Proteins involved in biophoton emission and flooding-stress responses in soybean under light and dark conditions

To know the molecular systems basically flooding conditions in soybean, biophoton emission measurements and proteomic analyses were carried out for flooding-stressed roots under light and dark conditions. Photon emission was analyzed using a photon counter. Gel-free quantitative proteomics were performed to identify significant changes proteins using the nano LC–MS along with SIEVE software. Biophoton emissions were significantly increased in both light and dark conditions after flooding stress, but gradually decreased with continued flooding exposure compared to the control plants. Among the 120 significantly identified proteins in the roots of soybean plants, 73 and 19 proteins were decreased and increased in the light condition, respectively, and 4 and 24 proteins were increased and decreased, respectively, in the dark condition. The proteins were mainly functionally grouped into cell organization, protein degradation/synthesis, and glycolysis. The highly abundant lactate/malate dehydrogenase proteins were decreased in flooding-stressed roots exposed to light, whereas the lysine ketoglutarate reductase/saccharopine dehydrogenase bifunctional enzyme was increased in both light and dark conditions. Notably, however, specific enzyme assays revealed that the activities of these enzymes and biophoton emission were sharply increased after 3 days of flooding stress. This finding suggests that the source of biophoton emission in roots might involve the chemical excitation of electron or proton through enzymatic or non-enzymatic oxidation and reduction reactions. Moreover, the lysine ketoglutarate reductase/saccharopine dehydrogenase bifunctional enzyme may play important roles in responses in flooding stress of soybean under the light condition and as a contributing factor to biophoton emission.     

The profile of enzymes relevant to solvent production during direct fermentation of sago starch by <Emphasis Type="Italic">Clostridium saccharobutylicum</Emphasis> P262 utilizing different pH control strategies

The profile of enzymes relevant to solvent production during direct fermentation of sago starch by Clostridium saccharobutylicum P262 in a 2 L stirred tank fermenter was determined utilizing different pH control strategies. During fermentation without pH control (initial pH of 6), the specific activity of crotonase, thiolase, and β-hydroxybutyryl-CoA dehydrogenase increased proportionally with solvent production. The highest crotonase (3,450.7 kat) and phosphotransbutyrylase activity (1,475.6 kat) was observed in fermentation where pH was maintained at 5 during the acidogenic phase and corresponded to a fairly high acid accumulation but low solvent production. During fermentation with a controlled pH of 5.25 during the sol-ventogenic phase, the highest thiolase specific activity (255.7 kat) was obtained and corresponded to the highest production of acetone. On the other hand, the highest specific activities of crotonase, β-hydroxybutyryl-CoA dehydrogenase, and phosphotransbutyrylase were observed at pH 5.5 and corresponded to the highest production of ethanol and butanol. Butyryl-CoA dehydrogenase had no significance role in solvent fermentation. These results suggested that pH control strategies were important for improvement of solvent production during direct fermentation of sago starch by C. saccharobutylicum.     

The effects of general anaesthetics on glucose and phosphate transport across the membrane of the human erythrocyte

A study has been carried out into the effects of clinically important general anaesthetics, althesin, thiopentone and propanidid, on the transport of glucose and phosphate across the membrane of the human erythrocyte. In general these three substances all inhibit both transport processes but with characteristic inhibition profiles and varying degrees of efficacy. Glucose transport was more sensitive to the hydrophobic steroids and phosphate transport to propanidid. Some hydrophobic agents, e.g., iodobenzene and its azide, were not inhibitory. Removal of cholesterol to some extent augmented the inhibitory effects of most of these compounds (not propanidid). It is argued that these effects are due to the penetration of the anaesthetics into the lipid bilayer and either subsequent disruption of the lipid annuli surrounding the integral membrane proteins and/or direct anaesthetic-protein interaction.     

Thermostable extracellular protease of Bacillus stearothermophilus: factors affecting its production

A strain of protease-producing Bacillus stearothermophilus has been isolated. Glycerol was the best carbon source for production whereas yeast extract was the best nitrogen source. The bacterium could grow up to 70°C but optimum protease production was at 60°C. Best initial pH for protease production was 5. Alkaline pH inhibited production. The enzyme was stable at 60°C for 18 h and was inhibited by EDTA, PMSF and HgCl₂.The authors are with the Enzyme and Microbial Technology Group, Faculty of Science and Environmental Studies, Universiti Pertanian Malaysia, 43400 UPM Serdang, Selangor, Malaysia     

The role of transaminases in realizing the protective effect of L-aspartate in hypoxia]

Activation of aspartate aminotransferase and alanine aminotransferase of mitochondria introduced to the incubation medium of pyridoxal-5'-phosphate (40 microM) is approximately 2 times higher than that of the corresponding cytoplasmic forms. At hypoxia aspartate aminotransferase activity in mitochondria and postmitochondrial supernatant tends to an increase while that of alanine aminotransferase decreases (above 2 times). The protection from hypoxic damage when using L-aspartate (100 mg/kg subcutaneously 3-5 min before hypoxia) intensifies an adaptive increase of aspartate aminotransferase activity and removes a decrease of alanine aminotransferase activity. Under these conditions stimulating effect of pyridoxal-5'-phosphate on transaminases activity in vitro weakens. A simultaneous administration of vitamin-coenzyme complex (thiamine pyrophosphate, lipoate, sodium 4-phospho-pantothenate, flavin-mononucleotide, nicotinate) intensifies these metabolic shifts and protective action of L-aspartate.     

Gene co-expression networks from RNA sequencing of dairy cattle identifies genes and pathways affecting feed efficiency

Background

Selection for feed efficiency is crucial for overall profitability and sustainability in dairy cattle production. Key regulator genes and genetic markers derived from co-expression networks underlying feed efficiency could be included in the genomic selection of the best cows. The present study identified co-expression networks associated with high and low feed efficiency and their regulator genes in Danish Holstein and Jersey cows.RNA-sequencing data from Holstein and Jersey cows with high and low residual feed intake (RFI) and treated with two diets (low and high concentrate) were used. Approximately 26 million and 25 million pair reads were mapped to bovine reference genome for Jersey and Holstein breed, respectively. Subsequently, the gene count expressions data were analysed using a Weighted Gene Co-expression Network Analysis (WGCNA) approach. Functional enrichment analysis from Ingenuity® Pathway Analysis (IPA®), ClueGO application and STRING of these modules was performed to identify relevant biological pathways and regulatory genes.

Results

WGCNA identified two groups of co-expressed genes (modules) significantly associated with RFI and one module significantly associated with diet. In Holstein cows, the salmon module with module trait relationship (MTR)?=?0.7 and the top upstream regulators ATP7B were involved in cholesterol biosynthesis, steroid biosynthesis, lipid biosynthesis and fatty acid metabolism. The magenta module has been significantly associated (MTR?=?0.51) with the treatment diet involved in the triglyceride homeostasis. In Jersey cows, the lightsteelblue1 (MTR?=???0.57) module controlled by IFNG and IL10RA was involved in the positive regulation of interferon-gamma production, lymphocyte differentiation, natural killer cell-mediated cytotoxicity and primary immunodeficiency.

Conclusion

The present study provides new information on the biological functions in liver that are potentially involved in controlling feed efficiency. The hub genes and upstream regulators (ATP7b, IFNG and IL10RA) involved in these functions are potential candidate genes for the development of new biomarkers. However, the hub genes, upstream regulators and pathways involved in the co-expressed networks were different in both breeds. Hence, additional studies are required to investigate and confirm these findings prior to their use as candidate genes.

     

Growth-mediated variations in fatty acids of Xenorhabdus sp

The bacterium Xenorhabdus sp. is symbiotically associated with the entomopathogenic nematode Steinernema riobravis. This nematode is produced in monoxenic culture with Xenorhabdus sp. and is sold as a biological insecticide. Acceptable yields in fermentors can only be achieved in the presence of vigorous growth of the bacterium. We investigated the fatty acid composition of Xenorhabdus species when grown at 15, 20, 25 or 30 degrees C on media containing one of two primary carbon sources: glucose or lipids from the insect host, Galleria mellonella. Both temperature and primary carbon source significantly affected lipid quantity and quality in Xenorhabdus sp. Bacteria grown with insect lipids as a primary carbon source accumulated more lipids with greater proportion of longer chain fatty acids than bacteria grown with glucose as a primary carbon source. Cells grown with insect lipids at 15 degrees C had a lower lipid content than cells grown on the same media at 20, 25 or 30 degrees C. Increasing growth temperature increased saturated fatty acids and decreased unsaturated fatty acids, irrespective of carbon source. We recommend addition of complex fatty acid sources that resemble natural host lipids to growth medium for mass producing entomopathogenic nematodes. This could provide nematode quality similar to in vivo-produced nematodes.