Polystyrene is a rigid plastic that is commonly used in crystalline and foamed form. Biodegradation of polystyrene is very slow in natural environment and it persists for longer period of time as solid waste. The aim of the study was to investigate the biodegradation process of polystyrene and explore the ways to enhance the biodegradation process. Soil burial method was used to isolate microorganisms. The plastic films recovered from soil after 8 months were incubated on mineral salts media (MSM) agar plates for 3 months to get the growth of only those microorganisms that were able to grow with polystyrene for longer time. Six fungal and five bacterial stains were isolated and identified. Three fungal isolates were selected on the basis of biodegradability of polystyrene films in shake flask transformation experiments analysed by Fourier transform Infrared (FTIR) spectroscopy. The selected fungal strains were characterized taxonomically on the basis of sequence homology of conserved regions of 18S rRNA and were identified as Rhizopus oryzae NA1, Aspergillus terreus NA2 and Phanerochaete chrysosporium NA3. The 18S rRNA sequences were deposited in NCBI database with accession numbers in Genbank FJ654430, FJ654431 and FJ654433 for strain NA1, NA2, NA3 respectively. The biodegradation of polystyrene was studied by CO 2 evolution test (Sturm test) all the isolated showed higher CO 2 levels in the test as compared to control showing effective mineralization of polystyrene. Biodegradation studies in liquid media with polystyrene films, expanded polystyrene (EPS) films and beads were conducted in the static and shake flask (120rpm) fermentation experiments at 30 oC. Scanning electron microscopic (SEM) analysis showed that the fungal isolates were able to establish mycelia on the polymer surface and maximum growth was observed in glucose added mineral salts media. FTIR spectra of the treated films showed increase in absorption spectra around 536 cm -1 , 748 cm -1 (mono substituted aromatic compound), 1026 cm -1 , 1450 cm -1 , 1492 cm - 1 (C=C stretching vibration of aromatic compounds), 2916 cm -1 , 3400 cm -1 (aryl-H stretching vibrations). Major changes were observed in 1000-1700 cm -1 and 3400 cm -1 region which indicated depolymerisation and degradation into monomers. xiiMolecular weight distribution was studied by gel permeation chromatography (GPC). The weight average molecular weight and number average molecular weight increased in the samples of polystyrene films and EPS beads treated with the fungal isolates as compared to control while decreased in case of expanded polystyrene. The polydispersity decreased in polystyrene and increased in EPS films. In proton nuclear magnetic resonance ( 1 H-NMR) spectra of polystyrene and expanded polystyrene intensities of the signals were increased in treated samples as compared to control but treated samples did not show any significant change in the spectra. The degradation products of the polystyrene and expanded polystyrene were analysed by HPLC. 1-phenyl-1,2-ethandiol, 2-phenylethanol and phenyacetaldehyde and styrene oxide, which were oxidation degradation products of monomer styrene, were detected in most of the cases. 1-phenyl-1,2-ethandiol was detected with highest concentration of 21.3 ppm in media sample of polystyrene incubated with A. terreus NA2 in shake flask and 34.7 ppm with P. chrysosporium NA3 in static conditions. Polystyrene films were given pretreatment of UV irradiation (1-2 hr. at λ 254 nm) and heat (60 ̊C and 80 ̊C for 1 hour) and then biodegradation was studied. UV pretreatment of 2 hours showed enhancing effect on biodegradation by fungal isolates indicated a decrease of weight average molecular weight in the treated samples. Heat pretreatments did not show enhancing effect on biodegradation except P. chrysosporium NA3 treatment of heat pretreated polystyrene films. Enhancing effect of glucose on biodegradation of polystyrene films was observed in FTIR spectral analysis, when glucose was used as additional carbon source in mineral salts media, The soil buried films of polystyrene for six months showed very significant degradation in FTIR and GPC analysis. The scanning electron micrographs of the treated films from all the samples also confirmed the biodegradation process by showing some changes in structure and colonization of fungi on the films. The selected fungal strains are capable of utilising polystyrene as a sole carbon source and have potential to be used for polystyrene biodegradation in the environment.
پروفیسر نجیب اشرف ندوی افسوس ہے کہ پچھلے دنوں ممبئی میں پروفیسر نجیب اشرف ندوی کا اور کراچی میں مفتی انتظام اﷲ صاحب شہابی اکبرآبادی کاانتقال ہوگیا۔پروفیسر اشرف کا اُٹھان بڑاشاندار تھااُنھوں نے معارف میں جو مقالات لکھے تھے اور رقعات عالمگیری کی تحقیق وترتیب اوراُس پرمستقل ایک جلد میں مقدمہ لکھ کر انھوں نے جس قابلیت کا ثبوت دیاتھا اُس کی وجہ سے ان سے بڑی توقعات تھیں۔لیکن احمدآباد اور پھر ممبئی کی آب وہوانے ان کو بجھا سادیا تھا پھر بھی انجمن اسلام اردو ریسرچ انسٹی ٹیوٹ ممبئی کے ڈائرکٹر اورانجمن کے سہ ماہی رسالہ ’’نوائے ادب‘‘ کے ایڈیٹر کی حیثیت سے ان کی علمی وادبی سرگرمیاں کسی نہ کسی صورت میں جاری رہیں۔ چنانچہ اس زمانہ میں ہی انھوں نے ’’لغت گجری‘‘ ترتیب دی تھی ۔ بہرحال اُن کے دم سے اردو زبان سے متعلق تحقیق وریسرچ کا ممبئی میں چرچا تھااور اس بناپر اُن کی وفات علم وادب کی دنیا کاایک بڑاسانحہ ہے۔ [اکتوبر۱۹۶۸ء]
According to the Prophetic injunction, the fasting in the month of Ramadan, end of the fasting in that month, and determination of Eid al-Adha date should be based on moon sighting by at least two authentic persons. But due to advanced lunar movement calculations majority of Muslim nations prefer the lunar calendar in determining dates of Ramadan and the two Islamic festivals, 6d al-Filr and Eid al-Adha. This article attempts to prove that a pre-calculated lunar calendar cannot be the basis of determining the dates of the fasting month and Islamic festive days; and the only Islamic way to begin fasting month and celebrate festive days is moonsighting.
Generally the information on the phytoplankton community occurring in the mangrove swamps at Sandspit backwaters (Pakistan) with considerable anthropogenic activities and influx of pollutants is lacking. The dearth of information has compelled to undertake the present study to assess the community structure of phytoplankton and its variability with respect to season and environmental conditions in Sandspit mangrove swamps. In addition, it was also aimed at the measurement of diatom growth in these polluted waters. The present study thus constitutes the first conclusive report on the ecology and chemistry of semiarid mangrove habitat of Sandspit back water at Karachi, Pakistan borders the northern Arabian Sea. In this research the distribution and diversity of marine phytoplankton are investigated. The results are presented as research chapters. The general introduction (Chapter 1) informs on the mangrove ecosystem and its importance on the coastal productivity. The research conducted in Pakistan in the planktonic community in the coastal waters is also summarized. The research summarizes that mangrove areas in the back waters of Karachi have particularly been ignored and a need to study phytoplankton and their behavior in the polluted mangrove environment is emphasized. The phytoplankton community occurring at the study site was assessed qualitatively and quantitatively (Chapter 2). Species of diatoms appeared to be more diverse and dominant as oppose to dinoflagellates which exhibited very low species diversity. Phytoplankton cell density varied seasonally and their abundance ranged from 0.25 x106-7.044x106 and 0.042x106-5.172x106 cells L‾1 during high and low tide, respectively. Pennate diatoms were highly diversified (23 taxa) as compare to centric diatoms (3 taxa). The low diversity and abundance of phytoplanktons is considered as the result of organic and inorganic pollution fluxed in through Layari River into the area. Chapter 3 presents diatom community composition and environmental variables affecting them in the mangrove ecosystem during summer and winter season, 2015. Centric diatoms were dominated by Cyclotella cf. menenghiana, whereas Cyilndrotheca closterium was the xvi most abundant species in pennate group (Chapter 2). The unfavorable conditions prevailing in the region appear to control low diversity and abundance of diatom species. As there exists no information with reference to their correlation with planktonic community, the present study was therefore carried out to assess the status of commonly polluting metals and pesticides in the sediment and water (Chapter 4) with an aim to present the current status of major components of effluent being fluxed in Sandspit backwaters through Layari and ascertain its influence on the distribution, abundance and diversity of phytoplankton. In this study seven metals (Cr, Cu, Fe, Hg, Mn, Pb, and Zn) were determined at high and low tidal conditions in water and sediments. Overall it was found that Fe and Mn had high concentrations and that Cu, Cr, Zn, Pband Hg maintained low concentrations. Generally, metal concentrations in in the area were found in the following order: Fe>Mn>Cu>Cr>Zn>Pb>Hg. The pollution/comtamination levels in the backwaters due to the Layri River input were assessed using different ecological tools, such as, Contimination factor (Cf), Ecological risk factor (Er) and Pollution load index (PLI). In water at both tidal conditions contamination factor (Cf) values of Cu and Pb were dominated over Cr and Zn and categorized as very high contamination. A comparison between stations for Cf showed preponderance of Cu at St 1 and Pb at St 2. The Cf values of all other metals indicate low contamination level at all stations. This is also evident from the data of PLI values which clearly show that the mangrove habitat in the study area is not as polluted as has been observed in the previous study from same habitat, except for St 1 where PLI was > 1 indicating polluted environment. The very high Rri mainly due to the Cu contamination in water at both high and low tides was noticed. However, no ecological risk in sediment was noted. The results thus endorse that this water body as significantly contaminated and therefore, accumulation of these metals may influence the aquatic life such as seen in case of phytoplankton abundance and diversity recorded in this study. The levels of organochlorine pesticides (OCPs) remained below detection limits though the area is generalviewed asheavilypolluted. Therefore it appears that bioaccumulation and transference of these chemicals from lower to higher trophic levels is not an issue in the area and that the low productivity may be influenced by metals and/or other environmental parameters. In Chapter V in-situ incubation experiments were conducted to assess the growth rate of the diatom community during winter at Sandspit backwater generally considered as polluted. Only a few pollution-resistant diatom species appear to grow in this habitat. A total of nine species were observed in the unfractionated (control) and fractionated samples. Growth rate of seven species were recorded ranging from -1.79 - 1.43 d-1 and 1.61 - 3.21 d-1 in unfractionated and fractionated samples, respectively. Average positive growth of diatom species, on the basis of cell abundance, was 0.8 d-1 in unfractionated (control) and 1.21 d-1 in fractionated samples.Positive growth was recorded for Coscinodiscus sp. (1.43 d-1), Navicula transitans var. derasa (1.39 d-1), C. cf. meneghiniana (0.37 d-1) and Cheaetoceros closterium (0.02 d-1) in unfractionated (control) samples, and Chaetoceros compressus (2.93 d-1), Cyclotella cf. meneghiniana (0.82 d-1), Coscinodiscus sp. (0.54 d-1), and Cylindrotheca closterium (0.53 d-1) in fractionated samples. Negative growth may be attributed to high grazing pressure or slow growth which fails to compete with grazing. The diatom diversity is low and the growth of many species is compromised in this polluted environment but the resistant species grow with the rates comparable to other species reported from cleaner waters.