Wasim Sajjad

Biodegradation of polyethylene by bacterial strains isolated from Kashmir Cave, Buner, Pakistan

Low density polyethylene (LDPE) is used for making common shopping bags and plastic sheets and is a significant source of environmental pollution. The present study was aimed at testing the ability of bacterial strains identified as Serratia sp. KC1-MRL, Bacillus licheniformis KC2-MRL, Bacillus sp. KC3-MRL and Stenotrophomonas sp. KC4MRL isolated from a limestone cave to degrade polyethylene. These strains were isolated from soil of Kashmir Smast, a limestone cave in Buner, Pakistan. These strains showed antibacterial activity against Micrococcus luteus, Klebsiella sp., Pseudomonas sp., and Staphylococcus aureus. The pieces of LDPE plastic were incubated along with bacterial strains for a period of one month and then analyzed. Degradation was observed in terms of growth of microorganisms used in consortia, chemical changes in the composition of LDPE by fourier-transform infrared spectroscopy, and changes in physical structure of LDPE by scanning electron microscopy. Maximum growth (107310 CFU mL ) at 28 8C and subsequent change in chemical and physical properties of plastic were observed in the presence of calcium and glucose. The cave soil sample had a very high concentration of calcium. The microscopy showed adherence of bacteria with lots of mechanical damage and erosion on the surface of plastic films incubated with bacterial consortia. The spectroscopy showed breakdown and formation of many compounds, as evident by the appearance and disappearance of peaks in LDPE treated with bacterial consortia as compared to the untreated control. We conclude that antibiotic-producing cave bacteria were able to bring about physical and chemical changes in LDPE pieces and degradation of LDPE was enhanced in media augmented with calcium.

Investigation of Sewage and Drinking Water in Major Healthcare Centres for Bacterial and Viral Pathogens

Water is a major source of microbes, including pathogens that can cause critical pathological conditions and outbreak of epidemics. Due to lack of proper medical waste-management system in Peshawar, most of the waste is disposed of near sewage lines which run parallel to drinking water supply increasing the chances of water contamination. This study was undertaken to examine bacterial and viral pathogens in fresh and waste water in major Health care units. Conventional culturing techniques were used to identify bacterial pathogens followed by biochemical analysis, whereas viral pathogens were detected by Polymerase Chain Reaction (PCR). Analysis of sewage and drinking water supply in major health care facilities of Peshawar city indicated that Klebsiella pneumoniae and Staphylococcus aureus were found in all water samples whereas serious health risk causing bacteria including Mycobactirium tuberculosis were also detected in some regions. Two viral pathogens, Hepatitis C virus (HCV) and Hepatitis B virus (HBV) were found in open sewage water of Khyber Teaching Hospital and Dabgari Garden (G). The presence of these pathogens in water is a serious threat to public health and the environment and calls for immediate action to enforce proper medical waste-management to eliminate the risks to human health.

Radio-protective and antioxidative activities of astaxanthin from newly isolated radio-resistant bacterium Deinococcus sp. strain WMA-LM9

A radio-resistant bacterium, designated as strain WMA-LM9, was isolated from desert soil. 16S rRNA gene sequencing indicated that the bacterium belongs to genus Deinococcus with maximum similarity to Deinococcus radiopugnans. Deinococcus sp. strain WMA-LM9 was found to be resistant to a ultraviolet (UV) dose of 5 × 103 J/m2, hydrogen peroxide (50 mM) and mitomycin C (10 μg/ml). A carotenoid pigment was extracted using chloroform/methanol/acetone (7:5:3) and purified by high-performance liquid chromatography on a C18 analytical column. The compound was characterised as mono-esterified astaxanthin by 1H, 13C nuclear magnetic resonance and mass spectrometry. It was tested for antioxidant activity, total flavonoids and phenolic content, radioprotective potential in correlation to the prevention of protein oxidation and DNA strand breaks in vitro. The carotenoid pigment showed a very potent antioxidant activity and significantly stronger scavenging ability against superoxides, with an IC50 (concentration causing 50% inhibition of the desired activity) of 41.6 μg/ml. The total phenolic and flavonoid contents were 12.1 and 7.4 μg in terms of gallic acid and quercetin equivalents per milligram of dried mass, respectively. astaxanthin also showed a higher inhibitory action against oxidative damage to collagen, elastin and bovine serum albumin than did β-carotene. The carotenoid also inhibited breaks to DNA strands, as indicated by the results of the DNA damage prevention assay. We conclude that astaxanthin from Deinococcus sp. strain WMA-LM9 has protective effects against radiation-mediated cell damage, and it also protects cellular protein and DNA against oxidative stress and other anti-oxidant activities.

Antiproliferative, antioxidant and binding mechanism analysis of prodigiosin from newly isolated radio-resistant Streptomyces sp. strain WMA-LM31

Streptomyces genus are filamentous Gram positive bacteria, of great intrest, producing biologically active compounds. Recent market and consumer curiosity in natural products have forced scientist and industry for the development of new products with therapeutic potential. This study focuses on evaluation of antioxidant and anticancerous properties of prodigiosin from radio-resistant Streptomyces sp. strain WMA-LM31. A molecular docking approach was adopted to understand theoretical binding mechanism and affinity for anticancer targets. A radio-resistant bacterium, labelled as strain WMA-LM31, was isolated from desert soil and screened for its radio-resistant potential and prodigiosin production. 16S rRNA gene sequencing showed that the bacterium clusters to genus Streptomyces and found resistant to ultraviolet radiation (dosage of 2u2009×u2009103xa0J/m2). Strain WMA-LM31 produced a red color pigment in tryptone glucose yeast (TGY) medium.The LC–MS analysis of the purified compound showed a molar mass of 324 [m/z]+ matched the chemical formula C20H25N3O, identified as prodigiosin. The compound showed strong antioxidant (62.51%) activities along with significant inhibitory action against oxidative damages to bovine serum albumin (BSA) and mice liver lipids in comparison to standard ascorbic acid. IC50 values of HepG2 and HeLa cell lines was found at 12.66 and 14.83xa0µg/mL of prodigiosin concentration, respectively. Furthermore, molecular docking was performed with two different cancers macromolecular targets: [2O2F (Bcl-2) and 1DI8 (CDK-2)], and BSA (PDB id: 3V03). The results indicated that the binding affinity of prodigiosin to its target molecules is due to the presence of terminal pyrrole rings. It is concluded from the results that prodigiosin from Streptomyces sp. strain WMA-LM31 has strong antioxidant, anticancer and apoptotic properties. The knowledge of binding mechanisms and interactions of prodigiosin could provide future directions in designing potent target specifc drugs.

Ectoine: a compatible solute in radio-halophilic Stenotrophomonas sp. WMA-LM19 strain to prevent ultraviolet-induced protein damage

Thiss study was conducted to investigate the possible role of a compatible solute from radio‐halophilic bacterium against desiccation and ultra‐violet radiation‐induced oxidative stress.

Health risks associated with genetic alterations in internal clock system by external factors

The circadian system maintains the main aspects of physiological and behavioral processes. Both circadian rhythm and sleep impact an organisms health through interaction with environmental factors. Variations in external factors influence the functionality of clock genes and disrupt 24-hour rhythmic cycle. The disrupted circadian rhythm and disregulated sleep affect an organisms health, thereby causing several disorders including cancer, depression and cardiac disorders. Considering the role of clock genes and environmental factors, extensive investigation is required focusing on pathways involved in development of life-threatening disorders. This review identifies the major risks and associated factors related with disruption in circadian system and sleep.