Prototrophic Thermophilic Bacillus: Isolation, Properties, and Kinetics of Growth

Abstract

A thermophilic bacillus (minimal growth temperature 41 C, optimal 55 to 58 C, and maximal 65 C) was isolated from a manure pile. It is very similar to Bacillus stearothermophilus, but it differs in its inability to hydrolyze starch. The thermophilic isolate is a prototroph which grows in a minimal medium consisting of glucose, ammonium salt, phosphate buffer, and inorganic salts. At all temperatures studied (low to high), the same minimal nutritional requirements prevailed. The Arrhenius constant for growth was found to be 15,000 and 13,500 cal/mole in the minimal and rich media, respectively.

Defined minimal media for the growth of prototrophic and auxotrophic strains of Bacillus stearothermophilus

“…T h e minimal chemically defined media formulated here confirmed the finding of Anderson & Friesen (1972) that the strain they studied (NCTC 10003 prototrophic) was capable of growing in medium unsupplemented with any amino acid or vitamin. A similar prototrophic strain of B. stearothermophilus was also reported by Epstein & Grossowicz (1969). It seems therefore that there are at least two distinct broad classes of B. stearothermophilus with one requiring complex supplementation of mineral salts a n d organic compounds and the other showing simple requirements of only glucose a n d mineral salts for growth.…”

Properties of α-Aminoisobutyric Acid Transport in a Thermophilic Microorganism

“…AIB apparently underwent no metabolic transformation during the uptake process. Unlike glutamate, aspartate, or alanine (7), AIB served neither as nitrogen source in the presence of glucose nor as a carbon source in the presence of ammonium ions. No formation of "4CO, could be detected under conditions which permitted [1-_ 4C IB uptake.…”

“…MATERIALS AND METHODS Bacterial strains. The thermophilic microorganism used was described by Epstein and Grossowicz (7). From the prototrophic wild type, several auxotrophic mutants were isolated by using ultraviolet light (UV) irradiation and the penicillin selection method.…”

“…Media and growth. Several media were used including a minimal medium (7) to grow the wild type strain. This medium when supplemented with L-tyrosine (20 gg/ml) and L-leucine (50 ug/ml) (TL-medium) was used for growing the mutant strain.…”

Respiration-linked proton translocation in the moderate thermophile Bacillus stearothermophilus

“…B. stearothermophilus [16] was grown in carbon substrate-limited continuous culture (D=0.08 h, temperature 37 °, 45 °, 55 ° or 65°C) using a Porton-style chemostat [17] of 580 ml capacity. The minimal salts medium [18] was supplemented with d-biotin (100 #g/l; added in 2 ml of 50% ethanol), nitrilotriacetic acid (sodium salt; 100 rag/l) and sodium succinate (10 mM).…”