A novel bioremediation strategy for petroleum hydrocarbon pollutants using salt tolerant Corynebacterium variabile HRJ4 and biochar.

The present work aimed to develop a novel strategy to bioremediate the petroleum hydrocarbon contaminants in the environment. Salt tolerant bacterium was isolated from Dagang oilfield, China and identified as Corynebacterium variabile HRJ4 based on 16S rRNA gene sequence analysis. The bacterium had a high salt tolerant capability and biochar was developed as carrier for the bacterium. The bacteria with biochar were most effective in degradation of n-alkanes (C16, C18, C19, C26, C28) and polycyclic aromatic hydrocarbons (NAP, PYR) mixture. The result demonstrated that immobilization of C. variabile HRJ4 with biochar showed higher degradation of total petroleum hydrocarbons (THPs) up to 78.9% after 7-day of incubation as compared to the free leaving bacteria. The approach of this study will be helpful in clean-up of petroleum-contamination in the environments through bioremediation process using eco-friendly and cost effective materials like biochar.

Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile.

The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

[Etiologic role of Corynebacterium non diphtheriae in patients with different pathology].

Bacteriologic examination of 1589 patients showed that, aside from C. diphtheriae, 11% of acute upper respiratory tract infections were caused by other Corynebacterium species. Such bacteria can cause infections of various localizations (bronchitis, pyelonephritis, urethritis, colpitis, dermatitis, arthritis, etc.). C. pseudodiphtheriticum and C. xerosis were isolated from clinical specimens most frequently. Corynebacterium spp. have adhesive, hemolytic, hemagglutinating, and neuraminidase activity; some of them are highly pathogenic. The most virulent, were following species: C. diphtheriae, C. pseudotuberculosis, C. urealyticum, and C. ulcerans. Corynebacterium non diphtheriae were frequently isolated from clinical specimens in association with staphylococci and streptococci. In such cases, factors of pathogenicity and resistance to antibiotics were more pronounced. Strains isolated with association with other bacteria have lost susceptibility to tetracycline, oleandomycin, penicillin, and erythromycin. It is important to be vigilant about bacteria from Corynebacterium genus in clinical settings, and thoroughly study their biologic characteristics, especially in immunocompromised patients.

Plant-microbe interactions: identification of epiphytic bacteria and their ability to alter leaf surface permeability.

Bacteria were either isolated from leaf surfaces of Hedera helix or obtained from a culture collection in order to analyse their effect on barrier properties of isolated Hedera and Prunus laurocerasus cuticles. On the basis of the 16S rDNA sequences the genera of the six bacterial isolates from Hedera were identified as Pseudomonas sp., Stenotrophomonas sp. and Achromobacter. Water permeability of cuticles isolated from H. helix was measured before and after inoculation with the six bacterial strains. In addition water permeability of cuticles isolated from P. laurocerasus was measured before and after inoculation with the three bacterial strains Pseudomonas aeruginosa, Xanthomonas campestris and Corynebacterium fascians. Rates of water diffusing across isolated cuticles of both species significantly increased by up to 50% after inoculation with all bacterial strains. Obtained results show that epiphytic bacteria have the ability of increasing water permeability of Hedera and Prunus cuticles, which in turn should increase the availability of water and dissolved compounds in the phyllopshere. Consequently, living conditions in the habitat phyllosphere are improved. It can be concluded that the ability to change leaf surface properties will improve epiphytic fitness of leaf surface bacteria.

Desulfurization of dibenzothiophene by a newly isolated Corynebacterium sp. ZD-1 in aqueous phase.

Sulfur emission through fuel combustion is a global problem because it is a major cause of acid rain. Crud oil contains many heterocyclic organic sulfur compounds, among which dibenzothiophene (DBT) and DBTs bearing alkyl substitutions usually are representative compounds. A strain was isolated from refinery sludge and identified as Corynebacterium ZD-1. The behavior of DBT degradation by ZD-1 in aqueous phase was investigated. Corynebacterium ZD-1 could metabolize DBT to 2-hydroxybiphenyl(2-HBP) as the dead-end metabolite through a sulfur-specific pathway. In shake flask culture, ZD-1 had its maximal desulfurization activity in the late exponential growth phase and the specific production rate of 2-HBP was about 0.14 (mmol x kg dry cell(-1) x min(-1), mmol x KDC(-1) x min(-1)). Active resting cells for desulfurization should be prepared only in this period. 2-HBP inhibited the growth of strain ZD-1, the production of DBT degradation enzymes, and the activity of enzymes. Sulfate inhibited the production of dibenzothiophene (DBT) degradation enzymes but had no effect on the enzymes' activity. The production rates of 2-HBP at lower cell densities were higher and the maximum amount conversion of DBT to 2-HBP (0.067 mmol/L) after 8 h was gained at 9.2 g dry cell/L rather higher cell density. The results indicated that this newly isolated strain could be a promising biocatalyst for DBT desulfurization.

A novel polygalacturonic acid bioflocculant REA-11 produced by Corynebacterium glutamicum: a proposed biosynthetic pathway and experimental confirmation.

Corynebacterium glutamicum CCTCC M201005 produces a novel polygalacturonic acid bioflocculant, REA-11, consisting of galacturonic acid as the main structural unit. A biosynthetic pathway of REA-11 in C. glutamicum CCTCC M201005 was proposed. Evidence for the biosynthetic pathway was provided by: (1) analyzing the response upon addition of UDP-glucose to the culture medium; (2) detecting the presence of several key intermediates in the pathway; and (3) correlating the activities of several key enzymes involved in the pathway with the yields of polygalacturonic acid. The production of polygalacturonic acid was improved by 24%, while the activities of UDP-galactose epimerase and UDP-galactose dehydrogenase were improved by 200% and 50%, respectively, upon addition of 100 microM UDP-glucose. In addition, the key intermediates in the proposed biosynthetic pathway, such as UDP-glucose, UDP-galactose, and UDP-glucuronic acid, were detected in cell-free extracts. Furthermore, the activities of UDP-glucose pyrophosphorylase (R2=0.97), UDP-galactose epimerase (R2=0.75) and UDP-galactose dehydrogenase (R2=0.89) were well correlated with the yields of polygalacturonic acid when different sugars were used as sole carbon sources. Therefore, the biosynthetic pathway of REA-11 in C. glutamicum CCTCC M201005 starts from phosphate-1-glucose, which was then converted to UDP-glucose by UDP-pyrophosphorylase. Predominantly, the UDP-glucose was converted to UDP-galactose by UDP-galactose epimerase; the latter was further converted to UDP-galacturonic acid by UDP-galactose dehydrogenase, which was presumably polymerized to polygalacturonic acid bioflocculant REA-11 by an unknown glucosyltransferase and a polymerase.

Characterization of a coryneform isolate from fasciated mugwort (Artemisia vulgaris).

The morphological and physiological features of coryneform isolated from fasciated mugwort (Artemisia vulgaris) display many morphological similarities with the plant pathogenic corynebacteria, but differ from Corynebacterium fascians in exhibiting motility albeit in only a small proportion of each cell population, and by its ability to hydrolyze asculin, its failure to produce urease and differences in pigmentation. The isolate appears to be related to Corynebacterium fascians in its ability to cause fasciation but physiologically and biochemically it resembles Cornyebacterium poinsettiae and C. flaccumfaciens, both of which were transferred to the genus Curtobacterium.

Identification of corynebacterium bovis and other coryneforms isolated from bovine mammary glands.

Bovine mastitis remains the most economically important disease in dairy cows. Corynebacterium bovis, a lipid-requiring Corynebacterium spp., is frequently isolated from the milk of infected mammary glands of dairy cows and is associated with reduced milk production. A total of 212 coryneform bacteria isolated from the milk of dairy cows were obtained from mastitis reference laboratories in the United States and Canada. All isolates had been presumptively identified as Corynebacterium bovis based on colony morphology and growth in the presence of butterfat. Preliminary identification of the isolates was based on Gram stain, oxidase, catalase, and growth on unsupplemented trypticase soy agar (TSA), TSA supplemented with 5% sheep blood, and TSA supplemented with 1% Tween 80. Of the 212 isolates tested, 183 were identified as Corynebacterium spp. based on preliminary characteristics. Of the strains misidentified, one was identified as a yeast, two as Bacillus spp., 11 as Enterobacteriaceae, 18 as staphylococci, one as a Streptococcus spp., and one as an Enterococcus spp. Eighty-seven coryneforms were selected for identification to the species level by direct sequencing of the 16S rRNA gene, the Biolog system and the API Coryne system. Fifty strains were identified as C. bovis by 16S rRNA gene similarity studies: the Biolog and API Coryne systems correctly identified 54.0 and 88.0% of these strains, respectively. The other coryneforms were identified as other Corynebacterium spp., Rhodococcus spp., or Microbacterium spp. These data indicate that the coryneform bacteria isolated from bovine mammary glands are a heterogeneous group of organisms. Routine identification of C. bovis should include Gram-stain, cell morphology, catalase production, nitrate reduction, stimulated growth on 1% Tween 80 supplemented media, and beta-galactosidase production as the minimum requirements.

Purification, amino acid sequence, and cDNA sequence of a novel calcium-precipitating proteolipid involved in calcification of corynebacterium matruchotii.

Corynebacterium matruchotii is a microbial inhabitant of the oral cavity associated with dental calculus formation. It produces membrane-associated proteolipid capable of inducing hydroxyapatite formation in vitro. This proteolipid was purified from chloroform:methanol extracts by chromatography on Sephadex LH-20 and migrated on SDS-polyacrylamide gel electrophoresis at 6-9 kDa. Removal of covalently attached acyl moieties by methanolic KOH decreased its molecular mass to approximately 5.5 kDa. The amino acid sequence of the apoproteolipid indicated a peptide of 50 amino acids, a calculated molecular weight of 5354 Da, and an isoelectric point of 4.28. Sequence analysis revealed an 8 amino acid sequence with homology to human phosphoprotein phosphatase 2A as well as several potential acylation sites and one phosphorylation site. The purified proteolipid induced calcium precipitation in vitro. Deacylation of the proteolipid by hydroxylamine treatment resulted in >50% loss of calcium-precipitating activity, suggesting that covalently attached lipids are required. Degenerate oligonucleotide primers, based on the amino acid sequence, were used to amplify the gene for the 5.5 kDa proteolipid from total chromosomal DNA of C. matruchotii by PCR. A 166 bp cDNA was isolated and sequenced, confirming the amino acid sequence of the proteolipid. Thus, we have sequenced a unique bacterial proteolipid that is involved in the formation of dental calculus by precipitating Ca2+ and possibly in transport of inorganic phosphate, necessary for hydroxyapatite formation.