A SURVEY ON PRESENCE OF BIOPOLYMER PRODUCING MICROORGANISMS IN MARINE SOILS& ENHANCEMENT OF SOIL STRENGTH USING POTENTIAL ISOLATED MICRO-ORGANISMS: A REVIEW

High population densities are attracting towards coastal area due to which the demand of infrastructure is continuously increasing in that region. The properties of marine soil are very challenging for construction practice. There are some techniques to improve soil but due to their adverse effect on natural properties of soil, biological soil improvement method is introduced. The use of biological process in geotechnical engineering as a soil improvement technique has a potential to change soil properties. This is environmentally sustainable method. This paper represents the review on physical, chemical and biological properties of marine soil and enhance the strength of soil with the use of microorganisms. Plants are helpful in producing biopolymer naturally into the soil. Polyhydroxyalkanoates (PHAs) and cyanophycean can produce naturally by plants. There are different methods to use micro-organisms in soil such as MICP, biofilm, bio cementation, biopolymer. The isolation and screening of microbes were presented. There are many reactions occur in soil due to microbes and chemical composition in soil. some parameters such as concentration of microbes, curing time, type of biopolymer effect the unconfined compressive strength is also studied. Strength of soil is increases with increase in microbe’s concentration and curing time. As the biopolymers are degrade with time by UV rays it generates Co2 and H2o. process such as swelling, hydrolysis, diffusion, erosion can control in plant field of plants. This biopolymer producing microbes use to reduce soil settlement, reduce liquefaction potential and increase water retention capacity.