# Microbial Biopolymers: From Production to Environmental Applications--A Review
## 6 Applications of Microbial Biopolymers
### Bioremediation and Soil Stabilization  
Bioremediation is an economical and time-consuming approach usually employed for degrading, neutralizing, and detoxifying contaminants predominantly from soil, water, and sediments. Bioremediation is chiefly performed by diverse means such as biodegradation, phytoremediation, bioaugmentation, and biostimulation. These incorporated methodologies usually accelerate metabolic activities and remediate contaminated sites [376; 377]. Biosorption can be accompanied by a variety of other techniques, which boost the recovery or removal of pollutants such as metalloids [378]. For example, there are challenges involved in removing metalloids. However, these challenges can be overcome by the formation of metalloid complexes with microbial biopolymers. Due to electrostatic interaction, the generation of stable complexes between metalloid and microbial biopolymers takes place [379]. Many microbial biopolymers contain negatively charged functional groups that help to bind metals, such as hydroxyl groups (OH\({}^{-}\)) on the matrix of bacterial cellulose, carboxyl groups (COOH\({}^{-}\)) in hyaluronic acid, xanthan gum, and alginate. Also, the charges present on some microbial biopolymers vary as per the pH of the surrounding environment. For example, at an acidic pH, chitosan gains hydrogen (H\({}^{+}\)) and becomes a positively charged ammonium group (NH\({}_{3}\)\({}^{+}\)), and at an alkaline pH, chitosan loses hydrogen ions and becomes an uncharged amine form (NH\({}_{2}\)) [380]. Depending upon the charge, microbial biopolymers can be employed for multiple applications, which are cited in previous sections. Additionally, microbial biopolymers act as nutrients, which directly promotes the microbial activity of microorganisms involved in the bioremediation process and allows them to thrive and flourish in a variety of unfavorable conditions. Furthermore, some microbial biopolymers such as PHA and PHB produce metabolizing enzymes under particular nutritional and environmental stresses, which helps to upsurge bacterial survival during the bioremediation process [11]. Soil stabilization is an approach for altering the physiochemical attributes of the soil; it enhances the soil's effectiveness in terms of physical aspects. Biofilm-oriented bioremediation is a potent tool for the removal of environmental pollutants. Soil stabilization promises the improved structural stability of soil [381; 382]. Microbial biofilms are collections of grouped microbial cells wrapped in an extracellular polymeric substance (EPS) matrix that they have self-assembled. Because they are resistant to harsh environments, biofilms serve as a shield for safeguarding microbes from factors such as exposure to ultraviolet rays, excessive temperature, elevated salinity, and abnormal pH [242]. Numerous kinds of unwanted substances have polluted both the ecosystems of land and water. The majority of these pollutants are polymers of polycyclic aromatic hydrocarbons and total petroleum hydrocarbons, which are generally considered a threat to public health [383; 384]. Industrial waste such as dyes and wastewater streams are usually comprised of the aforementioned pollutants and are responsible for polluting the soil and water. The primary approaches to eliminating the metals from polluted soil are thermal desorption, adsorption, precipitation by chemicals, ion exchange, and electroplating accumulation [385]. With the advent of recent developments in microbial biopolymers, the latest developments in the industry are investigating the strategic application of microbial biopolymers and bioremediation methods as environmentally satisfactory alternatives for soil stabilization. Microbial biopolymers have prospective benefits in terms of sustainable development, biological degradation, and minimal carbon footprint [386]. Due to their distinctive qualities and compatibility with the environment, various biopolymers have been employed for dust control, erosion control, and strengthening soil [387].