Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6

Abstract

Stenotrophomonas maltophilia strain C6, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from creosote-contaminated sites at Hilo, Hawaii. Twenty-two metabolites of phenanthrene, covering from dihydrodiol to protocatechuic acid, were isolated and characterized. Phenanthrene was degraded via an initial dioxygenation on 1,2-, 3,4-, and 9,10-C, where the 3,4-dioxygenation and subsequent metabolisms were most dominant. The metabolic pathways were further branched by ortho- and meta-cleavage of phenanthrenediols to produce 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, and naphthalene-1,2-dicarboxylic acid. These intermediates were then transformed to naphthalene-1,2-diol. 1-Hydroxy-2-naphthoic acid was also degraded via a direct ring cleavage. Naphthalene-1,2-diol underwent primarily ortho-cleavage to produce trans-2-carboxycinnamic acid and then to form phthalic acid, 4,5-dihydroxyphthalic acid and protocatechuic acid. Accumulation of salicylic acid in prolonged incubation indicated that a limited extent of meta-cleavage of naphthalene-1, 2-diol also occurred. This is the first study of detailed phenanthrene metabolic pathways by Stenotrophomonas maltophilia.

Pyrene Degradation by Biosurfactant Producing Bacterium Stenotrophomonas maltophilia

“…In this experiment, a range of 45-110 lg mL -1 of cell pellet protein concentration was recorded within 10-20 days of incubation. S. maltophilia strain C6 also reported for utilization of Phenanthrene as a sole carbon and energy source [9]. In case of S. maltophilia BR-12, maximum amount of cell pellet and soluble protein (50 lg mL -1 ) was recorded between 15 and 20 days of growth.…”

“…Among various biosurfactant producing microorganisms S. maltophilia is known to degrade number of PAHs including Phenenthrene, Benzopyrene, Benzophenanthrene, and Anthracene etc. [9,13]. In this study, a bacterial isolate BR-12 isolated from Vadodra oil refinery soil with biosurfactant production capability was evaluated for biodegradation of Pyrene with an aim to produce an effective bioremediation strategy for such contaminated soils.…”

Biodegradation of phenanthrene by Pseudomonas sp. BZ-3, isolated from crude oil contaminated soil

“…USTB-RU degrading PHE via protocatechuate pathway. PHE degradation by the strain Stenotrophomonas maltophilia C6 has been proposed as protocatechuate and salicylate pathway (Gao et al, 2013). Seo et al (2012) reported a highly branched metabolic pathways of PHE biodegradation, including dioxygenation on C-1, 2 and C-3,4 and C-9,10 positions and ring opening by both ortho-and meta-cleavage by Mycobacterium aromativorans strain JS19b1…”

“…Due to their adaptability, rapid population growth and highly efficient metabolism, microorganisms are accepted as a significant role in treating those PAHs contaminated sites (Roy et al, 2012). Phenanthrene (PHE), a tricyclic aromatic hydrocarbon with three-fused rings in an angular fashion, is commonly used as a model compound for PAH biodegradation studies (Roy et al, 2012;Gao et al, 2013). Halophilic or halotolerant PHE-degrading bacteria have the capability of using PHE as a source of carbon and energy (Bogan et al, 2003).…”

Characterization of a Microbial Consortium for the Bioremoval of Polycyclic Aromatic Hydrocarbons (PAHs) in Water

“…In this study, Chitinophagaceae was dominant with 40.9% for pyrene. Moreover, several authors [36,51,52] have conducted research presenting Stenotrophomonas as excellent candidates for PAH removal, particularly phenanthrene. Table 4 shows Stenotrophomonas as the dominant group in the phenanthrene sample with a 23% presence.…”