Microbial degradation and community structure analysis of hydroxyl-terminated polybutadiene (HTPB)

Hydroxyl-terminated polybutadiene (HTPB) is a curing adhesive that is commonly used in the production of ammunition, and it emerged during the time of war. After entering the peaceful era, several countries around the globe have focused on the destruction of expired ammunition using safe and economical methods in terms of consumption of energy. Microorganisms exhibit a highly efficient and environment friendly degradation capability for variety of refractory substances. Therefore, in this study we screened five strains of microorganisms from five environmental soil samples for their ability to degrade HTPB. These microorganisms were identified as Microbacterium trichothecenolyticum, Microbacterium esteraromaticum, Arthrobacter pascens, Pseudonocardia carboxydivorans and Ochrobactrum anthropic based on 16S rRNA gene similarity index. We observed the uncorroded and corroded HTPB sample through scanning electron microscopy and observed the formation of lot of holes and gullies in HTPB after corrosion. An 18S rRNA gene clone library was constructed for HTPB-degrading fungi. Based on the results of library evaluation, it was found that the structure of the HTPB-degrading fungi community was relatively simple. A total of 54 positive clones were obtained. These clones represented some uncultured microorganisms that were closely related to Scytalidium lignicola, Pseudokahliella and Gonostomum strenuum. This study will help in the implementation of environment friendly degradation strategies for HTPB degradation.

Transcriptome Analysis, CmMYB1 Gene Clone From Cucumis Melo L. And Its Functional Roles Under Salt Stress

MYB TFs plays an important role in plant adaptation to abiotic stress, especially in response to salt stress. Preliminary research found that the stress resistance of the two melon varieties ‘M15’ and ‘baogua’ are quite different. To this end, we compared the transcriptomes of ‘M15’ and ‘baogua’. Transcriptome analysis found that the expression levels of 12 MYB transcription factors were significantly different between the two varieties.CmMYB1 gene was cloned from muskmelon (Cucumis melo L.), and the subcellular localization results showed that CmMYB1 was expressed in the cytoplasm and nucleus. Transform CmMYB1 gene into Arabidopsis thaliana, observe T3 phenotypes during the vegetative and reproductive growth periods.The results showed that the transgenic A. thaliana phenotype did not change significantly compared with the wild type . After treatment with 200 mM sodium chloride solution for 1 h and 3 h, the CmMYB1 expression increased significantly and began to decline after 6 h of salt stress, indicating that it functions in the early response to salt stress. These results provide a theoretical basis for the further study of the biological function of CmMYB1.

Exploration of coliform diversity in drinking water resources by culture-independent approaches

The coliform group has been widely used as an indicator of water quality and has historically led to a public health protection concept. Presence of pathogens in drinking water may raise several health problems in humans from mild illnesses to serious waterborne diseases. In spite of several measures taken, water quality is always a pertinent issue prevailing in diverse water systems. So far, coliform contamination and diversity could not be adequately explored as traditionally used culture-dependent methods have a limited capacity to characterize microbiota from their respective sources. The study was designed for assessment of microbial diversity by culture-independent approaches placing emphasis on exploring the total coliform diversity in two drinking water reservoirs, Raman Pahad and Koilsagar of Mahabubnagar district, Telangana, India. Principal analysis based on 16S rRNA gene clone libraries revealed that Raman Pahad library clones belonged to genus Enterobacter (41.5%), followed by Citrobacter (25.03%), Klebsiella (17.86%), Escherichia (12.20%), and the least being Hafnia (3.39%). The clones in Koilsagar belonged to genus Enterobacter (46.42%) as the most predominant, followed by Citrobacter (32.14%) and Escherichia (21.42%). Comparatively, Enterobacter was observed to be the most predominant (representing 50%) of the total clones in both reservoirs.

Inhibitory Effects of Plant Trypsin Inhibitors Msti-94 and Msti-16 on Therioaphis trifolii (Monell) (Homoptera: Aphididae) in Alfalfa

The spotted alfalfa aphid (Therioaphis trifolii (Monell)) is a known destructive pest that can significantly reduce alfalfa yields. Two differentially up-regulated alfalfa trypsin inhibitors ‘Msti-94’ and ‘Msti-16’ in transcriptome were verified in terms of their mRNA levels using RT-qPCR. The prokaryotic expression vector was constructed and its biological functions, including phenotypic and physiological responses, were verified through feeding spotted alfalfa aphids with active recombinant protein mixed with an artificial diet. Gene clone and gene prokaryotic expression confirmed that Msti-94 had a size of 651 bp, encoded 216 amino acids with a predicted protein weight of 23.5 kDa, and a pI value of 6.91. Similarly, the size of Msti-16 was 612 bp, encoded 203 amino acids, and had a predicted protein weight of 22.2 kDa with a pI value of 9.06. We concluded that both Msti-94 and Msti-16 acted as a stomach poison with survival rates reduced to 21.7% and 18.3%, respectively, as compared to the control, where the survival rate was significantly (p < 0.05) higher (60.0%). Aphid reproduction rates were significantly reduced, after 72 h of feeding, in both the Msti-94 and Msti-16 treatments compared to the controls. A concentration of 800 μg/mL (0.8 mg/mL) of recombinant protein and 5000 μg/mL (5 mg/mL) of recombinant expressing bacteria that inhibits the total protease, which ultimately disrupted the activity of trypsin, chymotrypsin, and aminopeptidase.

Feedback regulation of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 via ATM/Chk2 pathway contributes to the resistance of MCF-7 breast cancer cells to cisplatin

The methyl methanesulfonate and ultraviolet-sensitive gene clone 81 protein is a structure-specific nuclease that plays important roles in DNA replication and repair. Knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 has been found to sensitize cancer cells to chemotherapy. However, the underlying molecular mechanism is not well understood. We found that methyl methanesulfonate and ultraviolet-sensitive gene clone 81 was upregulated and the ATM/Chk2 pathway was activated at the same time when MCF-7 cells were treated with cisplatin. By using lentivirus targeting methyl methanesulfonate and ultraviolet-sensitive gene clone 81 gene, we showed that knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 enhanced cell apoptosis and inhibited cell proliferation in MCF-7 cells under cisplatin treatment. Abrogation of ATM/Chk2 pathway inhibited cell viability in MCF-7 cells in response to cisplatin. Importantly, we revealed that ATM/Chk2 was required for the upregulation of methyl methanesulfonate and ultraviolet-sensitive gene clone 81, and knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 resulted in inactivation of ATM/Chk2 pathway in response to cisplatin. Meanwhile, knockdown of methyl methanesulfonate and ultraviolet-sensitive gene clone 81 activated the p53/Bcl-2 pathway in response to cisplatin. These data suggest that the ATM/Chk2 may promote the repair of DNA damage caused by cisplatin by sustaining methyl methanesulfonate and ultraviolet-sensitive gene clone 81, and the double-strand breaks generated by methyl methanesulfonate and ultraviolet-sensitive gene clone 81 may activate the ATM/Chk2 pathway in turn, which provide a novel mechanism of how methyl methanesulfonate and ultraviolet-sensitive gene clone 81 modulates DNA damage response and repair.