Pollution potential reduction of cheese whey through yeast fermentation

Batch and continuous pilot-scale aerobic fermenters of 4.8 L operating volume were designed and constructed from plexiglass materials. The fermenters were used to study the kinetics of cheese whey fermentation using the yeast K. fragilis for pollution potential reduction and single cell protein production. Four retention times (6, 12, 18, and 24 h) were used in this study. The fermentation process was successful in reducing the total chemical oxygen demand (COD) by 42%, the soluble COD by 65%, the total solids by 53%, and the ammonium nitrogen by 90%. There were also gains in the suspended solids and the organic nitrogen of 60 and 17%, respectively. The reductions in the COD, total solids, and ammonium nitrogen, and the gains in the suspended solids and organic nitrogen were affected by the hydraulic retention time. More soluble material was converted to insoluble microbial cells at the 12-h hydraulic retention time, whereas greater pollution potential reduction was achieved at the 24-h hydraulic retention time for both batch and continuous operations.

Affinity purification of cellular retinoic acid-binding protein on 14-carboxy-13-cis-retinamide-sepharose 4B

A biologically active bifunctional retinoid, ethyl 14-carboxyretinoate, has been synthesized and shown to bind cellular retinoic acid (RA)-binding protein (CRABP) via its free carboxy group. We describe herein the synthesis of 14-carboxy-13-cis-retinamide-Sepharose 4B, which is an affinity matrix bearing an all-trans-RA moiety, and thus was used to purify and characterize CRABP from chick-embryo skin. An amide bond was first formed between the free carboxy group of the retinoid and a primary amino group of aminohexyl-Sepharose 4B, by reaction with carbodi-imide, and the ester group of the resin-bound retinoid was then hydrolysed in an alkaline medium. Polyacrylamide-gel electrophoresis and f.p.l.c. Superose column-chromatographic analysis demonstrated that the affinity-purified CRABP (Mr 15,000) was close to electrophoretic homogeneity (greater than 90%) and specifically interacts with RA. By using affinity gel chromatography, conversion of holo-CRABP into apo-CRABP by treatment with p-hydroxymercuribenzoate and a possible involvement of a thiol group in RA binding to CRABP were established. This affinity procedure provides several advantages: (i) 14-carboxy-13-cis-retinamide-Sepharose exhibited high efficiency and selectivity for RA-binding protein (i.e. retinol- or fatty-acid-binding proteins did not bind); (ii) the presence of the amide linkage between the ligand and the matrix makes this affinity resin relatively stable to cytosolic enzymes; and (iii) other RA-binding proteins, e.g. nuclear receptor(s), may be purified.

Effect of bone injury on circadian periodicity of plasma 17-hydroxy corticosteroids (17-OHCS) in rabbits

Bone injury inflicted at varying time intervals during 24 hr day-night cycle caused significant varying increase in plasma 17-OHCS levels in all traumatized animals and the levels remained elevated up to 24 hr after trauma. The level of plasma 17-OHCS was found to be aberrated in all the traumatized animals. Thus, adequate adrenocortical response to trauma and aberration in the adrenocortical secretory activity appears inevitable irrespective of the time at which the trauma is produced. However, the degree of response depends on the particular time at which the trauma is inflicted.

Safety evaluation of a male injectable antifertility agent, styrene maleic anhydride, in rats

Injection of a polymer, styrene maleic anhydride (SMA), into the lumen of the vas deferens of rats, was observed to have effective and reversible contraception. The safety evaluation of the polymer, for 90 days, was carried out in Charles Foster male rats. There have been no significant changes in any of the toxicity parameters in the test animals as compared to the control animals. Hence, it is concluded that the compound is non-toxic to rodents.

Catabolic instability, plasmid gene deletion and recombination in Alcaligenes sp. BR60

An Alcaligenes sp. BR60, isolated from surface runoff waters of the Hyde Park industrial landfill, contained a novel 85 kb catabolic plasmid (pBR60) functional in 3-chlorobenzoate (3Cba) degradation. The plasmid exhibited a spontaneous 3.2% frequency of deletion of a 14 kb fragment specifying 3Cba degradation. The deletion mutant BR 40 and mitomycin C cured strains were not able to grow on 3Cba and had reversion frequencies of less than 10(-10) cell-1 generation-1. Transformation or conjugation of pBR60 into cured strains restored catabolic activity. An EcoRI, BglII, HindIII and SalI restriction map of the deletion region was constructed, and EcoRI and HindIII fragments spanning the deletion region of the plasmid were cloned in pUC18. Conjugation of resistance plasmid R68.45 into Alcaligenes sp. BR 60, with selection on antibiotics, resulted in the elimination of pBR60 and maintenance of unaltered R68.45. In 30% of the exconjugants, 3Cba degradative capacity was retained, although variation in the regulation of 3Cba degradation was observed in these strains. Hybridization of deletion region fragments to BglII digested total DNA of BR60 and the R68.45 cured exconjugants revealed the presence of pBR60 deletion region sequences in the chromosome of exconjugants. Hybridization also revealed a repeated sequence flanking the deletion region of pBR60. Selection on 4-chlorobenzoate as a sole source of carbon and energy resulted in the isolation of 4Cba+ mutants of Alcaligenes sp. BR60.

Effect of 24 mm levonorgestrel IUD on uterine endometrium of female rhesus monkeys, Macaca mulatta

Hysterectomy specimens were obtained from ten adult female rhesus monkeys treated with levonorgestrel-releasing intrauterine devices (IUDs) for a period of three, six and twelve months. The effect of levonorgestrel on the endometria, ovaries and fallopian tubes of removed uteri was examined in luteal phase of cycle. A uniform suppression of endometrium with glandular atrophy and pseudodecidualization of stromal cells was observed in endometrial biopsies, whereas ovaries and tubal epithelium exhibited normal physiological changes as evidenced by presence of ovulatory stigma along with well formed corpus luteum and secretory activity of tubal epithelium.

Binding of glucocorticoid receptors to mammary chromatin acceptor sites

We have recently characterized the interaction of mouse mammary estrogen receptors (ER) with mammary chromatin acceptor sites and demonstrated that ER from estrogen resistant lactating mammary glands do not bind to chromatin. In this study we have characterized the chromatin binding of the glucocorticoid receptor from mouse mammary glands isolated from nulliparous and lactating mice in order to better understand the relationship between receptor binding to chromatin and steroidogenic sensitivity of the tissue. Mammary chromatin was linked covalently to cellulose and deproteinized sequentially by 0-8 M Gdn-HCl. Binding to intact chromatin as well as to chromatin deproteinized by Gdn-HCl was determined using partially purified [3H]dexamethasone labelled glucocorticoid-receptor complexes (GR) obtained by fractionation on DEAE-cellulose columns. The binding of [3H]GR from mammary glands of nulliparous mice to chromatin fractions from the same tissue revealed maximal binding activity (acceptor sites) on chromatin previously extracted with 5-6 M Gdn-HCl. Binding of [3H]GR was of high affinity (Kd = 0.2 nM) and saturable. A simultaneous comparison of the chromatin binding patterns for [3H]ER and [3H]GR isolated from mammary glands of nulliparous mice revealed that the chromatin subfractions obtained with 4-6 M Gdn-HCl extraction contained acceptor sites for both [3H]ER and [3H]GR; however, while the [3H]ER bound to a 4.5 M and a 5.5 M site, the [3]GR bound a 5 M and a 6 M site. Competition experiments supported the steroid receptor specificity of the chromatin acceptor sites. Thus, the 4-6 M chromatin fractions contain distinct acceptor sites for the glucocorticoid receptor and for the estrogen receptor. In addition our studies reveal that the binding patterns of [3H]GR isolated from mammary glands of nulliparous and lactating mice to their homologous chromatin is essentially similar. Thus, in contrast to estrogen receptors, glucocorticoid receptors from lactating mammary glands are able to effectively bind to chromatin acceptor sites which supports our previous suggestion that the estrogenic insensitivity of lactating mouse mammary glands may at least be in part due to the impeded interaction of ER with chromatin acceptor sites.