A multiple mutant of bacteriophage T4, which had been proved to contain cytosine-substituted DNA, was grown in a suppressor-containing or non-containing (sup°) strain of Escherichia coli B or K12, and the progeny phage obtained was grown on test strains carrying various restriction systems. As a result, the growth of this phage was found to be subject to the rK, rB, and rP1 restriction systems. Two T4 strains, named UNF-r1 and UNF-r+1, sensitive to the rK, rB, and rP1 restriction systems, were newly derived by the genetic cross and mutagenesis. The former had the unf-39 mutation instead of the alc-8 mutation, the latter had the rII+ region and the unf-39 mutation, besides the amE51 (gene 56; dCTPase), denA (endonuclease II), and denB (endonuclease IV) mutations. It was demonstrated that UNF-r+1 DNA possessed a SalI recognition site in the rII-denB region which was deleted in UNF-r1 DNA.
Sublethal concentration of the antibiotic, novobiocin, or ethylenediaminetetraacetate was found to induce formation of large regular cell packets in Micrococcus luteus (lysodeikticus), which usually grows in pairs, fours, and short chains of cells. Teichuronic acid, normal constituent of the cell walls of M. luteus, seemed to be absent or present in a very small amount in the cell wall of the cell packets, judged by the agglutination test with antiserum or by chemical analysis of hexose, a component of teichuronic acid. At much higher concentrations, novobiocin also inhibited the enzymic synthesis of teichuronic acids by a particulate fraction of M. luteus. Therefore, it was hypothesized that loss of teichuronic acid was the reason for formation of cell packets by this bacterium in the presence of novobiocin or ethylenediaminetetraacetate.
Examination of non-methanogenic anaerobic bacteria in sewage digestor fluid was attempted by the anaerobic roll tube method. For the enumeration of anaerobic bacteria in digestor fluid, rumen fluid-glucose-cellobiose-agar (RGCA) gave as good results as previously reported in the rumen and other ecosystems like intestines and feces, under the 100% CO2 gas phase. However, under the mixed gas phase (95% N2 and 5% CO2), higher colony counts were obtained with YLS agar, which contained the supernatant of autoclaved sewage digestor fluid, than with RGCA. Colony counts of anaerobic bacteria decreased with the progress of fermentation of waste and the proportion of facultative anaerobes in the isolated anaerobes also decreased. Large variations in the distribution pattern of bacteria were usually observed between the results obtained from three digestors investigated. However, Streptococcus and Gram-negative curved rods were commonly isolated from the three digestors as predominant groups.
Specific activities of superoxide dismutase (SOD) were found to range limitedly from 9.3 to 18.3U/mg protein among 11 typical strains of facultatively anaerobic bacteria grown under the same condition. All of the SOD's in these bacteria were resistant to 1mM KCN, suggesting the exclusion of cupro-zinc-SOD. Every bacterium examined had SOD's resistant to 5mM H2O2, suggesting manganese-SOD's. Some had H2O2-sensitive SOD's which were presumed to be iron-SOD's. Several cultural factors were examined in their effect on SOD activities in Escherichia coli B, a typical facultative anaerobe. Aeration and manganese sulfate supplementation to media clearly affected both the levels and the acrylamide gel electrophoretograms of SOD's. Aeration was proved to induce two of the three isoenzymes, the third-SOD and manganese-SOD. Manganese sulfate was proved to promote the induction of manganese-SOD by aeration.
Infrared spectrometric analysis and thin-layer chromatography were employed to detect sphingolipids in the genus Bacteroides species. Sphingolipids were found in the bacteria belonging to B. fragilis, B. melaninogenicus, B. oralis, and B. ruminicola, but not in B. succinogenes, B. furcosus, B. hypermegas, B. amylophilus, and B. multiacidus. The taxonomical position of the bacteria that contain no sphingolipids has come into the question.
Edited and published by : Applied Microbiology, Molecular and Cellular Biosciences Research Foundation/Center for Academic Publications Japan Produced and listed by : TERRAPUB, Center for Academic Publications Japan/Shobi Printing Co., Ltd. (-Vol.60,No12), Center for Academic Publications Japan/InternationalAcademic Printing Co., Ltd.(-Vol.54,No1)