Research progress on osmotic pressure adaptation strategy and salt tolerance enhancement of microorganisms under high salinity environment

Abstract:

High salinity wastewater is one of the most difficult treating industrial wastewater because of its high hardness,poor biodegradability and complex composition.Traditional physical and chemical treatment technologies have many disadvantages,such as high operating cost,low treatment efficiency and serious secondary pollution.Considering halotolerant microorganism and halophilic microorganism can achieve normal physiological metabolism in high salinity environment,exploring economical,efficient and reliable biological treatment technology for high salinity wastewater is expected to become the mainstream of high salinity wastewater treatment.In this review,halotolerant/halophilic microbial strategies,such as salting-in,accumulation of compatible solutes (intracellular small molecules),protein stabilization,and cell surface stabilization,were systematically summarized.However,due to the severe growth conditions of halophilic microorganisms and the scarcity of functional microorganism species,halotolerant microorganisms were more likely to be used in the treatment of high salinity wastewater in the future.Latest research indicated that enhanced regulation technologies (electricity,light and magnetism) could improve the adaptability of microorganisms to high osmotic pressure,and electric regulation technology might be the key research direction of biological treatment for high salinity wastewater in the future.