Lawrence University in Canton, New York. His research focuses on integrating Darwinian approaches to human behavior and psychology with literary studies. The other authors are undergraduate students at St. Lawrence University.     

Global Warming Impact of E85 Fuel Derived from Forest Biomass: A Case Study from Southern USA

This study estimates global warming impact (GWI) of E85 fuel needed to run a small passenger car for its average lifetime, i.e., 241,402 km (150,000 miles). The ethanol needed for the production of E85 fuel was derived from an intensively managed slash pine (Pinus elliottii) plantation in the southern USA. We assumed that only pulpwood and harvesting residues obtained at the time of harvesting were used for ethanol production. A suitable system boundary was defined and a detailed life-cycle assessment was undertaken to determine GWI of all the steps present within the system boundary. Results indicate that the overall GWI of the E85 fuel was about 76% less than an equivalent amount of gasoline needed to run a small passenger car for its average lifetime. Within the system boundary, the GWI of the ethanol production stage was highest followed by the stage of E85 fuel consumption in a small passenger car. A need exists to evaluate impacts of utilizing forest biomass for E85 fuel production on forest ecology and traditional forest biomass-based industries.     

Expression of beta-amyloid precursor protein in reactive astrocytes following neuronal damage

Although the beta-amyloid peptide is an established core component of neuritic plaques that accumulate in Alzheimer's disease, the mechanisms responsible for its deposition are not well understood. We now report that lesions of rat hippocampal neurons cause a time-dependent, long-lasting elevation of immunoreactivity for the beta-amyloid precursor protein (APP) in neighboring astrocytes, a cell type not normally containing the protein. The increase represents astroglial expression of the protein rather than a scavenging of APP released by damaged neurons. Immunoelectron microscopy confirmed that APP-containing cells are reactive astroglia, both surrounding capillaries and within the neuropil. These results demonstrate that neuronal damage stimulates APP expression in adult brain and suggest that reactive astrocytes may be a source of the beta-amyloid that forms neuropathological plaques in Alzheimer's disease.     

Regulation of axonemal Mg2+-ATPase from Paramecium cilia: effects of Ca2+ and cyclic nucleotides

Ciliary activity is regulated by Ca2+ and cyclic nucleotides, but the molecular mechanisms of the regulation are unknown. We have tested the ability of Ca2+ and cyclic nucleotides to alter ciliary Mg2+-ATPase or to stimulate phosphorylation of axonemal dynein. Mg2+-ATPase activity in cilia and axonemes from Paramecium was stimulated 2-fold by micromolar Ca2+, but this Ca2+ sensitivity was lost upon solubilization of the dyneins from the axoneme. The Ca2+-sensitive component of ciliary Mg2+-ATPase activity was inhibited by the dynein inhibitors vanadate and Zn2+, but was insensitive to the calmodulin antagonists calmidazolium and melittin. Dynein activity in the high-salt extract from axonemes was also insensitive to calmidazolium. Calmodulin did not sediment with 22 S or 12 S dyneins on sucrose gradients containing Ca2+, but it did sediment in the region from 19 S to 14 S. Mg2+-ATPase activity in ciliary fractions was unaltered in the presence of cAMP or cGMP. However, polypeptides associated with the 22 S and 12 S dyneins, as well as proteins of 19 S, 15 S, and 8 S, were substrates for endogenous ciliary kinases. High molecular weight polypeptides that sedimented at 22 S and 19 S were phosphorylated in a cyclic nucleotide-stimulated manner.