Evaluation of the robustness of FT-IR spectra of lactobacilli towards changes in the bacterial growth conditions.

In order to use Fourier Transform Infrared (FT-IR) spectroscopy for identification of microorganisms on a routine basis, it is important that the spectra are robust against small, uncontrollable variations in the bacterial growth conditions. In this study, the effect of small variations in growth temperature, growth time, growth medium and atmospheric conditions on the separation of Lactobacillus based on their FT-IR spectra was investigated. The resulting spectra were shown to be robust against the variations in the cultivation conditions, and the separation of both strains and species was unaffected.

Identification of a region involved in the pheromone receptor function of the histidine kinase PlnB.

Bacteriocin biosynthesis in Lactobacillus plantarum is an inducible process, triggered by the secreted inducer peptide pheromone IP-C11. The environmental concentration of IP-C11 is monitored by the membrane-bound histidine protein kinase PlnB, which is part of a two-component signal transduction pathway. Upon interaction with IP-C11, PlnB phosphorylates the cognate response regulator PlnC.

Detection, integration and persistence of aeromonads in water distribution pipe biofilms.

The occurrence of Aeromonas spp. within biofilms formed on stainless steel (SS), unplasticized polyvinyl chloride (uPVC) and glass (GL) substrata was investigated in modified Robbins Devices (MRD) in potable (MRD-p) and recycled (MRD-r) water systems, a Biofilm Reactor (BR) and a laboratory-scale pipe loop (PL) receiving simulated recycled wastewater. No aeromonads were isolated from the MRD-p whereas 3-10% of SS and uPVC coupons (mean 3.

Rational engineering of enzyme stability.

During the past 15 years there has been a continuous flow of reports describing proteins stabilized by the introduction of mutations. These reports span a period from pioneering rational design work on small enzymes such as T4 lysozyme and barnase to protein design, and directed evolution. Concomitantly, the purification and characterization of naturally occurring hyperstable proteins has added to our understanding of protein stability.

Short communication: bivariate genetic analysis of clinical mastitis and somatic cell count in Norwegian dairy cattle.

Clinical mastitis (CM) and lactation mean somatic cell score (LSCS) were analyzed with a bivariate linear sire model. Nearly 1.4 million primiparous cows of Norwegian Dairy Cattle from 2043 sires were used.

Multivariate threshold model analysis of clinical mastitis in multiparous norwegian dairy cattle.

A Bayesian multivariate threshold model was fitted to clinical mastitis (CM) records from 372,227 daughters of 2411 Norwegian Dairy Cattle (NRF) sires. All cases of veterinary-treated CM occurring from 30 d before first calving to culling or 300 d after third calving were included. Lactations were divided into 4 intervals: -30 to 0 d, 1 to 30 d, 31 to 120 d, and 121 to 300 d after calving.

FT-IR spectroscopy for identification of closely related lactobacilli.

Fourier Transform Infrared (FT-IR) spectroscopy was used to analyse 56 strains from four closely related species of Lactobacillus, L. sakei, L. plantarum, L.

Priming nonlinear searches for pathway identification.

Background: Dense time series of metabolite concentrations or of the expression patterns of proteins may be available in the near future as a result of the rapid development of novel, high-throughput experimental techniques. Such time series implicitly contain valuable information about the connectivity and regulatory structure of the underlying metabolic or proteomic networks. The extraction of this information is a challenging task because it usually requires nonlinear estimation methods that involve iterative search algorithms.

Physicochemical traits of Dekoko (Pisum sativum var. abyssinicum) seeds.

Dekoko (Pisum sativum var. abyssinicum) has high appreciation for its taste and obtains a premium price in local markets compared to Ater (Pisum sativum var. sativum).

Can sunspot activity and ultraviolet-B radiation explain cyclic outbreaks of forest moth pest species?

Cyclic outbreaks of forest moth pest species have long remained a puzzle for foresters and ecologists. This paper presents time-series exhibiting a strong negative relationship between sunspot numbers and population indices of autumnal and winter moths, both in a mountain birch forest in central Norway and in a mixed lowland forest in southern Norway. In the latter area, also the population level of a moth species feeding entirely on lichens was negatively related to sunspot numbers.

A genetic and spatial Bayesian analysis of mastitis resistance.

A nationwide health card recording system for dairy cattle was introduced in Norway in 1975 (the Norwegian Cattle Health Services). The data base holds information on mastitis occurrences on an individual cow basis. A reduction in mastitis frequency across the population is desired, and for this purpose risk factors are investigated.

A sensory map of the meat universe. Sensory profile of meat from 15 species.

The aim of the study was to investigate if meat from different species could be described and related to each other by sensory analysis. Muscle meat from 15 different species commercially available in Norway was assessed by a 22 sensory attribute profile and analysed by multivariate analysis. The different species were significantly different on attributes that gave adequate descriptions of all species.

Formation of 3-hexuloses in aldol reactions, analysis of the products as their O-isopropylidene derivatives by GC-MS.

A method for analysis of mixtures of 3-hexuloses by gas chromatography mass spectrometry of their di-O-isopropylidene derivatives has been elaborated. The origin of characteristic fragment ions in the mass spectra is suggested on the basis of the spectra of d(12) analogues, obtained by acetonation with acetone-d(6) and on MS/MS investigations. The method has been applied to product mixtures from aldol reactions between glycero-tetrulose and glycolaldehyde and between 2-pentuloses and formaldehyde.

Transformation of positively charged aluminium-species in unstable mixing zones following liming.

Liming is widely used to counteract chronic toxicity of positively charged monomeric aluminium species (Ali). Immediately after liming, unstable mixing zones are formed due to the sudden increase in pH. Transformation of monomeric Ali species takes place instantaneously and transient positively charged Al polymers, being acute toxic to fish, are formed in the mixing zones.

Quantification of photoperiodic effects on growth of Phleum pratense.

Background And Aims: Accurate quantifications of plant responses to photoperiod are useful for physiological studies, in growth modelling and in other studies of environmental effects. The objective of the current work was a mathematical description of photoperiodic influence on plant morphological traits, using functions with few and common parameters related to key plant characteristics and typical response patterns.

Methods: Two latitudinal cultivars of timothy (Phleum pratense) were studied in a climate chamber experiment at 9, 12, 15, 18, 21 and 24 h photoperiods.

Lipid oxidation in frozen, mechanically deboned turkey meat as affected by packaging parameters and storage conditions.

Mechanically deboned turkey meat (MDTM) was stored in different packaging materials (film produced with natural antioxidant (alpha-tocopherol) or synthetic antioxidant) at -20 degrees C for 12 mo in a vacuum, modified atmosphere, or air. One-half of the samples were thawed at 4 degrees C for 24 h after 1 mo of storage and then refrozen. Oxidative rancidity was evaluated during storage by measuring the development of 2-thiobarbituric acid reactive substances (TBARS), and hexanal, a volatile oxidation product.

Plutonium in the arctic marine environment--a short review.

Anthropogenic plutonium has been introduced into the environment over the past 50 years as the result of the detonation of nuclear weapons and operational releases from the nuclear industry. In the Arctic environment, the main source of plutonium is from atmospheric weapons testing, which has resulted in a relatively uniform, underlying global distribution of plutonium. Previous studies of plutonium in the Kara Sea have shown that, at certain sites, other releases have given rise to enhanced local concentrations.

Phenotypic and PCR-based characterization of the microflora in Norvegia cheese during ripening.

Microbiological sampling of Norvegia cheese from three cheese factories was done during ripening. The evolution of aerobic mesophilic bacteria, lactococci, lactobacilli, enterococci, presumptive leuconostoc and pediococci was investigated after 30, 90, 180 and 270 days of ripening. Isolates (135) of non-starter lactic acid bacteria (NSLAB) from nine Norvegia cheeses after 90, 180 and 270 days of ripening were examined.

High-level gene expression in Lactobacillus plantarum using a pheromone-regulated bacteriocin promoter.

Aims: To use promoters and regulatory genes involved in the production of the bacteriocin sakacin P to obtain high-level regulated gene expression in Lactobacillus plantarum.

Methods And Results: In a plasmid containing all three operons naturally involved in sakacin P production, the genes encoding sakacin P and its immunity protein were replaced by the aminopeptidase N gene from Lactococcus lactis (pepN) or the beta-glucuronidase gene from Escherichia coli (gusA). The new genes were precisely fused to the start codon of the sakacin P gene and the stop codon of the immunity gene.

Determination of CH4, CO2 and N2O in air samples and soil atmosphere by gas chromatography mass spectrometry, GC-MS.

A method for determination of the climate gases CH4, CO2 and N2O in air samples and soil atmosphere was developed using GC-MS. The method uses straightforward gas chromatography (separation of the gases) with a mass spectrometric detector in single ion mode (specific determination). The gases were determined with high sensitivity and high sample throughput (18 samples h(-1)).

Sample displacement chromatography of Atlantic Salmon (Salmo salar) thrombin.

A modified method of sample displacement chromatography (SDC) was used to purify active salmon thrombin on a heparin-coupled matrix to near homogeneity in milligram amounts from 117 ml plasma. This was achieved by combining a low-pressure multi-column affinity chromatography system with non-homogenous sample application in the order of increasing affinity to Heparin Sepharose. The results suggest that this modified method could be useful in protein purification.

Epigenetic regulation of aging in honeybee workers.

Aging and longevity are complex life history traits that are influenced by both genes and environment and exhibit significant phenotypic plasticity in a broad range of organisms. A striking example of this plasticity is seen in social insects, such as ants and bees, where different castes can have very different life spans. In particular, the honeybee worker offers an intriguing example of environmental control on aging rate, because workers are conditionally sterile and display very different aging patterns depending on which temporal caste they belong to (hive bee, forager, or a long-lived caste capable of surviving for several months on honey alone).

Bacterial removal and protozoan grazing in biological sand filters.

The objective of the study was to investigate the importance of protozoan predation as a biological removal mechanism in sand filters used for purification of bacteria from wastewater. Eleven sand filter columns were seeded with a high dose of wastewater (70 mm d(-1)) and a high concentration (10(8) colony forming units [CFU] mL(-1)) of Aeromonas hydrophila (American Type Culture Collection [ATCC] 14715) for a period of 30 d. Water samples from three filter outlets were analyzed for the concentration of A.