Formation of specialized aerial architectures by Rhodococcus during utilization of vaporized p-cresol

Abstract

When grown with vaporized alkylphenols such as p-cresol as the sole carbon and energy source, several isolated Rhodococcus strains formed growth structures like miniature mushrooms, termed here specialized aerial architectures (SAA), that reached sizes of up to 0.8 mm in height. Microscopic examination allowed us to view the distinct developmental stages during the formation of SAA from a selected strain, Rhodococcus sp. KL96. Initially, mounds consisting of long rod cells arose from a lawn of cells, and then highly branched structures were formed from the mounds. During the secondary stage of development, branching began after long rod cells grew outward and twisted longitudinally, serving as growth points, and the cells at the base of the mound became short rods that supported upward growth. Cells in the highly fluffy structures were eventually converted, via reductive division, into structures that resembled cocci, with a diameter of approximately 0.5 mm, that were arranged in chains. Most cells inside the SAA underwent a phase variation in order to form wrinkled colonies from cells that originally formed smooth colonies. Approximately 2 months was needed for complete development of the SAA, and viable cells were recovered from SAA that were incubated for more than a year. An extracellular polymeric matrix layer and lipid bodies appeared to play an important role in structural integrity and as a metabolic energy source, respectively. To our knowledge, similar formation of aerial structures for the purpose of substrate utilization has not been reported previously for Grampositive bacteria.

Aerobic Growth of Rhodococcus aetherivorans BCP1 Using Selected Naphthenic Acids as the Sole Carbon and Energy Sources

“…Further, mainly CPCA- but also CHCA-grown long and short rod cells exhibited irregular shape and an increased number of division septa ( Figures 3B,C,F ). The presence of unresolved division septa has been often associated to uneven or incomplete cell division as a consequence of an altered bacterial cell cycle ( Veeranagouda et al, 2009 ). CPCA grown cells were also surrounded and connected through a diffuse matrix which could be either glycocalyx or exopolymeric substances (EPS) ( Figures 3C,F ).…”

Ssg, a putative glycosyltransferase, functions in lipo- and exopolysaccharide biosynthesis and cell surface-related properties in Pseudomonas alkylphenolia

“…The samples were subsequently freeze‐dried for storage. The sugar composition of the exopolysaccharide was analyzed with trifluoroacetic acid hydrolysates by a high‐performance anion‐exchange chromatography (HPAEC) with a Pulsed Amperometric Detection system (Dionex, Sunnyvale, CA) using a CarboPac ™ PA‐1 column as described previously (Veeranagouda et al , 2009).…”

Treatment of wastewater containing high concentrations of terephthalic acid by Comamonas sp. and Rhodococcus sp.: kinetic and stoichiometric characterization

“…; Veeranagouda et al . ). The genus Rhodococcus has been reported as capable to degrade phthalate and terephthalate (Choi et al .…”

“…The genus Comamonas has been reported as aerobic degraders of isophthalate and terephthalate as sole carbon and energy source (Wang et al 1995;Vamsee-Krishna & Prashant 2008) and has also been used during the degradation of similar aromatic compounds such as phenol, chlorophenolic and polychlorinated biphenyls compounds (Furukawa & Fujihara 2008;Tobajas et al 2012). Rhodococcus are gram-positive bacteria with rod-to-coccus variation and filamentous cells during the growth cycle (Stoecker et al 1994;Veeranagouda et al 2009). The genus Rhodococcus has been reported as capable to degrade phthalate and terephthalate (Choi et al 2005).…”