Industrial revolution has played a positive role in the economic growth and development but environment is affected negatively. This has led to the contamination of environment with toxic chemicals. Biodegradation of these harmful pollutants using microbes is strongly recommended as this is more efficient than other costly physicochemical processes. Current study was aimed to isolate indigenous bacteria capable of biodegrading toxic chemicals. For this purpose effluent samples were collected from Hattar Industrial Estate, Haripur, Pakistan and characterized. Initially, forty eight distinct bacterial isolates were obtained by plating on mixed metal nutrient agar medium supplemented with 200μg/ml each of chromium, lead, nickel salts. Further screening on solid agar medium both in rich and minimal medium (M9 and BH) supplemented with 12 different metal salts (Cr, Cu, Cd, As, Ag, Hg, Zn, Fe, Mn, Ni and Co) was done. Representatives of different classes of aromatic compounds including polyaromatic hydrocarbons phenanthrene (500-6000 μg/ml), biphenyl and naphthalene (1000-4000 μg/ml); petroleum hydrocarbons (1-3%) benzene, toluene, xylene; aromatic amines (1mM) aniline, chloroaniline; phenolic compounds (50-200μg/ml) phenol, p-nitrophenol, pentachlorophenol and azo dyes (50-100μg/ml) methyl orange, methyl yellow, methyl red, erichrome black T and congo red were used to determine the degradation potential of isolates. Results revealed that these bacteria had multiple heavy metal resistances. They were potentially able to utilize multiple hydrocarbons and azo dyes as carbon/ energy sources after degradation. Based on these tolerance/utilization profiles sixteen morphologically, physiologically and biochemically different isolates were chosen for metal remediation/ organic pollutant utilization/ degradation studies. Quantitative and qualitative investigation of transformation ability of these sixteen isolates for phenanthrene (1000mg/l), aniline (1mM), p-nitrophenol (50mg/l), pentachlorophenol (100mg/l) and azo dyes (50mg/l) congo red, methyl red was achieved by high performance liquid chromatography (HPLC), UV-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR). Five potent strains were identified as Stenotrophomonas sp. MB339 (Acc No. KP723528), Staphylococcus sp. MB371 (Acc No. KP723530), Bacillus sp. MB366 (Acc No. KP723529), Klebsiella pneumoniae MB361 (Acc No. KP723532), Klebsiella pneumoniae MB373 (Acc No. KP723531) by 16S rRNA gene sequencing. Among metal remediating strains, Staphylococcus MB371, Stenotrophomonas MB339, Klebsiella pneumoniae MB361 showed maximum accumulation of Pb, Cr and Ni (i.e. 75.33, 34.07, 54.98%), respectively at 37°C. In addition, these strains efficiently reduced more than 70% of 200mg/l Cr (VI) to Cr (III) and >90% of phenanthrene, p-nitrophenol, pentachlorophenol at different pHs (5-9) and temperature (25-45°C). In case of aniline up to 91% degradation was achieved by Bacillus MB366, Stenotrophomonas MB339, Klebsiella pneumoniae MB373 at pH 7, 37°C. While, Staphylococcus sp. MB371, Klebsiella pneumoniae MB361 were unable to use aniline at pHs 5, 6. Decolorization of methyl red (>75%) was achieved by all five strains within pH range 5-9 and 30-37°C. However, less or even no decolorization was observed at 45°C especially by Stenotrophomonas MB339. Complete genome sequence analysis of these five strains was done using Ilumina Miseq and annotated with IMG ER pipeline. Genomic features of strains were different from one another in many attributes like size, total number of genes, protein coding genes, rRNA genes and G+C content. Functional annotations depicted that these strains were highly diverse in their metabolism. Heavy metal resistance genes organized in operons for arsenic, copper, mercury were identified in Stenotrophomonas MB339, for arsenic in Staphylococcus MB371 and Bacillus MB366. While genes for metal (Cr, As) reductase, efflux pump and other membrane proteins (Co, Cd, Fe, Zn, Mn) were annotated in genomes of Klebsiella quasipneumoniae subsp. similipneumoniae MB373, Stenotrophomonas MB339, Staphylococcus MB371 and Bacillus MB366. Genome annotations indicated that these genomes have variety of metabolic pathways for xenobiotics degradation. Aromatic ring hydroxylating dioxygenase genes responsible for degradation of PNP, PCP, phenanthrene. While genes for FMN-dependent, NADH-azo reductase might be supportive for methyl red decolorization. For nitroaromatic compounds, nitroreductase genes were found in Klebsiella pneumoniae MB361, Stenotrophomonas MB339 and Bacillus MB366. Indigenous bacteria isolated from industrial effluents play a significant role to detoxify metals and transform variety of chemicals present in contaminated environment. Present study revealed the molecular mechanisms behind adaptability of these biotopes to changing environmental conditions. This detailed research comprising of analytical and molecular approaches, highlight the biodegradation potential of strains which paves way for future bioprospecting of the potential enzymes vital for biodegradation perspective.
Background: Coronavirus disease 2019 (Covid-19), declared as a pandemic in March 2020, is an acute respiratory tract illness caused by coronavirus 2 (SARS-CoV2) with clinical manifestations ranging from mild upper respiratory tract symptoms to severe pneumonia. Objectives: To determine the disease spectrum of Covid-19 in a cohort with a travel history from Iran. Materials & Methods: This cross-sectional study with a retrospective collection of data was conducted at Agha Khan University, Karachi from 15th March to 19th April 2020. One hundred and fifty-five laboratory-confirmed cases of Covid-19 were recruited from a government quarantine facility. Data were obtained from the Punjab Emergency Services (Rescue 1122) database where a record of SARS-CoV-2 positive cases and quarantined persons is maintained. Study subjects with a travel history to Iran were contacted by telephone to obtain information about demographics, symptoms, and co-morbid conditions. SPSS version 24 was used to analyze the data. Frequencies and percentages were calculated. Results: Among the returning travelers, 213 had laboratory-confirmed Covid-19, out of which 155 were included in this study. 56.1% were males with a mean age of 40 years. Among the study participants, 91.6% remained asymptomatic throughout the stay, while 8.4 % became symptomatic. 77.5% of the participants had received BCG vaccination in childhood. Among symptomatic cases 15.4% had asthma and 7.7% had hypertension. The most common clinical manifestation was cough which was present in 38.5% of the study participants. None died among the study participants. Conclusion: A mild presentation of COVID-19 was seen in our study participants with 91.6% among them being asymptomatic, while 8.4% were symptomatic. There was a high positivity rate in males as compared to females.
Human body is very delicate towards harsh environmental variations. High energy UV radiations intentionally or unintentionally interact with our skin and eyes, causing some acute effect such as, photokeratitis, skin aging and also some chronic effects like melanoma skin cancer and DNA damage. Clothing is an important precautionary measure to combat with these damages, but low weight and high porosity of cotton fabric make it unfit for protection against UV rays. Hence, to improve the protection factor of white cotton fabric, computational approach was utilized to search the effective UV absorbers for cotton fabric. The Density Functional Theory (DFT) theory with three functionals was utilized to study the design molecules and results indicated that all the five design molecules (1-5) absorbed inthe UV region of the solar spectrum. These deigned molecules were synthesized via a condensation reaction and their structure confirmation attained through UV/Vis., FTIR and ESI-MS analysis. The theoretically calculated λmax and experimental λmax of all the five UV absorbers were in close agreement. The cottonfabric was treated with designed and synthesized UV absorbers via the exhaust method of dying and its processing conditions optimized by adapting a statistical design “central composite rotatable design” of response surface methodology. The outcomes directed that all the synthesized molecules showed 65-78 % exhaustion and 62-80 % fixation at the acquired optimized conditions. Maximum exhaustion with cotton fabric was presented by 1 and minimum shown by 5. The protection factor of the treated cotton fabric was assessed and results directed that the treated fabric with 1-4 fells in the very good Ultraviolet Protection Factor (UPF) range at 3 % concentration while fabric treated with 5 fells in good range. The UPF increased as follows: 5 <4 < 2<3<1. Whiteness index test results revealed that all the synthesized molecules did not decrease the whiteness of the fabric as much at 3 % concentration, but after exposition to light fastness testing decreased its whiteness little bit as compared to standard. Washing test results indicated that UPF of treated fabric decreased after washing process, with UV absorbers (1-4), it remained in the very good range of UPF after ten washings. While the 5 showed more reduction in UPF value after washing. Degradation studies revealed that synthesized molecules were degradable by safer advance oxidation process technology. Current study opened a new prospect for search of such molecules having more persistent nature after laundry action.