The attaching ability of a number of bacteria, isolated from bovine rumen, to cellulose powder was examined in vitro. Within the range of organisms examined in this investigation, bacteria possessing the attaching ability to cellulose were strains belonging to Bacteroides succinogenes, Ruminococcus flavefaciens, Ruminococcus albus, Eubacterium cellulosolvens, Eubacterium sp., Megasphaera elsdenii, Veillonella alcalescens, Veillonella parvula, and Fusobacterium sp. The reaction temperature, among factor which influence the attachment of bacteria to cellulose, had a profound effect. All of bacteria listed above attached to cellulose at 38°. Strains of B. succinogenes, R. flavefaciens, and R. albus did not attach to cellulose at 4°. On the other hand, those of E. cellulosolvens, M. elsdenii, V. alcalescens, and V. parvula attached well to cellulose even at the reaction temperature of 4°. Effect of the presence of various carbohydrates on the attachment of bacteria to cellulose was examined. Methylcellulose almost completely inhibited the attachment of all of bacteria tested to cellulose. The degree of this inhibition by methylcellulose depended on its concentration. Amylopectin partly inhibited the attachment of bacteria to cellulose. Cellobiose specifically inhibited the attachment of B. succinogenes strain to cellulose. An attempt was made to detach or elute bacteria from cellulose by some means. Cells of B. succinogenes, R. flavefaciens, and R. albus, attached once to cellulose at 38°, were detached by cooling treatment at 4°. Cells of bacteria, attached once to cellulose at 38°, except E. cellulosolvens, were eluted with an aqueous solution of methylcellulose. E. cellulosolvens cells, attached to cellulose, were not detached by cooling treatment at 4° or by elution with a solution of methylcellulose. Ecological implications of the attachment of bacteria to cellulose is also discussed.
A strain of yeast labeled Candida rugosa was found to represent a new species and was named Candida pararugosa. C. pararugosa had a GC content of 48%, assimilated L-sorbose and L-arabinose but not glycerol, required pyridoxine, had a maximum growth temperature of 36-37°, and differed from C. rugosa in these characteristics. Further, C. pararugosa differed from C. rugosa also in serological characteristics and proton-NMR spectrum of mannose-containing polysaccharide in the cell wall. A description of the new yeast was given.
Syntheses of carotovoricin Er, a bacteriocin from Erwinia carotovora strain Er, induced by mitomycin-C, was accompanied with cell lysis. Carotovoricin Er is a thermolabile particulate, sedimentable by centrifugation at 100, 000×g for 60min, sensitive to sodium dodecyl sulfate, and unstable at acidic and basic pH, indicating protein in nature. Carotovoricin Er, however, is resistant to hydrolytic digestion by various proteolytic enzymes. Carotovoricin Er was purified approximately 70 fold by ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography, Sepharose 2B gel filtration, and sucrose density gradient centrifugation. Single peak of carotovoricin activity coincided with a protein peak in the sucrose density gradient. Negatively stained specimens of purified carotovoricin Er revealed that its structure consists of a contractible sheath, a core, and fibers, and resembled that of the tail part of bacteriophages.
Composition of cellular fatty acids in methanol-utilizing bacteria was examined from the viewpoint of taxonomy. This group of bacteria showed a rather simple composition of cellular fatty acids, and was divided into two major groups on the basis of this composition. Pseudomonasmethylotropha NCIB 10510, 10511, 10512, 10513, and 10515 showed the presence of a large amount of straight-chain saturated and unsaturated acids of C16:0 and C16:1, a small amount of straight-chain 3-hydroxy acid of C10:0, and a minor amount of other acids. Other methanol-utilizing bacteria, Pseudomonas extorquens NCIB 9399, Pseudomonas spp. NCIB 9133, 9686, and 10597, and Protaminobacterrubes NCIB 2879, showed the presence of a large amount of straight-chain unsaturated acid of C18:1, and a minor amount of other acids. Almost identical fatty acid composition was obtained from Microcycluspolymorphum NCIB 10516 and Hyphomicrobium variabile NCIB 10517, with the exception of the presence of cyclopropane acid of C19:0 and other unknown acids. It was noteworthy that almost identical fatty acid composition was found in the cells grown on methanol-containing media and in the cells grown on media not containing methanol, in the both groups of methanol-utilizing bacteria.
Ca2+- or Ba2+-dependent uptake of microvirid phage DNA was not affected by the presence or absence of a phage receptor on the cell surface of E. coli C. Structural changes of cell wall lipopolysaccharide in E. coli C, however, affected the development of Ca2+- or Ba2+-dependent competence. Thus, efficiency of transfection was low in strain C61 (lacking branch heptose) and in C23•1 (deficient in galactose residues and branch glucose). Ba2+-induced competence was low in the terminal galactose-less strain C23 as well. Deficiency in murein lipoprotein resulted in an increased competence for single-stranded DNA and double-stranded replicative form DNA. Level of the competence of mutants resistant to T5 and/or T1 was not much different from that of the sensitive bacteria. In various strains of E. coli, Ca2+ (Ba2+)-induced competence for single-stranded DNA was parallel with that for double-stranded replicative form DNA. On the other hand, the ratio of Ca2+- and the Ba2+-dependent competence varied considerably in several derivatives of strain C.
Two groups of bacteria were determined as oligotrophs and eutrophs. The former can grow only on a poor medium and not on a rich medium, and the latter can grow on a rich medium. Based on such trophic nature of bacterial groups, a method was established for counting viable cell number of oligotrophs and eutrophs, employing poor and rich media. The present method was used to examine water samples of fresh and sea water areas including rivers and lakes in Toyama Prefecture, off the coast of Toyama Bay, and open sea area at Yamato Bank in the Japan Sea. Physical and chemical environmental factors in these areas were also estimated. Based on the result of an extensive survey on these oligotrophic and eutrophic water samples, two general conclusions were deduced: (a) Oligotrophs and eutrophs responded quite similarly to respective chemical environmental factors, and (b) the number of these trophic groups remained almost constant at even higher concentrations of these factors. In fresh water areas, the number of oligotrophs usually exceeded that of eutrophs, and limiting substances for the size of these bacterial populations were considered to be nitrate-nitrogen and dissolved organic nitrogen. From the effect of rainfall on the number and trophic flora of bacteria in a river, the source of river bacteria was suggested at least in part to be attributed to the soil bacteria.