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Exopolysaccharide Production from Marine Bacteria and Its Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Prashakha J. Shukla, Shivang B. Vhora, Ankita G. Murnal, Unnati B. Yagnik, Maheshwari Patadiya
Hypersaline systems are harsh environments that have salt concentrations much greater than that of seawater, often close to or exceeding salt saturation (Oren, 2010; Biswas and Paul, 2014; Oren, 2016). Usually, hypersaline environments have high salinity and alkaline pH. The factors affecting biodiversity in such an environment include pressure, low nutrient availability, solar radiation and the presence of heavy metals and toxic compounds (Rodriguez-Valera, 1988). The EPS-producing microorganisms inhabiting such environments are members of archaea of the order Halobacteriales, namely, Halobacterium, Halomonasalmeriensis, Haloarcula, Halorubrum, Haloferax, Natronobacterium, Natronococcus and Salinibacter ruber. Haloferax mediterranei has been isolated from Mediterranean Sea that synthesizes high amounts of EPSs, which has an application in oil recovery (especially in oil deposits with high salinity; Anton et al., 1988; Parolis et al., 1996; Llamas et al., 2012).
Bioprospecting of Microbial Diversity for Sustainable Agriculture and Environment
Published in Vineet Kumar, Vinod Kumar Garg, Sunil Kumar, Jayanta Kumar Biswas, Omics for Environmental Engineering and Microbiology Systems, 2023
Hiren K. Patel, Nensi K. Thumar, Priyank D. Patel, Azaruddin V. Gohil
Salinization due to salt accumulation in soil is one of the major threats and obstacles in agricultural process. According to World Atlas of Desertification, soil which was naturally salinated (primary salinization) is around 1 billion hectors and 77 million hectors was salinated due to man-made activity (secondary salinization). Excess salt can be accumulated at root zone of agricultural crops due to the evaporation of irrigated water. Excess salt deposition around root hinders the water absorption of agricultural plants. Excess amount of sodium ion lowers down the potassium level in agricultural crops due to competitive effect. This will create an imbalance of sodium-to-potassium ratio and affect various cellular processes such as protein synthesis, enzyme activities, and stomata opening and closing (Sharma et al. 2016). These hurdles negatively affect total crop yield quantitatively as well as qualitatively. As agricultural crop is not sufficiently produced, it will also decrease the economic gain. Hypersaline regions have mostly salt concentration greater than 15%. Halophilic microbes can tolerate a high range of sodium chloride, and high salt concentration is a prerequisite of halophiles for their growth (Yadav and Saxena 2018). Halophiles are divided into three categories. True halophilic microbes can tolerate salt concentration of sodium chloride ranging from 15% to 30%, moderate halophilic microbes can tolerate salt between 3% and 15%, and slight halophilic microbes can tolerate salt ranging between 1% and 2% (Yadav et al. 2015b).
Overview of past, current, and future ecosystem and biodiversity trends of inland saline lakes of Europe and Central Asia
Published in Inland Waters, 2020
Egor Zadereev, Oksana Lipka, Bakhtiyor Karimov, Marina Krylenko, Victoria Elias, Isabel Sousa Pinto, Valida Alizade, Yaakov Anker, Alan Feest, Daria Kuznetsova, Andre Mader, Rashad Salimov, Markus Fischer
Saline lakes in the ECA provide numerous ecosystem services and have a high and often underestimated economic value. Saline aquatic ecosystems, especially in arid regions, are important habitats for aquatic, semiaquatic, and riparian wildlife. Many saline lakes have a high degree of endemism and a number of threatened and endangered species (e.g., Caspian Sea, Lake Balkhash, Lake Salda, saline lakes in Spain). Hypersaline lakes support unique extreme ecosystems and species biodiversity, especially among microorganisms (e.g., Oren 2006). Since ancient times, saline lakes have provided local human populations with various commercially exploited minerals, such as potassium, sodium, magnesium, bromine, lithium, and others (e.g., Bass-Becking 1931), and biological resources (e.g., Artemia; e.g., Lavens and Sorgeloos 2000). A number of saline lakes of various size and salinity in the ECA provide cultural and recreational ecosystem services (e.g., the Dead Sea, Lake Issyk-Kul, Lake Shira, Aydar-Arnasay lake system, and many others). Unbalanced exploitation of some ecosystem services may negatively affect the provision of others. For example, physical disturbance and pollution associated with mineral extraction can threaten species richness and ecosystem health (Jellison et al. 2008).