It was found that Pediococcus cerevisiae ATCC 8081 can grow and produce acid on μg amounts of thymidine instead of mμg amounts of folinic acid SF (citrovorum factor) to a considerably better extent with a "thymidine enhancement factor". The "factor" present in some microbiological media was identified as an effect of Tween 80 present in the medium. Similar effect was obtained also by other non-toxic detergents and was considered to be surface tension lowering, since it was (a) unspecific for the chemical nature of the "factor" (b) of the "all-or-none" type (c) dependent on a defined water/liquid interfacial tension. The bearing of changes in surface tension of the environment causing selective nutritional effects was discussed.
An aminotransferase with broad specificity was partially purified from Pseudomonas savastanoi. The enzyme catalyzes the conversion of L-tryptophan to indole-3-pyruvic acid (IPYA) but transaminates more readily with other amino acids. Optimal activity occurs at pH 8.8. The aminotransferase shows broad specificity for both amino donors and acceptors. Indole- 3-acetic acid (IAA) and indole-3-acetamide (IAM) at 3×10-3M inhibit minotransferase activity 30% and 26%, respectively. Specific activity of aminotransferase from cells grown in a medium with L-tryptophan or IAA does not appear to affect production of the enzyme. Whole cells of Pseudomonassavastanoi convert IPYA to IAA but the overall conversion is slower than the rate of conversion of IAM to IAA. The role of aminotransferase in the synthesis of IAA from tryptophan is considered to be minor to that of the oxidative decarboxylase-hydrolase system in this bacterium.
Two types of pyocins were found in Pseudomonas aeruginosa and named pyocin type S and type R. Production of both types of pyocin was inducible by ultraviolet ray or by mitomycin. An S-type pyocin was prepared from strain P28 and its nature was investigated. The pyocin activity was labile to heat or proteinase treatment. Its molecular weight was estimated to be around 1×105. The same type of pyocin was found in M11, a fertile strain originally isolated by Holloway. Pyocin type R, which has a structure very similar to some phage tails, was found among three strains of Japanese and Australian origin and named pyocin R2, R3, and R4. These pyocins distinguished by the difference in their action spectrum but were otherwise indiscernible. They behaved in the same manner during the purification process including DEAE-cellulose chromatography. Moreover an immunological cross reaction was observed among these R-type pyocins. Anti-pyocin R or R2 serum also neutralized other R-type pyocins. Electron microscopy revealed a similar dimension for each pyocin particle; 15Å×1, 300Å.
The DNA base composition (GC content) of 114 strains belonging to the so-called coryneform bacteria was examined from the viewpoint of bacterial taxonomy. The GC content of these bacteria ranged widely from 46 to 78%. Although the GC content of Cellulomonas fell into a relatively narrow range near 72%, those of Corynebacterium, Arthrobacter, Microbacterium, and Brevibacterium did not exhibit the specific range to characterize the genus. This fact probably shows that the genera of coryneform bacteria, except Cellulomonas, are taxonomically heterogeneous. A new method for the isolation of DNA from lysozyme-insensitive or poorly sensitive strains was described.
Crude leaf extract of Achyranthes aspera, Aloe barbadens, Capsicum frutescens and Carica papaya inhibit the activity of mild mosaic, distortion ringspot and ringspot viruses of papaya; Argemone mexicana and Carumcopticum extracts inhibit the infectivity of DR and RS while Adenocalymnaalliaceae is effective against MM only. Infectivity of all the three isolates was also inhibited by the seed extracts of Argemone mexicana, Daturafastuosa, Rhyncosia asnaris and Raphanus sativus. Seed extract of Rhyncosiaasnaris which completely inhibited the infectivity of MM in vitro reduced its infectivity when sprayed on the leaves of host plants prior to inoculation or when applied as a soil drench. It was found to be stable against heat, dilution, ethyl alcohol and was partially dialysable. This seems to be of a complex nature having a protein and sugar as its components.
A bacteriophage related to R-type pyocins was isolated from a lysogenic strain of Pseudomonas aeruginosa and named PS3. It was composed of a head and a contractile tail which resembled R-type pyocins. The character of the phage was studied comparing with R-type pyocins. The activity of this phage was neutralized by anti-R or R2 serum and the antiserum against PS3 was also active in inhibiting pyocins R and R2. However, the anti-R sheath serum, while showing a strong neutralizing activity against pyocin R or R2, was almost ineffective against the phage PS3. The phage and the pyocins were further related in some way in the receptor specificity. Mutants resistant to one of the killer particles were isolated and their behavior to other agents were studied. From this result, a working hypothesis was presented with regard to the structure of the receptor for the phage and pyocins.
The base composition of DNA (GC content) of 31 cultures of Hanseniaspora and its imperfect counterpart Kloeckera, which represented 14 species, was studied. The GC content of these apiculate yeasts ranged from 26.8 to 38.0%. Thirty-one cultures employed were divided into 4 groups on the basis of their GC contents, and this grouping agreed with that based on biochemical criteria commonly employed in yeast taxonomy. The first group (H. osmophila-K. africana) exhibited the GC content of 37.3-38.0%, and assimilated maltose but not glycerol or calcium-2-ketogluconate. The second group (K. javanica) exhibited the GC content of 33.7-34.6% and assimilated glycerol but not maltose or calcium-2-ketogluconate. The third group (H. guilliermondii, H. uvarum-K. apiculate) exhibited the GC content of 31.0-31.7% and assimilated calcium-2-ketogluconate but not maltose or glycerol. The last group (H. valbyensis-K. japonica) exhibited the GC content of 26.8-27.6%, and did not assimilate maltose, glycerol, and calcium-2-ketogluconate. Relationship between the species of Hanseniaspora and its counterpart species of Kloeckera was discussed.
The paper deals with the development of ascocarp and ascus cytology in Anixiella indica. The ascocarp arises by the coiling of a hyphal branch. The septate ascogonial coil soon became invested with vegetative hyphae forming a spherical ball of pseudoparenchymatous tissue, which, as the development proceeds, becomes distinguishable in two layers of peridium and the central sporogenous tissue. The asci developed from typical croziers, which were produced by binucleate ascogenous cells, that developed from the basal compressed sporogenous tissue. The haploid number of chromosomes is 4. Chromosome behaviour during ascus development has been described.
Energy-dependent L-glutamate transport system in Brevibacterium ammoniagenes was studied. Its activity was repressed by biotin deficiency and was restored to its normal level by the addition of sugars or salts in high concentration. In the restored system, however, a decrease was observed in its substrate specificity, while other properties remained similar to those in biotin-sufficient one. Penicillin induced requirement for hypertonicity to activate the transport system even in biotin-sufficient state, and chloramphenicol acted to reduce the rate of the restoration of substrate specificity which occurred during biotin deficient-sufficient transition. It was concluded that biotin was bifunctional in the L-glutamate transport system in this organism.