Uptake and Conversion of Selenium by a Marine Bacterium

1983 ◽  
Vol 40 (S2) ◽  
pp. s215-s220 ◽  
Author(s):  
A. Foda ◽  
J. H. Vandermeulen ◽  
J. J. Wrench

Bio-conversion of Se was examined by incubating Pseudomonas marina in seawater containing either selenite (Na2SeIVO3) or selenate (Na2SeVIO4). At the concentrations of selenite and selenate used (10−4–10−7 mol/L), the growth of P. marina was not inhibited. Under these conditions, selenite was taken up by P. marina, but selenate was not found to enter the cells. Pseudomonas marina incorporated selenite from filtered seawater into sub-cellular fractions, primarily protein (30–50%) and amino acids (44–70%). When incubated in marine broth, P. marina incorporated 75selenite primarily into protein (up to 75%), with a lesser amount into the amino acid fraction (approximately 25%). Insignificant amounts were associated with the bacterial lipid fraction. SeIV was found in the protein and amino acid fractions within 10 min of incubation in medium containing selenite. In uptake studies the level of SeIV in the incubating medium decreased markedly, corresponding presumably to SeIV entering the bacterial cells from the medium. However, simultaneous measurements of total Se in the medium (gas–liquid chromatography following photooxidation) revealed an increasing amount of non-SeIV species of Se in the medium throughout the same period. These results were interpreted as due to the bioconversion of selenite by P. marina into water-soluble non-SeIV metabolite(s) and their subsequent release back into the medium. Up to 35% of the total Se found in the medium after 24 h can be accounted for by this conversion of SeIV into another oxidation state. Pseudomonas marina is also capable of reducing SeIV to elemental Se; this pathway becomes increasingly evident at higher concentrations of Na2SeO3.

2012 ◽  
Vol 12 (50) ◽  
pp. 5959-5977
Author(s):  
MW Mburu ◽  
◽  
NK Gikonyo ◽  
GM Kenji ◽  
AM Mwasaru ◽  
...  

The objective of this study was to determine the nutritional and functional properties of Amaranthus cruentus grain grown in Kenya for preparation of a ready-to-eat product that can be recommended as infant complementary food. Amaranth grains were subjected to steeping and steam pre-gelatinization to produce a ready-to-eat nutritious product with improved solubility during reconstitution. The effect of processing on the functional and nutritional properties of amaranth grain was analyzed. Two blends were prepared from raw and processed amaranth grains. Standard procedures of Association of Official Analytical Chemists (AOAC) were used to determine the proximate chemical composition. High Performance Liquid Chromatography (HPLC) was used quantify amino acid, water soluble vitamins, αtocopherols and phytates, while Atomic Absorption Flame Emission spectrophotometry was used to determine the mineral element composition. Fatty acid composition was determined using Gas Liquid Chromatography (GLC). Tannin composition was determined using vanillin hydrochloric acid method. The overall results indicated that processing amaranth grain did not significantly affect its nutritional and physicochemical properties. Amaranth grain product was rich in protein with 0.5 g/10g of lysine, a limiting amino acid in cereals, and methionine, a limiting amino acid in pulses. The product had good amount 44.4 mg/100g of αtocopherols important for infant development. The product was also rich in oleic acid (36.3%) and linoleic acid (35.9%) with some amounts of linolenic acid (3.4%) that are important for infant growth. It also had good amounts of minerals of importance such as potassium (324.4 mg/100g), phosphorous (322.8 mg/100g), calcium 189.1 (mg/100g), magnesium (219.5 mg/100g), iron (13.0 mg/100g) and zinc (4.8mg/100g). Considering amaranth grain product fed to infant three times a day, at a reconstitution of 15% product, the levels of magnesium, manganese and tocopherols were far above the recommended intakes, while protein, phosphorous, iron, zinc, riboflavin and niacin were above the average requirements. Therefore, reconstituting the product with milk would enrich the deficient nutrients, especially for iron and zinc which are crucial nutrients for infants. The processing method is a practical approach aimed at combating the problem of malnutrition among infants and young children in Kenya and other developing countries. The product developed in this study would also be appropriate for use in geriatrics care and also in immuno-compromised individuals. The technique in this study can be easily adopted at both household and village levels to produce high protein-energy weaning food to help enhance the nutritional status of Kenyans.


1957 ◽  
Vol 23 (104) ◽  
pp. 843-849 ◽  
Author(s):  
Junzo Noguchi ◽  
Tadao Hayakawa ◽  
Mituo Ebata
Keyword(s):  

2003 ◽  
Vol 77 (9) ◽  
pp. 5192-5200 ◽  
Author(s):  
Chisu Song ◽  
Susan R. Dubay ◽  
Eric Hunter

ABSTRACT Mason-Pfizer monkey virus (M-PMV) encodes a transmembrane (TM) glycoprotein with a 38-amino-acid-long cytoplasmic domain. After the release of the immature virus, a viral protease-mediated cleavage occurs within the cytoplasmic domain, resulting in the loss of 17 amino acids from the carboxy terminus. This maturational cleavage occurs between a histidine at position 21 and a tyrosine at position 22 in the cytoplasmic domain of the TM protein. We have demonstrated previously that a truncated TM glycoprotein with a 21-amino-acid-long cytoplasmic tail showed enhanced fusogenicity but could not be incorporated into virions. These results suggest that postassembly cleavage of the cytoplasmic domain removes a necessary incorporation signal and activates fusion activity. To investigate the contribution of tyrosine residues to the function of the glycoprotein complex and virus replication, we have introduced amino acid substitutions into two tyrosine residues found in the cytoplasmic domain. The effects of these mutations on glycoprotein biosynthesis and function, as well as on virus infectivity, have been examined. Mutation of tyrosine 34 to alanine had little effect on glycoprotein function. In contrast, substitutions at tyrosine 22 modulated fusion activity in either a positive or negative manner, depending on the substituting amino acid. Moreover, any nonaromatic substitution at this position blocked glycoprotein incorporation into virions and abolished infectivity. These results demonstrate that M-PMV employs a tyrosine signal for the selective incorporation of glycoprotein into budding virions. Antibody uptake studies show that tyrosine 22 is part of an efficient internalization signal in the cytoplasmic domain of the M-PMV glycoprotein that can also be positively and negatively influenced by changes at this site.


2018 ◽  
Vol 10 (464) ◽  
pp. eaal0033 ◽  
Author(s):  
Ahsan R. Akram ◽  
Sunay V. Chankeshwara ◽  
Emma Scholefield ◽  
Tashfeen Aslam ◽  
Neil McDonald ◽  
...  

Respiratory infections in mechanically ventilated patients caused by Gram-negative bacteria are a major cause of morbidity. Rapid and unequivocal determination of the presence, localization, and abundance of bacteria is critical for positive resolution of the infections and could be used for patient stratification and for monitoring treatment efficacy. Here, we developed an in situ approach to visualize Gram-negative bacterial species and cellular infiltrates in distal human lungs in real time. We used optical endomicroscopy to visualize a water-soluble optical imaging probe based on the antimicrobial peptide polymyxin conjugated to an environmentally sensitive fluorophore. The probe was chemically stable and nontoxic and, after in-human intrapulmonary microdosing, enabled the specific detection of Gram-negative bacteria in distal human airways and alveoli within minutes. The results suggest that pulmonary molecular imaging using a topically administered fluorescent probe targeting bacterial lipid A is safe and practical, enabling rapid in situ identification of Gram-negative bacteria in humans.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 82-83
Author(s):  
Pornpim Aparachita ◽  
Scott Carter ◽  
Afton Sawyer ◽  
Jared Harshman ◽  
Zach Rambo ◽  
...  

Abstract Previously, we reported that supplementing a water soluble zinc via drinking water (0 to 80 mg/L) to nursery pigs improved ADG and G:F. To evaluate the efficacy of higher titrated levels of this water soluble zinc amino acid complex (ProPath®Zn LQ, Zinpro Corporation, Eden Prairie, MN) on growth performance, 280 crossbred pigs (5.5 kg BW; 19 d of age) were randomly allotted to four water treatments (7 pens/treatment; 10 pigs/pen). The water treatments were 0, 40, 80 and 160 mg Zn/L of water. Pigs were fed in 4 dietary phases with complex, nutrient-dense, corn-soybean meal-based diets: Phase 1 and 2 (2,500 and 1,750 mg Zn as ZnO/kg; d 1–7 and 7–14, respectively) and Phase 3 and 4 (200 mg Cu as CuSO4/kg; d 14–23 and 23–42, respectively). Pigs and feeders were weighed weekly to determine ADG, ADFI, and G:F. Water meters were used to record and calculate water disappearance and zinc intake. Data were analyzed as a randomized complete block design. Orthogonal polynomial contrasts were used to determine linear and curvilinear effects. Water and total zinc intake increased linearly (P < 0.001) with increasing water zinc concentration. From d 0–14 when high dietary zinc was fed, there were no differences (P > 0.10) in ADG, ADFI, or G:F. However, from d 14–42 when basal levels of zinc were fed, quadratic improvements in ADG (0.545, 0.561, 0.578, 0.546 kg; P < 0.05) and G:F (0.686, 0.706, 0.723, 0.702; P < 0.01) were observed with increasing zinc via water. Similarly for d 0–42, ADG (0.435, 0.440, 0.454; 0.434 kg; P = 0.07), G:F (0.726, 0.740, 0.763, 0.749; P = 0.05) and average ending wt (23.73, 23.97, 24.55, 23.70 kg; P = 0.07) improved quadratically with increasing zinc. In conclusion, supplementing ProPath®Zn LQ via water resulted in improvements in ADG and G:F for nursery pigs.


2010 ◽  
Vol 7 (3) ◽  
pp. 350-353
Author(s):  
Abdullah Rasyid ◽  
Kyoko Adachi

The bioactive substance producing strain, a marine bacterium A5S-46 was found in the antibacterial screening. This strain was isolated from the artificial sponge set in the coastal seawater at Iriomote islands (Japan). The crude extract from culture broth of the strain A5S-46 was assayed to the antibacterial activity test against the seven kinds of bacterial test strains. The active substance accumulated in the both bacterial cells and culture supernatant. Based on the 1H NMR and the LC/PDA/MS data, the bioactive substance was identified to be actinomycin D.   Keywords: Marine bacteria, Actinomycin D, Antibacterial, Anticancer


1996 ◽  
Vol 61 (22) ◽  
pp. 7650-7651 ◽  
Author(s):  
Christopher L. Wysong ◽  
T. Scott Yokum ◽  
Guillermo A. Morales ◽  
Rebekah L. Gundry ◽  
Mark L. McLaughlin ◽  
...  

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