Abstract

Pseudomonas aeruginosa strains are well-known for producing rhamnolipid biosurfactants. Their distinct physico-chemical characteristics and diverse biological functions make biosurfactants useful in the detergent, cosmetics, food, pharmaceutical, bioremediation, and agricultural industries. The primary objective of this study was to identify bacteria that could use inexpensive carbon sources to produce rhamnolipid biosurfactants to reduce the production cost of this significant industrial compound. From the oil-contaminated sites along the Karachi coast, a total of 17 bacterial strains were isolated and subjected to biosurfactant screening. Out of these, DGEF106 was chosen as a possible source of rhamnolipid biosurfactant on CTAB agar plates. A partial 16S ribosomal RNA gene sequence revealed that the selected rhamnolipid (Rhl)-producing bacteria were P. aeruginosa, accession number OK147928. The selected bacterial strains were used to maximize the production of rhamnolipid biosurfactants on a low-cost carbon substrate with varied quantities of glycerol, brown sugar, coconut pulp, and mango juice. Minitab 19 was used to statistically analyze data, which has been displayed in a box plot. When low-cost carbon and nitrogen sources were evaluated, it was shown that carbon sources significantly affected the formation of biosurfactants. When ammonium nitrate, ammonium chloride, and urea were combined with an inexpensive carbon supply, the yield of rhamnolipids changed significantly. These microbes could exploit a variety of renewable resources, including agro-industrial waste, as possible sources of carbon. This increases the likelihood of producing biosurfactants at a reasonable cost and lessens the pollution produced by synthetic surfactants.