Turning The Tables

This chapter outlines the different ways of combatting viruses. Smallpox was the most lethal of the recurrent childhood infections, and, until the late eighteenth century, had it all its own way. But in 1715, when smallpox virus infected Lady Mary Wortley Montagu, the fightback began. This turn of events gave Lady Mary a keen interest in smallpox that led, a few years later, to the first successful prevention of the disease in Europe. However, inoculation was obviously not entirely safe and was not universally accepted. Despite this, it continued to be popular until 1798, when Edward Jenner published the details of a safer alternative: vaccination. Following smallpox, rabies virus was the next to be prevented by a vaccine, this time produced by microbiologist Louis Pasteur working in Paris in the mid 1800s. From the mid 1950s onwards, a surge in production saw vaccines against common viruses like polio, measles, rubella, and mumps, as well as common bacterial infections like diphtheria, pertussis, and tetanus, being rolled out to all children in western countries. The chapter then looks at how these vaccines were prepared and the recent advances in vaccinology spurred on by the COVID-19 pandemic. It also considers flu vaccines, subunit vaccines, and microbial treatments.

Profiling of Plant Growth-Promoting Metabolites by Phosphate-Solubilizing Bacteria in Maize Rhizosphere

Microbial treatment has recently been attracting attention as a sustainable agricultural strategy addressing the current problems caused by unreasonable agricultural practices. However, the mechanism through which microbial inoculants promote plant growth is not well understood. In this study, two phosphate-solubilizing bacteria (PSB) were screened, and their growth-promoting abilities were explored. At day 7 (D7), the lengths of the root and sprout with three microbial treatments, M16, M44, and the combination of M16 and M44 (Com), were significantly greater than those with the non-microbial control, with mean values of 9.08 and 4.73, 7.15 and 4.83, and 13.98 and 5.68 cm, respectively. At day 14 (D14), M16, M44, and Com significantly increased not only the length of the root and sprout but also the underground and aboveground biomass. Differential metabolites were identified, and various amino acids, amino acid derivatives, and other plant growth-regulating molecules were significantly enhanced by the three microbial treatments. The profiling of key metabolites associated with plant growth in different microbial treatments showed consistent results with their performances in the germination experiment, which revealed the metabolic mechanism of plant growth-promoting processes mediated by screened PSB. This study provides a theoretical basis for the application of PSB in sustainable agriculture.

Salinity Stress Mitigation Using Encapsulated Biofertilizers for Sustainable Agriculture

The harmful effect of salinity stress on crops needs to be mitigated. Therefore, the application of microbial inoculum in combination with nanomaterials and methyl salicylate was investigated. Initially, different seeds were exposed to salinity levels treated with variable microbial treatments using different modes of applications. The microbial treatments included application of cyanobacterial strain Cyanothece sp. and the rhizobacterium Enterobacter cloacae, alone or in combination with one another, and a final treatment using combined microbial inoculum supplied with methyl salicylate. Later, different nanomaterials were used, namely, graphene, graphene oxide, and carbon nanotubes in combination with biofertilizers on the highest salinity level. The nanomaterial with microbial treatment and methyl salicylate were applied partly as a mixture in soil and partly as capsules. Results showed that salinity stress had a drastic inhibitory effect on growth parameters, especially at −5 MPa level. Nonetheless, the microbial treatments significantly alleviated the deleterious effect of salinity stress, especially when combined with methyl salicylate. When the nanomaterials were added to biofertilizers at highest salinity level, the inhibitory effect of salinity was mostly alleviated. Smart use of synergistic biofertilizers alongside the right nanomaterial, both encapsulated and in soil, would allow for mitigation and alleviation of inhibitory effect of salinity.

Possibility of using Bacillus and Trichoderma strains for decomposition of crop residues

The objective of this study was to investigate the possibility of using microbial strains as residue decomposers and to determine the effect of these strains on chemical and microbial properties in the residue-amended soil. Greenhouse experiment consisted of eight Bacillus treatments, three Trichoderma treatments, and their combination, all applied to non-sterile chernozem soil amended with wheat straw. Incorporation of wheat straw improved soil chemical and microbial properties, while the extent of residue decom?position under microbial strains was intensified. Microbial treatments significantly affected the soil pH, the content of carbonate, total carbon, soil organic carbon, humus, and available phosphorus and potassium. Bacterial and fungal treatments also significantly influenced the total microbial number, ammonifiers, N2-fixers, fungi, actinomycetes, oligotrophs, copiotrophs, and cellulolytic microorganisms. The effect of microbial treatments varied depending on the applied strains and examined properties, with Bacillus strains being more promising residue decomposers compared to Trichoderma strains. The most effective microbial strains could be used as potential decomposers of crop residues.

Genetically Engineered Probiotics and Therapies Applications

The idea of using probiotics for health benefits in the human body is still biased since there is skepticism and since it is quite a new field of research. However, recent experiments are trying to debate that given the naturality of their consumption and the successful results from in vitro tests in combination with other therapies. Food scientists are eager to take advantage of the known beneficial properties of probiotics by using engineering technologies in order to enhance them. Using CRISPR systems present in lactobacilli aids in strain identification, while offering information on phylogeny and ecological interactions. Also, the use of genetic engineering tools could also allow the use of plasmid vaccines to prevent antibiotic resistance and the development of synthetic probiotics as microbial treatments.

Antimicrobial, Anticancer Drug Carrying Properties of Biopolymers-based Nanocomposites- A Mini Review

Biopolymers are ubiquitous in biomedical and healthcare application. Its nanocomposites have gained more attention as antimicrobials, a drug carrier, sensors, disease diagnosis, tissue engineering, wound healing, and cancer therapy. These biopolymer composites are efficient in holding, protecting and releasing bioactive drugs such as pharmaceutics, nutraceuticals, enzymes, and probiotics. Several studies revealed a polymer-based drug delivery system in cancer therapy and microbial treatments. However, this mini-review emphasized the source, extraction, and characterizations of the biopolymers and their use in the fabrication of various drug or metals based nanocomposites followed by its utilization as drug carrier or drug to treat the various diseases such as antimicrobial infections and cancer.

Ability of sulfur-oxidising bacteria to hasten degradation of ground rubber particles in soil for release of zinc as a fertiliser to correct deficiency in wheat

Previous research has shown that ground rubber from tyres can be used to supply fertiliser zinc (Zn) for prevention of Zn-deficiency in crops, and that inoculation of the ground rubber with several bacterial species hastens the release of Zn to the soil. We evaluated the ability of several microbial combinations to speed the release of Zn from ground rubber and to decrease soil pH to favour phytoavailability of Zn to crops. In a batch experiment, treatment combinations of two rates of ground crumb rubber (nil or 300mg kg–1, equal to 0 or 3.4mg Zn kg–1) and 24 bacterial inoculants were incorporated into a Zn-deficient calcareous soil. In a pot experiment, two wheat cultivars were grown on the soil without or with ground rubber amendment or with equivalent Zn from ZnSO4 (15mg kg–1) in combination with two selected microbial treatments. All microbial treatments significantly decreased soil pH at week 3, most notably the inoculant comprising Rhodococcus erythropolis and Acinetobacter calcoaceticus (RA)+Pseudomonas putida P41 (P1)+mixed Thiobacillus spp. (Mt). In the presence of tyre rubber, soil pH at week 10 was still significantly lower than the initial value, and soil DTPA-extractable Zn concentration increased until week 6 and then remained unchanged or slightly reduced at week 10. The greatest increase in DTPA-Zn concentration occurred with the RA inoculation. Microbial inoculation treatments were classified by cluster analysis into eight groups based on soil pH and concentrations of iron (Fe) and Zn. Group 8 produced the lowest pH and highest concentrations of DTPA-Fe ( average 6.92mg kg–1) and DTPA-Zn (average 2.67mg kg–1). Inoculations with RA and with RA+P1+T. thioparus were the most effective in hastening an increase in DTPA-extractable Zn and significantly enhanced Zn uptake by wheat plants, whereas inoculations with P. putida P168 and with RA+P2+Mt were most effective in decreasing soil pH and increasing plant Fe concentration.