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The current study focused on the exploration of bacterial community in heavy metal contaminated soil using culture dependent and independent approaches that might be applied to the bioremediation process. A total of 150 bacterial colonies were examined from the heavy metal-contaminated soil at initial level, and 25 isolates were chosen for further examination. Finally, twelve strains were chosen for future research based on their high levels of heavy metal resistance. The 10 bacterial strains i.e.,1K-10K were then characterized on the basis of their morphology and microscopic analysis. The morphological and biochemical characteristic relied on the basis of Bergey's manual of bacterial classification that 1K as Pseudomonas sp., 2K as Enterobacter sp., 3K as Streptococcus sp., 4K as Staphylococcus sp.,5K as Staphylococcus sp., 6K as Pseudomonas sp., 7K as Micrococcus sp., 8K as Staphylococcus sp., 9K as Staphylococcus sp. & 10K as Staphylococcus sp. In metagenomics analysis, the most prevalent bacteria present in samples were "Actinobacteria, Proteobacteria, Acidobacteria, Pseudomonas Cyanobacteria, Bacteriodes, and Sphingomonas. Among the 29 identified phyla, Chloroflexi and Tenericutes were the most dominant phyla and their relative abundance ranged from 0.75-1.00. While, on the genera level, the most abundant genera were Blautia, Rhodoplanes followed by Prevotella and Arenimonas. The relative abundance of these genera ranged from 0.75% to 1.00%. Depending on the relative abundance of taxons, the results of this study showed Proteobacteria, Synergistetes and Bacteriodes were most abundant phylum while the least abundant phylum present in heavy metal contaminated soil was Chlamydia and Tenericutes. Screening of soil-based libraries using functional and sequence-based specifications, which has disclosed information on soil microbial communities, has made it possible to identify new microbial communities. Thus, the culture dependent and independent approaches revealed that even heavy metal contaminated soil compose of diverse group of bacterial community that could be explored for bioremediation purposes. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CPX), is a broad-spectrum fluoroquinolone antibiotic widely used to treat bacterial infections in humans and animals. In recent years, ecological problems caused by the disposal of CPX-waste product have attracted increasing attention. This study aimed to evaluate the ability of different bacteria to remove CPX from water. The ability of five bacterial strains namely; Acenitobacter sp., Acenitobacter lwofii, Bacillus. pumilus, Burkholderia phytofirmans, and Mesorihizobium sp. were examined in this study. Tests were performed on Luria Bertani (LB) as well as on Mueller-Hinton (MH) agar at different CPX concentrations (20-100 mg L-1). All five tested bacterial strains showed growth on LB as well as on MH agar plates at all concentrations between 20 to 100 mg L-1 CPX. Three bacterial species: Acenitobacter lwofii, Bacillus pumilus, and Mesorihizobium sp. were reported more resistant to CPX of the five strains tested. In a shake flask study, the strain B. pumilus initially showed higher degradation rate (75.53%) followed by Acenitobacter lwofii (72.3%), Mesorihizobium sp. (70.32), Burkholderia phytofirmans (67.10%), and Acenitobacter sp. (63.2%) at low CPX concentration (5 mg L-1) in minimal saline media. However, Mesorihizobium sp. showed higher degradation efficiency (76.32%) at a higher CPX concentration (10 mg L-1). A group of three bacterial strains, A. lowfi, B. pumilus, and Mesorihizobium sp. showed good CPX degradation rate (95.4%), and achieved higher degradation efficiency than the single strains at 20 mg L-1 CPX concentration. Overall, the results suggest that using a combination of bacteria may be a useful tool for the remediation of antibiotic pollution. In addition, this study reveals the ability of previously isolated bacteria to biodegrade CPX as a sole source of carbon, providing new insights into the biodegradation of CPX. [ABSTRACT FROM AUTHOR]

This study emphasized the alpha-amylase gene from Bacillus licheniformis as this species has been witnessed as the most prolific bio-factories for the alpha amylase production on industrial scales with particular reference to its wide commercial applicability. In the present study, a gene encoding alpha-amylase from an indigenously isolated B. licheniformis 208 strain was PCR amplified and sequenced. The obtained 1313 bp long nucleotide sequence (GenBank KM27230) exhibited the closest match with its homologous genes in B. licheniformis ATCC 9945A and ATCC 14580 strains. Gene translation retrieved 437 amino acid long enzyme sequence and exhibits a molecular weight of 50231.8 KDa. Other computed parameters include isoelectric point (5.95), aliphatic index (67.4), instability index (27.45), and GRAVY (-0.627) values. The structure of alphaamylase 208 was found to exhibit a 17 residues long active site, a conserved catalytic site with 3 residues, and a ligand-binding site comprised of 3 residues. Secondary structure configuration in the alpha-amylase 208 was predominated with a-helix and random coils followed by extended strands. The number of ß-turns was found comparatively less. ITASSER assigned E.C number to the BLA 208 sequence was 3.2.1.1 with extracellular origin. Deduced tertiary structure of BLA 208 showed the 7 residues long active site comprising of histidine, arginine, aspartic acid, glutamic acid, tryptophan, histidine, and aspartic acid at position 122, 246, 248, 278, 280, 344, 345 respectively. Na, K, and Ca were observed as the ligand-binding sites existing as a metal triad. Natural selection analysis explains that the alpha-amylase gene in B. licheniformis species is under purifying or negative selection i.e. it stabilizes itself by removing the deleterious mutation. Recombination event analysis was done using GARD (Genetic algorithm for recombination detection). Although, it rather inferred the presence of two break points which were found insignificant when validated via Kishino-Hasegawa test which demonstrates topological incongruence. [ABSTRACT FROM AUTHOR]

Amylase enzyme is used in various industries due to its diverse applications. In this study, bacteria from soil sample were primarily screened on starch agar medium to identify amylase producer through the detection of prominent clear zone. Total of five soil samples namely bakery points (A-1), sugar cane juice point (A-2), Lichi chinesis garden soil (A-3), rice field (A-4) and sugar industrial waste (A-5) were used in this study. Among the 17 strains isolated from three samples A-1, A-2 and A-3 were found positive for amylase production. The strains were further screened on the production medium. The N-1 bacterial strain revealed higher enzyme activity (92.21 ± 17 IU/ml) compared to the other strain and was thus selected for further work. The strain was identified as Bacillus lichenoformis from the 16S rRNA analysis. Enzyme production was enhanced by optimizing various parameters by one factor at a time technique. The agro industrial waste rice polish was used as substrate. The optimum temperature of the enzyme was 35°C, pH 5.5 and 2% (w/v) of substrate concentration. Qualitative detection by using sodium dodecyl polyacrylamide gel electrophoresis showed that molecular weight of enzyme was 35 kDa. This indicated that the enzyme requires a moderately high temperature and neutral pH to show greatest activity. [ABSTRACT FROM AUTHOR]

The pollution caused by heavy metals is a major problem for our environment, as the high levels of exposure to these metals have harmful consequences for wildlife, vegetation, and human health. Even in trace amounts, several heavy metals, including lead, mercury, cadmium, zinc, arsenic, and nickel, not only possess carcinogenic properties but also have the capacity to cause genetic mutations. In this study, a total of 150 bacteria were isolated, out of which 25 were selected for secondary screening. After secondary screening, five strains were further processed based on their maximum tolerance level. The required indigenous metallotolerant bacterial strains were isolated and identified based on phenotypical and genotypical characterization. The phenotypical characteristics and topology of the phylogram confirm that the bacterial isolate 1LB is Kingella sp., 2LB is Listeria sp., 3LB is Bacillus sp., 4LB is Pseudomonas putida, and 5LB is Cupriavidus necator. According to the result while using LB medium, all the bacterial isolates showed the highest tolerance level against different heavy metal concentrations, i.e., 1LB and 4LB bacterial isolates showed the highest tolerance rate against copper (Cu), while 2LB and 5LB bacterial isolates showed maximum tolerance against chromium (Cr), and 3LB bacterial isolates showed the highest tolerance rate against lead (Pb). Thus, the LB medium was used for the optimization of bioremediation purposes. For bioremediation of heavy metal-contaminated soil, the maximum removal efficiency was 83.80% of the 4LB bacterial strain for Pb, 90.49% of the 5LB bacterial strain for Cu, and 81.87% of the 1LB and 2LB bacterial strains for Cr in the YPG medium. Thus, the results indicate that indigenous heavy metal-tolerant bacterial strains of the area could be used for biological remediation of heavy-metal-contaminated soil, which is the most effective, economical, and environmentally friendly approach as an alternative to traditional methods. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aimed to determine the bacteriological profile of childhood acute bacterial meningitis in Pakistan. PATIENTS AND METHODS: The study included a total of 100 children aged between 1 month and 5 years, who were admitted with a diagnosis of meningitis based on clinical findings and positive cerebrospinal fluid (CSF) tests. Out of the 100 CSF samples collected, 21 isolates were confirmed to contain Enterobacteriaceae. The most prevalent Enterobacteriaceae species were Pseudomonas (n=8, 38.09%), Klebsiella (n=4, 19.04%), E. coli (n=4, 19.04%), and Acinetobacter (n=4, 19.04%), while Citrobacter (n=1, 4.76%) was less common. Antibiotic susceptibility patterns were analyzed for these isolates. RESULTS: Pseudomonas (n=8) exhibited 25% resistance to cefepime and 38% resistance to imipenem. Klebsiella (n=4) s howed 7 5% r esistance to imipenem. Acinetobacter (n=4) demonstrated 50% resistance to imipenem, along with varying resistance to cefepime, amikacin, ciprofloxacin, and gentamicin. E. coli (n=4) showed 0% resistance to imipenem and amikacin. However, Citrobacter (n=1) showed 0% resistance to ciprofloxacin, aztreonam, gentamicin, amikacin, levofloxacin, and cefepime. Acute bacterial meningitis primarily affects children under 1 year of age. CONCLUSIONS: CSF culture revealed that Gram-negative bacteria, specifically Pseudomonas spp., were the predominant pathogens in this family based on Pakistani data. [ABSTRACT FROM AUTHOR]