In the course of screening of antibiotics, a new antibiotic was obtained from the cells of a bacterium which was isolated from a soil sample collected in Chiba Prefecture, Japan.
The cultural characteristic of the bacterium was investigated by the authors1). The antibiotic was named pyrrolnitrin and isolated as pale yellow crystals. Pyrrolnitrin has a growth inhibitory effect against fungi, yeasts and Gram-positive bacteria, and has low toxicity.
This paper deals with fermentation, isolation and properties of pyrrolnitrin.
Pyrrolnitrin (hereinafter referred to as PN) is a new antifungal antibiotic, recently isolated from Pseudomonas pyrrocinia n. sp. by Arima et al1)., and the chemical structure of this substance is established as follows : 1)
The above chemical structure was confirmed synthetically by this laboratories2).
Comprehensive studies of PN were undertaken to observe its antimicrobial activity in vitro, its distribution in the body and excretion after oral administration, its therapeutic activity on animals with experimentally-induced fungal infection and its toxicity.
The antifungal activities of PN were compared with those of other widely used antifungal agents.
Neocarzinostatin is a new antibiotic isolated from culture filtrate of Streptomyces carzinostaticus F-411). The antibiotic exerts a striking inhibitory effect on growth of some experimental tumors1) and various studies have been made in this laboratory to elucidate the mode of action of neocarzinostatin2,3). The present report concerns with the cytological changes of sarcoma 180 tumor cells produced by neocarzinostatin in vivo.
Fusidic1) and helvolinic2) acids are produced by fungi and belong to the group of steroidal antibiotics of protolanostane skeleton, together with helvolic acid3) and cephalosporin P14). Helvolinic acid is also obtained by partial hydrolysis of helvolic acid. They exhibit an antibacterial activity against Gram-positive organisms, including penicillinresistant Staphylococci.
The morphological changes in bacteria induced by antibiotics and chemotherapeutic agents have been reported in the literatures(1~5).
Since elongation of E. coli cells was noticed under the influence of anticancer agents, we studied this respect in details and divided chemotherapeutic agents and antibiotics into 3 groups and 6 types according to the morphological changes in E.coli B cells treated with these substances6). Most of anticancer agents are grouped into the 1 st group (elongation group); most of antibacterial and antifungal agents into the 2nd group (agglomeration group); and some anticancer and antibacterial agents into the 3rd group (apparently no morphological change). The followings are the detailed description of the morphological changes in the cells of E.coli B and other Gram-positive and Gram-negative bacteria induced by several representative substances belonging to the respective group.