The Separation and Characterization of the Growth Factor in Serum and Ascitic Fluid Which Is Required by Certain Pleuropneumonialike Organisms

Abstract

A characteristic of the parasitic pleuropneumonialike organisms (PPLO) is the requirement of serum or ascitic fluid for growth in vitro. Reference has been made by previous workers to some of the properties of the growth factor contained in serum. Tang, Wei, McWhirter, and Edgar (1935) reported that a hemoglobin solution had an enriching property for the bovine pleuropneumonia organisms. The apparent heat stability of this growth factor was alluded to by Nelson (1939). Tissue cultures employed for the cultivation of the fowl coryza bodies, considered to be PPLO, still supported their growth after being heated at 100 C for 1 hour or being stored in the refrigerator for 6 months. Chocolate agar, used for isolating the gonococcus, supported growth of PPLO according to Salaman (1946). Gilmore and Sprince (1949) reported that as little as 0.02 per cent bovine hemoglobin (Armour) permitted growth of PPLO in a liquid medium in the absence of serum. It was emphasized by Morton, Smith, and Leberman (1949) that native animal protein was unnecessary when these investigators observed symbiotic growth of PPLO with bacteria. Since the PPLO comprise a group of microorganisms with peculiar properties and the addition of serum or ascitic fluid to the medium is undesirable for many types of experiments, an attempt was made to isolate and characterize the growth factor present in serum and ascitic fluid. On the basis of work to be reported, it is thought that the essential growth factor for PPLO furnished by serum or ascitic fluid is a protein of low molecular weight, possibly of the globin type, or a degradation product of protein. EXPERIMENTAL METHODS AND RESULTS Eight strains of PPLO isolated from the male and female genitourinary tract served as the test organisms for all of the preparations tested for activity. These are the same eight strains used in previous work (

Mycoplasma growth factors in bovine serum fraction

“…Culture media for the sterol-requiring mycoplasmas usually contain serum, which supplies protein (21,29,30) and lipid (5, 17-19, 21, 22, 24, 31) essential for in vitro growth. In 1951 Smith and Morton (32), using ammonium sulfate precipitation, prepared a serum fraction later reported to be an alpha-lipoprotein (30), which retained all the growth-supporting activity of serum. The process described by Smith and Morton for the preparation of this serum fraction is employed in the commercial production of a bovine serum fraction (BSF) often used in mycoplasma culture media in place of whole serum.…”

Quantitative Measurement of the Growth of Pleuropneumonia-like Organisms1

“…Extreme variation in growth response to different lots of Bacto PPLO serum fraction was noted. The use of lots of the fraction comparable to the preparation originally described by Smith and Morton (1951) permitted optimal yields of about 109 organisms per ml when added at the level of 1 per cent. Increasingly lower optimal yields were obtained with other lots.…”

“…These were selected because of their typical nature, and because they represent two different types in regard to their nutritional requirements (Smith, 1955). The media employed were the broth described by Morton et al (1951) supplemented with Difco PPLO serum fraction (Smith and Morton, 1951) and the synthetic medium reported by Smith (1955). Measurement of dose response in the crude medium was performed with the PPLO serum fraction as the required component; in the synthetic medium arginine was the required factor.…”

Characterization of avian Mycoplasma

“…All, except the saprophytic isolates, require a protein enriched medium. Smith and Morton (155) demonstrated that the essential growth factor was a low molecular weight protein which could be separated from serum and ascitic fluid. They .also found that the growth factor was present in certain yeast preparations.…”