Advances in bioinspired nanomaterials managing microbial biofilms and virulence: A critical analysis.

Microbial virulence and biofilm formation stand as a big concern against the goal of achieving a green and sustainable future. Microbial pathogenesis is the process by which the microbes (bacterial, fungal, and viral) cause illness in their respective host organism. 'Nanotechnology' is a state-of-art discipline to address this problem. The use of conventional techniques against microbial proliferation has been challenging against the environment. To tackle this problem, there has been a revolution in this multi-disciplinary field, to address the aspect of bioinspired nanomaterials in the antibiofilm and antimicrobial sector. Bioinspired nanomaterials prove to be a potential antibiofilm and antimicrobial agent as they are non-hazardous to the environment and mostly synthesized using a single-step reduction protocol. They exhibit synergistic effects against bacterial, fungal, and viral pathogens and thereby, control the virulence. In this literature review, we have elucidated the potential of bioinspired nanoparticles as well as nanomaterials as a promising anti-microbial treatment pedagogy and throw light on the advancements in how smart photo-switchable platforms have been designed to exhibit both bacterial releasing as well as bacterial-killing properties. Certain limitations and possible outcomes of these bio-based nanomaterials have been discussed in the hope of achieving a green and sustainable ecosystem.

Antimicrobial, antibiofilm, antioxidant, anticancer, and phytochemical composition of the seed extract of Pongamia pinnata.

Ethyl acetate seed extract of Pongamia pinnata displayed the highest antimicrobial potential against all test pathogens and Staphylococcus epidermidis was reported as the most sensitive strain with MIC/MBC 1.56/3.12 mg ml-1. It inhibited S. epidermidis biofilm 97.43% at MIC and LM as well as FE-SEM micrographs displayed extensive disintegration in biofilm. It showed the highest TPC (1.23 ± 0.04 g GAE g-1), TFC (0.95 ± 0.05 g CE g-1), and antioxidant activity with IC50 18.47 ± 0.33 µg ml-1. MTT assay displayed concentration-dependent strong cytotoxicity on K562 cells on the treatment of ethyl acetate extract with an IC50 value of 84.41 µg ml-1. On the other hand, it showed minute cytotoxicity on normal PBMCs with an IC50 value of 410.14 µg ml-1. GC-MS analysis revealed that Hexadecanoic acid (35.97%); 2-(1,3-Benzodioxol-5-yl)furo[2,3-h]chromen-4-one (Pongaglabrone) (22.82%); 2,2-Dimethylindane-1,3-dione- (13.05%) were the three major components in ethyl acetate extract. The present investigation showcases ethyl acetate extract as a potent antimicrobial, antibiofilm, antioxidant, and anticancer agent that opens a new avenue for its phytochemicals as a therapeutic agent.

A feasible approach for azo-dye (methyl orange) degradation by textile effluent isolate Serratia marcescens ED1 strain for water sustainability: AST identification, degradation optimization and pathway hypothesis.

Methyl orange (MO) is a dye commonly used in the textile industry that harms aquatic life, soil and human health due to its potential as an environmental pollutant. The present study describes the dye degradation ability of Serratia marcescens strain ED1 isolated from textile effluent and characterized by 16S rRNA gene sequence analysis. The laccase property of bacterial isolate was confirmed qualitatively. The effects of various factors (pH, temperature, incubation time, and dye concentration) were evaluated using Response Surface Methodology (RSM). The maximum dye (MO) degradation was 81.02 % achieved at 37 °C temperature and 7.0 pH with 200 mg/L dye concentration after 48 h of incubation. The beef extract, ammonium nitrate and fructose supplementation showed better response during bioremediation among the different carbon and nitrogen sources. The degree of pathogenicity was confirmed through the simple plate-based method, and an antibiotic resistance profile was used to check the low-risk rate of antibiotic resistance. However, the fate and extinct of degraded MO products were analysed through UV-Vis spectroscopy, FT-IR, and GC-MS analysis to confirm the biodegradation potential of the bacterial strain ED1 and intermediate metabolites were identified to propose metabolic pathway. The phytotoxicity study on Vigna radiata L. seeds confirmed nontoxic effect of degraded MO metabolites and indicates promising degradation potential of S. marcescens strain ED1 to successfully remediate MO dye ecologically sustainably.

Phytochemical characterization and evaluation of antioxidant, antimicrobial, antibiofilm and anticancer activities of ethyl acetate seed extract of Hydnocarpus laurifolia (Dennst) Sleummer.

Various functional groups were observed in the FTIR analysis of Hydnocarpus laurifolia seeds ethyl acetate extract such as O-H, N-H, C-H, -CH2, O=C=O, C=O, C=O-NH, and CH3, etc. Eleven bioactive compounds were detected via GC-MS and the predominant compounds include (1S)-2-cyclopentene-1-tridecanoicacid (chaulmoogric acid) (80.59%); 2-cyclopentene-1-undecanoic acid (hydnocarpic acid) (6.76%); cyclobutylamine (5.28%); methyl thioacetate (ethanethioic acid) (4.84%); lignoceric acid (2.21%). The TPC and TFC values were 0.110 ± 0.04 GAE g-1 and 0.175 ± 0.05 g CE g-1 respectively. Ethyl acetate extract showed strong DDPH free radical scavenging activity with IC50 value 10.64 ± 0.48 µg ml-1 and antioxidant activity index 3.759. The ethyl acetate extract also exhibited potential ABTS radical scavenging efficacy with a very low IC50 value, i.e., 07.81 ± 0.48 µg ml-1. P. aeruginosa was the most sensitive bacteria to the extract with 33.16 ± 0.88 mm inhibition zone and MIC: 3.12 mg ml-1, MBC: 6.25 mg ml-1. P. aeruginosa biofilm was inhibited by ethyl acetate extract 99.22% at MIC concentration. The LM images displayed a decrease in the number of biofilm cells and FE-SEM micrographs showcased the extensive decrease as well as disintegration in biofilm. Additionally, ethyl acetate extract was found selectively cytotoxic to the K562 cancer cells having an IC50 of 25.41 µg ml-1 and barely cytotoxic to normal PBMCs having an IC50 of 482.54 µg ml-1, and the selectivity index value was 18.99. Data validate scientifically the traditional use of H. laurifolia seeds in folk medicines and confirmed that it can be used in modern phytomedicines as an antioxidant, antimicrobial, antibiofilm, and anticancer agent and is toxicologically safe.

Bioformulation Containing Cohorts of Ensifer adhaerens MSN12 and Bacillus cereus MEN8 for the Nutrient Enhancement of Cicer arietinum L.

Here we examine the effects of different carrier based bioinoculants on the growth, yield and nutritional value of chickpea and on associated soil nutrients. A consortium of two taxonomically distinct endophytic bacteria-Ensifer adhaerens MSN12 and Bacillus cereus MEN8-have promising plant growth promoting (PGP) attributes. We demonstrate their delivery from the laboratory to the field via the formulation of an effective bioinoculant with economic and accessible carriers. Sugarcane straw ash (SCSA) was found to be an efficient carrier and bioformulation for enhancing viability and shelf-life of strains up to 12 months. A bioformulation containing an SCSA-based consortium (MSN12 + MEN8) increased seed germination by 7%, plant weight by 29%, length by 17%, seed-yield by 12%, harvesting index by 14% and proximate nutritional constituents by 20% over consortium treatment without SCSA. In addition, the bioformulation of post-harvest treated soil improved the physico-chemical properties of the soil in comparison to a pre-sowing SCSA-based bioformulation treated crop, being fortified in different proximate nutritional constituents including dry matter (30%), crude protein (45%), crude fiber (35%), and ether extract (40%) in comparison to the control. Principal component analysis and scattered matrix plots showed a positive correlation among the treatments, which also validates improvement in the soil nutrient components and proximate constituents by T6 treatment (MSN12 + MEN8 + SCSA). The above results suggest efficiency of SCSA not only as a carrier material but also to support microbial growth for adequate delivery of lab strains as a substitute for chemi-fertilizers.

Bioprospects of Endophytic Bacteria in Plant Growth Promotion and Ag-Nanoparticle Biosynthesis.

In this study, five endophytic bacterial strains, namely Rhizobium pusense (MS-1), Bacillus cereus MS-2, Bacillus flexus (MS-3), Methylophilus flavus (MS-4), and Pseudomonas aeruginosa (MS-5), were used to investigate their potential role in the enhancement of growth yields of two types of tomato varieties, viz. hybrid and local, and in the biosynthesis of silver nanoparticles (AgNPs). The inoculation of bacterial strains enhanced the root and shoot length, biomass, and leaf chlorophyll contents. The fruit weight of the tomato (kg/plant) was also higher in the bacteria inoculated plants of both hybrid and local varieties than in the control (untreated). A significant increase was recorded in the fruit yield (g/plant) in all the treatments, whereas Methylophilus flavus (MS-4) inoculated plants yielded nearly 2.5 times more fruit weight compared to the control in the hybrid variety and two times higher in the local variety. The response to M. flavus as a microbial inoculant was greater than to the other strains. Biosynthesis of Ag nanoparticles was also carried out using all five endophytic bacterial strains. The weakest producers of AgNPs were Rhizobium pusense (MS-1) and Methylophilus flavus (MS-4), while Bacillus cereus MS-2, Bacillus flexus (MS-3), and Pseudomonas aeruginosa (MS-5) were strong producers of AgNPs. Nanoparticles were further characterized using high-resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), UV-Vis spectrophotometry, and X-ray diffraction (XRD) analysis, and revealed cuboidal shaped AgNPs in the Bacillus cereus MS-2 strain. In addition, the biosynthesized AgNPs showed antibacterial activity against various pathogenic and endophytic bacterial strains.