Genomically Defined Paenibacillus polymyxa ND24 for Efficient Cellulase Production Utilizing Sugarcane Bagasse as a Substrate

Cellulolytic bacteria from cattle rumen with ability to hydrolyze cellulose rich biomass were explored. The study selected Paenibacillus polymyxa ND24 from 847 isolates as the most potent strain, which can efficiently produce cellulase by utilizing sugarcane bagasse, rice straw, corn starch, CMC, and avicel as a sole carbon source. On annotation of P. polymyxa ND24 genome, 116 members of glycoside hydrolase (GH) family from CAZy clusters were identified and the presence of 10 potential cellulases was validated using protein folding information. Cellulase production was further demonstrated at lab-scale 5-L bioreactor exhibiting maximum endoglucanase activity up to 0.72 U/mL when cultivated in the medium containing bagasse (2% w/v) after 72 h. The bagasse hydrolysate so produced was further utilized for efficient biogas production. The presence of diverse hydrolytic enzymes and formidable cellulase activity supports the use of P. polymyxa ND24 for cost-effective bioprocessing of cellulosic biomass

Emergence of environmental antibiotic resistance: Mechanism, monitoring and management

The rapid development and spread of antimicrobial resistance in the post-antibiotic era has become a global concern. Recent evidence indicates that, at present, antibiotic resistance is evolving at an alarming rate as a defense mechanism against anthropogenic chemical stresses. Mechanistically, bacterial resistance to antibiotics involves reduced permeability, active efflux, modification of the target site, and/or inactivation of the antibiotic molecule and is encoded by antibiotic resistance genes (ARGs) that are majorly carried by mobile genetic elements (MGEs). Horizontal gene transfer (HGT) facilitates the inter and intra-species dissemination of MGEs and drives the spread of ARGs, which leads to the development of environmental resistome. Clinical and environmental antibiotic resistance has severe consequences on global health and the economy if left unchecked. For routine monitoring of the resistance, traditional culture-based methods, reliable polymerase chain reaction (PCR)-based methods, in addition to recent high throughput and rapid next-generation sequencing (NGS)-based methods, are often used. The present work critically reviews the mechanisms for the evolution of antimicrobial resistance, tools to monitor the emergence of such resistance and the global efforts for management of the growing threat of antimicrobial resistance spearheaded by the World Health Organization (WHO) in collaboration with developed and developing countries alike. The work highlights the policies at global and national levels to monitor and implement stewardship programs, awareness campaigns, prevention practices, and healthcare guidelines to promote and ensure the judicious prescription of antimicrobials for the containment of antimicrobial resistance

Control of Multidrug-Resistant Gene Flow in the Environment Through Bacteriophage Intervention

The spread of multidrug-resistant (MDR) bacteria is an emerging threat to the environment and public wellness. Inappropriate use and indiscriminate release of antibiotics in the environment through un-metabolized form create a scenario for the emergence of virulent pathogens and MDR bugs in the surroundings. Mechanisms underlying the spread of resistance include horizontal and vertical gene transfers causing the transmittance of MDR genes packed in different host, which pass across different food webs. Several controlling agents have been used for combating pathogens; however, the use of lytic bacteriophages proves to be one of the most eco-friendly due to their specificity, killing only target bacteria without damaging the indigenous beneficial flora of the habitat. Phages are part of the natural microflora present in different environmental niches and are remarkably stable in the environment. Diverse range of phage products, such as phage enzymes, phage peptides having antimicrobial properties, and phage cocktails also have been used to eradicate pathogens along with whole phages. Recently, the ability of phages to control pathogens has extended from the different areas of medicine, agriculture, aquaculture, food industry, and into the environment. To avoid the arrival of pre-antibiotic epoch, phage intervention proves to be a potential option to eradicate harmful pathogens generated by the MDR gene flow which are uneasy to cure by conventional treatments

Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance

Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms. Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics. In order to overcome the resistance problem and to safely use antibiotics, the correct measurement of potency and bioactivity of antibiotics is essential. Microbiological assay and high performance liquid chromatography (HPLC) method are used to quantify the potency of antibiotics. HPLC method is commonly used for the quantification of potency of antibiotics, but unable to determine the bioactivity; whereas microbiological assay estimates both potency and bioactivity of antibiotics. Additionally, bioassay is used to estimate the effective dose against antibiotic resistant microbes. Simultaneously, microbiological assay addresses the several parameters such as minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC), mutation prevention concentration (MPC) and critical concentration (Ccr) which are used to describe the potency in a more informative way. Microbiological assay is a simple, sensitive, precise and cost effective method which gives reproducible results similar to HPLC. However, the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results

Development and validation of microbial bioassay for quantification of Levofloxacin in pharmaceutical preparations

The aim of this study was to develop and validate a simple, sensitive, precise and cost-effective one-level agar diffusion (5+1) bioassay for estimation of potency and bioactivity of Levofloxacin in pharmaceutical preparation which has not yet been reported in any pharmacopoeia. Among 16 microbial strains, Bacillus pumilus ATCC-14884 was selected as the most significant strain against Levofloxacin. Bioassay was optimized by investigating several factors such as buffer pH, inoculums concentration and reference standard concentration. Identification of Levofloxacin in commercial sample Levoflox tablet was done by FTIR spectroscopy. Mean potency recovery value for Levofloxacin in Levoflox tablet was estimated as 100.90%. A validated bioassay method showed linearity (r2=0.988), precision (Interday RSD=1.05%, between analyst RSD=1.02%) and accuracy (101.23%, RSD=0.72%). Bioassay was correlated with HPLC using same sample and estimated potencies were 100.90% and 99.37%, respectively. Results show that bioassay is a suitable method for estimation of potency and bioactivity of Levofloxacin pharmaceutical preparations. Keywords: Levofloxacin, Antibiotic resistance, Microbiological bioassay, HPLC, Pharmacopoei

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Not AvailableCellulose is the most abundant natural polymer present on Earth in the form of agriculture waste. Hydrolysis of agriculture waste for simple fermentable reducing sugars is the bottleneck in the area of biofuel generation and other value-added products. The present study aims to utilize the camel rumen as a bioreactor for potent cellulolytic and hemicellulolytic bacteria by altering the feed types with varying cellulosic concentrations. A total of 6716 bacterial cultures were subjected to three layers of screening, where plate zymography and chromophoric substrate screening served as primary screening method for cellulolytic and hemicellulolytic potential. The potential isolates were genetically grouped using RAPD, and 51 representative isolates from each group were subjected to molecular identification through 16S rDNA sequencing, followed by quantification of various cellulolytic and hemicellulolytic enzymes. Out of 51 potent isolates, 5 isolates had high endoglucanase activity ranging from 0.3 to 0.48 U/ml. The selected five key isolates identified as Pseudomonas, Paenibacillus, Citrobacter, Bacillus subtilis, and Enterobacter were employed for hydrolyzing the various agriculture residues and resulted in approximately 0.4 mg/ml of reducing sugar. Furthermore, the metaculturomics approach was implemented to deduce the total cultured diversity through 16S rRNA amplicon library sequencing. The metaculturomics data revealed the dominance of proteobacteria and unidentified bacterial population in all four feed types, which indicates the possibility of culturing novel cellulose-deconstructing bacteria. Moreover, the presence of diverse hydrolytic enzymes in cultured isolates supports the usage of these bacteria in bio-processing of agriculture waste residues and obtaining the biofuels and other value-added products.Not Availabl

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An environment friendly and cost-effective approach is a major bottleneck in biofuels production from agriculture waste residue. The present study unravels the enzymatic hydrolytic potential of a designed bacterial consortium (SNH-1) comprised of camel rumen derived B. safensis CRN 13, B. subtilis CRN 16, C. braakii CRN 21, B. circulans CRN 24, and P. dendritiformis CRN18. The consortium SNH-1 was evaluated for exo-glucanase (0.29 U/ml), β-glucosidase (0.69U/ml), β-glucuronidase (0.29U/ml), endoxylanase (0.79U/ml), arabinosidase (0.62U/ml), α-galactosidase (0.36 U/ml), and endoglucanase (0.51U/ml) activity. Genome analysis of consortium members identified 660 carbohydrate-active enzymes (CAZyme) responsible for breaking the structural intricacy. These include 296 glycoside hydrolase, 19 auxiliary activity, 186 glycosyl transferases, and 37 carbohydrate-binding modules genes. The designed consortium hydrolyzed sugarcane bagasse, wheat straw, and rice straw effectively. Response surface methodology (RSM) was applied to optimize the pH, temperature, and substrate concentration, which has resulted in a 23% higher saccharification of wheat straw. Further, 6.2% bioethanol production was estimated from wheat straw hydrolysate using S. cerevisiae. The wheat straw saccharification by the designed consortium is a cost-effective, chemical-free, cleaner, and promising approach for producing lignocellulosic bioethanol.Not Availabl

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Not AvailableBackground Camels are known for their survival under harsh and nutrient deficient climates. Camel rumen ecosystem presents a unique opportunity to study the ruminal microbes helping the camel in this task. The genus Aspergillus is extensively studied filamentous fungus due to its ability to secret industrially important enzymes. The present study was aimed to isolate and characterize microbes with lignocellulolytic capacity from camel rumen.Not Availabl