Termites Improve the Horizontal Movement of Carbonized Particles: A Step towards Sustainable Utilization of Biochar

Soil amendments containing carbonized materials increase the soil carbon reservoir, influence plant productivity, and, ultimately, help to clean the environment. There is data on the effect of such additions on soil physicochemical properties or plant growth, but few studies have focused on how these carbonized materials are distributed by termite species in the soil ecosystem. It is the first comprehensive study of the transportation of biochar (BC) by termite species under tropical environmental conditions in Pakistan. The present study was carried out to test the hypothesis that if termite species I) were involved in the distribution of biochar particles II) if yes, then how far these particles were transported during the study period (10 days) and III) check their preference between the enriched BC (EBC) and non-enriched BC. BC was enriched with the cattle slurry after its pyrolysis in the study. The results showed that EBC particles were significantly more widely distributed than non-enriched BC particles, but both types of BC were transported more than 4 cm (ring 4) within 10 days (at the end of the experiment). The current study also revealed that EBC was easily attached to the setae, cuticle, and legs of termites, implying that it could potentially be transported over a greater distance. Furthermore, transportation of EBC over larger distances indicated a potential preference of termite species between the EBC and BC particles. During the study, however, the preference among the termite species was also observed. Under the prevailing study conditions, the Coptotermes heimi and Heteroterme indicola species transported the EBC further than Microtermes obesi and Odontotermes obesus. These findings revealed that transportation preferences were observed among the four termite species. In conclusion, the current study found that termites were involved in the distribution of BC particles, with a preference for EBC and that these have the potential to transport BC particles more than 4 cm within 10 days. Furthermore, two species Coptotermes heimi and Heteroterme indicola may be more suitable candidates for EBC transpiration in Pakistani soils. It was necessary to conduct additional research into the effect of temperature on the transportation process.     

ESAT-6 (EsxA) and TB10.4 (EsxH) Based Vaccines for Pre- and Post-Exposure Tuberculosis Vaccination

The ESX systems from Mycobacterium tuberculosis are responsible for the secretion of highly immunogenic proteins of key importance for bacterial survival and growth. The two prototypic proteins, ESAT-6 (EsxA from ESX-1) and TB10.4 (EsxH from ESX-3) share a lot of characteristics regarding genome organization, size, antigenic properties, and vaccine potential but the two molecules clearly have very different roles in bacterial physiology. To further investigate the role of ESAT-6 and TB10.4 as preventive and post-exposure tuberculosis vaccines, we evaluated four different fusion-protein vaccines; H1, H4, H56 and H28, that differ only in these two components. We found that all of these vaccines give rise to protection in a conventional prophylactic vaccination model. In contrast, only the ESAT-6-containing vaccines resulted in significant protection against reactivation, when administered post-exposure. This difference in post-exposure activity did not correlate with a difference in gene expression during infection or a differential magnitude or quality of the vaccine-specific CD4 T cells induced by ESAT-6 versus TB10.4-containing vaccines. The post-exposure effect of the ESAT-6 based vaccines was found to be influenced by the infectious load at the time-point of vaccination and was abolished in chronically infected animals with high bacterial loads at the onset of vaccination. Our data demonstrate that there are specific requirements for the immune system to target an already established tuberculosis infection and that ESAT-6 has a unique potential in post-exposure vaccination strategies.     

Genetic transformation of green bean callus via Agrobacterium mediated DNA transfer

Summary Kanamycin resistant callus was produced from leaf disc or hypocotyl expiants of green bean (Phaseolus vulgaris L.) when cultured on a defined medium containing 50 mg/l kanamycin after 4 days of co-cultivation with Agrobacterium tumefaciens strain EHA101 containing the binary vector pKYLX71GUS. The presence of neomycin phosphotransferase II (NPT-II) in crude cellular extracts from the kanamycin resistant callus was confirmed by ELISA. The expression of the ß-glucuronidase (GUS) reporter gene was confirmed by histochemical and fluorimetric analyses. Southern blot border analysis confirmed the integration of the foreign DNA. In addition to the evidence obtained from Southern analysis, the absence of Agrobacterium in the transformed callus cultures was confirmed by microscopic observation and through test cultures. Using the above protocol, bean callus cultures were also transformed with a bean chalcone synthase promoter-GUS fusion. These cultures, when treated with the elicitor glutathione, showed higher levels of GUS expression than the unelicited callus clumps.     

Environmental applications of immobilized microbial cells: A review

Immobilized microbial cells have been used extensively in various industrial and scientific endeavours. However, immobilized cells have not been used widely for environmental applications. This review examines many of the scientific and technical aspects involved in using immobilized microbial cells in environmental applications, with a particular focus on cells encapsulated in biopolymer gels. Some advantages and limitations of using immobilized cells in bioreactor studies are also discussed.     

Variations in collagen fibril structure in tendons

Variation of collagen fibril structure in tendon was investigated by x-ray diffraction. Anatomically distinct tendons from single species, as well as tendons from different species, were examined to determine the variations that exist in both the axial and lateral structure of the collagen fibrils. The meridional diffraction is derived from the axial collagen fibril structure. Anatomically distinct tendons of a particular species give meridional patterns that are indistinguishable within experimental error. The meridional diffraction patterns from tendons of different mammals are similar but show small species-specific variations, most noticeably in the 14th–18th orders. Tendons of birds also give meridional patterns that are similar to each other, but the avian patterns differ considerably from the mammalian ones. Avian tendons give stronger odd and weaker even low orders, a feature consistent with a reduced gap:overlap ratio, and have a distinctive intensity pattern for the higher meridional orders. Interpretation of these differences has been approached using biochemical data, diffraction by reconsituted fibers of purified collagen, and Fourier transform analysis. From these methods, it appears that the variations observed in the lower orders (2nd–8th) and in the higher orders (29th–52nd) are probably related to differences in the primary structure of the Type I collagen found in the different species. The variations observed in the 14th–18th orders appear not to be related to features within the triple-helical domain of the molecule. Equatorial diffraction yields information on the lateral packing of collagen molecules in the fibrils, and considerable variation was seen in different tendons. Rat tail tendon gives sharp Bragg reflections, demonstrating the presence of a crystalline lateral arrangement of molecules in the fibril. For the first time, sharp lattice reflections similar to those in rat tail tendon have been observed in nontail tendons, including rat achilles tendon, rabbit leg tendon, and wing and leg tendons of quail. In the rabbit and quail tendons, one of the strong equatorial reflections characteristic of the rat tendon pattern, at 1.26 nm, was absent. The positions of the equatorial maxima, which are a measure of intermolecular spacing, varied considerably, being smallest in the specimens displaying crystalline packing. The intermolecular distance in chiken and turkey leg tendons is longer than that found in mammalian tendons, or in avian wing tendons, which supports the hypothesis that a larger intermolecular spacing is characteristic of tendons that calcify. Thus, x-ray diffraction indicates there are reproducible differences in both the axial and lateral structure of collagen fibrils among different tendons. This work on tendon, a tissue containing almost exclusively Type I collagen as its major component, should serve as a basis for analyzing the structure of other connective tissues, which contain different genetic types of collagen and larger amounts of noncollagenous components.