Effect of gamma-ray irradiation on alcohol production from corn

Cracked corn was irradiated with gamma rays at 0-100 Mrad and the effects of the irradiation on sugar yield, susceptibility to enzymatic hydrolysis of starch, yeast growth, and alcohol production were studied. Gamma irradiation at 50 Mrad or greater produced a considerable amount of reducing sugar but little glucose. At lower dosages, gamma irradiation significantly increased the susceptibility of corn starch to enzymatic hydrolysis, but dosages of 50 Mrad or greater decomposed the starch molecules as indicated by the reduction in iodine uptake. About 12.5% reducing sugar was produced by amylase treatment of uncooked, irradiated corn. This amount exceeded the level of sugar produced from cooked (gelatinized) corn by the same enzyme treatment. The yeast numbers in submerged cultivation were lower on a corn substrate that was irradiated at 50 Mrad or greater compared to that on an unirradiated control. About the same level of alcohol was produced on uncooked, irradiated (10(5)-10(6) rad) corn as from cooked (121 degrees C for 30 min) corn. Therefore, the conventional cooking process for gelatinization of starch prior to its saccharification can be eliminated by irradiation. Irradiation also eliminated the necessity of sterilization of the medium and reduced the viscosity of high levels of substrate in the fermentation broth.     

Effect of parasympathetic denervation on acetylcholine levels in the rat parotid gland. Is there an extraneuronal pool of acetylcholine?

Parasympathetic denervation of the rat parotid gland by avulsion of the auriculotemporal nerve caused a marked and lasting decrease in gland weight. Parasympathectomy did not change the levels of choline in the gland but decreased by 60% the levels of acetylcholine (ACh) ten days after surgery and 65% at 28 days. It is puzzling that relatively high levels of ACh remained after parasympathetic denervation. The presence of additional cholinergic nerves that innervate the gland, or pass through it en route to other structures may account for some of the remaining ACh. Also, Schwann cells from denervated nerves might have contributed to some of the ACh. The existence of an extraneuronal source of ACh is considered.     

Alterations in the Structure of the Oligosaccharide of Vesicular Stomatitis Virus G Protein by Swainsonine

Swainsonine, an inhibitor of glycoprotein processing, inhibits the formation of the normal oligosaccharide chain of the G protein of vesicular stomatitis virus. Thus, when vesicular stomatitis virus was grown in baby hamster kidney cells in the presence of swainsonine (15 to 500 ng/ml) and labeled with [2-(3)H]mannose, the oligosaccharide portion of the G protein was completely susceptible to the action of endoglucosaminidase H. However, the normal viral glycoprotein is not susceptible to this enzyme. Various enzymatic treatments and methylation studies of the mannose-labeled oligosaccharides suggest that swainsonine causes the formation of a hybrid-type oligosaccharide having an oligomannosyl core (Man(5)GlcNAc(2)-Asn) characteristic of neutral oligosaccharides plus the branch structure (NeuNAc-Gal-GlcNAc) characteristic of the complex oligosaccharides. A structure for this hybrid oligosaccharide is proposed. Swainsonine had no effect on the incorporation of [(14)C]leucine into viral proteins, nor did it change the number of PFU produced in these cultures. It did, however, slightly decrease the incorporation of [(3)H]glucosamine and increase the incorporation of [(3)H]mannose. Vesicular stomatitis virus raised in the presence of swainsonine bound much more tightly to columns of concanavalin A-Sepharose than did control virus. Swainsonine had to be added within the first 4 or 5 h of virus infection to be effective. Thus, when 100 ng of the alkaloid per ml was added at any time within the first 3 h of infection, essentially all of the glycoprotein was susceptible to digestion by endoglucosaminidase H. However, when swainsonine was added 4 h after the start of infection, 30% of the glycopeptides became resistant to endoglucosaminidase H; at 5 h, 70% were resistant. The effect of swainsonine was reversible since removal of the alkaloid allowed the cells to form the normal complex glycoproteins. However, the time of removal was critical in terms of oligosaccharide structure.     

Deoxyribonucleic Acid Replication in Simian Virus 40-Infected Cells IV. Two Different Requirements for Protein Synthesis During Simian Virus 40 Deoxyribonucleic Acid Replication

The replication of simian virus 40 (SV40) deoxyribonucleic acid (DNA) was inhibited by 99% 2 hr after the addition of cycloheximide to SV40-infected primary African green monkey kidney cells. The levels of 25S (replicating) and 21S (mature) SV40 DNA synthesized after cycloheximide treatment were always lower than those observed in an infected untreated control culture. This is consistent with a requirement for a protein(s) or for protein synthesis at the initiation step in SV40 DNA replication. The relative proportion of 25S DNA as compared with 21S viral DNA increased with increasing time after cycloheximide treatment. Removal of cycloheximide from inhibited cultures allowed the recovery of viral DNA synthesis to normal levels within 3 hr. During the recovery period, the ratio of 25S DNA to 21S DNA was 10 times higher than that observed after a 30-min pulse with (3)H-thymidine with an infected untreated control culture. The accumulation of 25S replicating SV40 DNA during cycloheximide inhibition or shortly after its removal is interpreted to mean that a protein(s) or protein synthesis is required to convert the 25S replicating DNA to 21S mature viral DNA. Further evidence of a requirement for protein synthesis in the 25S to 21S conversion was obtained by comparing the rate of this conversion in growing and resting cells. The conversion of 25S DNA to 21S DNA took place at a faster rate in infected growing cells than in infected confluent monolayer cultures. A temperature-sensitive SV40 coat protein mutation (large-plaque SV40) had no effect on the replication of SV40 DNA at the nonpermissive temperature.     

Progesterone transformations as a diagnostic feature in the generaAlternaria,Stemphylium andCladosporium

Various species of the generaAlternaria, Stemphylium andCladosporium were shown to display a specific reaction characteristic for the given genus. In theAlternaria genus this is a 1-2-dehydrogenation of the A ring of the steroid molecule, inStemphylium 14α-hydroxylation and inCladosporium 7β-hydroxylation. This chemotaxonomic feature may supplement morphological and functional criteria in the taxonomy of filamentous fungi (Hyphomycetes).     

Proteins of Vasicular Stomatitis Virus: I. Polyacrylamide Gel Analysis of Viral Antigens

Infection of L cells with vesicular stomatitis virus results in the release, into the cell-free fluid, of four antigenic components separable by rate zonal centrifugation on sucrose gradients. The largest antigens are the infectious (B) particle and a shorter noninfectious, autointerfering (T) particle. The two small antigens are characterized by sedimentation coefficients of approximately 20S and 6S. Treatment of purified B or T particles with sodium deoxycholate results in the release from the particle of a nucleoprotein core which can be purified on sucrose gradient and which has a sedimentation coefficient characteristic of the virus from which it arose. Utilizing purified antigens labeled with (14)C-amino acids during growth, we examined the protein constituents of each antigen by acrylamide-gel electrophoresis. The proteins of B and T particles are identical, each containing one minor (virus protein 1) and three major (virus proteins 2, 3, and 4) proteins, numbered in order of increasing mobility. Virus protein 3 originates from the nucleoprotein core, whereas proteins 2 and 4 come from the coat. The origin of virus protein 1 is not known. The 20S antigen contains a single protein equivalent to virus protein 3, whereas the 6S antigen shows a single protein which is similar to, but probably distinct from, virus protein 2.