Physicochemical Characterization of Tween 80‐Hydrolyzing Esterases Produced by Rapidly Growing Mycobacteria

Abstract

Tween 80-hydrolyzing esterases produced by various species of rapidly growing mycobacteria were partially purified from sonicated cell lysates by diethylaminoethyl (DEAE) cellulose and subsequent Sephadex G-150 column chromatographies. The amount of the esterase produced per gram of bacterial cells varied markedly with each species. Mycobacterium smegmatis, M. chelonei, and M. phlei were high producers and M. chitae and M. diernhoferi were low producers of Tween-hydrolyzing esterase. The resistance of each mycobacterial strain to oleic acid correlated well with their esterase-producing ability. All the esterases studied were adsorbed on DEAE cellulose in 50 mM Tris-HCl buffer (pH 7.5), indicating that they are acidic proteins. Esterases of M. smegmatis, M. chitae, M. fortuitum, and M. phlei were eluted from DEAE at high concentrations (0.11-0.18 M) of ammonium sulfate, while those of M. parafortuitum and M. diernhoferi were eluted at lower concentrations (0.05-0.08 M). With Sephadex G-150 gel filtration, all esterases were shown to have similar molecular weights (36,000 to 58,000). On the basis of heat-stability and trypsin- or chymotrypsin-sensitivity, these esterases were divided into three groups: one was heat-stable and protease-sensitive (M. smegmatis and M. fortuitum), another was heat-labile and protease-resistant (M. chelonei), and the other was the intermediate of the above two groups (M. diernhoferi).

Tween-hydrolyzing esterase produced by Acidiphilium sp.

“…In the acidophilic bacteria, Wichlacz and Unz (20) have described that Tween 80 appeared to stimulate growth of the acidophilic bacteria strains. Wichlacz et al (21) and Kishimoto et al (10) have reported that Acidiphilium facilis and A. aminolytica grew on a medium containing Tween 80 as the sole carbon source. However, the lipolytic enzyme of the acidophilic bacteria was not identified, and the enzyme production conditions were not investigated.…”

Effects of gamma radiation on phase behaviour and critical micelle concentration of Triton X-100 aqueous solutions

“…Surfactants are often utilized in formulations above their critical micelle concentration (CMC) values. For example, recombinant human factor XIII is protected against both agitation and freeze-thaw-induced aggregation in the presence of polysorbate 20 at concentrations corresponding to the CMC (0.007%, w/v) [3]; however, at concentrations below this CMC value, it is not stabilized. It has also been reported that surfactant degradation products can impact the stability of the formulation [2].…”