Effect of premix ingredients and its inoculation with lactic acid-producing bacteria on ensiling of poultry droppings with conventional feeds

A premix of poultry droppings (25 parts) and wheat straw (65 parts) was inoculated with a mixed culture of Lactobacillus plantarum and Streptococcus faecalis in the presence or absence of sugarcane molasses. The inclusion of lactic acid-producing bacteria and molasses in the premix resulted in reduced pH, ammonia nitrogen and total volatile fatty acids and increased production of lactic acid during a fermentation time of 20 d at 32–35°C. The sugarcane molasses and part of the wheat straw can be replaced with green maize fodder in the vegetative stage without any adverse effect on the silage characteristics. With an increasing level of green maize in the premix, there was a decrease in pH, dry matter of premix and wastelage and a significant increase in soluble sugars of premix and titrable acidity and lactic acid content of wastelage. A good wastelage can be produced when the premix consists of poultry droppings, wheat straw and green maize in the ratio of 25: 15:60, respectively, and it is inoculated with lactic acid-producing bacteria.     

Glutathione S-transferases of the bovine retina. Evidence that glutathione peroxidase activity is the result of glutathione S-transferase.

We have purified two isoenzymes of glutathione S-transferase from bovine retina to apparent homogeneity through a combination of gel-filtration chromatography, affinity chromatography and isoelectric focusing. The more anionic (pI = 6.34) and less anionic (pI = 6.87) isoenzymes were comparable with respect to kinetic and structural parameters. The Km for both substrates, reduced glutathione and 1-chloro-2,4-dinitrobenzene, bilirubin inhibition of glutathione conjugation to 1-chloro-2,4-dinitrobenzene, 1-chloro-2,4-dinitrobenzene inactivation of enzyme activity and molecular weight were similar. However, pH optimum and energy of activation were found to differ considerably. Retina was found to have no selenium-dependent glutathione peroxidase activity. The total glutathione peroxidase activity fractionated with the transferases in the gel-filtration range of mol.wt. 49000 and expressed activity with only organic hydroperoxides as substrate. Only the more anionic isoenzyme expressed both transferase and peroxidase activity.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Regulation of nitrate reductase activity in higher plants

Nitrate reductase is one of the most important enzymes in the assimilation of exogenous nitrate—the predominant form of nitrogen available to green plants growing in soil. Activity of this enzyme in plants gives a good estimate of the nitrogen status of the plant and is very often correlated with growth and yield. Although it is difficult to explain the physiological significance and the mechanism of effects of several factors on the enzyme activity, in some cases suitable postulates have been advanced. In general, the enzyme activity in a plant tissue is a balance between its relative rates of synthesis/degradation and activation/inactivation. Factors may affect the overall activity by interfering with either of these processes.     

Cotugnia digonopora: Transport of leucine

The uptake of leucine through the tegument of Cotugnia digonopora, a cestode found in the fowl intestine, occurs by a process of active transport. The K_t of transport is 0.87 mM and the V_max is 0.223 μmol/min/g. Uptake of the amino acid is competitively inhibited by valine (K_t = 1.30 mM). Potassium cyanide and 2,4-dinitrophenol do not completely block the entry of leucine into the parasite.     

An investigation into the role of SH1 and SH2 groups of myosin in calcium binding and tension generation

Myosin heavy chains influence the Ca²⁺ binding properties of the light chains. When the SH₁ + SH₂ moieties of myosin, located on heavy meromyosin S-1, are blocked, myosin loses its Ca²⁺ binding capabilities. Furthermore, (SH₁ + SH₂)-blocked myosin no longer expresses tension when analyzed as modified actomyosin threads. When the SH₁ moiety of myosin is blocked, myosin continues to express normal Ca²⁺ binding properties as well as normal tension.     

The fine structure of psychrophilic and mesophilic Rhodotorula rubra

Transmission electron microscopy of thin sections of two mesophilic and a psychrophilic Rhodotorula rubra revealed structures normally associated with yeast. The capsule of all three strains was thicker in the cells grown in glucose than those grown in glucose-free media. The cell wall of all three strains showed more lamellae in the cells grown in a medium containing glycerol. Budding was of the Rhodoturula type. Endoplasmic reticula running parallel to the nucleus were commonly observed in the psychrophiles but not in the mesophiles. In the psychrophile, in association with the plasmalemma, lomasomes and plasmalemmasomes were observed. Giant mitochondria were commonly seen in the cells grown in a fermentable carbohydrate-free medium. Vacuoles were mostly empty.