Efficient biodegradation of Polyethylene terephthalate (PET) plastic by Gordonia sp. CN2K isolated from plastic contaminated environment.

Since we rely entirely on plastics or their products in our daily lives, plastics are the invention of the hour. Polyester plastics, such as Polyethylene Terephthalate (PET), are among the most often used types of plastics. PET plastics have a high ratio of aromatic components, which makes them very resistant to microbial attack and highly persistent. As a result, massive amounts of plastic trash accumulate in the environment, where they eventually transform into microplastic (<5 mm). Rather than macroplastics, microplastics are starting to pose a serious hazard to the environment. It is imperative that these polymer microplastics be broken down. Through the use of enrichment culture, the PET microplastic-degrading bacterium was isolated from solid waste management yards. Bacterial strain was identified as Gordonia sp. CN2K by 16 S rDNA sequence analysis and biochemical characterization. It is able to use polyethylene terephthalate as its only energy and carbon source. In 45 days, 40.43 % of the PET microplastic was degraded. By using mass spectral analysis and HPLC to characterize the metabolites produced during PET breakdown, the degradation of PET is verified. The metabolites identified in the spent medium included dimer compound, bis (2-hydroxyethyl) terephthalate (BHET), mono (2-hydroxyethyl) terephthalate (MHET), and terephthalate. Furthermore, the PET sheet exposed to the culture showed considerable surface alterations in the scanning electron microscope images. This illustrates how new the current work is.

SERS characterization of biochemical changes associated with biodesulfurization of dibenzothiophene using Gordonia sp. HS126-4N.

In this study, Gordonia sp. HS126-4N was employed for dibenzothiophene (DBT) biodesulfurization, tracked over 9 days using SERS. During the initial lag phase, no significant spectral changes were observed, but after 48 h, elevated metabolic activity was evident. At 72 h, maximal bacterial population correlated with peak spectrum variance, followed by stable spectral patterns. Despite 2-hydroxybiphenyl (2-HBP) induced enzyme suppression, DBT biodesulfurization persisted. PCA and PLS-DA analysis of the SERS spectra revealed distinctive features linked to both bacteria and DBT, showcasing successful desulfurization and bacterial growth stimulation. PLS-DA achieved a specificity of 95.5 %, sensitivity of 94.3 %, and AUC of 74 %, indicating excellent classification of bacteria exposed to DBT. SERS effectively tracked DBT biodesulfurization and bacterial metabolic changes, offering insights into biodesulfurization mechanisms and bacterial development phases. This study highlights SERS' utility in biodesulfurization research, including its use in promising advancements in the field.

A Patient of Spontaneous Bacterial Peritonitis in Hepatitis C Cirrhosis Caused by Gordonia terrae: A Case Report.

Background: Gordonia terrae is an opportunistic pathogen that rarely causes clinical infections. Here, we first report a case of spontaneous bacterial peritonitis in patients with hepatitis C cirrhosis caused by Gordonia terrea. Case Presentation: A 71-year-old male patient was diagnosed with spontaneous bacteria peritonitis secondary to hepatitis C cirrhosis. The result of bacterial culture in ascites was positive, and the pathogenic bacteria was preliminarily identified as the Gordonia genus by matrix-assisted laser desorption ionization-time of flight mass spectrometry. After 16S rRNA sequencing analysis, it was determined to be the Gordonia terrea. Symptoms relieved after treatment with ceftazidime. Conclusion: This case indicates that the clinical infections caused by Gordonia terrea should be brought to the forefront. Accurate and rapid bacterial identification results are highly beneficial to the diagnosis and therapeutic regime.

Optimized carotenoid production and antioxidant capacity of Gordonia hongkongensis.

The current emphasis within the cosmetic market on sustainable ingredients has heightened the exploration of new sources for natural, active components. Actinomycetota, recognized for producing pigments with bioactive potential, offer promising functional cosmetic ingredients. This study aimed to optimize pigment and antioxidant metabolite production from the Gordonia hongkongensis strain EUFUS-Z928 by implementing the Plackett-Burman experimental design and response surface methodology. Extracts derived from this strain exhibited no cytotoxic activity against human primary dermal fibroblast (HDFa, ATCC® PCS-201-012™, Primary Dermal Fibroblast; Normal, Human, Adult). Eight variables, including inoculum concentration, carbon and nitrogen source concentration, NaCl concentration, pH, incubation time, temperature, and stirring speed, were analyzed using the Plackett-Burman experimental design. Subsequently, factors significantly influencing pigment and antioxidant metabolite production, such as temperature, inoculum concentration, and agitation speed, were further optimized using response surface methodology and Box-Behnken design. The results demonstrated a substantial increase in absorbance (from 0.091 to 0.32), DPPH radical scavenging capacity (from 27.60% to 84.61%), and ABTS radical scavenging capacity (from 17.39% to 79.77%) compared to responses obtained in the isolation medium. The validation of the mathematical model accuracy exceeded 90% for all cases. Furthermore, liquid chromatography coupled with mass spectrometry (LC-MS) facilitated the identification of compounds potentially responsible for enhanced pigment production and antioxidant capacity in extracts derived from G. hongkongensis. Specifically, six carotenoids, red-orange pigments with inherent antioxidant capacity, were identified as the main enhanced compounds. This comprehensive approach effectively optimized the culture conditions and medium of a G. hongkongensis strain, resulting in enhanced carotenoid production and antioxidant capacity. Beyond identifying bioactive compounds and their potential cosmetic applications, this study offers insights into the broader industrial applicability of these extracts. It underscores the potential of G. hongkongensis and hints at the future utilization of other untapped sources of rare actinomycetes within the industry.

Genomic, Phylogenetic and Physiological Characterization of the PAH-Degrading Strain Gordonia polyisoprenivorans 135.

The strain Gordonia polyisoprenivorans 135 is able to utilize a wide range of aromatic compounds. The aim of this work was to study the features of genetic organization and biotechnological potential of the strain G. polyisoprenivorans 135 as a degrader of aromatic compounds. The study of the genome of the strain 135 and the pangenome of the G. polyisoprenivorans species revealed that some genes, presumably involved in PAH catabolism, are atypical for Gordonia and belong to the pangenome of Actinobacteria. Analyzing the intergenic regions of strain 135 alongside the "panIGRome" of G. polyisoprenivorans showed that some intergenic regions in strain 135 also differ from those located between the same pairs of genes in related strains. The strain G. polyisoprenivorans 135 in our work utilized naphthalene (degradation degree 39.43%) and grew actively on salicylate. At present, this is the only known strain of G. polyisoprenivorans with experimentally confirmed ability to utilize these compounds.

Biodegradation of low-density polyethylene film by two bacteria isolated from plastic debris in coastal beach.

Low-density polyethylene (LDPE) conduces massive environmental accumulation due to its high production and recalcitrance to environment. In this study, We successfully enriched and isolated two strains, Nitratireductor sp. Z-1 and Gordonia sp. Z-2, from coastal plastic debris capable of degrading LDPE film. After a 30-day incubation at 30 ℃, strains Z-1 and Z-2 decreased the weight of branched-LDPE (BLDPE) film by 2.59 % and 10.27 % respectively. Furthermore, high temperature gel permeation chromatography (HT-GPC) analysis revealed molecular weight reductions of 7.69 % (Z-1) and 23.22 % (Z-2) in the BLDPE film. Scanning electron microscope (SEM) image showed the presence of microbial colonization and perforations on the film's surface. Fourier transform infrared spectroscopy (FTIR) analysis indicated novel functional groups, such as carbonyl and carbon-carbon double bonds in LDPE films. During LDPE degradation, both strains produced extracellular reactive oxygen species (ROS). GC-MS analysis revealed the degradation products included short-chain alkanes, alkanols, fatty acids, and esters. Genomic analysis identified numerous extracellular enzymes potentially involved in LDPE chain scission. A model was proposed suggesting a coordinated role between ROS and extracellular enzymes in the biodegradation of LDPE. This indicates strains Z-1 and Z-2 can degrade LDPE, providing a basis for deeper exploration of biodegradation mechanisms.

Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov., two novel actinobacteria isolated from mangrove sediments and leaves of halophyte Sesuvium portulacastrum in Thailand.

A polyphasic approach was used to characterize two novel actinobacterial strains, designated PKS22-38T and LSe1-13T, which were isolated from mangrove soils and leaves of halophyte Sesuvium portulacastrum (L.), respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that they belonged to the genus Gordonia and were most closely related to three validly published species with similarities ranging from 98.6 to 98.1 %. The genomic DNA G+C contents of strains PKS22-38T and LSe1-13T were 67.3 and 67.2 mol%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 93.3 and 54.9 %, respectively, revealing that they are independent species. Meanwhile, the ANI and dDDH values between the two novel strains and closely related type strains were below 80.5 and 24.0 %, respectively. Strains PKS22-38T and LSe1-13T contained C16 : 0, C18 : 1 ω9c and C18 : 0 10-methyl (TBSA) as the major fatty acids and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol as the main phospholipids. The predominant menaquinone was MK-9(H2). Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strains PKS22-38T and LSe1-13T are considered to represent two novel species within the genus Gordonia, for which the names Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov. are proposed, with strain PKS22-38T (=TBRC 17540T=NBRC 116256T) and strain LSe1-13T (=TBRC 17706T=NBRC 116396T) as the type strains, respectively.

Recurrent sternal wound infection caused by Gordonia bronchialis after open heart surgery.

Gordonia bronchialis is an aerobic gram-positive bacilli and also weakly acid fast. It requires a long incubation time and extensive biochemical reactions for identification. Therefore, use of broad-range polymerase chain reaction (PCR) for amplification of genes such as 16S rRNA or hsp65 followed by sequencing or advanced techniques like MALDI-TOF MS is needed for identification. Here, we present a case of persistent sternal wound infection following open heart surgery, caused by G. bronchialis in a 58 years old male, identified using MALDI-TOF MS-based system. The patient improved with oral Cefpodoxime 200 mg BD for four weeks.

Antimicrobial treatment in invasive infections caused by Gordonia bronchialis: systematic review.

Background: Corynebacterium, Nocardia, Rhodococcus, Mycobacterium, as well as Gordonia genera belongs to the genus Gordonia, Actinomycetia class. Gordonia bronchialis is a nitrate-reducing, urease-producing, non-motile, force aerobe with a rod-like figure that is known to arrangement into sessile, cord-like groups. This systematic review aimed to establish whether and what invasive infections in humans were caused by Gordonia bronchialis, and to evaluate outcomes of administered antibiotic treatment. Methods: We have registered this systematic review in PROSPERO database of systematic reviews and meta-analyses with the number CRD42022369974. Results: A total of 24 publications were included (22 case reports and two case series) with 28 individual cases. The oldest patients had 92 years, and the youngest patients had 13 years. Clinical signs of infection were present in six patients (21%). All isolates were susceptible to ciprofloxacin, imipenem, and amikacin. Vancomycin was the most frequently used antibiotic with nine cases followed by ciprofloxacin, ceftriaxone, and amoxicillin/clavulanic acid. Conclusion: Although there are no standardized recommendations to date, successful treatment with a favorable outcome has most often been carried out with fluoroquinolones, vancomycin with or without aminoglycosides, as well as carbapenems.

Study of sequential abiotic and biotic degradation of styrene butadiene rubber.

Styrene butadiene rubber is one of the main constituents of tire tread. During tire life, the tread material undergoes different stresses that impact its structure and chemical composition. Wear particles are then released into the environment as weathered material. To understand their fate, it is important to start with a better characterization of abiotic and biotic degradation of the elastomer material. A multi-disciplinary approach was implemented to study the photo- and thermo- degradation of non-vulcanized SBR films containing 15 w% styrene as well as their potential biodegradation by Rhodoccocus ruber and Gordonia polyisoprenivorans bacterial strains. Each ageing process leads to crosslinking reactions, much surface oxidation of the films and the production of hundreds of short chain compounds. These degradation products present a high level of unsaturation and oxidation and can be released into water to become potential substrates for microorganisms. Both strains were able to degrade from 0.2 to 1.2 % (% ThOD) of the aged SBR film after 30-day incubation while no biodegradation was observed on the pristine material. A 25-75 % decrease in the signal intensity of water extractable compounds was observed, suggesting that biomass production was linked to the consumption of low-molecular-weight degradation products. These results evidence the positive impact of abiotic degradation on the biodegradation process of styrene butadiene rubber.

Chemical Method for Recovery and Regeneration of Graphene Oxide.

Graphene oxide (GO) has been developed as a very effective medium for filtration and removal of microbial contaminants in fuel. GO is capable of filtering out microorganisms without needing micrometer and submicrometer pores for filtration. Our previous studies showed that microorganisms are attracted by GO and bind irreversibly to GO without promoting bacterial growth. Therefore, GO was tested as a filter medium to remove microorganisms in fuel. The characterization results showed that GO removed microbes in diesel fuel with >99% efficiency. However, the synthesis of GO using Hummers' method is labor intensive and a time-consuming. We present in this paper an economical, less labor intensive and a simple chemical approach to recover GO after it has been used as a filtration medium for the removal of microorganisms in fuels. In the GO recovery process, microbial and fuel contaminated GO is washed with hexane to remove any fuel from the GO sample. The hexane-washed GO is further washed with acetone and mixed with ethanol to kill and remove any microorganisms. After washing with ethanol, the GO sample is sonicated in water to remove impurities and re-establish the oxygen functionalities. The final recovered-GO (rec-GO) is obtained after removing water by rotary evaporation. The chemical characterization of rec-GO showed that rec-GO is similar in both chemical and physical properties compared to freshly synthesized-GO (as-syn-GO). Rec-GO was shown to perform similarly to as-syn-GO in filtration of biocontaminated fuel. We estimate that our rec-GO is at least 90% cheaper than high quality commercially available GO.

From compost to culver: genome sequence and annotation of a cluster CQ1 Gordonia phage.

Phage Culver, with a siphovirus morphology, was isolated using Gordonia terrae CAG3. Culver is assigned to phage cluster CQ1 based on gene content similarity to actinobacteriophages. Notably, Culver is predicted to encode eight tRNAs, lysin A by two adjacent genes, and, unlike other CQ1 phages, two putative integrase genes.

Gordonia metallireducens sp. nov., a tellurite- and selenite-resistant bacterium isolated from the sediment of an acid mine drainage stream.

A polyphasic taxonomic study was carried out on strain TSed Te1T, isolated from sediment of a stream contaminated with acid drainage from a coal mine. The bacterium forms pink-pigmented colonies and has a rod-coccus growth cycle, which also includes some coryneform arrangements. This bacterium is capable of growing in the presence of up to 750 µg ml-1 tellurite and 5000 µg ml-1 selenite, reducing each to elemental form. Nearly complete 16S rRNA gene sequence analysis associated the strain with Gordonia, with 99.5 and 99.3 % similarity to Gordonia namibiensis and Gordonia rubripertincta, respectively. Computation of the average nucleotide identity and digital DNA-DNA hybridization comparisons with the closest phylogenetic neighbour of TSed Te1T revealed genetic differences at the species level, which were further substantiated by differences in several physiological characteristics. The dominant fatty acids were C16 : 0, C18 : 1, C16 : 1 and tuberculostearic acid. The DNA G+C content was 67.6 mol%. Major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside, while MK-9(H2) was the only menaquinone found. Mycolic acids of C56-C60 were present. Whole-cell hydrolysates contained meso-diaminopimelic acid along with arabinose and galactose as the major cell-wall sugars. On the basis of the results obtained in this study, the bacterium was assigned to the genus Gordonia and represents a new species with the name Gordonia metallireducens sp. nov. The type strain is TSed Te1T (=NRRL B-65678T=DSM 114093T).

Focusing on Gordonia Infections: Distribution, Antimicrobial Susceptibilities and Phylogeny.

The immunosuppression conditions and the presence of medical devices in patients favor the Gordonia infections. However, the features of this aerobic actinomycete have been little explored. Strains (n = 164) were characterized with 16S rDNA and secA1 genes to define their phylogenetic relationships, and subjected to broth microdilution to profile the antimicrobial susceptibilities of Gordonia species that caused infections in Spain during the 2005-2021 period. Four out of the eleven identified species were responsible for 86.0% of the infections: Gordonia sputi (53.0%), Gordonia bronchialis (18.3%), Gordonia terrae (8.5%) and Gordonia otitidis (6.1%). Respiratory tract infections (61.6%) and bacteremia (21.9%) were the most common infections. The secA1 gene resolved the inconclusive identification, and two major clonal lineages were observed for G. sputi and G. bronchialis. Species showed a wide antimicrobial susceptibility profile. Cefoxitin resistance varies depending on the species, reaching 94.2% for G. sputi and 36.0% for G. terrae. What is noteworthy is the minocycline resistance in G. sputi (11.5%), the clarithromycin resistance in G. bronchialis secA1 lineage II (30.0%) and the amoxicillin-clavulanate and cefepime resistance in G. terrae (21.4% and 42.8%, respectively). G. sputi and G. bronchialis stand out as the prevalent species causing infections in Spain. Resistance against cefoxitin and other antimicrobials should be considered.

Biofilm formation promoted biodegradation of polyethylene in Gordonia polyisoprenivorans B251 isolated from bacterial enrichment acclimated by hexadecane for two years.

Polyethylene (PE) mulch films have been widely used in agriculture and led to a significant pollution in cultivated soils. It is desirable to develop the sustainable method for the degradation of PE. As an environment friendly approach, microbial or enzymatic degradation of PE could meet this demanding. Thus, more microbial strains are required for illustrating biodegrading pathway and developing efficient biological method. In this study, Gordonia polyisoprenivorans B251 capable of degrading PE was isolated from bacterial enrichment with hexadecane as a sole carbon source for two years, in which genus Gordonia had dominated. As revealed by microbial growth curve, the strain B251 had the highest growth rate than other tested strains in the mediums either with hexadecane or PE particles as sole carbon source. The formation of biofilms in both enriched culture and G. polyisoprenivorans B251 pure culture attached to PE film was observed. The capability for PE degradation of individual strain was screened by 30-day incubation with PE film and confirmed by the presence of hydroxyl, carbonyl, carbon-carbon double bond and ether groups in FT-IR analysis and cracks on the surface of PE film observed by scanning electron microscopy (SEM). Therefore, Gordonia polyisoprenivorans, reported as their degradation of environmental contaminants in previous study, were also identified in current study as a candidate for polyethylene biodegradation.

Genome sequence of Gordonia alkaliphila strain WW102, isolated from influent wastewater at a research center with multiple-species research animal facilities.

Gordonia alkaliphila is a little known mesophilic Gram-positive rod-shaped bacterium. We report the 3.85-Mbp genome sequence of G. alkaliphila strain WW102, isolated from wastewater at a research center with multiple-species laboratory animal facilities. The genome predicted FadD32 gene clusters that are involved in the biosynthesis of mycolic acids as found in Mycobacterium tuberculosis.

Complete genome sequences of Gordonia rubripertincta phages OtterstedtS21 and Patos.

We report the genomes of two viruses with siphovirus morphology, OtterstedtS21 and Patos, from Albany, New York, using Gordonia rubripertincta. The genomes of OtterstedtS21 and Patos are ~68 kbp long with 58% GC content. Both phages group with cluster DV based on gene content similarity to phages in the Actinobacteriophage database.

Genome sequence of cluster A15 Gordonia terrae bacteriophage Nebulosus.

The temperate Gordonia phage Nebulosus was isolated from soil on Gordonia terrae and is a siphovirus. The genome is 52,175 bp in length, has 62% GC content, and encodes 96 protein-coding genes. Nebulosus encodes a partitioning system, ParABS, which is likely involved in lysogeny maintenance.

Annotation of Secretariat and Hydrus, two DJ cluster phages isolated on Gordonia rubripertincta.

Secretariat and Hydrus are phages grouped into the DJ cluster that were isolated on Gordonia rubripertincta NRRL B-16540. The phages have 75% nucleotide identity and share 73% gene content. Secretariat has a genome with 84 predicted genes, while Hydrus has 91 predicted genes and can also infect Gordonia terrae 3612.

Isolation of Environmental Bacteria Able to Degrade Sterols and/or Bile Acids: Determination of Cholesterol Oxidase and Several Hydroxysteroid Dehydrogenase Activities in Rhodococcus, Gordonia, and Pseudomonas putida.

Interest about the isolation and characterization of steroid-catabolizing bacteria has increased over time due to the massive release of these recalcitrant compounds and their deleterious effects or their biotransformation derivatives as endocrine disruptors for wildlife, as well as their potential use in biotechnological approaches for the synthesis of pharmacological compounds. Thus, in this chapter, an isolation protocol to select environmental bacteria able to degrade sterols, bile acids, and androgens is shown. Moreover, procedures for the determination of cholesterol oxidase or different hydroxysteroid dehydrogenase activities in Pseudomonas putida DOC21, Rhodococcus sp. HE24.12, Gordonia sp. HE24.4J and Gordonia sp. HE24.3 are also detailed.