Production of ethanol from cassava whey

Investigations were conducted into the potential use of enzyme hydrolysed cassava whey for ethanol production by Saccharomyces cerevisiae Aspergillus niger grown on whct bran was used as crude enzyme source to saccharify the whey starch. The whey with an initial HCN concentration of 54.0μg/ml was fermented at pH 4.5 and 30°C in a one-step process to produce ethanol. A maximum ethanol concentration of 4.5% (v/v) was obtained in 120 h with a decrease in HCN level to 4.0 μg/ml. In a two-stage fermentation, in which the raw whey was pre-hydrolysed and under the same fermentation conditions, the unsterilized hydrolysate yielded alcohol content of 5.5% (v/v), while the sterilized hydrolysate gave higher alcohol yield, 7.5% (v/v), in 48 h. No HCN was detected in the fermented liquour at the end of the two-stage process.     

Glucose transport into rat skeletal muscle: interaction between exercise and insulin

This study was done to evaluate the effect of insulin on sugar transport into skeletal muscle after exercise. The permeability of rat epitrochlearis muscle to 3-O-methylglucose (3-MG) was measured after exposure to a range of insulin concentrations 30, 60, and 180 min after a bout of exercise. Thirty and 60 min after exercise, the effects of exercise and insulin on 3-MG transport were additive over a wide range of insulin concentrations, with no increase in sensitivity or responsiveness to insulin. After 180 min, when approximately 66% of the exercise-induced increase in sugar transport had worn off, both the responsiveness and sensitivity of the glucose transport process to insulin were increased. These findings appear compatible with the hypothesis that the actions of exercise and insulin result in activation and/or translocation into the plasma membrane of two separate pools of glucose transporters in mammalian skeletal muscle.     

Inhomogeneity during deflation of excised canine lungs. I. Alveolar pressures

Factors both intrinsic and extrinsic to the lung may cause inhomogeneity of alveolar pressures during deflation. Wilson et al. (J. Appl. Physiol. 59: 1924-1928, 1985) predicted that any such inhomogeneity would be limited by interdependence of regional expiratory flows. To test this hypothesis and to explore how the pleural pressure gradient might affect inhomogeneity of alveolar pressures, we deflated at submaximal flows excised canine lobes that first were suspended in air and then were immersed in foams that simulated the vertical gradient of pleural pressure. Interregional inhomogeneity of regional transpulmonary pressures was measured with use of an alveolar capsule technique. Flow-dependent inhomogeneity of alveolar pressures was present, with differences in alveolar pressure quickly relaxing to a constant limiting value at each flow. Foam immersion increased inhomogeneity at a given flow. We conclude that factors intrinsic to the lung cause significant inhomogeneity of alveolar pressures at submaximal expiratory flows and that this inhomogeneity is enhanced by the extrinsic gradient of pleural pressure. These observations are consistent with the interdependence of flow proposed by Wilson et al.     

Ventilation inhomogeneity during controlled ventilation. Which index should be used?

Six indexes for diagnosing uneven ventilation by tracer gas washout were studied. The indexes were lung clearance index, mixing ratio, Becklake index, multiple-breath alveolar mixing inefficiency, moment ratio, and pulmonary clearance delay, all of which increase with impaired pulmonary gas mixing. In model lung tests, indexes that compared the actual washout curve with a calculated ideal curve (mixing ratio, multiple-breath alveolar mixing inefficiency, and pulmonary clearance delay) were unaffected by changes in tidal volume and series dead space, whereas the others varied markedly. In both spontaneously breathing and mechanically ventilated patients all indexes showed a significant difference between smokers and nonsmokers (P less than 0.002), but the indexes were somewhat different in their assessment of different ventilatory patterns. However, the mean value for all indexes, with the exception of mixing ratio, was smallest with a fast insufflation followed by an end-inspiratory pause. Any of the indexes may be useful if its limitations are recognized, but mixing ratio, multiple-breath alveolar mixing inefficiency, and pulmonary clearance delay seem preferable, because they are not affected by changes in tidal volume and dead space fraction.     

A hormone-sensitive stage in the development of the retinal pigment epithelium in Hunter rats with hereditary retinal dystrophy

The sensitivity of the retinal pigment epithelium (RPE) to the melanotropic effects of alpha-MSH and dbcAMP was assayed in an organ culture of the eye scleral part in the Hunter rats with inherited retinal dystrophy. The melanin synthesis was estimated by liquid scintillation on the RPE isolated enzymatically after 48-h cultivation. One eye from every animal was cultivated in a medium without natural components and with the hormone or dbcAMP (experiment), while the other in a hormone-free medium (control). The melanin synthesis was estimated by 14C-thiouracil incorporation. The result was expressed as a cpm/microgram DNA (experiment) to cpm/microgram DNA (control) ratio. In addition, the index of labelled nuclei was determined using 3H-thymidine autoradiography in the central RPE zone of the eyes from young rats of the same litter. The experiments with alpha-MSH confirmed the earlier data according to which the RPE of the 3 day old Hunter rats were insensitive to melanotropic hormones. This was not due to defects in the cytoplasmic melanin-synthesizing system, since under the influence of dbcAMP the melanin synthesis in the RPE increases more than four-fold as compared with the control; dbcAMP stimulates also the total protein synthesis, as estimated by 3H-leucine incorporation. The RPE of the 4 day old rats proved to be sensitive to alpha-MSH: the melanin synthesis increases more than twice suggesting the healthy state of the RPE membrane melanotropic receptors. alpha-MSH also stimulates the total protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection by the use of silver ions of additional protein zones in gradient polyacrylamide gels stained with Coomassie

A simple method of revealing the additional zones of proteins in gradient polyacrylamide gels, preliminary dyed Coomassie by means of silver ions is described. The dyeing of Coomassie allows to avoid the time-consuming stages of preliminary treatment of gels as well to reveal more sensitive zones in gels. On the second stage of dyeing silver minor zones appear there which were not seen while Coomassie was dyed. The suggested method preserves high sensitivity characteristic of the methods of gel dyeing with silver.     

Receptor-like cytokinin-binding protein(s) from barley leaves

Purified fractions of soluble proteins from barley leaves have been shown to contain specific binding sites fortrans-zeatin, a natural cytokinin. Such binding is very strong in vitro in concentrated solutions of some salts (ammonium sulfate or potassium phosphate) with optimum at pH 7–8 and temperature within the range 0–20°C. The cytokinin-binding sites have high affinity for zeatin (K_d1.5·10^–8 M) and low capacity corresponding to 1–1.5 pmol zeatin per milligram of initial soluble protein. Cytokinin binding is reversible; it is due to protein (or proteins) with molecular weight 40–45 kDa. This protein(s) does not bind³H-adenine and³H-abscisic acid. The ability of various compounds to displace³H-zeatin from its high-affinity binding sites is in strict accordance with their biological cytokinin activities. Other phytohormones as well as fusicoccin do not displace³H-zeatin from its binding sites. Specific zeatin binding is sensitive to heat, alkali, and pronase, but not to RNase treatment. The 150- to 200-fold purification of cytokinin-binding proteins was achieved by a combination of ammonium sulfate precipitation and Ultrogel AcA-54- and DEAE-cellulose chromatography. The zeatin-binding protein(s) from barley leaves is suggested to take part in cytokinin action in vivo.     

Identification of cytokinins in young wheat spikes (Triticum aestivum cv. Chinese spring)

Cytokinins in young wheat (Triticum aestivum cv. Chinese spring) spikes (2–15 mm) were isolated by immunoaffinity chromatography. High-performance liquid chromatography-radioimmunoassay and gas chromatography-mass spectrometry indicated that major cytokinins present weretrans-zeatin, ribosyl-trans-zeatin, ribosyldihydrozeatintrans-zeatin-9-glucoside, and the glucosides oftrans-zeatin, ribosyl-trans-zeatin, andtrans-zeatin-9-glucoside. Dihydrozeatin,iso-pentenyladenosine, andiso-pentenyladenine were also present but at lower concentrations.Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply approval to the exclusion of other products that may also be suitable. R. C. Durley's present address is Biological Sciences, Monsanto Company, St. Louis, Missouri 63167.     

Celery transformation by Agrobacterium tumefaciens: cytological and genetic analysis of transgenic plants

Transgenic celery plants were obtained following co-cultivation of petiole explants with Agrobacterlum tumefaciens containing pMON200, a cointegrate vector carrying genes for kanamycin resistance and nopaline synthase. Transformants were selected by ability of callus to grow in the presence of 50mg/l kanamycin. Transformation was confirmed either by the presence of nopaline or by Southern blots. Cytological analysis of 14 transformed plants revealed chromosomal aberrations, both in structure and number. Only 20% of the regenerated plants had the normal karyotype. Kanamycin resistance behaved as a monogenic, dominant trait, segregating in a 3:1 ratio in three families derived from plants with normal karyotypes.Abbreviations KB Kilobases - 2-4D 2,4-diphenoxyacetic acid     

Identification and characterization of a novel postlarval hemolymph protein from Manduca sexta

The identification, purification and characterization of a new postlarval specific hemolymph protein from Manduca sexta is described. Incorporation of [³⁵S]methionine into Manduca sexta hemolymph proteins in vivo was investigated as a function of development. A major protein band of M_r ≈ 50,000 was highly labeled during the prepupal and adult stage but not in feeding larvae. This postlarval protein (PLP) was isolated from adult male hemolymph and its chemical and immunological properties determined. PLP is a basic protein (pI ～8.6). Electrophoresis under denaturing conditions reveals a subunit M_r ≈ 50,000 while the native protein has an apparent M_r ～ 85,000 by gel permeation chromatography. Anti-PLP serum recognized PLP but not other hemolymph proteins on immunoblots. In vitro translation of fat body mRNA followed by immunoprecipitation revealed that fat body is the site of PLP synthesis. Quantitation of PLP levels in hemolymph throughout development was performed and suggests PLP may play a role in adult development of M. sexta.