Isolation and Identification of n-Butane-assimilating Bacterium

A bacterial strain capable of assimilating gaseous n-alkanes was newly isolated from activated sludge by enrichment culture technique using n-butane as the sole carbon source. The strain was identified as Pseudomonas butanovora sp. nov. It utilised n-alkanes of C₂~C₉, primary alcohols and carboxylic acids for growth, but did not utilize sugars and C₁ compounds. The cell yields on gaseous n-alkanes, such as ethane, propane and n-butane, were 80% or more. The maximum specific growth rate on n-butane was 0.22 hr^?1 at 30°C, pH 7.0. Dried cells of this new isolate grown on n-butane contained 73% pure protein.     

Studies on the Photolysis of l-Cysteine and l-Cystine

In the presence and absende of riboflavin, the aqueous solutions of l-cysteine and l-cystine were exposed to sunlight. The solutions in the presence of riboflavin developed the typical flavor of cooked rice. Hydrogen sulfide, ammonia, carbon dioxide and acetaldeohyde were found from the solutions that formed the flavor.

The component responsible for the flavor was not a single one but consisted of three compounds, such as hydrogen sulfide, ammonia and acetaldehyde. An aqueous solution of the mixture containing these three compounds developed organoleptically the typical flavor of cooked rice. These compounds were also present in the vapor of cooked rice.     

Studies on the Biosynthesis of Fosfomycin. Conversion of 2-Hydroxyethylphosphonic Acid and 2-Aminoethylphosphonic Acid to Fosfomycin

Two types of 130 kDa insecticidal protein genes isolated from large plasmid DNAs of Bacillus thuringiensis var. israelensis HDS22 were cloned in an Escherichia coli plasmid vector. Analysis of the nucleotide sequences revealed that the two genes encoded a 127,500-dalton protein (ISRH3) consisting of 1,135 amino acids and a 134,400-dalton protein (ISRH4) consisting of 1,180 amino acids. The two insecticidal proteins were identical in a region of the C-terminal 467 amino acids.     

Biochemical Effects of Fatty Acid and its Derivatives on l-Glutamic Acid Fermentation

Tween 60 (polyoxyethylene sorbitan monostearate) has been found to be the most effective derivative of fatty acid in accumulating l-glutamic acid in biotin-sufficient medium. The effect was exceedingly subject to the influence of the addition time of the ester, and this was observed also on the growth curve of Brev. lactofermentum. Changes of the growth curve caused by the varied addition time of the ester corresponded to those by the concentration of biotin in the medium that did not contain Tween 60. The patterns of fermentation course in the two corresponding conditions, such as biotin 3 μg/l and biotin 20 μg/l-Tween 60 mg/ml, agreed closely with each other. It seemed that identical cells were grown on the conditions. The only difference between the cells was observed as to the contents of intracellular biotin. Although l-glutamic acid was not accumulated by biotin-sufficient cells, cells with sufficient biotin and capable of accumulating l-glutamic acid were obtained in the presence of Tween 60, in which case the ester neither prevented the cells from taking up biotin nor controlled the level of intracellular biotin.     

Studies on Lysine Fermentation

In order to clarify the mechanism of l-lysine accumulation by Micrococcus glutamicus No. 901, a homoserine-auxotrophic mutant, the effects of various amino acids on the two enzymic reactions on the biosynthetic pathway of lysine, the phosphorylation of aspartate and the condensation of aspartic β-semialdehyde (ASA) with pyruvate, were studied using the cell-free extracts of the organism.

The aspartokinase received a multivalent inhibition by threonine plus lysine. Lysine exerted no feedback inhibition in its first step condensing reaction. From these results, the mechanism of the accumulation of lysine by the organism was discussed.     

Production of l-Valine by 2-Thiazolealanine Resistant Mutants Derived from Glutamic Acid Producing Bacteria

Potent l-valine producers were screened among 2-thiazolealanine resistant mutants derived from three typical l-glutamic acid producing bacteria: Brevibacterium lactofermentum, Corynebacterium acetoacidophilum, Arthrobacter citreus. By strain No. 487, the best producer derived from Brevibacterium, 31 mg/ml of l-valine was produced after 72 hr when 10% glucose was supplied as a carbon source, thus giving the yield of 31% from glucose. Accumulation of the other amino acids was negligible. The addition of l-isoleucine and l-leucine in the culture medium did not reduce the l-valine production, indicating that the l-valine biosynthesis is insensitive to these end products in the l-valine producer.     

Microbial 16β-Hydroxylation of Steroids with Aspergillus niger

Microbial 16β-hydroxylation of some steroids with Wojnowicia graminis, Corticium centrifugum and Bacillus megaterium has been reported, but not 16β-hydroxylation of normal 17-oxo steroids with Aspergillus niger. This time, we tried microbial transformation of dehydroepiandrosterone with this fungus, and obtained 4-androstene-3,17-dione, 17β-hydroxy-4-androstene-3,16-dione, 16β,17β-dihydroxy-4-androsten-3-one and a new compound, 16β-hydroxy-4-androstene-3,17-dione. This new compound was also obtained by the fermentation of 4-androstene-3,17-dione and testosterone.     

Bioelectrochemical analysis of a hyperthermophilic microbial fuel cell generating electricity at temperatures above 80 °C

We examined whether a hyperthermophilic microbial fuel cell (MFC) would be technically feasible. Two-chamber MFC reactors were inoculated with subsurface microorganisms indigenous to formation water from a petroleum reservoir and were started up at operating temperature 80 °C. The MFC generated a maximum current of 1.3 mA 45 h after the inoculation. Performance of the MFC improved with an increase in the operating temperature; the best performance was achieved at 95 °C with the maximum power density of 165 mWm^?2, which was approximately fourfold higher than that at 75 °C. Thus, to our knowledge, our study is the first to demonstrate generation of electricity in a hyperthermophilic MFC (operating temperature as high as 95 °C). Scanning electron microscopy showed that filamentous microbial cells were attached on the anode surface. The anodic microbial consortium showed limited phylogenetic diversity and primarily consisted of hyperthermophilic bacteria closely related to Caldanaerobacter subterraneus and Thermodesulfobacterium commune.     

In vitro immunization of Epstein–Barr virus-immortalized B cells augments antigen-specific antibody production

The current method for in vitro immunization (IVI) uses several antigens including toxins, food allergens, pathogenic bacteria, and self-antigen-derived peptides that induce an antigen-specific immune response in peripheral blood mononuclear cells (PBMCs). This protocol, however, requires donor blood collection and preparation of PBMCs before every IVI. In the present study, we aimed to design a more efficient system utilizing B cells immortalized with Epstein–Barr virus (EBV-B) as host cells for IVI to make antigen-specific antibodies. Results showed that previously antigen-sensitized, EBV-B cells exposed to the antigen along with IL-6, CpG oligonucleotides, and CD40 ligand signal produced antigen-specific antibodies. These results provide evidence for a novel and easy method to expand memory-type B cells and produce antigen-specific antibodies.