Both Cl. butyricum and Cl. acetobutylicum did not produce enough spores in several media which have been reported as sporulation media for the anaerobes up to the present, while high percentages of sporulation in both organisms were observed within 32 hours in the medium containing glucose, 1.0 per cent; yeast extract, 0.5 per cent; peptone, 0.5 per cent; adjusted to pH 6.0. The effects of concentration of medium, glucose, yeast extract, peptone, temperature, pH, oxygen, and strain difference on sporulation in both anaerobes have been studied using the above medium as a basal one. Depression of spore formation occurred in diluted media in both Clostridium, especially, in Cl. acetobutylicum. It was caused by the lack of carbon and nitrogen sources in Cl. butyricum, whereas yeast extracts was a limitting factor in Cl. acetobutylicum. This fact suggested that growth factors such as biotin, thiamin and p-aminobenzoic acid were exacting for growth and sporulation in the latter anaerobes. Being different from many cases of usual spore-forming bacteria, optimum pH for sporogenesis in both organisms was at pH 6.0 in acid medium, but coincided with optimal pH for growth. Optimum temperature for sporulation as well as for growth was 37°C in both species. Spore yields of Cl. butyricum were independent of presence of oxygen, while oxygen inhibited spore production of Cl. acetobutylicum. Differences of ability to sporulate among the strains of both species were very significant respectively. For instance, sporulations above 80 per cent in some strain, but below several per cent in another strain were observed.
The hot water extract of conidiospores of Aspergillus niger was previously found to contain two types of sulfur compounds (1). Major one of these compounds (Substance A) was isolated from the extract and obtained in a crystalline form. This was identified as choline sulfate by chemical and physical methods. The amount of this sulfate ester in the spores was found to be exceedingly large, being as much as 1.5 per cent of the dry weight of the spores. It is suggested that this substance acts as a store of reserve sulfur in the spores of this fungus.
A bacteriophage, Phage S-a, originally isolated from a culture of Bacillussubtilis var. amyloliquefacus was investigated with respect to its host specificity. It was discoverd that the phage attacks 8 strains out of 23 tested, all belonging to the subtilis-group. The 8 susceptible strains were all chracterized by their capacity for producing amylase in the liquid culture medium. Electron photomicrographs of the phage are presented. It was necessary for obtaining clear images of the phage, to treat the ultracentrifuge-purified samples with deoxyribonuclease in order to remove a mucous contaminant. Antiserum was prepared and kinetic studies were performed concerning the neutralization reaction of the serum toward the phage. The stability of the phage was investigated at varied temperature and pH of the incubation medium.
(1) Absolute values of turbidity in cell suspensions were measured under the narrow beam condition, giving, thereby, correct values of scattering cross section per cell. (2) By using zero method, average indicies of refraction were obtained for Saccharomyces cerevisiae, Rhodotorula glutinis and Micrococcus luteus. (3) If cells are assumed as homogeneous spheres, the cross section could be computed by RAYLEIGH-GANS' and HART-MONTROLL'S expressions. The computed values agreed well with the observed ones for the specimen used. (4) The equations mentioned above will make, accordingly, a convenient theoretical basis for further studies on scattering of light in cell suspensions as will be shown in succeeding papers.
The present authors, in this paper, proposed a new process for the production of l-malate, natural form. In this new process the dried cells or the growing culture of Lactobacillus brevis was employed as fumarase preparation and divalent-metallo fumarate such as Ca- or Zn-fumarate was used as substrate. The enzyme reaction was carried out in the heterogenous phase, almost all the substrate being presented as water suspension. From the relationship between the equilibrium constant and the solubility ratio of product and substrate, the reaction proceeded onesidedly to the formation of l-malate. Thus, crystals of the substrate were apparently transformed into the crystals of the product in the heterogenous reaction mixture. For this category of reactions the authors proposed the name "enzymatic transcrystallization"