86 research outputs found
Letter from Martin Gardner to Tapan Kumar MukherJee 27 April 88
A letter the author received from Martin Gardner
Engineering bacteria for bioremediation of persistent organochlorine pesticide lindane (γ-hexachlorocyclohexane)
Strategies were designed for bioremediation of the highly persistent toxic pesticide γ-hexachlorocyclohexane (γ-HCH) or lindane from the environment. Lindane caused the loss of stress-protective chaperone GroEL, and inhibited photosynthesis, respiration and nitrogen-fixation in Anabaena, resulting in growth arrest. To alleviate lindane toxicity, the linA2 gene, encoding HCH dehydrochlorinase from Sphingomonas paucimobilis B90, was knocked-in at an innocuous locus in Anabaena genome and over-expressed from an eco-friendly light-inducible PpsbA1 promoter. The recombinant Anabaena degraded >98% of 10 ppm lindane within 6-10 days. A LinA2 overexpressing Escherichia coli strain could degrade 10 ppm of all the isomers of lindane within 1h and displayed a visual degradation zone on a newly designed histochemical plate containing 50mg lindane within 12h. The study demonstrates (a) bioremediation of traces of lindane prevalent in paddy fields, using bioengineered photoautotrophic Anabaena, and, (b) biodegradation of huge stockpiles of lindane, by employing recombinant live/dead E. coli
The Indian nitrogen challenge in a global perspective
Human activities have massively altered the global nitrogen (N) cycle, doubling annual production of reactive N (Nr) compounds from atmospheric dinitrogen (N2). The use of 120 Mt year−1 fertilizer N, with a global terrestrial/atmospheric N fixation of 285 Mt year−1, has provided huge benefits for global food production. However, nitrogen use efficiency (NUE) of the world food system is only ∼15%. The lost Nr creates a cascade of air and water pollution and greenhouse gas emissions, until it is eventually denitrified back to N2.
India clearly illustrates a dual N challenge for food and environment, consuming 17 Mt of N fertilizer annually (14% of the global total), which has increased since 1970 at 6% year−1 approximately. Emissions of nitrogen oxides (NOx) from combustion sources are also increasing rapidly at 6.5% year−1 currently. By comparison, population growth rate is lower (2% year−1), while ammonia (NH3) emission increase is even less (1%), pertaining to smaller changes in livestock numbers. At current rate, Indian NOx emissions will exceed NH3 emissions by 2055. India currently loses Nr worth US75 (38–151) billion year−1.
Only a small fraction of the Indian population consumes animal products, hence per capita Nr use and pollution is much less than in many developed countries. However, rates of meat consumption are increasing. While published projections from the UN Food and Agriculture Organization anticipate a doubling of South Asian fertilizer consumption from 2006 to 2050 (equivalent to 1.9% year−1 increase), these projections lack transparency and require reevaluation. In practice, the future nitrogen cycle for India will depend on scientific advances in agronomy, genetics and environment, and the extent to which government and society grasp the emerging opportunities for optimizing N management
Whether conversion of mangrove forest to rice cropland is environmentally and economically viable?
Escherichia coli, but Not Staphylococcus aureus, Functions as a Chelating Agent That Exhibits Antifungal Activity against the Pathogenic Yeast Candida albicans
Humans are colonized by diverse populations of microbes. Infections by Candida albicans, an opportunistic fungal pathogen, are a result of imbalances in the gut microbial ecosystem and are due to the suppressed immunity of the host. Here, we explored the potential effects of the polymicrobial interactions of C. albicans with Staphylococcus aureus, a Gram-positive bacterium, and Escherichia coli, a Gram-negative bacterium, in dual and triple in vitro culture systems on their respective growth, morphology, and biofilms. We found that S. aureus promoted the fungal growth and hyphal transition of C. albicans through cell-to-cell contacts; contrarily, both the cell and cell-free culture filtrate of E. coli inhibited fungal growth. A yet to be identified secretory metabolite of E. coli functionally mimicked EDTA and EGTA to exhibit antifungal activity. These findings suggested that E. coli, but not S. aureus, functions as a chelating agent and that E. coli plays a dominant role in regulating excessive growth and, potentially, the commensalism of C. albicans. Using animal models of systemic candidiasis, we found that the E. coli cell-free filtrate suppressed the virulence of C. albicans. In general, this study unraveled a significant antimicrobial activity and a potential role in the nutritional immunity of E. coli, and further determining the underlying processes behind the E. coli–C. albicans interaction could provide critical information in understanding the pathogenicity of C. albicans
Enhanced biodegradation of γ‐hexachlorocyclohexane (γ‐HCH) in HCH (commercial) acclimatized flooded soil: Factors affecting its development and persistence
Collected Papers (on Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics), Volume XI
This eleventh volume of Collected Papers includes 90 papers comprising 988 pages on Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics, written between 2001-2022 by the author alone or in collaboration with the following 84 co-authors (alphabetically ordered) from 19 countries: Abhijit Saha, Abu Sufian, Jack Allen, Shahbaz Ali, Ali Safaa Sadiq, Aliya Fahmi, Atiqa Fakhar, Atiqa Firdous, Sukanto Bhattacharya, Robert N. Boyd, Victor Chang, Victor Christianto, V. Christy, Dao The Son, Debjit Dutta, Azeddine Elhassouny, Fazal Ghani, Fazli Amin, Anirudha Ghosha, Nasruddin Hassan, Hoang Viet Long, Jhulaneswar Baidya, Jin Kim, Jun Ye, Darjan Karabašević, Vasilios N. Katsikis, Ieva Meidutė-Kavaliauskienė, F. Kaymarm, Nour Eldeen M. Khalifa, Madad Khan, Qaisar Khan, M. Khoshnevisan, Kifayat Ullah,, Volodymyr Krasnoholovets, Mukesh Kumar, Le Hoang Son, Luong Thi Hong Lan, Tahir Mahmood, Mahmoud Ismail, Mohamed Abdel-Basset, Siti Nurul Fitriah Mohamad, Mohamed Loey, Mai Mohamed, K. Mohana, Kalyan Mondal, Muhammad Gulfam, Muhammad Khalid Mahmood, Muhammad Jamil, Muhammad Yaqub Khan, Muhammad Riaz, Nguyen Dinh Hoa, Cu Nguyen Giap, Nguyen Tho Thong, Peide Liu, Pham Huy Thong, Gabrijela Popović, Surapati Pramanik, Dmitri Rabounski, Roslan Hasni, Rumi Roy, Tapan Kumar Roy, Said Broumi, Saleem Abdullah, Muzafer Saračević, Ganeshsree Selvachandran, Shariful Alam, Shyamal Dalapati, Housila P. Singh, R. Singh, Rajesh Singh, Predrag S. Stanimirović, Kasan Susilo, Dragiša Stanujkić, Alexandra Şandru, Ovidiu Ilie Şandru, Zenonas Turskis, Yunita Umniyati, Alptekin Ulutaș, Maikel Yelandi Leyva Vázquez, Binyamin Yusoff, Edmundas Kazimieras Zavadskas, Zhao Loon Wang.
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