Biofilm development on acrylic coupons during the initial 24 hour period of submersion in a tropical coastal environment

The sequence of biofilm formation on a hard surface during the first 24 hours in a coastal environment was studied by suspending acrylic coupons. Adsorption of carbohydrates, proteins, calcium, magnesium, nitrite, nitrate and phosphate were monitored along with microbes. The results showed that carbohydrate, protein, nitrite and nitrate were adsorbed on the coupons within an hour of exposure. Carbohydrates showed a maximum value of 0.28 mg cm^-2 after 24 hours and protein concentration reached up to a maximum of 0.41 mg cm^-2. Adsorption of calcium and magnesium was observed after three hours. Settlement of bacteria was also observed on coupons within an hour and diatoms were observed after 15 hours. Diatoms such as Navicula and Nitzschia were the dominant colonizers during the early stages of biofilm development.