Cr(VI) resistant and reducing profiling of Bacillus thuringiensis 407 and genomic-wide analysis of the corresponding genes

Huang Tianpei and Guan Xiong

Bioremediation of Cr(VI) by microbes provided one of ecologically valuable choices for Cr(VI) treatment. In this study, Bacillus thuringiensis (Bt) 407 exhibiting highly speedy reduction of Cr(VI) was characterized. Bt 407 can tolerate 300 mg L-1 Cr(VI) and reduced 50 mg L-1 Cr(VI) after 84 h treatment. Cr(VI) at high concentrations was apt to slow down the reduction while higher Bt cell concentrations conferred better reduction rates. In addition, the reduction was under the influence of pH, temperature and other toxic metals and was glucose-dependent. Under optimum conditions, reduction of 200 mg L-1 Cr(VI) after treatment of 96 h was 9.25 times what it was before optimum. Since total Cr was nearly identical throughout the period, our data indicated that the principal removal mechanism was Cr(VI) reduction by Bt 407, but not adsorption. Based on genomic-wide analysis, Bt 407 harbored putative Cr(VI) reduction genes which are likely to be in charge of the rapid reduction of chromate. A putative chromate transporter ChrA with chromate resistance was also detected. Since Bt is safe to environment with the merits of strong Cr(VI) reduction capacity, Bt 407 would significantly improve Cr(VI) bioremediation.

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Bio mat formation and in vitro growth of Candida species isolated from sugarcane juice

- Vasuki S. and Suresh K.

This study acquired the microbial consortium of 4 sugar cane samples collected from different location in Tamilnadu. A total of 18 isolates dominative 4 isolates of Candida sp MGR1 KY209900, Candida sp MGR7 KY209904, Candida sp MGR8 KY209905 and Candida sp MGR1KY2099011 were identified by biochemical, morphological and molecular techniques. The highest cell growth was MGR 7 (1.84 OD) determined in single wavelength. Filamentous growth and budding yeast were photographed.

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Antimicrobial Activity of a Novel Biodegradable Edible Film produced from Pistacia vera Resin and Origanum vulgare Essential Oil

Barazi Aykut and Erkmen Osman

Edible films are environmental friendly packaging materials due to their biodegradable compositions having popular trend with increasing consumer demand. In this research, edible films were produced from Pistacia vera tree resin (PVR), Origanum vulgare essential oils and wheat gluten with different concentrations. Antimicrobial activities of edible films prepared by using these essential oils were determined against; E. coli O157:H7, S. Typhimurium, S. aureus, B. cereus and L. monocytogenes by using broth microdilution and disc diffusion methods. The lowest minimum inhibitory concentration (MIC) obtained for PVR essential oil (0.1 %) was determined (v/v) against S. aureus and for O. vulgare essential oil, it was 0.075 % (v/v) against B. cereus. E. coli O157:H7 and S. Typhimurium were more resistant than, S. aureus, B. cereus and L. monocytogenes (p<0.05) against both essential oils. Antibacterial activity of PVR films incorporated with 0.5, 1, 1.5 and 2 % oregano or PVR essential oil was evaluated by inhibition zone test. The zones of the edible films were significantly higher (p<0.05) with the increase in concentration of the essential oils incorporated. The maximum inhibition zone obtained for the films with PVR and oregano essential oils against B. cereus and L. monocytogenes was 22 and 21 mm respectively.

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Antimicrobial, antioxidant and anticancer activity of in vivo and in vitro extracts of Ceropegia juncea Roxb, a medicinally important threatened species

Saraswathy M., Kalimuthu K., Chinnadurai V. and Vanitha A.

Variations in antimicrobial, antioxidant and anticancer activities between in vivo and in vitro ethanol and methanol plant extracts of medicinally important threatened Ceropegia juncea were evaluated. The in vivo ethanol extract showed effective antimicrobial activity against Escherichia coli, Klebsiella pneumoniae and Streptococcus pyogenes where as in vivo methanol extracts, showed effective antibacterial activity against all the four bacterial strains. When compared to in vivo extracts the in vitro ethanol and methanol extracts showed moderate inhibition against all the bacterial strains. The in vivo and in vitro ethanol and methanol extracts exhibited antioxidant activity in the DPPH with IC50 value 4.66 µg/ml, 5.17 µg/ml, 4.43 µg/ml and 4.80 µg/ml respectively in the ABTS with IC50 value 2.49 µg/ml, 3.14 µg/ml, 4.23 µg/ml and 4.48 µg/ml respectively. Regarding FRAP the absorbance was more in in vitro ethanol and methanol extracts when compared to in vivo extracts. The both the extracts exhibited notable anticancer activity (MTT assay) with IC50 value 113.87 µg/ml and 199.09 µg/ml of in vivo ethanol and methanol extracts respectively. Based on our results we can claim that in vivo and in vitro C. juncea possesses antimicrobial, antioxidant and anticancer potentials.

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Heavy Metal Biosorption and Plasmid Profiles of Heavy Metal Resistance Bacteria isolated from Soil Samples of Thermal power, Canakkale, Turkey

Gorkem Dulger and Cuneyt Aki

The aim of this study is to investigate the isolation, characterization, determination of plasmid contents and metal absorption capacities of heavy metal-resistant bacteria from soil samples of thermal power. Samples were collected from soil in the area of thermal power. To define the resistance of heavy metal, metal solutions of ZnCl2, FeCl3 6.H2O, Pb(NO3)2 and CuSO4 in varying concentrations were added to culture media by using MIC method. The bacteria of highest MIC level were defined through VİTEK 2 system and their plasmid profiles were determined. The metal biosorption capacities of two isolates were defined through ICP-AES. In total, 37 heavy metal resistant bacteria were isolated from soil samples. Results showed that 15 of them contained plasmid DNA. Finally, biosorption experiments with two isolates with the highest metal resistance were performed. While the metal having the highest growing speed of biosorption among Fe, Zn, Pb and Cu metals which were used in this study for Bacillus mycoides (isolate 26) is Zn, it is followed by Pb, Fe and Cu orderly. While the metal having the highest growing speed of biosorption for Enterobacter cloacea complex (isolate 10) is Pb, it is followed by Zn, Fe and Cu orderly.

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Comparative initial study of Polygalacturonase Production by Bacillus VIT-Sun2 and Actinomycetes VIT-SP5

Praveen Kumar G. and Suneetha V.

In recent years, microbes are exploited significantly for the production of industrially useful enzymes. Microbial pectinase types play a vital role in clarification of fruit juice and it accounts for one-third of global food processing industrial sector. In this research work, the potential isolates which includes bacteria and actinomycetes were screened for the polygalacturonase activity from soil samples of fruit industrial dumps as it was enriched with mango, papaya, guava etc. fruit industrial waste for more than 30 years. The screening of potential pectinolytic bacteria and actinomycetes was carried out by using selective media enrichment techniques. The biochemical and molecular characterization were carried out for the potential isolates. Further, the crude pectinase was partially purified by using ammonium sulfate precipitation, column and DEAE sephadex chromatography. The specific activities of partially purified enzyme from potential microbes were enhanced up to two-fold of about 2438 and 633U/mg of protein respectively. The molecular weights of the enzyme from Bacillus and Actinomycetes were determined as 34.9 and 45.1 kDa by SDS-PAGE.

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Stimulation and Optimization production of the Bacteriocin RC20975-a novelty lactic acid bacteria

Jinjin Pei

The influences of inductive factors on production of bacteriocin RC20975 were identified and evaluated by using a resting cell system. Regulation by the quorum sensing system in regard to the bacteriocin synthesis was primarily identified. When the inoculum concentration is greater than 104 CFU/ml, bacteriocin synthesis was able to be induced. Synthesis of bacteriocin RC 20975 was self-induced with a threshold at 10 AU. Inducing effectiveness was observed if inducer was added at the beginning of the exponential phase. Glycine, vitamin B1, vitamin B2, glycerol and pyruvic acid were able to induce bacteriocin RC 20975 synthesis. Sensitive strains co-cultured with bacteriocin producer strain successfully induced the synthesis. Resting cell technology has seldom reported as a means to screen for inductive factors on bacteriocin production. These findings are of importance for the further study of bacteriocin bio-synthesis regulation and for the improvement of bacteriocin production yields.

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Next-Generation Sequencing for Discovery of the Microorganism and Pathogenic Bacteria in the source water in winter

Yingliang Ge, Shuili Yu, Wenxin Shi, Fan Yang and Qi Yin

Source water may be the main source of pathogen in drinking water. This study applied next-generation sequencing (NGS) to investigate the diversity of microorganism and pathogenic bacteria in source water in Tai Lake, China in winter. The physico-chemical characteristics of water were measured. Then the DNA of the samples was extracted and amplified by PCR. The PCR products were performed for pyrosequencing on a Miseq PE300 pyro sequencing platform. The result of 16s rDNA was anlayzed using the visualization software Gephi and the 16s rDNA gene pool of the known pathogenic bacteria was established. A total of 144,29216S rDNA gene sequences with average length of 395.66bps were obtained. These sequences revealed 580 operational taxonomic units (OTUs). The full length 16S rDNA gene database of common pathogenic bacteria was established. After blasting, 17 species of pathogenic bacteria were found. The most abundant potential human pathogenic bacteria were affiliated with B. tribocorum. The approaches used in this study could simultaneously detect most of the known potentially pathogenic bacteria in source water. The relationship between the microorganisms and source water in different periods would help us understand the diversity of microorganisms in source water in winter.

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Molecular Diversity Analysis as An Improvement Tool for Pigeonpea [Cajanus Cajan (L.)]

Yadav Manju, Yadava Yashwant Kumar, Kumar Pushpendra, Singh Rajesh Kumar, Yadav Renu, Kumar Pawan, Javeria Shaily, Rao Mahesh, Yadav Neelam, Upadhyaya H.D. and Kumar Rajendra

Simple sequence repeat (SSR) marker system was used to assess the genetic diversity among forty pigeonpea genotypes using eighty primer pairs. The banding pattern was recorded in the form of 0-1 data sheet which was analyzed using unweighted pair group method with arithmetic mean based on Jaccard's similarity coefficient. The results revealed that out of 80 SSR primers, 65 primers showed distinct polymorphism indicating the robust nature of microsatellites in revealing polymorphism. The number of alleles generated by each marker ranged from 2 to 7, with an average of 3.4 alleles. The polymorphism information content values for the SSR loci ranged from 0.24 to 0.86. Higher PIC value was observed for SSR primer CZ681974 (0.86) and lowest PIC value (0.24) was observed for the primer CZ682005. The SSR markers showed an average PIC value of 0.50. Markers with PIC values of 0.5 or higher are highly efficient in revealing genetic studies and are extremely valuable in distinguishing the polymorphism rate of a marker at a specific locus. The cluster analysis showed higher level of genetic variation among the genotypes. Similarity coefficients ranged from 0.45 to 0.93. The dendrogram based on the cluster analysis by microsatellite polymorphism, grouped 40 pigeonpea varieties into 2 major clusters which were further grouped into different sub-clusters. Based on the present study, the large range of similarity values for related genotypes using simple sequence repeats (SSR) provides greater certainty for the evaluation of genetic diversity and relationships for background selections during hybridization based crop improvement programmes.

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Synthesis and Modification of Iron Oxide Nanoparticles (Magnetite) for Biomedical Applications

Sadjadi Mir Abdollah, Fathi Fereshteh and Farhadyar Nazanin

Superparamagnetic iron oxide nanoparticles (SPIONs) such as magnetite have strong attractions toward magnetic fields due to the unpaired electrons. But, they lose remnant magnetization after removal of external fields. This property causes to maintain their colloidal stability and attract them for biomedical applications. Of course, some interesting properties such as superparamagnetism, high saturation field, high susceptibility and biocompability etc. enable them to be used for biomedical applications including magnetic resonance imaging(MRI), drug delivery and hyperthermia. They are suitable for drug delivering at target tumors in cancer therapy because they have superparamagnetic properties. They can be sent to the target tissue by an external magnetic field. There are many reports of the use of magnetite nanoparticles as cathode materials for lithium-batteries, ferrofluids and drug targeting also. In this review, methods for synthesis of magnetite nanoparticles and modification with biocompatible materials was explained.

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