Isolation, characterization, and multimodal evaluation of novel glycolipid biosurfactant derived from Bacillus species: A promising Staphylococcus aureus tyrosyl-tRNA synthetase inhibitor through molecular docking and MD simulations.

Glycolipid-based biosurfactants (BSs), known for their intriguing and diverse properties, represent a largely uncharted territory in the realm of potential biomedical applications. This field holds great promise yet remains largely unexplored. This investigation provides new insights into the isolation, characterization, and comprehensive biomedical assessment of a novel glycolipid biosurfactant derived from Bacillus species, meeting the growing demand for understanding its multifaceted impact on various biomedical issues. Within this framework, two glycolipids, BG2A and BG2B, emerged as the most proficient strains in biosurfactant (BS) production. The biosurfactants (BSs) ascertained as glycolipids via thin layer chromatography (TLC) exhibited antimicrobial activity against S. aureus and E. coli. Both isolates exhibited anticancer effects against cervical carcinoma cells and demonstrated significant anti-biofilm activity against V. cholerae. Moreover, molecular docking and molecular dynamics (MD) simulations were employed to explore their antimicrobial resistance properties against Tyrosyl-tRNA synthetase (TyrRS) of Staphylococcus aureus, a well-annotated molecular target. Characterization and interpretation using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H and 13C NMR) confirmed that the BSs produced by each strain were glycolipids. These findings suggest that the isolated BSs can serve as effective agents with antibiofilm, antimicrobial, antioxidant, and anticancer properties, in addition to their considerable antibacterial resistance attributes.

Adsorption of antimicrobial peptide onto chitosan-coated iron oxide nanoparticles fosters oxidative stress triggering bacterial cell death.

In the prevailing environmental status quo, bacterial resistance has made antibiotics and antimicrobial peptides (AMPs) ineffective, imparting a serious threat and putting a much greater financial burden on the biomedical and food industries. For this reason, the present study investigates the potential of iron oxide nanoparticles (IONPs) coated with chitosan (CS-IONP) as a platform for augmenting the antimicrobial activity of antimicrobial peptides like nisin. Hence, the nisin is allowed to be adsorbed onto chitosan-coated IONPs to formulate nisin-loaded CS-IONP nanoconjugates. The nanoconjugates were characterized by various optical techniques, such as XRD, FTIR, SEM, zeta and DLS. Remarkably, lower concentrations of N-CS-IONP nanoconjugate exhibited significant and broad-spectrum antibacterial potency compared to bare IONPs and nisin against both Gram-positive and Gram-negative bacteria. Biofilm production was also found to be drastically reduced in the presence of nanoconjugates. Further investigation established a relationship between an increase in antibacterial activity and the enhanced generation of reactive oxygen species (ROS). Oxidative stress exhibited due to enhanced ROS generation is a conclusive reason for the rupturing of bacterial membranes and leakage of cytoplasmic contents, eventually leading to the death of the bacteria. Thus, the current study emphasizes the formulation of a novel antimicrobial agent which exploits magnetic nanoparticles modulated with chitosan for enhanced remediation of resistant bacteria due to oxidative stress imparted by the nanoconjugates upon interaction with the bacteria, leading to cell death.

Oxidative stress generated due to photocatalytic activity of biosynthesized selenium nanoparticles triggers cytoplasmic leakage leading to bacterial cell death.

The present work investigates the role of oxidative stress generated at biosynthesized selenium nanoparticles (SeNPs) interface in defining the antimicrobial and anti-biofilm activity. To this end, SeNPs with average size of 119 nm were synthesized rapidly during the growth of Staphylococcus aureus using the principle of green chemistry. The synthesis of SeNPs was confirmed by using different biophysical techniques like UV-vis spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), EDX and zeta potential analysis. The obtained data from antimicrobial study revealed strong antimicrobial activity against both Gram-positive bacteria like Bacillus subtilis (MTCC 441) and Gram-negative bacteria like Escherichia coli (MTCC 443) and anti-biofilm activity against biofilm forming bacteria. The mechanism behind antimicrobial activity of biosynthesized SeNPs was explored by evaluating the amount of reactive oxygen species (ROS) generated at SeNPs interface due to photocatalytic activity. The experimental data obtained altogether concluded that, the ROS generated at SeNPs interface put stress on bacterial cell membrane causing leakage of cytoplasmic contents, leading to bacterial cell death.

Photocatalytic activity of biosynthesized silver nanoparticle fosters oxidative stress at nanoparticle interface resulting in antimicrobial and cytotoxic activities.

Inside the biological milieu, nanoparticles with photocatalytic activity have potential to trigger cell death non-specifically due to production of reactive oxygen species (ROS) upon reacting with biological entities. Silver nanoparticle (AgNP) possessing narrow band gap energy can exhibit high light absorption property and significant photocatalytic activity. This study intends to explore the effects of ROS generated due to photocatalytic activity of AgNP on antimicrobial and cytotoxic propensities. To this end, AgNP was synthesized using the principle of green chemistry from the peel extract of Punica granatum L., and was characterized using UV-Vis spectroscope, transmission electron microscope and x-ray diffraction, and so forth. The antimicrobial activity of AgNP against studied bacteria indicated that, ROS generated at AgNP interface develop stress on bacterial membrane leading to bacterial cell death, whereas Alamar Blue dye reduction assay indicated that increased cytotoxic activity with increasing concentrations of AgNP. The γH2AX activity assay revealed that increasing the concentrations of AgNP increased DNA damaging activity. The results altogether demonstrated that both antimicrobial and cytotoxic propensities are triggered primarily due interfacial ROS generation by photocatalytic AgNP, which caused membrane deformation in bacteria and DNA damage in HT1080 cells resulting in cell death.

Removal of lindane in liquid culture using soil bacteria and toxicity assessment in human skin fibroblast and HCT116 cell lines.

The development of effective measures for the remediation of lindane contaminated sites is the need of the hour. In this study, a potent lindane degrading bacteria, identified as Rhodococcus rhodochrous NITDBS9 was isolated from an agricultural field of Odisha that could utilize up to 87% of 100 mg L-1 lindane when grown under liquid culture conditions in mineral salt media in 10 days. The bacteria could produce biofilm in lindane-containing media. Rhodococcus rhodochrous NITDBS9 was further characterized for its plant growth-promoting properties and it was found that the bacteria showed abilities for phytohormone, ammonia and biosurfactant production, etc. This could be beneficial for the bioremediation and improvement of crop production in contaminated sites. Ecotoxicity studies carried out for lindane, and its degradation products in mung bean and mustard seeds showed a reduction in toxicity of lindane after treatment with NITDBS9. NITDBS9 was used with a previously isolated potent lindane degrading strain Paracoccus sp. NITDBR1 in a dual mixed culture for the enhanced removal of lindane in the liquid system i.e. up to 93% in 10 days. Cytotoxicity studies were conducted with lindane before and after treatment with the single and dual mixed cultures on human skin fibroblast and HCT116 cell lines. They revealed a significant reduction in toxicity of lindane after it was bioremediated with the single and dual mixed cultures. Therefore, our proposed strategy could be efficiently used for the detoxification of the lindane-contaminated system, and further work should be done to study the use of these cultures in the contaminated soil system.

Nanotheranostics and its role in diagnosis, treatment and prevention of COVID-19.

Microbe-related, especially viral-related pandemics have currently paralyzed the world and such pathogenesis is expected to rise in the upcoming years. Although tremendous efforts are being made to develop antiviral drugs, very limited progress has been made in this direction. The nanotheranostic approach can be a highly potential rescue to combat this pandemic. Nanoparticles (NPs) due to their high specificity and biofunctionalization ability could be utilized efficiently for prophylaxis, diagnosis and treatment against microbial infections. In this context, titanium oxide, silver, gold NPs, etc. have already been utilized against deadly viruses like influenza, Ebola, HIV, and HBV. The discovery of sophisticated nanovaccines is under investigation and of prime importance to induce reproducible and strong immune responses against difficult pathogens. This review focuses on highlighting the role of various nano-domain materials such as metallic NPs, magnetic NPs, and quantum dots in the biomedical applications to combat the deadly microbial infections. Further, it also discusses the nanovaccines those are already available for various microbial diseases or are in clinical trials. Finally, it gives a perspective on the various nanotechnologies presently employed for efficient diagnosis and therapy against disease causing microbial infections, and how advancement in this field can benefit the health sector remarkably.

Lindane removal in contaminated soil by defined microbial consortia and evaluation of its effectiveness by bioassays and cytotoxicity studies / Eliminación de lindano en suelos contaminados por consorcios microbianos definidos y evaluación de su eficacia mediante bioensayos y estudios de citotoxicidad

Lindane contamination in different environmental matrices has been a global concern for long. Bacterial consortia consisting of Paracoccus sp. NITDBR1, Rhodococcus rhodochrous NITDBS9, Ochrobactrum sp. NITDBR3, NITDBR4 and NITDBR5 were used for the bioremediation of soil artificially contaminated with lindane. The bacteria, Paracoccus sp. NITDBR1 and Rhodococcus rhodochrous NITDBS9, have been selected based on their lindane degrading capacity in liquid culture conditions (~80-90 %). The remaining three bacteria were chosen for their auxiliary properties for plant growth promotion, such as nitrogen fixation, phosphate solubilization, indole-3-acetic acid production and ammonia production under in vitro conditions. In this study, market wastes, mainly vegetable wastes, were added to the soil as a biostimulant to form a biomixture for assisting the degradation of lindane by bioaugmentation. Residual lindane was measured at regular intervals of 7 days to monitor the biodegradation process. It was observed that the consortium could degrade ~80% of 50 mg kg-1 lindane in soil which was further increased in the biomixture after six weeks of incubation. Bioassays performed on plant seeds and cytotoxicity studies performed on human skin fibroblast and HCT116 cell lines revealed that the groups contaminated with lindane and treated with the bacterial consortium showed lower toxicity than their respective controls without any bacteria. Hence, the use of both pesticide degrading and plant growth-promoting bacteria in a consortium can be a promising strategy for improved bioremediation against chemical pesticides, particularly in soil and agricultural fields, simultaneously enhancing crop productivity in those contaminated soil(AU)

Lindane removal in contaminated soil by defined microbial consortia and evaluation of its effectiveness by bioassays and cytotoxicity studies.

Lindane contamination in different environmental matrices has been a global concern for long. Bacterial consortia consisting of Paracoccus sp. NITDBR1, Rhodococcus rhodochrous NITDBS9, Ochrobactrum sp. NITDBR3, NITDBR4 and NITDBR5 were used for the bioremediation of soil artificially contaminated with lindane. The bacteria, Paracoccus sp. NITDBR1 and Rhodococcus rhodochrous NITDBS9, have been selected based on their lindane degrading capacity in liquid culture conditions (~80-90 %). The remaining three bacteria were chosen for their auxiliary properties for plant growth promotion, such as nitrogen fixation, phosphate solubilization, indole-3-acetic acid production and ammonia production under in vitro conditions. In this study, market wastes, mainly vegetable wastes, were added to the soil as a biostimulant to form a biomixture for assisting the degradation of lindane by bioaugmentation. Residual lindane was measured at regular intervals of 7 days to monitor the biodegradation process. It was observed that the consortium could degrade ~80% of 50 mg kg-1 lindane in soil which was further increased in the biomixture after six weeks of incubation. Bioassays performed on plant seeds and cytotoxicity studies performed on human skin fibroblast and HCT116 cell lines revealed that the groups contaminated with lindane and treated with the bacterial consortium showed lower toxicity than their respective controls without any bacteria. Hence, the use of both pesticide degrading and plant growth-promoting bacteria in a consortium can be a promising strategy for improved bioremediation against chemical pesticides, particularly in soil and agricultural fields, simultaneously enhancing crop productivity in those contaminated soil.

Isolation and characterization of a lindane degrading bacteria Paracoccus sp. NITDBR1 and evaluation of its plant growth promoting traits

Lindane contamination in different environmental compartments is still posing a serious threat to our environment and effective measures need to be taken for the detoxification of lindane. Soil bacteria isolated from agricultural fields are known to possess certain plant growth promoting traits like the production of phytohormones, production of ammonia, nitrogen fixation and solubilization of phosphorus, etc. In the present study, an indigenous bacterial strain Paracoccus sp. NITDBR1 have been isolated from an agricultural field in Manipur, India which could grow on 100 mg L−1 lindane as the sole source of carbon and could degrade up to 90% of lindane in mineral salt media under liquid culture conditions in 8 days. The strain NITDBR1 was able to form biofilm in lindane media and the addition of substrate like glucose and sucrose enhanced the biofilm formation by 1.3 and 1.17-fold respectively in 3 days. The strain NITDBR1 could produce glycolipid and glycoprotein based biosurfactants. It was also found to possess plant growth promoting traits like nitrogen fixation and indole-3-acetic acid production to assist crop production. The phytotoxicity studies carried out on mustard seeds revealed that the degradation products formed after treatment with NITDBR1 could lower the toxicity of lindane for root elongation by 1.3-fold. Therefore, strain NITDBR1 could be useful for the bioremediation of soil contaminated with lindane with lesser damage to the environment, biofilm forming ability may help the bacteria survive under stressed environmental conditions, and biosurfactant production will help in increasing the bioavailability of contaminants. The plant growth promoting traits can be beneficial for agriculture. With such soil friendly activities coupled with pesticide degradation, this strain can be used for environmental as well as agricultural applications

No disponible

Isolation and characterization of a lindane degrading bacteria Paracoccus sp. NITDBR1 and evaluation of its plant growth promoting traits.

Lindane contamination in different environmental compartments is still posing a serious threat to our environment and effective measures need to be taken for the detoxification of lindane. Soil bacteria isolated from agricultural fields are known to possess certain plant growth promoting traits like the production of phytohormones, production of ammonia, nitrogen fixation and solubilization of phosphorus, etc. In the present study, an indigenous bacterial strain Paracoccus sp. NITDBR1 have been isolated from an agricultural field in Manipur, India which could grow on 100 mg L-1 lindane as the sole source of carbon and could degrade up to 90% of lindane in mineral salt media under liquid culture conditions in 8 days. The strain NITDBR1 was able to form biofilm in lindane media and the addition of substrate like glucose and sucrose enhanced the biofilm formation by 1.3 and 1.17-fold respectively in 3 days. The strain NITDBR1 could produce glycolipid and glycoprotein based biosurfactants. It was also found to possess plant growth promoting traits like nitrogen fixation and indole-3-acetic acid production to assist crop production. The phytotoxicity studies carried out on mustard seeds revealed that the degradation products formed after treatment with NITDBR1 could lower the toxicity of lindane for root elongation by 1.3-fold. Therefore, strain NITDBR1 could be useful for the bioremediation of soil contaminated with lindane with lesser damage to the environment, biofilm forming ability may help the bacteria survive under stressed environmental conditions, and biosurfactant production will help in increasing the bioavailability of contaminants. The plant growth promoting traits can be beneficial for agriculture. With such soil friendly activities coupled with pesticide degradation, this strain can be used for environmental as well as agricultural applications.