Bactericidal Efficacy of Allium sativum (garlic) Against Multidrug Resistant Vibrio cholerae O1 Epidemic Strains

In recent years, emerging trend of antibiotic resistance in Vibrio cholerae associated with cholera epidemics is a matter of serious concern for the management of the disease. Indiscriminate use of antibiotics generally results in selection of antibiotic resistant strains. Introduction of newer antibiotics is a challenging task for the researchers as bacteria soon attain resistance. Therefore, identifying natural compounds of medicinal importance for control of cholera would be the best alternative. Garlic (Allium sativum) was recognised for many centuries in early Chinese, Egyptian and Indian civilisations as an herbal or traditional medicine. In present study, garlic was selected for screening of antimicrobial efficacy against V. cholerae. A total of 55 V. cholerae strains isolated from various outbreaks/epidemics were subjected to antimicrobial testing as per CLSI, USA 2010 guidelines. Antimicrobial screening of garlic extract was performed against all the multidrug resistant strains of V. cholerae. The garlic extracts showed antibacterial activity against all the V. cholerae strains tested, irrespective of their origin, multidrug resistance and virulence. Antibacterial efficacy of garlic on V. cholerae was also evident from in vivo study on sealed adult mice model. Thus, the Garlic extract harnesses the potential to control infection of multidrug resistant V. cholerae, especially in outbreak like situations in remote and under developed areas where drug supply itself is a challeng

Investigating microcrystalline cellulose crystallinity using Raman spectroscopy

Microcrystalline cellulose (MCC) is a semi-crystalline material with inherent variable crystallinity due to raw material source and variable manufacturing conditions. MCC crystallinity variability can result in downstream process variability. The aim of this study was to develop models to determine MCC crystallinity index (%CI) from Raman spectra of 30 commercial batches using Raman probes with spot sizes of 100 µm (MR probe) and 6 mm (PhAT probe). A principal component analysis model separated Raman spectra of the same samples captured using the different probes. The %CI was determined using a previously reported univariate model based on the ratio of the peaks at 380 and 1096 cm−1. The univariate model was adjusted for each probe. The %CI was also predicted from spectral data from each probe using partial least squares regression models (where Raman spectra and univariate %CI were the dependent and independent variables, respectively). Both models showed adequate predictive power. For these models a general reference amorphous spectrum was proposed for each instrument. The development of the PLS model substantially reduced the analysis time as it eliminates the need for spectral deconvolution. A web application containing all the models was developed

Studies on Microbial Production and Extraction of poly β-hydroxybutyrate using Bacillus Subtilis

Poly-β-hydroxybutyrate (PHB) has wide applications in industry as it has properties similar to that of conventional plastics. Most important properties of PHB are its biodegradable nature, thermo-stability, and biocompatibility, durability, non-toxicity and water insolubility. Bacillus subtilis is a well-known bacterium that has been used for the industrial production of several proteins and biochemicals. Bacillus subtilis (ATCC®6051™) was used for PHB production. PHB was quantified using UV-VIS spectrophotometer and High-Pressure Liquid Chromatography (HPLC). The PHB yield of B. subtilis (ATCC®6051™) was estimated in batch cultivation by HPLC and GC methods. In this study, B. subtilis was employed for intracellular PHB Production in batch and fed-batch cultivation. The batch kinetic study of B. subtilis culture was conducted in an optimized medium in stirred tank bioreactor. The B. subtilis culture showed maximum biomass formation (1.78±0.1 g/l) and PHB accumulation (1.18±0.04 g/l) with 66.29 % PHB content of dry cell weight (DCW) at 28 h in optimized media using shake flask cultivation. The overall productivity was found to be 0.039 g/l/h. B. subtilis culture showed maximum biomass (1.79±0.026 g/l) and PHB accumulation (1.23±0.024 g/l) with the PHB content of 68.72% of DCW after 24 h in a bioreactor. The overall productivity was found to be 0.051 g/l/h. Substrate inhibition reduces the overall production in microbial production of PHB. Therefore, substrate (glucose, phosphate, and ammonium) inhibition studies were performed in shake flask conditions. The complete inhibition of growth of bacterial culture was seen at glucose, phosphate, and ammonium concentration of 120 g/l, 80 g/l, and 100 g/l, respectively. The optimum value of kinetic parameters was estimated to be: 0.376 h-1 for μm, 4.162 g/l for KSG, 1.611 g/l for KSN, 0.427 g/l for KSP, 123.6 g/l for KIG, 103 g/l for KIN, 82.4 g/l for KIP, 1.646 g/g for 1/Y(x/SG), 0.0923 g/g/h for mSG, 0.688 g/g for k1, 0.0041 for k2 and 9.671 for n. Initial values of biomass (=0.05 /), substrate (=7.3 /,) and PHB concentration (P = 0.012 g/l) and optimum parameters values were utilized to get a modified Monod model for PHB production. Inhibition kinetics data was also utilized for the prediction of inhibition kinetics parameters in the batch model. The productivity was found to be 0.041 g/l/h. The batch model was utilized for the prediction of the best fed-batch strategy. In constant feed rate fed-batch cultivation in shake flask, B. subtilis culture showed maximum biomass (1.91±0.05 g/l) and PHB production (1.37±0.08 g/l) with PHB content of 71.73% of dry cell weight at 30 h. The productivity was found to be 0.046 g/l/h. PHB production was enhanced 1.16 folds in constant feed rate fed-batch conditions, as compared to batch cultivation of B. subtilis. In this study, batch kinetic parameters for biomass production, substrate utilization and PHB production were estimated for B. subtilis culture. The resulting data was utilized for the development of mathematical model for production of biomass and PHB. This constant feed rate fed-batch cultivation was performed in a bioreactor using statistically optimized media. The maximum biomass obtained was 1.66±0.050 g/l and PHB was 1.42±0.05 g/l with the PHB content of 85.54% of DCW at 30 h cultivation. Two-stage cultivation of B. subtilis was performed using two medium of different composition for growth and production in bioreactor using constant fed-batch strategy. In bioreactor, in which maximum biomass (1.95±0.045 g/l) and PHB production (1.396±0.017 g/l) were obtained in 8th h of production with a PHB content of 93.33% of DCW. This is the highest reported PHB yield by fermentation to the best of our knowledge. The maximum biomass (1.953±0.045 g/l) at 4 h and PHB production (1.396±0.017 g/l) at 8 h were obtained during mass production of PHB in a bioreactor. In this study, several off-line feeding strategies were examined for enhanced biomass and PHB production by B. subtilis. After shake flask trials it was established that enhanced PHB production took place by constant feed rate fed-batch cultivation strategy. The successful model based feeding strategy can be applied for the production of PHB on commercial scale. A new extraction process with non-toxic and cheaper solvent was developed. In this study, different parameters like acetone percentage, and solvent pH, temperature, and incubation period were optimized using statistical tools such as Plackett-Burman (PB) design and Response Surface Methodology (RSM). An attempt was made to develop a robust process for the extraction of PHB from cells by liquid-liquid extraction. Different parameters like acetone percentage (30 % to 70 %), and pH (5 to 9), temperature (30 °C to 70 °C), and incubation periods (30 to 70 min) were chosen for optimization using Central Composite Design (CCD). The most effective factors predicted by PB design were cell biomass (t-value of 0.0404), incubation temperature (t-value of 0.0057), solvent pH (t-value of 0.0039), solvent percentage (t-value of 0.0023), incubation period (t-value of 0.0009). The agitation speed (t-value of -0.0094) did not show a significant effect on PHB recovery. The optimum conditions for the enhanced PHB recovery and purity were found to be solvent pH 7, extraction temperature - 43 °C, incubation time - 70 min, and percentage acetone – 30 % by Central Composite Design (CCD). The experimentaly recovered PHB was 0.87 g/g with a purity of 95.02% which is higher than the model predicted value of PHB recovery of 0.84 g/g of biomass with a purity of 97.23 %. In this study, PHB extraction process parameters were optimized for PHB recovery (g/g) and purity (%) using PB design and RSM statistical tools. The cheaper and green solvent acetone was employed for extraction of PHB. PHB extracted from this process is less toxic as compared to the PHB extracted using the halogenated solvents (chloroform, di-chloromethane, dichloroethane and sodium hypochlorite). The extracted PHB can be utilized in food industries, pharmaceutical and tissue engineering applications

Distribution of airborne microbes and antibiotic susceptibility pattern of bacteria during Gwalior trade fair, Central India

Research into the distribution of bioaerosols during events associated with huge groups of people is lacking, especially in developing countries. The purpose of this study was to understand the distribution pattern of bioaerosols during an annual trade fair in the historical city of Gwalior, central India, a very important historical fair that was started by the King of Gwalior Maharaja Madho Rao in 1905. Methods: Air samples were collected from six different sites at the fair ground and three different sites in a residential area before/during/after the fair using an impactor sampler on microbial content test agar and rose bengal agar for total bacteria and fungi, respectively. The representative strains of bacteria and fungi were further identified and selected bacterial strains were subjected to antibiotic susceptibility testing according to US Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: The bacterial bioaerosol count [colony-forming units (CFU)/m3] at fair sites was found to be 9.0 × 103, 4.0 × 104, and 1.0 × 104 before the start of the fair, during the fair, and after the fair, respectively. The fungal bioaerosol count at fair sites was 2.6 × 103 CFU/m3, 6.3 × 103 CFU/m3, and 1.7 × 103 CFU/m3 before the fair, during the fair, and after the fair, respectively. Bacterial/fungal bioaerosols during-fair were increased significantly from the bacterial/fungal bioaerosols of the before-fair period (p < 0.05); they were also significantly higher than the bacterial/fungal bioaerosols at non-fair sites during the event (p < 0.0001). The proportion of antibiotic-resistant bacteria over the fair ground was significantly increased during-fair and was still higher in the after-fair period. Methicillin-resistant staphylococci (MRS) were also reported at the fair ground. Conclusion: The study indicates significantly higher bacterial and fungal bioaerosols during the fair event. Therefore, further research is needed to explore the health aspects and guidelines to control microbial load during such types of events

Antibacterial activity of actinomycetes isolated from different soil samples of Sheopur (A city of central India)

The main objective of the present study was isolation, purification, and characterization of actinomycetes from soil samples, having antimicrobial activity against 12 selected pathogenic strains. Soils samples were taken from different niche habitats of Sheopur district, Madhya Pradesh, India. These samples were serially diluted and plated on actinomycete isolation agar media. Potential colonies were screened, purified, and stored in glycerol stock. Isolates were morphologically and biochemically characterized. These isolates were subjected to extraction for production of the antibacterial compound. Antibacterial activity and Minimum Inhibitory Concentration (MIC) of the purified extract of isolates were evaluated. Totally 31 actinomycete isolates were tested for antagonistic activity against 12 pathogenic microorganisms. Isolates AS14, AS27, and AS28 were highly active, while AS1 showed less activity against the pathogenic microorganisms. Isolate AS7 exhibited the highest antagonistic activity against Bacillus cereus (24 mm) and AS16 showed the highest activity against Enterococcus faecalis (21 mm). MIC was also determined for actinomycete isolates against all the tested microorganisms. MIC of actinomycete isolates was found to be 2.5 mg/ml against Shigella dysenteriae, Vancomycin-resistant enterococci, and Klebsiella pneumoniae, and was 1.25 mg/ml for Staphylococcus saprophyticus, Streptococcus pyogenes, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus, Bacillus cereus, Staphylococcus xylosus, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, and Staphylococcus aureus. All actinomycetes isolates showed antibacterial activity against S. aureus, while they showed less activity against S. dysenteriae. These isolates had antibacterial activity and could be used in the development of new antibiotics for pharmaceutical or agricultural purposes

Correlating Single Crystal Structure, Nanomechanical, and Bulk Compaction Behavior of Febuxostat Polymorphs

Febuxostat exhibits unprecedented solid forms with a total of 40 polymorphs and pseudopolymorphs reported. Polymorphs differ in molecular arrangement and conformation, intermolecular interactions, and various physicochemical properties, including mechanical properties. Febuxostat Form Q (FXT Q) and Form H1 (FXT H1) were investigated for crystal structure, nanomechanical parameters, and bulk deformation behavior. FXT Q showed greater compressibility, densification, and plastic deformation as compared to FXT H1 at a given compaction pressure. Lower mechanical hardness of FXT Q (0.214 GPa) as compared to FXT H1 (0.310 GPa) was found to be consistent with greater compressibility and lower mean yield pressure (38 MPa) of FXT Q. Superior compaction behavior of FXT Q was attributed to the presence of active slip systems in crystals which offered greater plastic deformation. By virtue of greater compressibility and densification, FXT Q showed higher tabletability over FXT H1. Significant correlation was found with anticipation that the preferred orientation of molecular planes into a crystal lattice translated nanomechanical parameters to a bulk compaction process. Moreover, prediction of compactibility of materials based on true density or molecular packing should be carefully evaluated, as slip-planes may cause deviation in the structure–property relationship. This study supported how molecular level crystal structure confers a bridge between particle level nanomechanical parameters and bulk level deformation behavior