Volume 10, Issue 12, January - June, 2026

Impact of chemical contaminants and process residues on biofilm formation of Serratia marcescens: implications for food and water system adulteration control

Bhanupratap Harishchandra Vishwakarma^1♦

¹Department of Microbiology, Faculty of Biochemistry, ZSCT’s Thakur Shyamnarayan Degree College, Thakur Complex, Kandivali (East), Mumbai – 400101, Maharashtra, India

^♦Corresponding Author
Bhanupratap Harishchandra Vishwakarma, Department of Microbiology, Faculty of Biochemistry, ZSCT’s Thakur Shyamnarayan Degree College, Thakur Complex, Kandivali (East), Mumbai – 400101, Maharashtra, India

ABSTRACT

Microbial biofilms are significant persistent contaminations in the food processing plants, drinking water distribution systems, pharmaceutical environments, and clinics. The role of chemical adulterants, residual disinfectants, nutrient supplements, and ambient contaminants is paramount in the modulation of microbial colonization, surface attachment, and long-standing persistence. Additionally, through the modulation of the physicochemical (pH, osmolarity, and nutrient) environment, these players also impact microbial interactions as well as help mediate cell wall-associated processes needed for attachment, thereby leading to biofilm formation. In addition, these compounds have inhibited EPS (extracellular polymeric substances) production and microbial metabolic activity temporally that are the stabilizing factors in biofilm development surrounding solid substrates. Understanding how chemical environments govern biofilm formation is key to a new class of effective strategies to control contamination. This study evaluated biofilm formation of Serratia marcescens (an opportunistic Gram-negative bacterium) recognized as an industrial fouler and water-borne contaminant in the presence of selected chemical agents (acetic acid, sodium hydroxide, ammonium chloride, dextrose, urea, and ethanol). Biofilm biomass (OD570 nm) was determined by crystal violet colorimetric and the planktonic growth spectrophotometric in a 600 nm static culture for 48 h; All experiments were performed as triplicate (n = 3 independent biological repeats). Statistical significance was analyzed using one-way ANOVA and Tukey's post-hoc test. Among the tested agents, acetic acid showed the most pronounced antibiofilm activity with about 40% increase in biofilm mass reduction from the untreated control. In contrast, ammonium chloride could enhance biofilm formation of 320% (over control). Biofilm growth is inhibited only to a moderate extent with nutrient supplements (urea and dextrose). At the tested concentrations, sodium hydroxide and ethanol showed very little inhibition. Furthermore, there was no significant correlation between planktonic growth and biofilm biomass (r = 0.377, p > 0.05) when analyzed using Pearson coefficients, suggesting that this effect is independent of the intercellular detection system that bacteria can use to modulate their growth as a whole. These findings suggest that nutrient-rich adulterants and nitrogenous contaminants can promote survival of industrial biofilms, while acidic treatments are highly effective in preventing detachment. The study offers a quantitative framework that elucidates how chemicals affect microbial pollution risk to food and water environments.

Keywords: Serratia marcescens; Biofilm formation; Chemical contaminants; Food adulteration; Water system contamination; Crystal violet assay

International journal of adulteration, 2026; 10(12): e3ijad3070

PDF

Published: 30 March 2026