Corynebacterium Flavescens Research Articles

Volatilome of brine-related microorganisms in a curd-based medium

The possible contribution of brine-derived microflora to the sensory attributes of cheese is still a rather unexplored field. In this study, 365 bacteria and 105 yeast strains isolated from 11 cheese brines were qualitatively tested for proteolytic and lipolytic activities, and positive strains were identified by sequencing. Among bacteria, Staphylococcus equorum was the most frequent, followed by Macrococcus caseolyticus and Corynebacterium flavescens. As for yeasts, Debaryomyces hansenii, Clavispora lusitaniae, and Torulaspora delbrueckii were most frequently identified. A total of 38% of bacteria and 59% of yeasts showed at least 1 of the metabolic activities tested, with lipolytic activity being the most widespread (81% of bacteria and 95% of yeasts). Subsequently 15 strains of bacteria and 10 yeasts were inoculated in a curd-based medium and assessed via headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry to determine their volatilome. After a 30-d incubation at 12°C, most strains showed a viability increase of about 2 log cfu/mL, suggesting good adaptability to the cheese environment. A total of 26 compounds were detected in the headspace, carbonyl compounds and alcohols being the major contributors to the volatile profile of the curd-based medium. Multivariate analysis was carried out to elucidate the overall differences in volatiles produced by selected strains. Principal component analysis and hierarchical clustering analysis demonstrated that the brine-related microorganisms were separated into 3 different groups, suggesting their different abilities to produce volatile compounds. Some of the selected strains have been shown to have interesting aromatic potential and to possibly contribute to the sensory properties of cheese.

Enzyme mediated transformation of CO2 into calcium carbonate using purified microbial carbonic anhydrase

In this study, a bacterial carbonic anhydrase (CA) was purified from Corynebacterium flavescens for the CO2 conversion into CaCO3. The synthesized CaCO3 can be utilized in the papermaking industry as filler material, construction material and in steel industry. Herein, the CA was purified by using a Sephadex G-100 column chromatography having 29.00 kDa molecular mass in SDS-PAGE analysis. The purified CA showed an optimal temperature of 35 °C and pH 7.5. In addition, a kinetic study of CA using p-NPA as substrate showed Vmax (166.66 μmoL/mL/min), Km (5.12 mM), and Kcat (80.56 sec−1) using Lineweaver Burk plot. The major inhibitors of CA activity were Na2+, K+, Mn2+, and Al3+, whereas Zn2+ and Fe2+ slightly enhanced it. The purified CA showed a good efficacy to convert the CO2 into CaCO3 with a total conversion rate of 65.05 mg CaCO3/mg of protein. In silico analysis suggested that the purified CA has conserved Zn2+ coordinating residues such as His 111, His 113, and His 130 in the active site center. Further analysis of the CO2 binding site showed conserved residues such as Val 132, Val 142, Leu 196, Thr 197, and Val 205. However, a substitution has been observed where Trp 208 of its closest structural homolog T. ammonificans CA is replaced with Arg 207 of C. flavescens. The presence of a hydrophilic mutation in the CO2 binding hydrophobic region is a further subject of investigation.

Microbial Biopesticides against Bacterial, Fungal and Oomycete Pathogens of Tomato, Cabbage and Chickpea

Biological control is an environmentally friendly approach that holds promise to complement or replace chemicals to effectively protect crop plants against pests and pathogens. Environmental samples with highly diverse and competitive microbiomes that harbor antagonistic microbes with diverse modes-of-action can provide a rich source of microbial biopesticides. In the current study, bacteria isolated from rhizosphere soil and food spoilage samples were subsequently screened against various plant fungal and oomycete pathogens in growth inhibition assays. These included the new potential biocontrol bacteria Corynebacterium flavescens, Sporosarcina aquimarina and Sporosarcina saromensis with anti-fungal and antioomycete activities. Potential candidates selected by preliminary screening in plant assays were then applied to tomato, cabbage and chickpea plants to control bacterial (Pseudomonas syringae pv. tomato), fungal (Alternaria brassicicola) and oomycete (Phytophtora medicaginis) phytopathogens. Ten potential microbial biopesticides were demonstrated to be effective against these diseases, and led to significant (p < 0.05) reductions in symptoms and/or pathogen DNA compared to mock-treated diseased plants. We conclude that new and effective microbial biopesticides to control crop pathogens can be rapidly isolated from biodiverse microbiomes, where bacteria may employ these features to effectively compete against each other.

Genomic Sequence and Characteristics of EmiRose, a Bacteriophage Isolated on Corynebacterium flavescens.

ABSTRACTBacteriophage EmiRose is a siphovirus infecting Corynebacterium flavescens. The EmiRose genome is 37,431 bp long and composed of 47 protein-coding genes. Based on gene content similarity, EmiRose is not closely related to any previously sequenced bacteriophages in the actinobacteriophage database to date, including other corynebacteriophages. EmiRose is classified as a singleton.

Protocol to select efficient microorganisms to treat coffee wastewater

The coffee processing wastewater (CPWW) requires treatment before being disposed of in the environment or reused due to its high organic and inorganic composition and a low pH. The indigenous microbiota from CPWW is highly diverse and could be selected as inoculums in treatment waste plants. Considering the physico-chemical characteristics of wastewater coffee, we elaborate on steps to select the microbial consortium that showed positive impact via decreasing the pollutant parameters of this effluent. The effectiveness was confirmed using wastewater from different origins with different chemical characteristics. A bacterial consortium composed by Serratia marcescens CCMA 1010 and CCMA 1012, Corynebacterium flavescens CCMA 1006, and Acetobacter indonesiensis CCMA 1002 was selected as the inoculums-based phenotypic assays. The mixed inoculum showed a highly active population (11.18 log CFU mL−1), promoting an 85% decrease in biochemical oxygen demand and a 60% decrease in chemical oxygen demand. There was also an 80% reduction in phosphorus and nitrogen. The final pH changed from 6.0 to 7.5. Additionally, the eco-toxicity using Daphnia similis was reduced by more than 59%. The microbial inoculum was efficient in the biological treatment in CPWWs, demonstrating the efficiency and robustness of the selected strains, independent of the physico-chemical characteristics of wastewater.

Bioprocess development for efficient conversion of CO2 into calcium carbonate using keratin microparticles immobilized Corynebacterium flavescens

Conversion of CO2 into calcium carbonate using microorganism is one of the promising methods of reducing the increased level of CO2 in the atmosphere. In the present study, a novel strain of Corynebacterium flavescens was isolated from cow saliva and screened for CO2 hydration activity. First of all, the effect of C. flavescens on CaCO3 precipitation was studied under optimized conditions. Various factors such as CO2 concentration, protein concentration, pH of the reaction system, and temperature were then optimized for maximum CO2 precipitation into CaCO3 using free cell lysate. After that, C. flavescens cells were immobilized onto highly porous keratin microparticles functionalized with glutaraldehyde (0.6 % v/v) to enhance the CO2 conversion efficiency. Maximum immobilization of bacterial cells was achieved after 25 h at 4 °C under shaking conditions. The covalently immobilized C. flavescens particles showed a 1.35-fold increase in CaCO3 production compared to their free counterparts. Under repeated batch conditions, the relative production of CaCO3 for immobilized and free cells was 53.46 and 22.15 %, respectively, after 10 cycles. This study demonstrated the advantages of keratin microparticles as a support for the immobilization of C. flavescens and the efficient conversion of CO2 to CaCO3.

Efficient reduction of CO2 using a novel carbonic anhydrase producing Corynebacterium flavescens

Efficient reduction of CO2 using a novel carbonic anhydrase producing Corynebacterium flavescens

Antibacterial Activity of Conifer Green Needle Complex Against Corynebacteria

Traditionally, preservatives have been used in cosmetic products to minimize bacterial contamination. Some opportunistic Corynebacterium spp. have become resistant to these preservatives and other alternatives are required. A potential candidate is Conifer Green Needle Complex (CGNC), a pharmaceutical-grade complex substance from the green verdure of Pinus sylvestris and Picea abies with antibacterial, antimycotic, and antitrichomonal activity. The susceptibility of Corynebacterium xerosis and Corynebacterium flavescens to CGNC (3.5, 7, 15, 30, 60, 125, 250, and 500 mg/mL) was evaluated using broth dilution and agar methods. The antibacterial effect of CGNC was also evaluated after exposure for 30 minutes and 1, 3, and 24 hours at concentrations of 0, 3.5, 7, 30, 125, and 500 mg/mL. Corynebacteria xerosis was inhibited when exposed to low levels of CGNC (1560 mg/mL), whereas an antibacterial effect on C. flavescens was observed at slightly higher levels (60 and 125 mg/mL). CGNC also inhibited the growth of C. xerosis and C. flavescens at various incubation time points. The most prominent effect was observed after 24 hours where all growth was inhibited at all concentrations. However, CGNC inhibited or decreased the growth of Corynebacterium spp. even at lower exposure times. The results obtained in this study demonstrated that CGNC is an effective bactericidal agent against C. xerosis and C. flavescens isolated from clinical samples and may have potential as an alternative to preservatives currently used in cosmetic products.

Corynebacterium endometrii sp. nov., isolated from the uterus of a cow with endometritis.

A Gram-stain-positive bacterial strain, designated LMM-1653T, was isolated from a uterus swab from a Holstein Frisian dairy cow in the frame of a clinical sampling trial. The isolated strain, which showed a rod to coccoid shape, was catalase-positive and oxidase-negative. Based on 16S rRNA gene sequence similarity, its closest relatives were Corynebacterium flavescens and Corynebacterium argatoratense (96.50 % similarity each), suggesting that this isolate represents a novel species. Strain LMM-1653T had a quinone system consisting mainly of menaquinones MK-8(H2) and MK-9(H2). The polar lipid profile showed presence of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol-mannoside as well as one unidentified glycolipid and one unidentified aminoglycolipid. Moderate to minor amounts of three unidentified glycolipids, β-gentiobiosyl diacylglycerol, one unidentified aminoglycolipid and three unidentified lipids without a functional group were also found. The cell wall contained meso-diaminopimelic acid and the strain also contained corynemycolic acids. The fatty acid profile was predominantly composed of straight-chain, saturated and mono-unsaturated fatty acids, dominated by C18 : 1ω9c and C16 : 0. Since this isolate differs from the nearest related established Corynebacterium species in its genetic and phenotypic traits, a novel species named Corynebacterium endometrii LMM-1653T (=LMG-31164T=CCM 8952T) of the genus Corynebacterium is proposed.

Assessing the efficiency in assisted depuration of coffee processing wastewater from mixed wild microbial selected inoculum.

This work evaluated the efficiency of bacterial bio-augmentation to the biological treatment of coffee processing wastewater (CPWW) in a pilot wastewater treatment plant (WTP). Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) values were the basis for the treatment efficiency. Serratia marcescens CCMA 1010 and CCMA 1013, Corynebacterium flavescens CCMA 1006 and Acetobacter indonesiensis CCMA 1002 were previously selected. The microbial cocktail was inoculated and persisted in CPWW during all treatments. The richness of wild species was a little altered over time and up to nine species were found in each sampled season. The microbiota composition presented variation of a total of 13 species, despite the inoculation of the microbial inoculum. The biodegradability index of effluent, close to 0.5, was favourable to biological treatment. The pollution parameters of CPWW were decreased in function of the variation of community composition and microbial activity. The greatest reduction of BOD (~ 33%) and COD (~ 25%) was observed between 72h and 8days of the biological treatment. The CPWW toxicity in Allium cepa seeds was lower by up to 60%, and the germination index (GI) exceeded 100% in the treated CPWW. The results of the CPWW biological treatment by bio-augmentation from native micro-organisms in the pilot-scale WTP indicated the greatest efficiency relating to the spontaneous biological treatment of CPWW. After this treatment, the discharge of effluent in the environment would not have toxic effects on the plants.

Diversity of microbiota found in coffee processing wastewater treatment plant.

Cultivable microbiota presents in a coffee semi-dry processing wastewater treatment plant (WTP) was identified. Thirty-two operational taxonomic units (OTUs) were detected, these being 16 bacteria, 11 yeasts and 4 filamentous fungi. Bacteria dominated the microbial population (11.61 log CFU mL- 1), and presented the highest total diversity index when observed in the WTP aerobic stage (Shannon = 1.94 and Simpson = 0.81). The most frequent bacterial species were Enterobacter asburiae, Sphingobacterium griseoflavum, Chryseobacterium bovis, Serratia marcescens, Corynebacterium flavescens, Acetobacter orientalis and Acetobacter indonesiensis; these showed the largest total bacteria populations in the WTP, with approximately 10 log CFU mL- 1. Yeasts were present at 7 log CFU mL- 1 of viable cells, with Hanseniaspora uvarum, Wickerhamomyces anomalus, Torulaspora delbrueckii, Saturnispora gosingensis, and Kazachstania gamospora being the prevalent species. Filamentous fungi were found at 6 log CFU mL- 1, with Fusarium oxysporum the most populous species. The identified species have the potential to act as a biological treatment in the WTP, and the application of them for this purpose must be better studied.

Kapok (Ceiba pentandra L. Gaertn.) Fibers Packed in Nylon Nets as Sorbent for Diesel Oil Spill and its ex-situ Bioremediation

The effects of oil spill on the ecosystem and human lives are unprecedented. Early response and containment of the oil spill is the best approach in reducing the environmental impacts. This study assessed the diesel oil absorption capacity of Kapok fiber packed in Nylon net then tested the ability of a consortium of bacterial species reported to have oil degrading properties. To evaluate the conditions for the application of ex situ bioremediation, the hydrocarbon conversion was determined qualitatively by monitoring some possible degradation products with hexadecane as reference. Kapok (Ceiba pentandra (L.) Gaertn.) fibers packed in Nylon net were found effective in adsorbing diesel oil with a sorption capacity of 15.5 g g-1 fibers. A consortium of Bacillus megaterium, Corynebacterium flavescens, Micrococcus luteus and Pseudomonas putida with nutrient amendment (0.15 g N and 0.03 g P gram-1 oil) was used to determine preliminary oil biodegradation. Microbial population was sustained for six weeks and all species were found to contribute in the degradation process. Biosurfactant production was also observed in the seawater media. Gas chromatographic analysis showed some degradation products of the adsorbed diesel oil after one week of treatment. The use of Kapok sorbents for Tier 1 and 2 oil spill clean-up and its bioremediation done ex situ to degrade the diesel oil hydrocarbons can be an option.

Application of Single Strand Conformation Polymorphism — PCR method for distinguishing cheese bacterial communities that inhibit Listeria monocytogenes

The aim of this study was to compare the microbial communities of different cheeses where Listeria monocytogenes either grew or did not grow. For this purpose, (i) isolates from the most inhibitory cheese ecosystem were identified and their ability to produce anti- Listeria substances was determined, (ii) bacterial communities of cheeses with and without L. monocytogenes growth were compared using the Single Strand Conformation Polymorphism method. The study showed SSCP to be an effective tool for differentiating between the bacterial communities of different cheeses manufactured with the same technology. All the cheeses with the lowest L. monocytogenes counts on day 8 were distinguished by the dominance in their SSCP profiles, after amplification of the V2 region of the 16S rRNA gene, of 3 peaks whose nucleotide sequences comigrated with Enterococcus faecium and Enterococcus saccharominimus, Chryseobacterium sp and Corynebacterium flavescens, Lactococcus garvieae and Lactococcus lactis respectively. However, no anti- Listeria compounds were produced under our experimental conditions. These six bacterial species were inoculated, separately or together, into pasteurised milk and their anti-listerial activity in cheese was evaluated. The area of inhibition between the control and trial curves confirmed that L. monocytogenes is inhibited by E. saccharominimus, C. flavescens, L. lactis, L. garvieae and the mixture of all six bacterial strains. Further studies should be performed to determine the metabolites involved in L. monocytogenes inhibition.

The chemical composition of essential oil and in vitro antibacterial activities of essential oil and methanol extract of Ziziphora persica Bunge

This study was designed to examine the chemical composition of essential oil and the in vitro antibacterial activities of essential oil and methanol extracts of Ziziphora persica. The inhibitory effects of essential oil and methanol extracts of Ziziphora persica were tested against 98 laboratory strains belonging to 51 bacteria species by using disc-diffusion assay and micro-broth dilution methods, respectively. GC and GC/MS analyses revealed that the essential oil predominantly contains (+)-pulegone (79.33%), limonene (6.78%) and piperitenone (4.2%). The antibacterial test results showed that both methanol extract and in particular essential oil of Ziziphora persica had antibacterial activity against a number of bacteria tested. The lowest MIC values (7.81 μg/ml) were obtained with the essential oil of Ziziphora persica against Bacillus dipsauri, Corynebacterium cystitidis and Corynebacterium flavescens.

Chemical characterization of root exudates from rice (Oryza sativa) and their effects on the chemotactic response of endophytic bacteria

Root exudates represent an important source of nutrients for microorganisms in the rhizosphere and seem to participate in early colonization inducing chemotactic responses of rhizospheric bacteria. We characterized the root exudates collected from rice plantlets cultured under hydroponic conditions and assessed their effects on the chemotaxis of two strains of endophytic bacteria, Corynebacterium flavescens and Bacillus pumilus, collected from the rice rhizosphere. We compared these chemotactic effects on endophytic bacteria with those on two strains of plant-growth-promoting bacteria, Azospirillum brasilense (isolated from the corn rhizosphere) and Bacillus sp. (from the rice rhizosphere). The root exudates were collected at different time intervals. The highest concentration and diversity of amino acids and carbohydrates were found during the first 2 weeks after seeding. Histidine, proline, valine, alanine, and glycine were the main amino acid residues identified during the 4 weeks of culture. The main carbohydrates identified were glucose, arabinose, mannose, galactose, and glucuronic acid. The chemotactic responses of the analyzed endophytic bacteria to root exudates were 3.9 to 5.1 times higher than those of A. brasilense and 2.2 to 2.8 times higher than Bacillus sp. Our results indicate that rice exudates may induce a higher chemotactic response for endophytic bacteria than for other bacterial strains present in the rice rhizosphere.

Surface ripened cheeses: the effects of Debaryomyces hansenii, NaCl and pH on the intensity of pigmentation produced by Brevibacterium linens and Corynebacterium flavescens

Abstract The influence of pH, NaCl and three strains of Debaryomyces hansenii (MD02, MD06 and D18335) on the intensity of pigmentation produced by four coryneform bacteria was investigated. Two strains of Brevibacterium linens (BL1 and BL3) producing an orange-reddish pigment, one strain of Brevibacterium linens (BL2) and Corynebacterium flavescens producing a yellow pigment were studied. A complete factorial design comprising the combination of the three parameters: pH (5.6, 6.0, and 7.0), NaCl (0%, 4.0% and 8.0% (w/v)) and the three strains of D. hansenii was conducted on a cheese agar. A significant effect of NaCl and pH on the intensity of pigment production was observed. The strongest intensity was seen at pH 7.0, the highest value examined. The intensity decreased at pH 6.0 and even more at pH 5.6. The intensity at 4.0% (w/v) NaCl was stronger than at 8.0% (w/v) and when NaCl was not added. At pH 6.0 and 5.6 pigment production was only observed when NaCl was added. D. hansenii had a significant effect on the intensity of the orange-reddish colour and significant differences between the three strains of D. hansenii were observed. The strongest intensity of colour was obtained for D. hansenii MD02.

Endophytic bacteria in rice seeds inhibit early colonization of roots by Azospirillum brasilense

From the rhizoplane of Oryza sativa, vars. Morelos A-88 and Apatzingan, rice plantlets, we isolated two bacterial strains: Corynebacterium flavescens and Bacillus pumilus. By scanning electron microscopy, endophytic bacteria were frequently identified at the base of secondary roots, between the epidermis and the mucilaginous layer. Endophytes were also identified in the intercellular spaces when the mucilaginous layer was disrupted. These endophytic bacteria were not pathogenic when assayed on tobacco leaves. Plantlets from the rice varieties cultured gnotobiotically under hydroponic conditions were inoculated with Azospirillum brasilense, 6-81 or UAP-154 strains. Control experiments were performed using non-inoculated plantlets or plantlets previously treated with nalidixic acid. Comparison of the length of inoculated or nalidixic acid-treated plantlets, with non-inoculated plantlets revealed a significant ( p<0.05) promotion of the growth of the shoots at 15 days of culture in plantlets colonized exclusively by endophytes. A. brasilense seems to be excluded from the rhizoplane by the endophytic bacteria, suggesting that endophytes compete with Azospirillum, and also that A. brasilense inhibits growth of rice. Our results indicate that endophytic bacteria could participate in the growth and development of rice plants.

Biological and Chemical Basis for the Reclassification of Microbacterium flavum Orla-Jensen as Corynebacterium flavescens nom. nov.

On the basis of its biological properties (cell morphology, staining reactions, cellular inclusions, guanine plus cytosine content of deoxyribonucleic acid, degree of deoxyribonucleic acid homology with Corynebacterium diphtheriae strain PW8, and pattern of enzymic capacities) and chemical structures (peptidoglycan type, major cell wall polysaccharide, major phospholipids and glycolipid, as well as characteristic cell wall fatty acids), Microbacterium flavum Orla-Jensen (synonym: Mycobacterium flavum Jensen) is renamed Corynebacterium flavescens nom. nov. The specific epithet “flavum” has been changed to “flavescens” in order to avoid the creation of a later homonym of Corynebacterium flavum Kisskalt and Berend 1918. Strain 8 of Orla-Jensen (= ATCC 10340 = NCIB 8707) is herein designated the type strain of C. flavescens. An updated description of the organism is given.