Sulfate-reducing bacteria in marine sediments

The occurrence of hydrogen sulfide in the waters of certain seas, fjords, and basins, as well as the presence of black or blue stinking sediments, can hardly escape the notice of any marine scientist. It is not surprising, therefore, that the eminent oceanographer Murray (Murray and Irvine, 1895) concerned himself with the nature of these materials and postulated their bacterial origin even before bacteriologists had described the specific organisms involved

Feeding a Brown Midrib Corn Silage-Based Diet to Growing Beef Steers Improves Growth Performance and Economic Returns

A feedlot experiment was performed to determine growth performance, ruminal fermentation characteristics, and economic returns for growing beef steers when fed a brown midrib corn silage-based total mixed ration (BMRT) compared with a conventional corn silage-based total mixed ration (CCST). Twenty-four Angus crossbred steers (initial body weight=258±23.2 kg) in individual pens were used in a completely randomized design (n=12). Intake of dry matter was not different between the treatments. Steers fed the BMRT tended to have greater average daily gain (1.54 vs. 1.42 kg d−1; P=0.09) and gain-to-feed ratio (0.165 vs. 0.146; P=0.07) compared with those fed the CCST. Feeding the BMRT increased total volatile fatty acid (VFA) concentration (P=0.01) compared with the CCST, while it decreased molar proportion of acetate (P\u3c0.01), and increased propionate proportion (P=0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P\u3c0.01). Steers fed the BMRT increased feed margin (P=0.05) and net return (P=0.02) compared with those fed the CCST throughout the trial. Overall results of this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth and economic performance of steers © 2015, Agricultural Institute of Canada. All Rights Reserved

Ökologische Untersuchungen zur Nitrifikation in Nord-und Ostsee

Ammonia, nitrite and nitrate were regularly estimated at several stations in the Kieler Bucht (western Baltic Sea) since November 1964. There are considerable seasonal changes in the contents of these 3 nitrogen compounds with impressive maxima of nitrite and nitrate in February or at the beginning of March. The great increase of nitrite and nitrate during the winter and also a smaller increase in summer are mainly caused by oxidation of ammonia, first to nitrite and then to nitrate, by nitrifying bacteria. In consequence chemoautotrophic nitrite- and nitratebacteria could be found in the water as well as in sediments all over the Kieler Bucht and also in the North Sea around the isle of Helgoland. These nitrifying bacteria are able to oxidize ammonia or nitrite in salinity conditions typical for the western Baltic Sea and the North Sea

SBP-domain transcription factors as possible effectors of cryptochrome-mediated blue light signalling in the moss Physcomitrella patens

Cryptochromes are blue light absorbing photoreceptors found in many organisms and involved in numerous developmental processes. At least two highly similar cryptochromes are known to affect branching during gametophytic development in the moss Physcomitrella patens. We uncovered a relationship between these cryptochromes and the expression of particular members of the SBP-box genes, a plant specific transcription factor family. Transcript levels of the respective moss SBP-box genes, all belonging to the LG1-subfamily, were found to be dependent, albeit not exclusively, on blue light. Moreover, disruptant lines generated for two moss representatives of this SBP-box gene subfamily, both showed enhanced caulonema side branch formation, a phenotype opposite to that of the ppcry1a/1b double disruptant line. In this report we show that PpCRY1a and PpCRY1b act negatively on the transcript levels of several related moss SBP-box genes and that at least PpSBP1 and PpSBP4 act as negative regulators of side branch formation