Production of alcohol from Jerusalem artichokes by yeasts

Various yeasts such as several strains of Saccharomyces diastaticus, S. cerevisiae, and Kluyveromyces fregilis were investigated for their ability to ferment the carbohydrates from Jerusalem artichokes to alcohol. Juice extracted of the carbohydrates. Fermentation was also carried out with raw artichokes without prior juice extraction. Result indicate that this row material has good potential for fuel alcohol production by fermentation.     

Protein-RNA crosslinking in Escherichia coli 30S ribosomal subunits. Identification of a 16S rRNA fragment crosslinked to protein S12 by the use of the chemical crosslinking reagent 1-ethyl-3-dimethyl-aminopropylcarbodiimide.

1-ethyl-3-dimethyl aminopropylcarbodiimide (EDC) was used to cross-link 30S ribosomal proteins to 16S rRNA within the E. coli 3OS ribosomal subunit. Covalently linked complexes containing 30S proteins and 16S rRNA, isolated by sedimentation of dissociated crosslinked 30S subunits through SDS containing sucrose gradients, were digested with RNase T1, and the resulting oligonucleotide-protein complexes were fractionated on SDS containing polyacrylamide gels. Eluted complexes containing 30S proteins S9 and S12 linked to oligonucleotides were obtained in pure form. Oligonucleotide 5'terminal labelling was successful in the case of S12 containing but not of the S9 containing complex and led to identification of the S12 bound oligonucleotide as CAACUCG which is located at positions 1316-1322 in the 16S rRNA sequence. Protein S12 is crosslinked to the terminal G of this heptanucleotide.     

The interaction of N alpha-alkylenkephalins with opiate receptors. Tissue-dependent shifts in the opiate activity of methionine-enkephalin following N alpha-alkylation

Experimental conditions for the small scale alkylation of the alpha-amino group of the opioid peptide methionine-enkephalin using the method of reductive alkylation are described. The generality of the method is established by describing in detail the synthesis, purification, and structure elucidation of the N alpha-ethyl, isopropyl, phenethyl, and cyclopropylmethyl derivatives of methionine-enkephalin. By a combination of amino acid and mass spectral analysis it is possible to carry out the structure analysis of nanomole quantities of these modified peptides, making direct chemical modification and structure elucidation of carrier-free tritiated and radioiodinated enkephalins feasible. Using these chemical procedures, a homologous series of N alpha-n-alkyl derivatives of methionine-enkephalin has has been synthesized. It is shown that the relative binding and opiate activity of these N alpha-alkyl derivatives, using several standard in vitro assay systems, depends on the tissue source used. The results of this study are analyzed by considering recent reports indicating the existence of multiple opiate receptors.     

Chou-Fasman analysis of the secondary structure of F and Le interferons

The Chou-Fasman method for calculating the secondary structure of $\text{F}$ and $\text{Le}$ interferons from their amino acid sequences predicts several regions of homologous structure in the two interferons. Those areas tend to be located in the middle and C- terminal ends of the molecules. Total predicted content of α helix is 55% for $\text{Le}$ interferon and 36% for $\text{F}$ interferon. Predicted β-pleated sheet residues total 33% for $\text{F}$ and 16% for $\text{Le}$.     

AQUATIC MATING STRATEGIES OF THE MALE PACIFIC HARBOR SEAL (PHOCA VITULINA RICHARDII): ARE MALES DEFENDING THE HOTSPOT?

Compared to the harem and resource defense systems of terrestrial mating pinnipeds, males of aquatic mating species appear unable to monopolize females or resources. We investigated movements, acoustics, and aquatic territorial behavior of male harbor seals, Phoca vitulina richardii , in Elkhorn Slough, California, using VHF telemetry, hydrophones, and acoustic playback experiments. During the mating season 22 males increased time spent in the water and away from haul-out locations, exhibiting activity patterns similar to Atlantic subspecies. Two acoustic display patterns were observed. At one location multiple males aggregated to display with acoustic activity peaking one month before peak estrus. At two other locations, lone males displayed primarily during peak estrus. Acoustic display areas were non-adjacent with a mean ± SE size of 4,228 ± 576 m², similar to harbor seal display patterns in the Moray Firth, Scotland. Underwater playbacks of male vocalizations were used to define territorial boundaries by inducing responses from territory-holding males. Four solitary males defended adjacent territories (mean area 39,571 ± 18,818 m²) along a travel corridor, similar to observations of harbor seals at Miquelon, Newfoundland. Acoustic display stations appeared to be subcomponents of larger territories. Males exhibited site fidelity to territories for at least 2–4 yr. Females moved through territories freely. The establishment of male-display territories along female-traffic corridors resembles terrestrial systems described as hotspot leks.     

Engineering protein-based machines to emulate key steps of metabolism (biological energy conversion)

Metabolism is the conversion of available energy sources to those energy forms required for sustaining and propagating living organisms; this is simply biological energy conversion. Proteins are the machines of metabolism; they are the engines of motility and the other machines that interconvert energy forms not involving motion. Accordingly, metabolic engineering becomes the use of natural protein-based machines for the good of society. In addition, metabolic engineering can utilize the principles, whereby proteins function, to design new protein-based machines to fulfill roles for society that proteins have never been called upon throughout evolution to fulfill. This article presents arguments for a universal mechanism whereby proteins perform their diverse energy conversions; it begins with background information, and then asserts a set of five axioms for protein folding, assembly, and function and for protein engineering. The key process is the hydrophobic folding and assembly transition exhibited by properly balanced amphiphilic protein sequences. The fundamental molecular process is the competition for hydration between hydrophobic and polar, e.g., charged, residues. This competition determines Tt, the onset temperature for the hydrophobic folding and assembly transition, Nhh, the numbers of waters of hydrophobic hydration, and the pKa of ionizable functions. Reported acid-base titrations and pH dependence of microwave dielectric relaxation data simultaneously demonstrate the interdependence of Tt, Nhh and the pKa using a series of microbially prepared protein-based poly(30mers) with one glutamic acid residue per 30mer and with an increasing number of more hydrophobic phenylalanine residues replacing valine residues. Also, reduction of nicotinamides and flavins is shown to lower Tt, i.e., to increase hydrophobicity. Furthermore, the argument is presented, and related to an extended Henderson-Hasselbalch equation, wherein reduction of nicotinamides represents an increase in hydrophobicity and resulting hydrophobic-induced pKa shifts become the basis for understanding a primary energy conversion (proton transport) process of mitochondria. Copyright 1998 John Wiley & Sons, Inc.     

Using satellite and real-time weather data to predict maize production

 Large-scale assessments of crop conditions prior to harvest are critical for providing early estimates of production. Satellite and weather information provide the opportunity for near real-time crop monitoring. The objective of this research was to develop an operational assessment system for crop production utilizing data from these sources. Maize (Zea mays) production was assessed in 42 Crop Reporting Districts (CRDs) across the United States Corn Belt, which produce 60% of all maize grown in the United States. Satellite, climatolocal, and agricultural data were collected for 8 years, 1985–1992, and aggregated into CRDs. A model predicting the normalized maize yields for each CRD was developed that included as independent variables a satellite data variable, the Vegetation Condition Index, and a climatological variable, the Crop Moisture Index. This model explained approximately three-quarters (R ²=0.73) of the variation observed in the normalized yields, and was examined both for its accuracy and its timeliness in providing production estimates. Predicted seasonal yields were summed to provide a maize production estimate for the entire Corn Belt study region. Production estimates deviated from the final USDA statistics, which become available several months after harvest, by less than 10% for all eight growing seasons. In addition, the production estimates were available approximately 2 months prior to the completion of the maize harvest. This system has the potential for providing timely in-formation to organizations monitoring regional or global agricultural production for humanitarian or economic benefits. Received: 23 July 1997 / Accepted: 17 February 1998     

In situ methane enrichment in anaerobic digestion

A major cost consideration in the use of anaerobic digestion to convert biomass and waste to utility-grade gas is the expense of separating CO(2) from the product gas. Anaerobic digestion has a number of inherent properties that can be exploited to increase the methane content of the gas directly produced by the digester, the most important of which is the high solubility of CO(2)(40-60 times that of methane) in water under digestion conditions. The methane enrichment concept examined in this study involved the recirculation of a liquid stream from the digester through a CO(2) desorption process and the return of the liquid stream back to the digester for absorption of additional CO(2) produced by the conversion of organic materials. A steady-state equilibrium model predicted that a digester gas methane content exceeding 94% could be achieved with this scheme using modest recirculation rates provided a desorption process could be designed to achieve a 60+% CO(2) removal efficiency in the degassing of the liquid recycle stream. Using fixed-film laboratory digesters operated on synthetic feedstocks, the technique of methane enrichment was tested under pressurized and unpressurized conditions. A 93 + 2% methane gas stream was produced from a volatile-acid-fed bench-scale digester simulating the methanogenic stage of two-phase digestion under conditions of (1) a pH swing achieved without caustic addition that allowed digestion at pH 7. 5 and air stripping at pH 6. 5-7. 0, (2) digester pressurization to 30 psig, and (3) a recycle rate of 0. 33 L/L reactor/day. Significant but lower levels of methane enrichment were achieved with the single-stage digester at the low experimental recycle rate. However, the narrow range among all experiments of CO(2) desorption efficiencies achieved in air stripping the recycle stream (35-60% CO(2) removal) suggests that comparable methane enrichment-may be achieved with unpressurized single-stage digestion using greater recycle rates. A materials balance analysis of data from an unpressurized, single-stage digester employing no chemical addition and using laboratory degassing efficiencies indicated that 94% methane could be produced at recycle rates of less than 1. 4 L/L reactor/day with a methane loss of less than 2%.     

Structure and partial amino acid sequence of calf thymus DNA topoisomerase II: comparison with other type II enzymes.

The partial amino acid sequence of p140 calf thymus DNA topoisomerase II was determined by analysis of cyanogen bromide peptides. Five peptides were aligned and shared extensive homology with sequences derived from cDNA clones for the human topoisomerase II isoenzyme forms. Less homology was seen with the Drosophila, yeast and bacterial type II enzymes. Calf and human enzymes shared epitopes allowing isolation of a cDNA clone to human topoisomerase II isoenzyme alpha. Our results indicate that calf thymus p140 topoisomerase II is an active N-terminal proteolytic fragment of the native p180 enzyme and demonstrate that mammalian type II enzymes exhibit close sequence similarity.