China
Africa
Explore chapters and articles related to this topic
Extremophiles for Sustainable Bio-energy Production
Published in Pratibha Dheeran, Sachin Kumar, Extremophiles, 2022
Amit Verma, Tirath Raj, Shulbhi Verma, Varun Kumar, Ruchi Agrawal
Microorganisms which are grown and thrive at temperature range of 50°C to 120°C are known as thermophiles. On the basis of temperature range, these microorganisms are further divided into thermophiles (50-85°C) and hyperthermophiles (85-120°C) (Bala and Singh 2018). Thermophiles mainly belong to prokaryotes, like spore forming anerobic Clostridium and aerobic and anerobic Bacilli, photosynthetic bacteria, blue green algae (micro algae), sulphur reducing and oxidizing bacteria, and methane producing and oxidizing bacteria. Besides, some eukaryotic microorganism such as filamentous fungi and algae are also thermophilic in nature. The main microbial members of hyperthermophiles group belong to archaea and bacteria (Zeldes et al. 2015). These microorganisms mainly have been isolated from manure, compost, piles of agricultural and forestry plant biomass, sands of beach, hot springs, desert soils, coal mine soils, nuclear reactor effluents, Dead Sea valley soils and natural water heaters (Singh et al. 2016, Bhagia et al. 2021).
Molecular Biology of Thermophilic and Psychrophilic Archaea
Published in Ajar Nath Yadav, Ali Asghar Rastegari, Neelam Yadav, Microbiomes of Extreme Environments, 2021
Chaitali Ghosh, Jitendra Singh Rathore
To survive in extreme conditions, thermophiles have adopted various molecular strategies to stabilize their proteins. For example thermophilic proteins reduced their number of flexible regions in the native protein structure, and hence have shorter amino acid lengths than their homologoues, in non-thermophilic organisms. Comparative proteomic analysis of more than 204 bacteria and archaea, have shown that the amino acids Glu, Leu, Val, Tyr, Arg, Trp and Ile have been preferred in many optimum growth temperatures (Zeldovich et al. 2007). Specific patterns of codon usage, amino acid composition, nucleotide content and solutes used to stabilize cell component in thermophiles has also been studied (Singer and Hickey 2003; Borges et al. 2010; Empadinhas and da Costa 2011; Faria et al. 2008; Santos and Da Costa 2002).
Alkaliphilic Bacteria and Thermophilic Actinomycetes as New Sources of Antimicrobial Compounds
Published in Devarajan Thangadurai, Jeyabalan Sangeetha, Industrial Biotechnology, 2017
Suchitra B. Borgave, Meghana S. Kulkarni, Pradnya P. Kanekar, Dattatraya G. Naik
Thermophilic organisms exhibit a variety of modifications and adaptations at the structural and molecular level imparting them with the ability to resist and repair thermal damage. Thermophiles are reported to contain specialized ‘chaperonins’ that are thermostable and resist denaturation by refolding the proteins to their native form and restoring their function (Kumar and Nussinov, 2001). The cell membrane of a thermophile contains abundant saturated fatty acids which provide a hydrophobic environment for the cell and keep the cell membrane rigid enough for the cell to survive at elevated temperatures. The presence of a reverse DNA gyrase that introduces positive supercoils in the DNA of thermophiles has been reported (Lopez, 1999). This results in raising the melting point of the DNA to at least as high as the organism’s optimum temperature for growth. Thermophiles also tolerate high temperatures by using increased number of interactions as compared to their mesophilic counterparts in terms of electrostatic and hydrophobic interactions as well as presence of other stabilizing bonds such as disulphide bridges. The structural flexibility of a thermophilic protein is more than its mesophilic analogue. Thus, it has been assumed that a mechanism characterized by entropic stabilization is responsible for the higher thermostability of thermophilic biocatalysts.
Modeling and evaluation of the sucrose-degrading activity of recombinantly produced oligo-1,6-glucosidase from A. gonensis
Published in Preparative Biochemistry & Biotechnology, 2023
Hakan Karaoglu, Zeynep Dengız Balta
According to the CAZy database (http://www.cazy.org/), oligo-1,6-glucosidase (O-1-6-glucosidase) (EC 3.2.1.10) is a member of the glycoside hydrolase family 13 subfamily 31 (GH13_31).[10] O-1-6-glucosidase hydrolyzes non-reducing ends of isomaltooligosaccharides, panose, palatinose, and an a-limit dextrin by breaking α-1,6-glucoside bonds, although it generally lacks activity on α-1,4-glucoside bonds of maltooligosaccharides.[11] The enzyme is also called isomaltase, sucrase-isomaltase, dextrin 6-α-D glucanohydrolase, palatinase, and α-limit dextrinase. O-1-6-glucosidase is commonly used in the saccharification step of HFS production because it hydrolyzes branched oligosaccharides of short lengths and increasing glucose yield.[12] O-1-6-glucosidase can also hydrolyze sucrose to its monomers, glucose and fructose (Figure 1), which are valuable for HFS.[13] While, sucrose hydrolyzing activity was not studied for HFS production before, isomaltooligosaccharides hydrolyzing activity of O-1-6-glucosidase has been well-studied.[14] The microorganisms surviving above the temperature of 40 °C are categorized as thermophilic. Thermophilic microorganisms generally inhabit hot springs and have unique metabolites, especially physically and chemically stable enzymes. Recently, thermophilic microorganisms and their enzymes have been extensively researched due to their advantages for industrial applications.[15]
Biotechnological Avenues in Mineral Processing: Fundamentals, Applications and Advances in Bioleaching and Bio-beneficiation
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Srabani Mishra, Sandeep Panda, Ata Akcil, Seydou Dembele
Extreme thermophilic microorganism can grow at a temperature range of 60–80ºC (Sukla et al. 2014) and are capable of oxidizing sulfur and iron as energy source. These microbes are different from the previous groups due to their spherical structure (1 µm diameter) and are members of the Archaea family. Most studied extremely thermophilic microorganisms are: Sulfolobus acidocaldarius, Sulfolobus metallicus and Acidianus brierleyi. Such microbes have been used in the pre-treatment of sulphide refractory gold ores through bio-heap leaching and in agitated bioleaching tanks of chalcopyrite concentrate (Çelik 2005; Zhang et al. 2010). An investigation on bioleaching with Sulfolobus metallicus have been conducted to recover base metal from secondary resource like spent petroleum refinery catalyst. The finding from these studies indicated that Sulfolobus metallicus is a suitable microorganism for Ni and Al extraction with a recovery rate of 97% and 59% respectively at 60°C (Kim et al. 2012). In the near future, it is believed that application of extreme thermophiles will gain momentum.
Screening of thermotolerant yeast by low-energy ion implantation for cellulosic ethanol fermentation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Ning Zhang, Jian-chun Jiang, Jing Yang, Min Wei, Jian Zhao, Hao Xu, Jing-cong Xie, Ya-juan Tong
Figure 3 shows that the growth rate of the mutant ST-1559 was slightly larger than the original S. cerevisiae at 30°C. When the temperature further increased to 45°C, the growth of ST-1559 was inhibited, but it still showed better growth, while the original S.cerevisiae could not grow. This meant the high thermotolerance of ST-1559 was significantly stronger than S. cerevisiae at 45°C. The reason why the thermophilic microorganisms can survive in a high-temperature environment may be that one or more parts of intracellular enzymes and protein molecules are replaced by some other amino acids which can be folded in a special way, leading to the denaturation against temperature. After mutagenesis treatments, the amount of GC pairs of tRNAs in specific base regions increases, making the nucleic acids have a thermally stable structure.