Production of oxytetracycline and rifamycins B and SV with cells immobilized on glass wool

The antibiotic producing microorganisms Streptomyces rimosus PFIZER 18234-2 and Amycolatopsis mediterranei CBS 42575 were immobilized in glass wool for the production of oxytetracycline and rifamycins B and SV. The growth of the immobilized cells was dependent on the type of the microorganism and on the amount of glass wool as well. After 5 exchanges of the medium, 530 mg O.T.C., 2138 mg rifamycin B and 8672 mg rifamycin SV were maintained. The periodic batch culture was continued for 20 days.     

Characteristic biochemical differences in human T and B lymphocytes separated on nylon wool

T and B lymphocytes from human tonsils were separated on a nylon wool column. T. cells are enriched in the nonadherent, B cells in the adherent fraction. Several enzymes and other markers were tested in separated and non separated lymphocyte populations. Certain enzymes and other properties can be used as T or B lymphocyte markers because of their preferential occurrence and because of the advantages of their estimation (simple, quick methods, objective evaluation). The following characteristics were considered as markers on the basis of our results: (I) acid phosphatase, Na+-K+-activated ATPase, BAEE-peptidase and chromium labeling in T lymphocytes; (II) 5'-nucleotidase, FITC-IgG binding, N-acetyl-D-glucosaminidase, thymidine and valine incorporation in B lymphocytes.     

A further study on the dietary-regulated biosynthesis of high-sulphur wool proteins

When the diet of sheep is supplemented by the infusion of sulphur-containing amino acids or casein into the abomasum, the newly synthesized wool shows characteristic changes in its amino acid composition, with significant increases in cystine, proline and serine and decreases in aspartic acid and phenylalanine. This modification seems to be due entirely to an alteration in the overall composition of the high-sulphur proteins and to an increase in their proportion in the fibre. These variations are not the result of a change in the composition of individual proteins, but are due to alterations in their relative proportions and to the initiation of the synthesis of `new' proteins, many of which are extremely rich in cystine. It is suggested that the heterogeneity of the high-sulphur proteins may be due, in part, to similar changes in composition caused by natural variations in the nutrition of sheep.     

The reactivity of the disulphide bonds of wool

1. Fully reduced and S-carboxymethylated wool samples were prepared in which either the readily reducible cystine bonds or those that could only be reduced with difficulty were specifically labelled with iodo[2-(14)C]acetate; these two cystine fractions correspond to the (A+B) and (C+D) cystine fractions respectively, of Middlebrook & Phillips (1942). 2. Radioactively labelled peptides were isolated from partial acid hydrolysates of these wool samples. 3. It appears that the (A+B) cystine residues probably owe their increased reactivity to being in a more polar environment. 4. The implication of these results for the problem of characterizing the disulphide bonds of wool is briefly discussed.     

Effects of zinc deficiency on the wool growth, skin and wool follicles of pre-ruminant lambs

Two groups of 1-month-old pre-ruminant lambs of similar mean liveweights were fed identical liquid milk-replacer diets except that the zinc contents were either 5 micrograms (deficient diet) or 32 micrograms per gram of dry matter (control diet). These diets were fed for 4 weeks, after which all the lambs received the control diet for 2 weeks. In the lambs fed the deficient diet plasma zinc concentration decreased markedly during the first 2 weeks and skin lesions developed around their mouths. Autophagic vacuoles also developed in most follicle bulbs along with a variety of defects in the wool fibres and progressive inhibition of wool growth. Food intake and liveweight increase were not significantly depressed until the third and fourth weeks of feeding the deficient diet. During this period the wool was shed from the zinc-deficient lambs as a result of the fibres being degraded and distorted within thickened outer root sheaths in the distal (upper) parts of the follicles. In addition, the epidermis of the wool-bearing skin became slightly acanthotic and hyperkeratotic, although not parakeratotic. When the deficient lambs were fed the control diet for 2 weeks, their food intake, liveweight gain and plasma zinc concentration increased to almost those of the control lambs, but their rate of wool growth was still low and the epidermis had not returned to normal. Compared with previous studies the findings of this study suggest that pre-ruminant lambs may be more susceptible to the effects of zinc deficiency than ruminant lambs.