Nano-microbial based technology employing polyvalent phage conjugate: A next generation weapon for antimicrobial resistance lurking behind wastewater.

Worldwide, due to a dearth of innovative interventions, new forms of antimicrobial resistance (AMR) are being discovered every day in clinical and environmental settings. Therefore, it is necessary to remove these contaminants directly or indirectly from the environment. Nanomicrobial-based technology employing nanomaterials with microbes is a new paradigm that finds a place in the antimicrobial crisis. Microbial entities such as phages can be used to treat antimicrobial resistance, but phage resistance is challenging and limits its applicability. Similarly, nanotechnology will not be able to selectively remove resistant strains from the environment individually. Therefore, we employ nanomicrobial-based technology that aims to fill these gaps. In the present study, polyvalent phages were isolated from wastewater with an easy-to-use modified multi-host sequential approach, characterized and conjugated with magnetite (Fe3O4) nanoparticles with the modified formulation to form nanomicrobial conjugates (NMCs). These NMCs were subjected to characterization and in vitro antibacterial studies. The results indicated a significant polyvalency of phages in the order of Caudovirales. Transmission electron microscopy (TEM) analysis of Fe3O4 nanoparticles formed by the co-precipitation method showed a particle size of 30 ± 5 nm and the selected area electron diffraction (SAED) pattern indicates a single-phase crystalline structure. To form NMCs, isolated phages (105 PFU/mL) were immobilized onto Fe3O4 nanoparticles. Further, surface modification of Fe3O4 nanoparticles enables the covalent association of phages. Biosurfactant-functionalized Fe3O4 nanoparticles (FNMCs) were found to have higher phage loading capacity, with a significant value of p < 0.0127 and a zeta potential of -22.2 mV. TEM studies and in vitro biofilm assay showed that NMCs exhibit promising antibacterial activity against various resistant bacterial strains. Pilot studies showed that NMCs can selectively eliminate up to 98.3% of AMR in wastewater. Thus, these findings indicate a synergistic effect of both phage and nanomaterial and this technology is expected to be a new lead in wastewater management.

Cyanobacteria as Natural Therapeutics and Pharmaceutical Potential: Role in Antitumor Activity and as Nanovectors.

Cyanobacteria (blue-green microalgae) are ubiquitous, Gram-negative photoautotrophic prokaryotes. They are considered as one of the most efficient sources of bioactive secondary metabolites. More than 50% of cyanobacteria are cultivated on commercial platforms to extract bioactive compounds, which have bene shown to possess anticancer activity. The chemically diverse natural compounds or their analogues induce cytotoxicity and potentially kill a variety of cancer cells via the induction of apoptosis, or altering the activation of cell signaling, involving especially the protein kinase-C family members, cell cycle arrest, mitochondrial dysfunctions and oxidative damage. These therapeutic properties enable their use in the pharma and healthcare sectors for the betterment of future generations. This review provides a baseline overview of the anti-cancerous cyanobacterial bioactive compounds, along with recently introduced nanomaterials that could be used for the development of new anticancer drugs to build a healthy future for mankind.

Screening of novel microorganisms for biosurfactant and biocontrol activity against Phytophthora infestans.

In the present study, 95 isolates of bacteria were tested for their biosurfactant as well as biocontrol activity against Phytophthora infestans. The results revealed that only 15.8% isolates showed biosurfactant activity. The emulsification index ranged from 0-68% and 24.2% isolates showed positive reaction for biosurfactant properties. In emulsification assay and oil spreading test, 18.95% and 5.26% isolates, respectively scored positive for biosurfactant production. Among all, only five isolates were found effective against P. infestans, for biocontrol properties. Pseudomonas aeruginosa-1 showed 62.22% inhibition zone after 72 hrs while P. aeruginosa-3 showed 46.42%. Forty-eight hrs old culture supernatants were highly effective in food-poisoning test, tuber slice test and detached leaf method against P. infestans. In whole potato plant test, bacterial cell based formulation, culture supernatant and bacterial cell suspension of P. aeruginosa-1 showed 10.42%, 9.94% and 17.96% diseases severity respectively, as against 53.96% in control. This isolate holds promise as biological control agent against P. infestans in field.

Drought and sorghum: a bibliometric analysis using VOS viewer.

Drought has emerged as a significant global concern in recent years, leading to a proliferation of research on sorghum, an important drought resistant crop. Consequently, conducting a bibliometric analysis of said publications has the potential to yield insights into current areas of interest and potential avenues for future research. The present study utilized the Web of Science database to gather literature published between the years 2000 and 2022. The search terms 'drought' AND 'sorghum' was employed to identify relevant publications and as a result, 1731 publications were obtained. The bibliometric analysis of the obtained articles was conducted using VOSviewer software (1.6.19). The keyword 'sorghum' was found to have the highest frequency, with a total link strength of 4238. This keyword exhibited a strong association with the terms 'drought' and 'drought tolerance'. The average number of citations for the 100 most-cited articles was 509.2. The journal Crop Science attained the top position with 60 published articles and secured the highest number of citations with a count of 2795. The academic works of Graeme L. Hammer, comprising 40 articles affiliated with the University of Queensland (UQ), have garnered a total of 3612 citations. Similarly, the same university has produced 112 articles that have been cited 5551 times, thereby establishing it as the most frequently cited organization, with Hammer receiving the highest citation count. UQ had a total of 41 collaborators, with a cumulative link strength of 115. The USA has the highest number of articles pertaining to drought and sorghum. The published literature has focused on abiotic stress tolerance, genetic analysis, and physiological traits, among others. It is anticipated that there will be a substantial rise in the quantity of worldwide publications pertaining to drought and sorghum. The USA offered a significant contribution to this emerging field.Communicated by Ramaswamy H. Sarma.

Counter-attack of biocontrol agents: Environmentally benign Approaches against Root-knot nematodes (Meloidogyne spp.) on Agricultural crops.

Root-knot nematodes (Meloidogyne spp.) are obligate sedentary endoparasites, considered severe crop-damaging taxa among all plant-parasitic nematodes globally. Their attacks through parasitic proteins alter the physiology and machinery of the host cells to favour parasitism and reduction in crop yield. Currently, the use of excessive pesticides as a fast remedy to manage this pest is hazardous for both the environment and humans. Keeping this view in mind, there is an urgent need for developing efficient eco-friendly strategies. Bio-control as an eco-friendly is considered the best approach to manage nematodes without disturbing non-target microbes. In bio-control, living agents such as fungi and bacteria are the natural enemies of nematodes and the best substitute for pesticides. Fungi, including nematode-trapping fungi, can sense host signals and produce special trapping devices viz., constricting rings and adhesive knobs/loops, to capture nematodes and kill them. Whereas, endo-parasitic fungi kill nematodes by enzymatic secretions and spore adhesion through their hyphae. Bacteria can also control nematodes by producing antibiotic compounds, competing for nutrients and rhizosphere, production of hydrolytic enzymes viz., chitinases, proteases, lipases, and induction of systemic resistance (ISR) in host plants. Scientists throughout the world are trying to evolve environmentally benign methods that sustain agricultural production and keep nematodes below a threshold level. Whatever methods evolve, in the future the focus should be on important aspects like green approaches for managing nematodes without disturbing human health and the environment.

Nanotechnology - A new frontier of nano-farming in agricultural and food production and its development.

The potential of nanotechnology for the development of sustainable agriculture has been promising. The initiatives to meet the rising food needs of the rapidly growing world population are mainly powered by sustainable agriculture. Nanoparticles are used in agriculture due to their distinct physicochemical characteristics. The interaction of nanomaterials with soil components is strongly determined in terms of soil quality and plant growth. Numerous research has been carried out to investigate how nanoparticles affect the growth and development of plants. Nanotechnology has been applied to improve the quality and reduce post-harvest loss of agricultural products by extending their shelf life, particularly for fruits and vegetables. This review assesses the latest literature on nanotechnology, which is used as a nano-biofertilizer as seen in the agricultural field for high productivity and better growth of plants, an important source of balanced nutrition for the crop, seed germination, and quality enrichment. Additionally, post-harvest food processing and packaging can benefit greatly from the use of nanotechnology to cut down on food waste and contamination. It also critically discusses the mechanisms involved in nanoparticle absorption and translocation within the plants and the synthesis of green nanoparticles.

The Emerging Trend of Bio-Engineering Approaches for Microbial Nanomaterial Synthesis and Its Applications.

Micro-organisms colonized the world before the multi-cellular organisms evolved. With the advent of microscopy, their existence became evident to the mankind and also the vast processes they regulate, that are in direct interest of the human beings. One such process that intrigued the researchers is the ability to grow in presence of toxic metals. The process seemed to be simple with the metal ions being sequestrated into the inclusion bodies or cell surfaces enabling the conversion into nontoxic nanostructures. However, the discovery of genome sequencing techniques highlighted the genetic makeup of these microbes as a quintessential aspect of these phenomena. The findings of metal resistance genes (MRG) in these microbes showed a rather complex regulation of these processes. Since most of these MRGs are plasmid encoded they can be transferred horizontally. With the discovery of nanoparticles and their many applications from polymer chemistry to drug delivery, the demand for innovative techniques of nanoparticle synthesis increased dramatically. It is now established that microbial synthesis of nanoparticles provides numerous advantages over the existing chemical methods. However, it is the explicit use of biotechnology, molecular biology, metabolic engineering, synthetic biology, and genetic engineering tools that revolutionized the world of microbial nanotechnology. Detailed study of the micro and even nanolevel assembly of microbial life also intrigued biologists and engineers to generate molecular motors that mimic bacterial flagellar motor. In this review, we highlight the importance and tremendous hidden potential of bio-engineering tools in exploiting the area of microbial nanoparticle synthesis. We also highlight the application oriented specific modulations that can be done in the stages involved in the synthesis of these nanoparticles. Finally, the role of these nanoparticles in the natural ecosystem is also addressed.

CuO Bionanocomposite with Enhanced Stability and Antibacterial Activity against Extended-Spectrum Beta-Lactamase Strains.

Worldwide, bacterial resistance to beta-lactam antibiotics is the greatest challenge in public health care. To overcome the issue, metal-based nanoparticles were extensively used as an alternative to traditional antibiotics. However, their unstable nature limits their use. In the present study a very simple, environmentally friendly, one-pot synthesis method that avoids the use of organic solvents has been proposed to design stable, novel nanocomposites. Formulation was done by mixing biogenic copper oxide (CuO) nanomaterial with glycerol and phospholipids isolated from egg yolk in an appropriate ratio at optimum conditions. Characterization was done using dynamic light scattering DLS, Zeta potential, high performance liquid chromatography (HPLC), and transmission electron microscopy (TEM). Further, its antibacterial activity was evaluated against the extended-spectrum beta-lactamase strains based on zone of inhibition and minimal inhibitory concentration (MIC) indices. Results from this study have demonstrated the formulation of stable nanocomposites with a zeta potential of 34.9 mV. TEM results indicated clear dispersed particles with an average of 59.3 ± 5 nm size. Furthermore, HPLC analysis of the egg yolk extract exhibits the presence of phospholipids in the sample and has significance in terms of stability. The newly formed nanocomposite has momentous antibacterial activity with MIC 62.5 µg/mL. The results suggest that it could be a good candidate for drug delivery in terms of bactericidal therapeutic applications.

A quantitative Real Time PCR based method for the detection of Phytophthora infestans causing Late blight of potato, in infested soil.

A fast and simple polymerase chain reaction method has been developed for detection of Phytophthora infestans oospores, the causal agent of Late blight of Potato in soil. The method involves the disruption of oospores by grinding dry soil, using abrasive properties, in the presence of glass powder and skimmed milk powder within a short time. The latter prevents loss of DNA by adsorption to soil particles or by degradation and reduces the co-extraction of PCR inhibitors with the DNA. After phenol/chloroform extraction; the DNA is suitable for direct PCR amplification without a precipitation step. This amplification leads to detection of pathogen in infested soils before planting of crop. The real-time PCR assay we describe is highly sensitive and specific, and has several advantages over conventional PCR assays used for P. infestans detection to confirm positive inoculum level in potato seeds and elsewhere. With increasing amounts of standard DNA templates, the respective threshold cycle (Ct) values were determined and a linear relationship was established between these Ct values and the logarithm of initial template amounts. The method is rapid, cost efficient, and when combined with suitable internal controls can be applied to the detection and quantification of P. infestans oospores on a large-scale basis.